Breast Cancer
Breast cancer occurs when cells in the breast become abnormal and divide uncontrollably. Breast cancer usually starts in the glands that produce milk (lobules) or the tubes (ducts) that carry milk from the glands to the nipple.
- Among women, breast cancer health tips is the most
common cancer and the second most common cause of cancer deaths.
- Typically, the first symptom is a painless
lump, usually noticed by the woman.
- Breast cancer screening recommendations
vary and include periodic mammography, breast examination by a doctor, and
breast self-examination.
- If a solid lump is detected, doctors use a
hollow needle to remove a sample of tissue or make an incision and remove
part or all of the lump and then examine the tissue under a microscope
(biopsy).
- Breast cancer almost always requires
surgery, sometimes with radiation therapy, chemotherapy, other drugs, or a
combination.
- Outcome is hard to predict and depends
partly on the characteristics and spread of the cancer.
Breast disorders may
be noncancerous (benign) or cancerous (malignant). Most are noncancerous and
not life threatening. Often, they do not require treatment. In contrast, breast
cancer can mean loss of a breast or of life. Thus, for many women, breast
cancer is their worst fear. However, potential problems can often be detected
early when women do both of the following:
- Are examined regularly by their doctor
- Have mammograms as recommended
Women should be
familiar with how their breasts normally look and feel, and men should also be
aware of changes in or around their nipples. If a woman notices a change, she
may want to do a breast self-examination. Women should report any changes to a
health care practitioner right away. Most medical organizations no longer
recommend that people do monthly or weekly breast self-examinations as
a routine way to check for cancer. Doing these examinations when there is no
lump or other change does not help detect breast cancer early in women who get
screening mammograms.
Early detection of
breast cancer can be essential to successful treatment.
Breast cancer is the
most common cancer among women and, of cancers, is the most common cause of
death among Hispanic women and the second most common cause of death in women
of other races (after lung cancer). In 2021 in the United States, the following
occurred in women:
- Invasive breast cancer was diagnosed
in about 281,550 women.
- Noninvasive (in situ) breast cancer was
diagnosed in almost 49,290 women.
- Almost 43,600 women died of breast cancer.
Breast cancers in men account
for about 1% of all breast cancers. In 2021, 2,650 new cases of invasive breast
cancer and 530 deaths from it occurred in men in the United States.
Many women fear breast
cancer, partly because it is common. However, some of the fear about breast
cancer is based on misunderstanding. For example, the statement, “One of every
eight women will get breast cancer,” is misleading. That figure is an estimate
of the risk of developing breast cancer during a woman's life. It means that
theoretically, one of eight women will develop breast cancer during her life.
However, a 40-year-old woman has only about a 1 in 70 chance of developing it
during the next decade. But as she ages, her risk increases.
Risk Factors for
Breast Cancer
Several factors affect
the risk of developing breast cancer. Thus, for some women, the risk is much
higher or lower than average. Most factors that increase risk, such as age and
certain abnormal genes, cannot be modified. However, regular exercise,
particularly during adolescence and young adulthood, may reduce the risk of
developing breast cancer.
Far more important
than trying to modify risk factors is being vigilant about detecting breast
cancer so that it can be diagnosed and treated early, when it is more likely to
be cured. Early detection is more likely when women have mammograms.
Regular breast self-examinations are also recommended by some
doctors, although these examinations have not been shown to reduce risk of
death from breast cancer.
Age
Increasing age is the
most important risk factor for breast cancer. Most breast cancers occur in
women older than 50. Risk is greatest after age 75.
Previous history of breast cancer
Having had breast
cancer increases the risk of breast cancer. After the diseased breast is
removed, the risk of developing cancer in the remaining breast is about 0.5 to
1.0% each year.
Family history of breast cancer
Breast cancer in a
first-degree relative (mother, sister, or daughter) increases a woman’s risk by
2 to 3 times, but breast cancer in more distant relatives (grandmother, aunt,
or cousin) increases the risk only slightly. Breast cancer in two or more
first-degree relatives increases a woman’s risk by 5 to 6 times.
Breast cancer gene
mutation
Mutations in two
separate genes for breast cancer (BRCA1 and BRCA2) have
been identified. Fewer than 1% of women have these gene mutations. About 5 to
10% of women with breast cancer have one of these gene mutations. If a woman
has one of these mutations, her lifetime risk of developing breast cancer is
about 50 to 85%. The risk of developing breast cancer by age 80 is about 72%
with a BRCA1 mutation and about 69% with a BRCA2 mutation.
However, if such a woman develops breast cancer, her chances of dying of breast
cancer are not necessarily greater than those of any other woman with breast
cancer.
These mutations are
most common among Ashkenazi Jews.
Women likely to have
one of these mutations are those who have at least two close, usually
first-degree relatives who have had breast or ovarian cancer. For this reason,
routine screening for these mutations does not appear necessary, except in
women who have such a family history.
Having a BRCA mutation
also increases the risk of ovarian cancer. During their life, women
with BRCA1 gene mutations have about a 40% risk of developing
ovarian cancer. For women with BRCA2 gene mutations, risk is
about 15%.
Men who have a BRCA gene
mutation have a 1 to 2% lifetime risk of developing breast cancer.
Women with one of these
mutations need to be tested monitored more closely for breast cancer—for
example, by more frequent testing or being screened with both mammography and
magnetic resonance imaging (MRI). Or they may need to try to prevent cancer
from developing by taking tamoxifen or raloxifene (which is
similar to tamoxifen) or sometimes by even having both breasts
removed (double mastectomy).
Certain benign changes
in the breast
Some changes in the
breast seem to slightly increase the risk of breast cancer. They include
- Changes in the breast that required a
biopsy to rule out cancer
- Conditions that change the structure,
increase the number of cells, or cause lumps or other abnormalities in
breast tissue, such as complex fibroadenoma, hyperplasia (abnormally
increased growth of tissue), atypical hyperplasia (hyperplasia with
abnormal tissue structure) in the milk ducts or milk-producing glands,
sclerosing adenosis (increased growth of tissue in the milk-producing
glands), or papilloma (a noncancerous tumor with fingerlike projections)
- Dense breast tissue seen on a mammogram
Having dense breast
tissue also makes it harder for doctors to identify breast cancer. Having dense
breasts means that women have more fibroglandular tissue (composed of fibrous
connective tissue and glands) and less fatty tissue in the breast.
For women with such
changes, the risk of breast cancer is increased only slightly unless abnormal
tissue structure is detected during a biopsy or they have a family history of
breast cancer.
Age at first menstrual
period, first pregnancy, and menopause
The earlier
menstruation begins (especially before age 12), the higher the risk of
developing breast cancer.
The later the first
pregnancy occurs and the later menopause occurs, the higher the risk. Never
having had a baby increases the risk of developing breast cancer. However,
women who have their first pregnancy after age 30 are at higher risk than those
who never have a baby.
These factors probably
increase risk because they involve longer exposure to estrogen, which
stimulates the growth of certain cancers. (Pregnancy, although it results in
high estrogen levels, may reduce the risk of breast cancer.)
Oral contraceptives or
hormonal therapy
Some studies show that
women taking oral contraceptives (birth control pills) have a slightly higher
risk of breast cancer. Once the pills are stopped, this risk seems to go back
to normal within about 10 years.
After menopause,
taking combination hormone therapy (estrogen with a progestin) for a
few years or more increases the risk of breast cancer. Taking estrogen alone
does not appear to increase the risk of breast cancer.
Diet and obesity
Diet may contribute to
the development or growth of breast cancers, but evidence about the effect of a
particular diet (such as a high-fat diet) is lacking.
Risk of developing
breast cancer is somewhat higher for women who are obese after menopause. Fat
cells produce estrogen, possibly contributing to the increased risk.
However, there is no proof that a high-fat diet contributes to the development
of breast cancer or that changing the diet can decrease risk. Some studies
suggest that obese women who are still menstruating are less likely to develop
breast cancer.
Lifestyle
Smoking and regularly
drinking alcoholic beverages may increase the risk of breast cancer. Experts
recommend that women limit themselves to one alcoholic drink a day. One drink
is about 12 ounces of beer, 5 ounces of wine, or 1.5 ounces of more
concentrated liquor, such as whiskey.
