Ovarian Cancer
Ovarian cancer, which typically starts on the surface of the
ovaries, is not usually diagnosed until it is advanced.
Ovarian cancer may not cause symptoms until it is large or
has spread.
If doctors suspect ovarian cancer, blood tests,
ultrasonography, and magnetic resonance imaging or computed tomography are
done.
Usually, both ovaries, both fallopian tubes, and the uterus
are removed.
Chemotherapy is often needed after surgery.
Cancer of the ovaries (ovarian carcinoma) develops most
often in women aged 50 to 70. This cancer eventually develops in about 1 of 70
women. In the United States, it is the second most common gynecologic cancer.
However, more women die of ovarian cancer than of any other gynecologic cancer.
It is the fifth most common cause of cancer deaths in women.
Locating the Internal Female Reproductive Organs
Internal Female Genital Organs
There are many types of ovarian cancer. They develop from the many different types of cells in the ovaries. Cancers that start on the surface of the ovaries (epithelial carcinomas) account for more that 90%. Most other ovarian cancers start from the cells that produce eggs (called germ cell tumors) or in connective tissue (called stromal cell tumors). Germ cell tumors usually occur in women younger than 30.
Sometimes cancers from other parts of the body spread to the
ovaries.
Ovarian cancer can spread as follows:
Directly to the surrounding area
Through the shedding of cancer cells into the abdominal
cavity
Through the lymphatic system to other parts of the pelvis
and abdomen
Less often, through the bloodstream, eventually appearing in
distant parts of the body, mainly the liver and lungs
Risk Factors of Ovarian Cancer
Factors that increase the risk of ovarian cancer include the
following:
Being older (the most important)
Having a first-degree relative (mother, sister, or daughter)
who has had ovarian cancer
Not having any children
Having a first child late in life
Starting menstruating early
Having menopause late
Having had cancer of the uterus, breast, or large intestine
(colon) or having a family member who has had one of these cancers
Use of oral contraceptives significantly decreases risk.
About 14 to 18% of cases are related to mutations in the
BRCA1 and BRCA2 genes, which are also involved in some breast cancers. When
mutations in these genes or other rare gene mutations are involved, ovarian and
breast cancers tend to run in families. Such cancers are sometimes called
hereditary breast and ovarian cancer syndromes. For women who have a BRCA1
mutation, the lifetime risk of developing ovarian cancer is 20 to 40%. Risk is
less (11 to 17%) for women with a BRCA2 mutation. The BRCA1 and BRCA2 genes are
more common among Ashkenazi Jewish women than the general population.
Symptoms of Ovarian Cancer
Ovarian cancer causes the affected ovary to enlarge. In young women, enlargement of an ovary is likely to be caused by a noncancerous fluid-filled sac (ovarian cyst). However, after menopause, an enlarged ovary can be a sign of ovarian cancer.
Many women have no symptoms until the cancer is advanced.
The first symptom may be vague discomfort in the lower abdomen, similar to
indigestion. Other symptoms may include bloating, loss of appetite (because the
stomach is compressed), gas pains, and backache. Ovarian cancer rarely causes
vaginal bleeding.
Eventually, the abdomen may swell because the ovary enlarges or fluid accumulates in the abdomen (called ascites). At this stage, pain in the pelvic area, anemia, and weight loss are common.
Rarely, germ cell or stromal cell tumors produce estrogens, which can cause tissue in the uterine lining to grow excessively and breasts to enlarge. Or these tumors may produce male hormones (androgens), which can cause body hair to grow excessively, or hormones that resemble thyroid hormones, which can cause symptoms of an overactive thyroid gland (hyperthyroidism).
Diagnosis of Ovarian Cancer
Ultrasonography
Sometimes computed tomography or magnetic resonance imaging
Blood tests
Diagnosing ovarian cancer in its early stages is difficult
because symptoms usually do not appear until the cancer is quite large or has
spread beyond the ovaries and because many less serious disorders cause similar
symptoms.
If doctors detect an enlarged ovary during a physical examination or suspect early ovarian cancer based on symptoms, ultrasonography is done first. Sometimes computed tomography (CT) or magnetic resonance imaging (MRI) is used to help distinguish an ovarian cyst from a solid cancerous mass. If advanced cancer is suspected, CT or MRI is usually done before surgery to determine extent of the cancer.
If cancer seems unlikely, doctors reexamine the woman
periodically.
If doctors suspect cancer or test results are unclear, blood tests are usually done to measure levels of substances that may indicate the presence of cancer (tumor markers), such as cancer antigen 125 (CA 125). Abnormal tumor marker levels alone do not confirm the diagnosis of cancer, but when combined with other information, they can support the diagnosis.
To confirm the diagnosis of ovarian cancer and to determine
whether and how far the cancer has spread (its stage), doctors examine the
ovaries in one of two ways:
Laparoscopy: Doctors may use a thin, flexible viewing tube (laparoscope) inserted through a small incision just below the navel, particularly if they think the cancer is not advanced. They use instruments threaded through the laparoscope, sometimes with robotic assistance, to take samples from various other tissues and to examine the ovaries and other organs. The information thus obtained can help doctors determine whether and how far the cancer has spread (its stage). The ovaries can also be removed to treat ovarian cancer using laparoscopy.
Open surgery: If doctors think the cancer may be advanced,
they make an incision in the abdomen and directly view the uterus and the
tissues around it. They determine the cancer's stage and remove as much of the
cancer as possible.
Doctors consider recommending genetic testing for any woman who is diagnosed with ovarian (or fallopian tube) cancer. Doctors also ask about any cancers family members have had. This information can help doctors identify women who are more likely to have a hereditary form of cancer, such as that caused by mutations in BRCA genes.
Staging of ovarian cancer
Stages are based on how far the cancer has spread. Stages
range from I (the earliest) to IV (advanced):
Stage I: The cancer