Radiation exposure
Radiation exposure
(such as radiation therapy for cancer or significant exposure to x-rays) before
age 30 increases risk.
Types of Breast
Cancer
Breast cancer is
usually classified by the following:
- The kind of tissue in which the cancer
starts
- The extent of the cancer's spread
- The type of tumor receptors on the cancer
cells
Kind of tissue
There are many
different kinds of tissue in the breast. Cancer can develop in most of these
tissues, including
- Milk ducts (called ductal carcinoma)
- Milk-producing glands, or lobules (called
lobular carcinoma)
- Fatty or connection tissue (called
sarcoma): This type is rare.
Ductal carcinoma accounts for about 90% of all breast
cancers.
Paget disease of
the nipple is a ductal
breast carcinoma that affects the skin over and around the nipple. The first
symptom is a crusty or scaly nipple sore or a discharge from the nipple. About
half of the women who have this cancer also have a lump in the breast that can
be felt. Women with Paget disease of the nipple may also have another breast
cancer that is not felt but that can be seen using imaging tests—mammography,
magnetic resonance imaging (MRI), or ultrasonography—done to look for another
cancer. Because this disease usually causes little discomfort, women may ignore
it for a year or more before seeing a doctor. The prognosis depends on how
invasive and how large the cancer is as well as whether it has spread to the
lymph nodes.
Phyllodes breast
tumors are relatively
rare, accounting for fewer than 1% of breast cancers. About 10 to 25% are
cancerous. They originate in breast tissue around milk ducts and milk-producing
glands. The tumor spreads to other parts of the body (metastasizes) in about 10
to 20% of women who have it. It recurs in the breast in about 20 to 35% of
women who have had it. The prognosis is good unless the tumor has metastasized.
Extent of spread
Breast cancer can
remain within the breast or spread anywhere in the body through the lymphatic
vessels or bloodstream. Cancer cells tend to move into the lymphatic
vessels in the breast. Most lymphatic vessels in the breast drain into lymph
nodes in the armpit (axillary lymph nodes). One function of lymph nodes is to
filter out and destroy abnormal or foreign cells, such as cancer cells. If
cancer cells get past these lymph nodes, the cancer can spread to other parts
of the body.
Breast cancer tends to
spread (metastasize) to the bones, brain, lungs, liver, and skin but can spread
to any area. Spread to the scalp is uncommon. Breast cancer can appear in these
areas years or even decades after it is first diagnosed and treated. If the
cancer has spread to one area, it probably has spread to other areas, even if
it cannot be detected right away.
Breast cancer can be
classified as
- Carcinoma in situ
- Invasive cancer
Carcinoma in situ means cancer in place. It is the earliest
stage of breast cancer. Carcinoma in situ may be large and may even affect a
substantial area of the breast, but it has not invaded the surrounding tissues
or spread to other parts of the body.
Ductal carcinoma in
situ is confined to the
milk ducts of the breast. It does not invade surrounding breast tissue, but it
can spread along the ducts and gradually affect a substantial area of the
breast. This type accounts for 85% of carcinoma in situ and at least half of breast
cancers. It is detected most often by mammography. This type may become
invasive.
Lobular carcinoma
in situ develops within
the milk-producing glands of the breast (lobules). It often occurs in several
areas of both breasts. Women with lobular carcinoma in situ have a 1 to 2%
chance each year of developing invasive breast cancer in the affected or the
other breast. Lobular carcinoma in situ accounts for 1 to 2% of breast cancers.
Usually, lobular carcinoma in situ cannot be seen on a mammogram and is
detected only by biopsy. There are two types of lobular carcinoma in situ:
classic and pleomorphic. The classic type is not invasive, but having it
increases the risk of developing invasive cancer in either breast. The
pleomorphic type leads to invasive cancer and, when detected, is surgically
removed.
Invasive cancer can be classified as follows:
- Localized: The cancer is confined to the
breast.
- Regional: The cancer has invaded tissues
near the breasts, such as the chest wall or lymph nodes.
- Distant (metastatic): The cancer has
spread from the breast to other parts of the body (metastasized).
Invasive ductal
carcinoma begins in the
milk ducts but breaks through the wall of the ducts, invading the surrounding
breast tissue. It can also spread to other parts of the body. It accounts for
about 80% of invasive breast cancers.
Invasive lobular
carcinoma begins in the
milk-producing glands of the breast but invades surrounding breast tissue and
spreads to other parts of the body. It is more likely than other types of
breast cancer to occur in both breasts. It accounts for most of the rest of
invasive breast cancers.
Rare types of invasive
breast cancers include
- Medullary carcinoma
- Tubular carcinoma
- Metaplastic carcinoma
- Mucinous carcinoma
Mucinous carcinoma
tends to develop in older women and to be slow growing. Women with most of
these rare types of breast cancer have a much better prognosis than women with
other types of invasive breast cancer. However, the prognosis is significantly
worse for women with metaplastic breast cancer than for those with other types
of ductal breast cancer.
Tumor receptors
All cells, including breast
cancer cells, have molecules on their surfaces called receptors. A receptor has
a specific structure that allows only particular substances to fit into it and
thus affect the cell’s activity. Whether breast cancer cells have certain
receptors affects how quickly the cancer spreads and how it should be treated.
Tumor receptors
include the following:
- Estrogen and progesterone receptors: Some breast cancer cells have
receptors for estrogen. The resulting cancer, described as estrogen receptor–positive,
grows or spreads when stimulated by estrogen. This type of cancer is
more common among postmenopausal women than among younger women. About two
thirds of postmenopausal women with cancer have estrogen receptor–positive
cancer. Some breast cancer cells have receptors for progesterone. The
resulting cancer, described as progesterone receptor–positive,
is stimulated by progesterone. Breast cancers with estrogen receptors
and possibly those with progesterone receptors grow more slowly
than those that do not have these receptors, and the prognosis is better.
( Estrogen and progesterone are female sex hormones.)
- HER2 (HER2/neu) receptors: Normal breast cells have HER2
receptors, which help them grow. (HER stands for human epithelial growth
factor receptor, which is involved in multiplication, survival, and
differentiation of cells.) In about 20% of breast cancers, cancer cells
have too many HER2 receptors. Such cancers tend to be very fast growing.
Other characteristics
Sometimes cancer is
also classified based on other characteristics.
Inflammatory breast
cancer is an example. The
name refers to the symptoms of the cancer rather than the affected tissue. This
type is fast growing, particularly aggressive, and often fatal. Cancer cells
block the lymphatic vessels in the skin of the breast, causing the breast to
appear inflamed: swollen, red, and warm. Usually, inflammatory breast cancer
spreads to the lymph nodes in the armpit. The lymph nodes can be felt as hard
lumps. However, often no lump may be felt in the breast itself because this
cancer is dispersed throughout the breast. Inflammatory breast cancer accounts
for about 1% of breast cancers.
Symptoms of Breast
Cancer
At first, breast
cancer causes no symptoms.
Most commonly, the
first symptom of breast cancer is a lump, which usually feels distinctly
different from the surrounding breast tissue. In many breast cancer cases,
women discover the lump themselves. Such a lump may be cancer if it is a firm,
distinctive thickening that appears in one breast but not the other. Usually,
scattered lumpy changes in the breast, especially the upper outer region, are
not cancerous and indicate fibrocystic changes.
Some women with breast
cancer have breast pain, but breast pain has many causes and usually does
not mean that a woman has breast cancer.
In the early stages,
the lump may move freely beneath the skin when it is pushed with the fingers.
In more advanced
stages, the lump usually adheres to the chest wall or the skin over it. In
these cases, the lump cannot be moved at all or it cannot be moved separately
from the skin over it. Sometimes women can determine whether they have a cancer
that even slightly adheres to the chest wall or skin by lifting their arms over
their head while standing in front of a mirror. If a breast contains cancer
that adheres to the chest wall or skin, this maneuver may make the skin pucker
or dimple or make one breast appear different from the other.
In very advanced
cancer, swollen bumps or festering sores may develop on the skin. Sometimes the
skin over the lump is dimpled and leathery and looks like the skin of an orange
(peau d’orange) except in color.
The lump may be
painful, but pain is an unreliable sign. Pain without a lump is rarely due to
breast cancer.
If the cancer has
spread, lymph nodes, particularly those in the armpit on the affected
side, may feel like hard small lumps. The lymph nodes may be stuck together or
adhere to the skin or chest wall. They are usually painless but may be slightly
tender.
Occasionally, the
first symptom occurs only when the cancer spreads to another organ. For
example, if it spreads to a bone, the bone may ache or become weak, resulting
in a fracture. If the cancer spreads to a lung, women may cough or have
difficulty breathing.
In Paget
disease of the nipple, the first symptom is a crusty or scaly nipple
sore or a discharge from the nipple. These changes may appear harmless, so
women may not think they need to see a health care practitioner. Many women who
have this cancer also have a lump in the breast.
In inflammatory
breast cancer, the breast is warm, red, and swollen, as if infected
(but it is not). The skin of the breast may become dimpled and leathery, like
the skin of an orange, or may have ridges. The nipple may turn inward (invert).
A discharge from the nipple is common. Often, no lump can be felt in the
breast, but the entire breast is enlarged.
Screening for
Breast Cancer
Because breast cancer
rarely causes symptoms in its early stages and because early treatment is more
likely to be successful, screening is important. Screening is the hunt for a
disorder before any symptoms occur.
Screening for breast
cancer may include
- Yearly breast examination by a health care
practitioner
- Mammography
- If women have an increased risk of breast
cancer, magnetic resonance imaging (MRI)
Concerns about
screening for breast cancer
It can be challenging
to keep up with the latest recommendations for breast cancer screening, such as
when to start mammograms. Also, medical organizations may change their
recommendations over time, or different organizations may have different
recommendations.
Some people think that
more testing is better, but testing may also have disadvantages. For example,
screening tests for breast cancer sometimes indicate a cancer is present when
no cancer is present (called a false-positive result). When results of a breast
screening test are positive, a breast biopsy is usually done. Having
a false-positive result means having a biopsy that is not needed and being
exposed to unnecessary anxiety, pain, and expense. Because of these potential
issues, organizations recommend that some people do not need to have a
screening test. These people include those who are younger or older than a
certain age (see sidebar Breast Cancer: When to Start Screening
Mammography?). Women should discuss current recommendations and their own risk
and priorities with their health care practitioner and decide which type of
screening, if any, is appropriate for them.
Mammography
Mammography is one of
the best ways to detect breast cancer early. Mammography is designed to be
sensitive enough to detect the possibility of cancer at an early stage,
sometimes years before it can be felt. Because mammography is so sensitive, it
may indicate cancer when none is present (a false-positive result). About 85 to
90% of abnormalities detected during screening (that is, in women with no
symptoms or lumps) are not cancer. Typically, when the result is positive, more
specific follow-up procedures, usually a breast biopsy, are scheduled to
confirm the result. Mammography may miss up to 15% of breast cancers. It is
less accurate in women with dense breast tissue. Thus, these women may require
additional tests, such as breast ultrasonography, 3-dimensional mammography
( tomosynthesis), or magnetic resonance imaging (MRI).
For mammography,
x-rays are used to check for abnormal areas in the breast. A technician
positions the woman’s breast on top of an x-ray plate. An adjustable plastic
cover is lowered on top of the breast, firmly compressing the breast. Thus, the
breast is flattened so that the maximum amount of tissue can be imaged and
examined. X-rays are aimed downward through the breast, producing an image on
the x-ray plate. Two x-rays are taken of each breast in this position. Then
plates may be placed vertically on either side of the breast, and x-rays are
aimed from the side. This position produces a side view of the breast.
Mammography:
Screening for Breast Cancer
Breast
tomosynthesis (3-dimensional
mammography) may be used with mammography to produce a clear, highly focused
3-dimensional picture of the breast. This technique makes it somewhat easier to
detect cancer, especially in women with dense breast tissue. However, this type
of mammography exposes women to more radiation as traditional mammography.
Recommendations for
routine screening with mammography vary. Experts disagree about
- When it should start
- How often it should be done
- When (or if) it should be stopped
Experts have different
recommendations about when to start routine mammography. Screening
mammography is recommended for all women starting at age 50, but some experts
recommend starting at age 40 or 45.
Some experts recommend
starting at age 50 because screening mammography is more accurate in women 50
or older. The reason is that as women age, fatty tissue replaces fibroglandular
tissue in the breast. Abnormalities next to fatty tissue are easier to detect
with a mammogram.
The benefit of
screening is not as clear in women aged 40 to 49. Experts are also concerned
about starting screening too soon or screening too often because exposure to
radiation would be increased.
Women with risk
factors for breast cancer are more likely to benefit from starting
mammography before age 50. They should discuss the risks and benefits of
screening mammograms with their doctor.
Whenever it is
started, mammography is then repeated every 1 or 2 years.
Routine mammography
may be stopped at age 75, depending on the woman's life expectancy and her wish
for continued screening.
Did You Know...
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The dose of radiation
used in mammography is very low and is considered safe.
Mammography may cause
some discomfort, but the discomfort lasts only a few seconds. Mammography
should be scheduled at a time during the menstrual period when the breasts are
less likely to be tender.
Deodorants and powders
should not be used on the day of the procedure because they can interfere with
the image obtained. The entire procedure takes about 15 minutes.
Breast Cancer: When to
Start Screening Mammography?
Breast Cancer: When
to Start Screening Mammography?
Experts sometimes
disagree about when regular screening with mammography should be started.
Because screening identifies cancer and cancers can be fatal, people might
think that screening should be started sooner (at age 40) rather than later
(at age 50). However, screening has some disadvantages, and the benefits for
younger women are not as clear as those for older women. The following are
some reasons for the controversy:
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Breast self-awareness
Women should be
familiar with how their breasts normally look and feel, and men should also be
aware of changes in or around their nipples. If a woman notices a change, she
may want to do a breast self-examination. Women should report any changes to a
health care practitioner right away. In the past, most doctors recommended that
women examine their breasts for lumps each month. Most medical organizations no
longer recommend that people do monthly or weekly breast self-examinations as
a routine way to check for cancer. Doing these examinations when there is no
lump or other change does not help detect breast cancer early in women who get
screening mammograms.
Breast
Self-Examination
Breast examination by
a health care practitioner
A breast examination
may be part of a routine physical examination. However, as with breast
self-examination, a doctor's examination may miss a cancer. If women need or
want screening, a more sensitive test, such as mammography, should be done,
even if a doctor's examination did not detect any abnormalities. Many doctors
and medical organizations no longer require an annual breast examination by a
doctor.
During the
examination, a doctor inspects the breasts for irregularities, dimpling,
tightened skin, lumps, and a discharge. The doctor feels (palpates) each breast
with a flat hand and checks for enlarged lymph nodes in the armpit—the area
most breast cancers invade first—and above the collarbone. Normal lymph nodes
cannot be felt through the skin, so those that can be felt are considered
enlarged. However, noncancerous conditions can also cause lymph nodes to
enlarge. Lymph nodes that can be felt are checked to see if they are abnormal.
Magnetic resonance
imaging
MRI is usually used to
screen women with a high risk of breast cancer, such as those with a BRCA mutation.
For these women, screening should also include mammography and breast
examination by a health care practitioner. MRI may be recommended for women with
dense breast tissue as part of an overall assessment that includes evaluation
of risk.
Diagnosis of Breast
Cancer
- Mammography
- Breast examination
- Biopsy
- Sometimes ultrasonography
If changes in the
breast (such nipple discharge or a lump) are detected during a physical
examination, ultrasonography is usually done. If results are inconclusive,
mammography is done.
Mammography can also
help identify tissue that should be removed and examined under a microscope
(biopsied).
If doctors suspect
advanced cancer based on results of a physical examination, a biopsy is done
first (see also evaluation of a breast lump).
Ultrasonography is sometimes used to help distinguish
between a fluid-filled sac ( cyst) and a solid lump. This distinction is
important because cysts are usually not cancerous. Cysts may be monitored (with
no treatment) or drained (aspirated) with a small needle and syringe. The fluid
from the cyst is examined to check for cancer cells only if any of the
following occurs:
- The fluid is bloody or cloudy.
- Little fluid is obtained.
- The lump remains after it is drained.
Otherwise, the woman
is checked again in a few weeks. If the cyst can no longer be felt at this
time, it is considered noncancerous. If it has reappeared, it is drained again,
and the fluid is examined under a microscope. If the cyst reappears a third
time or if it is still present after it was drained, a biopsy may be done.
Rarely, when cancer is suspected, cysts are surgically removed.
Breast biopsy
All abnormalities that
suggest cancer are biopsied.
Doctors may do one of
several types of biopsy:
- Core needle biopsy: A wide, hollow needle with a special
tip is used to remove a sample of breast tissue.
- Open (surgical) biopsy: Doctors make a small cut in the skin
and breast tissue and remove part or all of a lump. This type of biopsy is
done when a needle biopsy is not possible. It may also be done after a
needle biopsy that does not detect cancer to be sure that the needle biopsy
did not miss a cancer.
Needle Breast
Biopsy
Imaging is often done
during a biopsy to help doctors determine where to place the biopsy needle.
Using imaging to guide the biopsy improves the accuracy of a core needle biopsy.
For example, for a mass (whether felt or seen on a mammogram), ultrasonography
is used during the core needle biopsy to accurately target the abnormal tissue.
When imaging is used to guide placement of the needle, a clip to mark the spot
is typically placed during the biopsy.
When an abnormality is
seen only on an MRI scan, MRI is used to guide the placement of the biopsy
needle.
A stereotactic core
biopsy is useful when there are abnormal patterns of tiny calcium deposits
(called microcalcifications) in the breast. This type of biopsy helps doctors accurately
locate and remove a sample of the abnormal tissue. For a stereotactic biopsy,
doctors take mammograms from two angles and send the two-dimensional images to
a computer. The computer compares them and calculates the precise location of
the abnormality in three dimensions. The breast tissue to be biopsied by
stereotactic core biopsy is x-rayed to make sure doctors get a sample of the
abnormal microcalcifications.
Stereotactic Breast
Biopsy
Most women do not need
to be hospitalized for these procedures. Usually, only a local anesthetic is
needed.
A pathologist examines
the biopsy samples under the microscope to determine whether cancer cells are
present. Generally, a biopsy confirms cancer in only a few women with an
abnormality detected during mammography.
Evaluation after
cancer diagnosis
If cancer is
diagnosed, women are seen by a cancer specialists (oncologists), which may
include surgeons, medical oncologists (cancer drug treatment specialists), and
radiation oncologists. These doctors determine which tests should be done and
plan treatment.
If cancer cells are
detected, the biopsy sample is analyzed to determine the characteristics of the
cancer cells, such as
- Whether the cancer cells have hormone (estrogen or progesterone) receptors
- How many HER2 receptors are present
- How quickly the cancer cells are dividing
- For some types of breast cancer, genetic
testing of the cancer cells (multigene panels)
This information helps
doctors estimate how rapidly the cancer may spread and which treatments are
more likely to be effective.
LAB TEST
After breast cancer is
diagnosed, tests may include
- A chest x-ray to determine whether the
cancer has spread
- Blood tests, including a complete blood
count (CBC), liver tests, and measurement of calcium, also to determine
whether the cancer has spread
- In women with risk factors for
inherited genes that increase the risk of breast cancer (such as BRCA
genes), analysis of blood or saliva to check for these genes
- Sometimes bone scanning (imaging
of bones throughout the body), computed tomography (CT) of the abdomen and
chest, and MRI
- Sometimes blood tests to measure substances
produced by cancer cells (cancer markers)
For genetic testing,
doctors may refer women to a genetic counselor, who can document a detailed
family history (including all relatives who have had cancer), choose the most
appropriate tests, and help interpret the results.
Staging of Breast
Cancer
When cancer is
diagnosed, a stage is assigned to it. The stage is a number from 0 to
IV (sometimes with substages indicated by letters) that reflects how extensive
and aggressive the cancer is:
- Stage 0 is assigned to in situ breast cancers, such as ductal
carcinoma in situ. In situ means cancer in place. That is, the cancer has
not invaded surrounding tissues or spread to other parts of the body.
- Stages I through III are assigned to cancer that has
spread to tissues within or near the breast ( localized or regional
breast cancer).
- Stage IV is assigned to metastatic breast cancer (cancer that has
spread from the breast and lymph nodes in the armpit to other parts of the
body).
Staging the cancer
helps doctors determine the appropriate treatment and the prognosis.
Many factors go into
determining the stage of breast cancer, such as the following:
- How large the cancer is
- Whether cancer has spread to the lymph
nodes
- Whether it has spread (metastasized) to
other organs, such as the lungs or brain
Other important
staging factors include the following:
- Grade: How abnormal the cancer
cells look under a microscope, scored from 1 to 3
- Hormone receptor status: Whether the
cancer cells have estrogen, progesterone, and/or HER2 receptors
- Genetic testing of the cancer (such as the
Oncotype DX test): For some breast cancers, how many and which abnormal
genes are present in the cancer
Grade varies because although all cancer cells
look abnormal, some look more abnormal than others. If the cancer cells do not
look very different from normal cells, the cancer is considered
well-differentiated. If the cancer cells look very abnormal, they are considered
undifferentiated or poorly differentiated. Well-differentiated cancers tend to
grow and spread more slowly than undifferentiated or poorly differentiated
cancers. Based on these and other differences in microscopic appearance,
doctors assign a grade to most cancers.
The presence of hormone
receptors and gene mutations in the cancer cells
affect how the cancer responds to different treatments and what the prognosis
is.
Prognosis for
Breast Cancer
Generally, a woman's
prognosis depends on
- How large the cancer is
- What type of cancer it is
- Whether it has spread to the lymph nodes
or other organs
(See also the National
Cancer Institute's Surveillance, Epidemiology, and End Results (SEER)
Program.)
The number and
location of lymph nodes that contain cancer cells is one of the main factors
that determine whether the cancer can be cured and, if not, how long women will
live.
The 5-year
survival rate for breast cancer (the percentage of women who are alive
5 years after diagnosis) is
- 99% if the cancer remains at its original
site (localized)
- 86% if the cancer has spread to nearby
lymph nodes but no further (regional)
- 29% if the cancer has spread to distant
sites (metastasized)
- 58% if a full evaluation has not been done
and the cancer has not been staged
Women with breast
cancer tend to have a worse prognosis if they have any of the following:
- Diagnosis of breast cancer during their
20s and 30s
- Larger tumors
- Cancer that has rapidly dividing cells,
such as tumors that do not have well-defined borders or cancer that is
dispersed throughout the breast
- Tumors that do not have estrogen or progesterone receptors
- Tumors that have too many HER2 receptors
- A BRCA1 gene mutation
In the United States,
women who are Black and non-Hispanic have higher rates of death from breast
cancer than women who are White and non-Hispanic.
Having the BRCA2 gene
mutation probably does not make the current cancer result in a worse outcome.
However, having either BRCA gene mutation increases the risk
of developing a second breast cancer.
Prevention of
Breast Cancer
Taking drugs that
decrease the risk of breast cancer (chemoprevention) may be recommended for the
following women:
- Those who are over age 35 and have had a
previous lobular carcinoma in situ or abnormal tissue structure (atypical
hyperplasia) in the milk ducts or milk-producing glands
- Those who have a BRCA1 or BRCA2 or
another high-risk gene mutation
- Those who are between the ages of 35 and
59 and have a high risk of developing breast cancer based on their current
age, age when menstruation began (menarche), age at the first birth of a child,
number of first-degree relatives with breast cancer, and results of prior
breast biopsies
Drugs that block estrogen receptors
in breast tissue may be used to prevent breast cancer. They include
- Tamoxifen
- Raloxifene
Women should ask their
doctor about possible side effects before taking these drugs.
Risks of tamoxifen include
- Cancer of the uterus (endometrial
cancer)
- Blood clots in the legs
- Blood clots in the lungs
- Cataracts
- Possibly stroke
These risks are higher
for older women.
Raloxifene appears to be about as effective as tamoxifen in
postmenopausal women and to have a lower risk of endometrial cancer, blood
clots, and cataracts.
Both drugs may also
increase bone density and thus benefit women who have osteoporosis.
Treatment of Breast
Cancer
- Surgery
- Usually radiation therapy
- Hormone-blocking drugs (endocrine
therapy), chemotherapy, or both
Treatment for breast
cancer begins after the woman’s condition has been thoroughly evaluated.
Treatment options
depend on the stage and type of breast cancer and the receptors that the cancer
has. However, treatment is complex because the different types of breast cancer
differ greatly in characteristics such as growth rate, tendency to spread
(metastasize), and response to various treatments. Also, much is still unknown
about breast cancer. Consequently, doctors may have different opinions about
the most appropriate treatment for a particular woman.
The preferences of a
woman and her doctor affect treatment decisions. Women with breast cancer
should ask for a clear explanation of what is known about the cancer and what
is still unknown, as well as a complete description of treatment options. Then,
they can consider the advantages and disadvantages of the different treatments
and accept or reject the options offered.
Doctors may ask women
with breast cancer to participate in research studies investigating a new
treatment. New treatments aim to improve the chances of survival or quality of
life. Women should ask their doctor to explain the risks and possible benefits
of participation, so that they can make a well-informed decision.
Treatment usually
involves surgery and often includes radiation therapy and chemotherapy or
hormone-blocking drugs. Sometimes a woman can choose whether surgery will
involve removing part or all of one or both breasts. Women may be referred to a
plastic or reconstruction surgeon, who can remove the cancer and reconstruct
the breast in the same operation.
Surgery
The cancerous tumor
and varying amounts of the surrounding tissue are removed. There are two main
options for removing the tumor:
- Breast-conserving surgery plus radiation
therapy
- Removal of the breast (mastectomy)
For women with
invasive cancer (stage I or higher), mastectomy is no more effective than breast-conserving
surgery plus radiation therapy as long as the entire tumor can be removed
during breast-conserving surgery. In breast-conserving surgery, doctors remove
the tumor plus some surrounding normal tissue to reduce the risk that tissue
that may contain cancer is left behind.
Before surgery,
chemotherapy may be used to shrink the tumor before removing it. This approach
sometimes enables some women to have breast-conserving surgery rather than
mastectomy.
Breast-conserving
surgery
Breast-conserving
surgery leaves as much of the breast intact as possible. When considering the
type of surgery, it is more important for doctors to be sure they remove the
whole cancer than to risk leaving tissue that may contain cancer.
For breast-conserving
surgery, doctors first determine how big the tumor is and how much tissue
around it (called margins) needs to be removed. The size of the margins is
based on how big the tumor is in relation to the breast. Then the tumor with
its margins is surgically removed. Tissue from the margins is examined under a
microscope to check for cancer cells that have spread outside the tumor. These
findings help doctors decide on whether further treatment is needed.
Various terms (for
example, lumpectomy, wide excision, quadrantectomy) are used to describe how
much breast tissue is removed.
Breast-conserving
surgery is usually followed by radiation therapy.
The main advantages of
breast-conserving surgery are the possibility of preserving breast tissue and
how the breast appears after surgery. When the tumor is large in relation to
the breast, this type of surgery is less likely to be useful. In such cases,
removing the tumor plus some surrounding normal tissue means removing most of
the breast. Breast-conserving surgery is usually more appropriate when tumors
are small. In about 15% of women who have breast-conserving surgery, the amount
of tissue removed is so small that little difference can be seen between the
treated and untreated breasts. However, in most women, the treated breast
shrinks somewhat and may change in contour.
If either
breast-conserving surgery or mastectomy is an option, a woman should consider
each option. Some women prefer breast-conserving surgery because they feel that
losing a breast would be a very difficult emotional and physical experience and
that breast-conserving surgery helps preserve body image. Other women prefer
mastectomy because they feel more comfortable having all the breast tissue
removed or because if they have a mastectomy, they may not need radiation
therapy.
Chemotherapy, given to
shrink the tumor before removing it, may enable some women to have
breast-conserving surgery rather than a mastectomy.
Mastectomy
Mastectomy is the
other main surgical option. There are several types. In all types, all breast
tissue is removed, but which other tissues and how much of them are left in
place or removed vary by type:
- Skin-sparing mastectomy leaves the muscle under the breast
and enough skin to cover the wound. Reconstruction of the breast is much
easier if these tissues are left. The lymph nodes in the armpit are not
removed.
- Nipple-sparing mastectomy is the same as skin-sparing mastectomy
plus it leaves the nipple and the area of pigmented skin around the nipple
(areola).
- Simple mastectomy leaves the muscle under the breast
(pectoral muscle) and the lymph nodes in the armpit.
- Modified radical mastectomy consists of removing some lymph nodes
in the armpit but leaves the muscle under the breast.
- Radical mastectomy consists of removing the lymph nodes
in the armpit and the muscle under the breast. This procedure is rarely
done now unless the cancer has invaded the muscle under the breast.
Lymph node assessment
Doctors assess lymph
nodes to determine whether cancer has spread to the lymph nodes in the armpit.
If cancer is detected in these lymph nodes, it is more likely to have spread to
other parts of the body. In such cases, different treatment may be needed.
A network of lymphatic
vessels and lymph nodes ( lymphatic system) drain fluid from the tissue in
the breast (and other areas of the body). Lymph nodes trap foreign or abnormal
cells (such as bacteria or cancer cells) that may be contained in this fluid.
Thus, breast cancer cells often end up in lymph nodes near the breast, such as
those in the armpit. Usually, foreign and abnormal cells are then destroyed.
However, the cancer cells sometimes continue to grow in the lymph nodes or pass
through the nodes into the lymphatic vessels and spread to other parts of the
body.
Doctors first feel the
armpit to check for enlarged lymph nodes. Depending on what doctors find, they
may do one or more of the following:
- Ultrasonography to check for lymph nodes that may be
enlarged
- A biopsy (by removing a
lymph node or taking a sample of tissue with a needle using
ultrasonography to guide placement of the needle)
- Axillary lymph node dissection: Removal of many (typically 10 to 20)
lymph nodes in the armpit
- Sentinel lymph node dissection: Removal of only the lymph node or
nodes that cancer cells are most likely to spread to
If doctors feel an
enlarged lymph node in the armpit or are uncertain whether lymph nodes are
enlarged, ultrasonography is done. If an enlarged lymph node is detected, a
needle is inserted into it to remove a sample of tissue to be examined ( fine-needle
aspiration or core needle biopsy). Ultrasonography is used to guide placement
of the needle.
If the biopsy
detects cancer, surgical
removal of lymph nodes from the armpit (axillary lymph node dissection) may be
needed. Removing many lymph nodes in the armpit, even if they contain cancer,
does not help cure the cancer. However, it does help doctors decide what
treatment to use. Axillary lymph nodes are evaluated again after chemotherapy
is given before surgery (called neoadjuvant chemotherapy).
If the biopsy after
ultrasonography does not detect cancer, a sentinel lymph node biopsy is done because even if there are no
cancer cells in a biopsy sample, cancer cells may be present in other parts of
a lymph node. A sentinel lymph node biopsy is usually done as part of the
operation to remove the cancer, such as lumpectomy or mastectomy. It enables
doctors to identify and test the most important lymph node related to a breast
cancer. If that lymph node is not cancerous, a woman does not need a more
extensive surgery to remove all axillary lymph nodes.
For a sentinel
lymph node biopsy, doctors inject a blue dye and/or a radioactive substance
into the breast. These substances map the pathway from the breast to the first
lymph node (or nodes) in the armpit. Doctors then make a small incision in the
armpit and look for a lymph node that looks blue and/or gives off a radioactive
signal (detected by a handheld device). This lymph node is the one that cancer
cells are most likely to have spread to. This node is called a sentinel lymph
node because it is the first to warn that cancer has spread. Doctors remove
this node and send it to a laboratory to be checked for cancer. More than one
lymph node may look blue and/or give off a radioactive signal and thus be
considered a sentinel lymph node.
If the sentinel lymph
nodes do not contain cancer cells, no other lymph nodes are removed.
If the sentinel nodes
contain cancer, axillary lymph node dissection may be done, depending on
various factors, such as
- Whether a mastectomy is planned
- How many sentinel nodes are present and
whether the cancer has spread outside the nodes
Sometimes during
surgery to remove the tumor, doctors discover that the cancer has spread to the
lymph nodes, and axillary lymph node dissection is required. Before the surgery
is done, women may be asked whether they are willing to let the surgeon do more
extensive surgery if cancer has spread to the lymph nodes. Otherwise, a second
surgical procedure, if needed, is done later.
Removal of lymph nodes
often causes problems because it affects the drainage of fluids in tissues. As
a result, fluids may accumulate, causing persistent swelling (lymphedema) of
the arm or hand. After surgery, the risk of developing lymphedema continues
throughout life. Arm and shoulder movement may be limited, requiring physical
therapy. The more lymph nodes removed, the worse the lymphedema. Sentinel lymph
node biopsy causes less lymphedema than axillary lymph node dissection.
If lymphedema
develops, it is treated by specially trained therapists. They teach women how
to massage the area, which may help the accumulated fluid drain, and how to
apply a bandage, which helps keep fluid from reaccumulating. The affected arm
should be used as normally as possible, except that the unaffected arm should
be used for heavy lifting. Women should exercise the affected arm daily as
instructed and bandage it overnight indefinitely.
If lymph nodes have
been removed, women may be advised to ask health care practitioners not to
insert catheters or needles in veins in the affected arm and not to measure
blood pressure in that arm. These procedures makes lymphedema more likely to
develop or worsen. Women are also advised to wear gloves whenever they are
doing work that may scratch or injure the skin of the hand and arm on the side
of the surgery. Avoiding injuries and infections can help reduce the risk of
developing lymphedema.
Other problems that
may occur after lymph nodes are removed include temporary or persistent
numbness, a persistent burning sensation, and infection.
What Is a Sentinel
Lymph Node?
A network of lymphatic
vessels and lymph nodes drain fluid from the tissue in the breast. The lymph
nodes are designed to trap foreign or abnormal cells (such as bacteria or
cancer cells) that may be contained in this fluid. Sometimes cancer cells
pass through the nodes into the lymphatic vessels and spread to other parts
of the body. Although fluid from
breast tissue eventually drains to many lymph nodes, the fluid usually drains
first through one or only a few nearby lymph nodes. Such lymph nodes are called
sentinel lymph nodes because they are the first to warn that cancer has
spread. |
Breast reconstruction
surgery
Breast reconstruction
surgery may be done at the same time as a mastectomy or later.
Women should consult
with a plastic surgeon early during treatment to plan the breast reconstruction
surgery. When reconstruction is done depends not only on the woman's preference
but also on the other treatments needed. For example, if radiation therapy is
done before reconstruction surgery, reconstruction options are limited.
Oncoplastic breast surgery, which combines cancer (oncologic) surgery and
plastic surgery, is one option. This type of surgery is designed to remove all
cancer from the breast and preserve or restore the natural appearance of the
breast.
Most often, the
surgery is done by
- Inserting an implant (made of silicone or
saline)
- Reconstructing the breast using tissue
taken from other parts of the woman’s body
Surgeons often obtain
tissue for breast reconstruction from a muscle in the lower abdomen.
Alternatively, skin and fatty tissue (instead of muscle) from the lower abdomen
can be used to reconstruct the breast.
Breast
Reconstruction
Before inserting an
implant, doctors use a tissue expander, which resembles a balloon, to stretch
the remaining chest skin and muscle to make room for the breast implant. The
tissue expander is placed under the chest muscle during mastectomy. The
expander has a small valve that health care practitioners can access by inserting
a needle through the skin. Over the next several weeks, a salt solution
(saline) is periodically injected through the valve to expand the expander a
little at a time. After expansion is complete, the expander is surgically
removed, and the implant is inserted.
Breast Reconstruction
Using the Transverse Rectus Abdominis Muscle (TRAM)...
Alternatively, tissues
taken from the woman's body (such as muscle and tissues under the skin) can be
used for reconstruction. These tissues are taken from the abdomen, back, or
buttock and moved to the chest area to create the shape of a breast.
The nipple and
surrounding skin are usually reconstructed in a separate operation done later.
Various techniques can be used. They include using tissue from the woman's body
and tattooing.
Surgery may also be
done to modify (augment, reduce, or lift) the other breast to make both breasts
match.
Rebuilding a Breast
After a general
surgeon removes a breast tumor and the surrounding breast tissue
(mastectomy), a plastic surgeon may reconstruct the breast. A silicone or
saline implant may be used. Or in a more complex operation, tissue may be
taken from other parts of the woman’s body, such as the abdomen, buttock, or
back. Reconstruction may
be done at the same time as the mastectomy—a choice that involves being under
anesthesia for a longer time—or later—a choice that involves being under
anesthesia a second time. Reconstruction of
the nipple and surrounding skin is done later, often in a doctor's office. A
general anesthetic is not required. In many women, a
reconstructed breast looks more natural than one that has been treated with
radiation therapy, especially if the tumor was large. If a silicone or
saline implant is used and enough skin was left to cover it, the sensation in
the skin over the implant is relatively normal. However, neither type of
implant feels like breast tissue to the touch. If skin from other parts of
the body is used to cover the breast, much of the sensation is lost. However,
tissue from other parts of the body feels more like breast tissue than does a
silicone or saline implant. Silicone
occasionally leaks out of its sack. As a result, an implant can become hard,
cause discomfort, and appear less attractive. Also, silicone sometimes enters
the bloodstream. Some women are concerned
about whether the leaking silicone causes cancer in other parts of the body
or rare diseases such as systemic lupus erythematosus (lupus). There is
almost no evidence suggesting that silicone leakage has these serious
effects, but because it might, the use of silicone implants has decreased,
especially among women who have not had breast cancer. |
Removal of the
Breast Without Cancer
Certain women with
breast cancer have a high risk of developing breast cancer in their other
breast (the one without cancer). Doctors may suggest that these women have the
other breast removed before cancer develops in it. This procedure is called
contralateral (opposite side) prophylactic (preventive) mastectomy. This
preventive surgery may be appropriate for women with any of the following:
- An inherited genetic mutation that
increases the risk of developing breast cancer (such as the BRCA1 or BRCA2 mutation)
- At least two close, usually first-degree
relatives who have had breast or ovarian cancer
- Radiation therapy directed at the chest
when women were under 30 years old
- Lobular carcinoma in situ (a noninvasive
type)
In women with lobular
carcinoma in situ in one breast, invasive cancer is equally likely to develop
in either breast. Thus, the only way to eliminate the risk of breast cancer for
these women is to remove both breasts. Some women, particularly those who are
at high risk of developing invasive breast cancer, choose this option.
Advantages of
contralateral prophylactic mastectomy include the following:
- Longer survival for women with breast
cancer and a genetic mutation that increases risk and possibly for women
who are under 50 years old when they are diagnosed with breast cancer
- Decreased need for cumbersome follow-up
imaging tests after treatment
- For some women, decreased anxiety
Disadvantages of this
procedure include the following:
- Twice the risk of complications
Instead of having a
contralateral prophylactic mastectomy, some women may choose to have their
doctor monitor the breast closely for cancer—for example with imaging tests.
Radiation Therapy
Radiation therapy is
used to kill cancer cells at and near the site from which the tumor was
removed, including nearby lymph nodes.
Radiation therapy
after mastectomy is done if the following are present:
- The tumor is 5 centimeters (about 2
inches) or larger.
- The cancer has spread to one or more lymph
nodes.
In such cases,
radiation therapy after mastectomy reduces the incidence of cancer recurring on
the chest wall and in nearby lymph nodes, and it improves the chances of
survival.
Radiation therapy
after breast-conserving surgery significantly reduces the incidence of breast
cancer recurring near the original tumor and in nearby lymph nodes, and it may
improve overall survival. However, if women are over 70 have a lumpectomy and
the cancer has estrogen receptors, radiation therapy may not be
necessary because it does not significantly reduce the risk of recurrence or
improve the chances of survival in these women.
Side effects of
radiation therapy include swelling in the breast, reddening and blistering of
the skin in the treated area, and fatigue. These effects usually disappear
within several months up to about 12 months. Fewer than 5% of women treated
with radiation therapy have rib fractures that cause minor discomfort. In about
1% of women, the lungs become mildly inflamed 6 to 18 months after radiation
therapy is completed. Inflammation causes a dry cough and shortness of breath
during physical activity that last for up to about 6 weeks. Lymphedema may
develop after radiation therapy.
Chemotherapy and
Hormone-Blocking Drugs
Chemotherapy and
hormone-blocking drugs can suppress the growth of cancer cells throughout the
body.
To decide whether to
treat with chemotherapy, doctors evaluate a few factors about a woman and her
breast cancer and discuss the risks and benefits with her. Factors that doctors
consider include
- Whether cancer has spread to lymph nodes
- Whether a woman is premenopausal or
postmenopausal
- What the results of tests for estrogen receptors
and progesterone receptors are
- What the results of tests for the human
epidermal growth factor 2 (HER2) oncogene are
- Genetic testing of the cancer (such as the
Oncotype DX test)
For women with
invasive breast cancer, chemotherapy and/or hormone-blocking drugs are usually
begun soon after surgery. These drugs are continued for months or years. Some,
such as tamoxifen, may be continued for 5 to 10 years. If tumors
are larger than 5 centimeters (about 2 inches), chemotherapy or
hormone-blocking drugs may be started before surgery. These drugs delay or
prevent the recurrence of cancer in most women and prolong survival in some.
Analyzing the genetic
material of the cancer (predictive genomic testing) may help predict which
cancers are susceptible to chemotherapy or hormone-blocking drugs.
If women have a breast
cancer with estrogen and progesterone receptors but no HER2
receptors and the lymph nodes are not affected, they may not need chemotherapy.
Hormone-blocking therapy alone may be sufficient.
Chemotherapy
Chemotherapy is used
to kill rapidly multiplying cells or slow their multiplication. Chemotherapy
alone cannot cure breast cancer. It must be used with surgery or radiation
therapy. Chemotherapy drugs are usually given intravenously in cycles.
Sometimes they are given by mouth. Typically, a day of treatment is followed by
2 or more weeks of recovery. Using several chemotherapy drugs together is more
effective than using a single drug. The choice of drugs depends partly on
whether cancer cells are detected in nearby lymph nodes.
Commonly used drugs
include cyclophosphamide, doxorubicin, epirubicin, 5-fluorouracil, methotrexate,
and paclitaxel (see Chemotherapy).
Side effects (such as
vomiting, nausea, hair loss, and fatigue) vary depending on which drugs are
used. Chemotherapy can cause infertility and early menopause by destroying the
eggs in the ovaries. Chemotherapy may also suppress the production of blood
cells by the bone marrow and thus cause anemia or bleeding or increase the risk
of infections. So drugs, such as filgrastim or pegfilgrastim,
may by used to stimulate the bone marrow to produce blood cells.
Hormone-blocking drugs
Hormone-blocking drugs
interfere with the actions of estrogen or progesterone, which
stimulate the growth of cancer cells that have estrogen and/or progesterone receptors.
Hormone-blocking drugs may be used when cancer cells have these receptors,
sometimes instead of chemotherapy. The benefits of hormone-blocking drugs are
greatest when cancer cells have both estrogen and progesterone receptors
and are almost as great when only estrogen receptors are present. The
benefit is minimal when only progesterone receptors are present.
Hormone-blocking drugs
include
- Tamoxifen: Tamoxifen, given by mouth, is a selective estrogen-receptor
modulator. It binds with estrogen receptors and inhibits growth
of breast tissue. In women who have estrogen receptor–positive
cancer, tamoxifen, taken for 5 years, increases the likelihood
of survival by about 25%, and 10 years of treatment may be even more
effective. Tamoxifen, which is related to estrogen, has
some of the benefits and risks of estrogen therapy taken after
menopause. For example, it decreases the risk of developing breast cancer
in the other breast. It may decrease the risk of osteoporosis and
fractures. However, it increases the risk of blood clots in the legs and
lungs. It also increases the risk of developing cancer of the uterus (endometrial
cancer). Thus, if women taking tamoxifen have spotting or
bleeding from the vagina, they should see their doctor. However, the
improvement in survival after breast cancer far outweighs the risk of
endometrial cancer. Tamoxifen, unlike estrogen therapy,
may worsen the vaginal dryness or hot flashes that occur after menopause.
- Aromatase inhibitors: These drugs (anastrozole, exemestane,
and letrozole) inhibit aromatase (an enzyme that converts some
hormones to estrogen) and thus reduce the production of estrogen.
In postmenopausal women, these drugs may be more effective than tamoxifen.
Aromatase inhibitors may be given instead of tamoxifen or
after tamoxifen treatment has been completed. Aromatase
inhibitors may increase the risk of osteoporosis and fractures.
Monoclonal antibodies
Monoclonal antibodies
are synthetic copies (or slightly modified versions) of natural substances that
are part of the body’s immune system. These drugs enhance the immune system’s
ability to fight cancer.
Treatment of Noninvasive
Cancer (Stage 0)
(See also table Treating
Breast Cancer Based on Type and Stage.)
For ductal
carcinoma in situ, treatment usually consists of one the following:
- A mastectomy
- Removal of the tumor and a large amount of
surrounding normal tissue (wide excision) with or without radiation
therapy
Some women with ductal
carcinoma in situ are also given hormone-blocking drugs as part of their
treatment.
For lobular
carcinoma in situ, treatment includes the following:
- Classic lobular carcinoma in situ:
Surgical removal to check for cancer and, if no cancer is detected, close
observation afterward and sometimes tamoxifen, raloxifene,
or an aromatase inhibitor to reduce the risk of developing invasive cancer
- Pleomorphic lobular carcinoma in situ:
Surgery to remove the abnormal area and sometimes tamoxifen or raloxifene to
reduce the risk of developing invasive cancer
Observation consists
of a physical examination every 6 to 12 months for 5 years and once a year
thereafter plus mammography once a year. Although invasive breast cancer may
develop, the invasive cancers that develop are usually not fast growing and can
usually be treated effectively. Furthermore, because invasive cancer is equally
likely to develop in either breast, the only way to eliminate the risk of
breast cancer for women with lobular carcinoma in situ is removal of both
breasts ( bilateral mastectomy). Some women, particularly those who are at
high risk of developing invasive breast cancer, choose this option.
Women with lobular
carcinoma in situ are often given tamoxifen, a hormone-blocking
drug, for 5 years. It reduces but does not eliminate the risk of developing
invasive cancer. Postmenopausal women may be given raloxifene or
sometimes an aromatase inhibitor instead.
Trastuzumab and pertuzumab are
a type of monoclonal antibody called anti-HER2 drugs. They are used with
chemotherapy to treat metastatic breast cancer only when the cancer cells have
too many HER2 receptors. These drugs bind with HER2 receptors and thus help
prevent cancer cells from multiplying. Sometimes both of these drugs are
used. Trastuzumab is usually taken for a year. Both drugs can
weaken the heart muscle. So doctors monitor heart function during treatment.
Treatment of
Early-Stage Invasive Cancer (Stages I and II)
For breast cancers
that are within the breast and may or may not have spread to nearby lymph
nodes, treatment almost always includes surgery to remove as much of the tumor
as possible. One of the following may be done:
- Breast-conserving surgery, followed by
radiation therapy
- Mastectomy with or without breast
reconstruction
The initial surgery
may include axillary lymph node dissection (removal of many lymph
nodes from the armpit) or sentinel lymph node biopsy (removal of the
lymph node nearest the breast or the first few nodes that are nearest the
breast).
Women may be given
chemotherapy before surgery (called neoadjuvant chemotherapy). If the tumor is
attached to the chest wall, chemotherapy helps make removing the tumor
possible. Chemotherapy is also helpful if a breast cancer is large in relation
to the rest of the breast. Neoadjuvant chemotherapy improves the chances of
having breast-conserving surgery. Breast-conserving surgery is used only when
the tumor is not too large because the entire tumor plus some of the
surrounding normal tissue must be removed. If the tumor is large, removing the
tumor plus some surrounding normal tissue essentially results in removing most
of the breast.
Neoadjuvant
chemotherapy is also considered for treatment of breast cancers that do not
have receptors for estrogen, progesterone, and HER2 (called triple
negative breast cancer) and cancers that have only HER2 receptors.
After surgery, women
may be given chemotherapy, hormone-blocking drugs, anti-HER2 drugs, or a
combination, depending on analysis of the tumor.
Treatment of
Locally Advanced Cancer (Stage III)
For breast cancers
that have spread to more lymph nodes, the following may be done:
- Before surgery, drugs, usually
chemotherapy, to shrink the tumor
- Breast-conserving surgery or mastectomy if
the drug given before surgery makes removing the tumor possible
- After surgery, usually radiation therapy
- After surgery, chemotherapy,
hormone-blocking drugs, or both
Whether radiation
therapy and/or chemotherapy or other drugs are used after surgery depends on
many factors, such as the following:
- How large the tumor is
- Whether menopause has occurred
- Whether the tumor has receptors for
hormones
- How many lymph nodes contain cancer cells
Treatment of Cancer
That Has Spread (Stage IV)
Breast cancer that has
spread beyond the lymph nodes is rarely cured, but most women who have it live
at least 2 years, and a few live 10 to 20 years. Treatment extends life only
slightly but may relieve symptoms and improve quality of life. However, some
treatments have troublesome side effects. Thus, deciding whether to be treated
and, if so, which treatment to choose can be highly personal.
Choice of therapy
depends on the following:
- Whether the cancer has estrogen and progesterone receptors
- How long the cancer had been in remission
before it spread
- How many organs and how many parts of the
body the cancer has spread to (where the metastases are)
- Whether the woman is postmenopausal or
still menstruating
If the cancer is
causing symptoms (pain or other discomfort), women are usually treated with
chemotherapy or hormone-blocking drugs. Pain is usually treated with
analgesics. Other drugs may be given to relieve other symptoms. Chemotherapy or
hormone-blocking drugs are given to relieve symptoms and improve quality of
life.
Hormone-blocking
drugs are preferred to
chemotherapy when the cancer has the following characteristics:
- The cancer is estrogen receptor–positive.
- Cancer has not recurred for more than 2
years after diagnosis and initial treatment.
- Cancer is not immediately life
threatening.
Different
hormone-blocking drugs are used in different situations:
- Tamoxifen: For women who are still menstruating, tamoxifen is
often the first hormone-blocking drug used.
- Aromatase inhibitors: For postmenopausal women who
have estrogen receptor–positive breast cancer, aromatase
inhibitors (such as anastrozole, letrozole,
and exemestane) may be more effective as a first treatment
than tamoxifen.
- Progestins: These drugs, such as medroxyprogesterone or megestrol,
may be used after aromatase inhibitors and tamoxifen when
these drugs are no longer effective.
- Fulvestrant: This drug may be used when tamoxifen is no
longer effective. It destroys the estrogen receptors in cancer
cells.
Alternatively, for
women who are still menstruating, surgery to remove the ovaries, radiation to
destroy them, or drugs to inhibit their activity (such as buserelin, goserelin,
or leuprolide) may be used to stop estrogen production.
These therapies may be used with tamoxifen.
Trastuzumab (a type of monoclonal antibody called an
anti-HER2 drug) can be used to treat cancers that have too many HER2 receptors
and that have spread throughout the body. Trastuzumab can be
used alone or with chemotherapy drugs (such as paclitaxel), with hormone-blocking
drugs, or with pertuzumab (another anti-HER2 drug). Trastuzumab plus
chemotherapy plus pertuzumab slows the growth of breast
cancers that have too many HER2 receptors and increases survival time more
than trastuzumab plus chemotherapy. Trastuzumab can
also be used with hormone-blocking drugs to treat women who have estrogen receptor–positive
breast cancer.
Tyrosine kinase
inhibitors (such as lapatinib and neratinib),
another type of anti-HER drug, block the activity of HER2. These drugs are being
increasingly used in women with cancers that have too many HER2 receptors.
In some
situations, radiation therapy may be used instead of or before
drugs. For example, if only one area of cancer is detected and that area is in
a bone, radiation to that bone might be the only treatment used. Radiation
therapy is usually the most effective treatment for cancer that has spread to
bone, sometimes keeping it in check for years. It is also often the most
effective treatment for cancer that has spread to the brain.
Surgery may be done to remove single tumors in
other parts of the body (such as the brain) because such surgery can relieve
symptoms. Mastectomy (removing the breast) may be done to help relieve
symptoms. But it is unclear whether removing the breast helps prolong life when
cancer has spread to other parts of the body and has been treated and
controlled.
Bisphosphonates (used to treat osteoporosis), such
as pamidronate or zoledronate, reduce bone pain and bone loss
and may prevent or delay bone problems that can result when cancer spreads to
bone.
Treatment of Specific
Types of Breast Cancer
For inflammatory
breast cancer, treatment usually consists of both chemotherapy and
radiation therapy. Mastectomy is usually done.
For Paget
disease of the nipple, treatment is usually similar to that of other
types of breast cancer. It often involves simple mastectomy or
breast-conserving surgery plus removal of the lymph nodes. Breast-conserving
surgery is usually followed by radiation therapy. Less commonly, only the
nipple with some surrounding normal tissue is removed. If another breast cancer
is also present, treatment is based on that type of breast cancer.
For phyllodes
tumors, treatment usually consists of removing the tumor and a large
amount of surrounding normal tissue (at least 1 centimeter (0.4 inch) around
the tumor)—called a wide margin. If the tumor is large in relation to the
breast, a simple mastectomy may be done to remove the tumor plus wide margins.
Whether phyllodes tumors recur depends on how wide the tumor-free margins are
and whether the phyllodes tumor is noncancerous or cancerous. Cancerous
phyllodes tumors can metastasize to distant sites, such as the lungs, bone, or
brain. Recommendations for treatment of metastatic phyllodes tumors are evolving,
but radiation therapy and chemotherapy may be useful.
Preservation of
Fertility
Women should not
become pregnant while being treated for breast cancer.
If women wish to have
children (preserve fertility) after being treated, they are referred to a reproductive
endocrinologist before treatment is started. These women can then find out
about the effect of different chemotherapy drugs on fertility and about
procedures that may enable them to have children after treatment.
Options to preserve
fertility include assisted reproductive techniques with ovarian
stimulation and freezing eggs or embryos.
Choice of the
procedure to be used to preserve fertility depends on the following:
- Type of breast cancer
- Type of breast cancer treatment that is
planned
- The woman's preferences
Assisted reproductive
techniques involve use of hormonal drugs. Doctors discuss the risks and
benefits of having these treatments with women who have estrogen or progesterone receptor–positive
cancer.
Follow-up Care
After the first phases
of treatment are completed, follow-up physical examinations, including
examination of the breasts, chest, neck, and armpits, are usually done every
year. Regular mammograms and breast self-examinations are also important. Women
should promptly report certain symptoms to their doctor:
- Any lumps or other changes in their
breasts
- Changes in nipples or a discharge
- Pain—for example in the arm or spine
- Swelling in the armpit
- Loss of appetite or weight
- Chest pain
- Chronic dry cough
- Bleeding from the vagina (if not
associated with menstrual periods)
- Severe headaches
- Blurred vision
- Dizziness or balance problems
- Numbness or weakness
- Any symptoms that seem unusual or that
persist
Diagnostic procedures,
such as chest x-rays, blood tests, bone scans, and computed tomography (CT),
are not needed unless symptoms suggest the cancer has recurred.
The effects of
treatment for breast cancer cause many changes in a woman’s life. Support from
family members and friends can help, as can support groups. Counseling may be
helpful.
End-of-Life Issues
For women with
metastatic breast cancer, quality of life may deteriorate, and the chances that
further treatment will prolong life may be small. Staying comfortable may
eventually become more important than trying to prolong life.
Cancer pain can
be adequately controlled with appropriate drugs. So if women are having pain,
they should ask their doctor for treatment to relieve it. Treatments can also
relieve other troublesome symptoms, such as constipation, difficulty breathing,
and nausea.
Psychologic and
spiritual counseling may also help.
Women with metastatic
breast cancer should prepare advance directives indicating the type
of care they desire in case they are no longer able to make such decisions.
Also, making or updating a will is important.
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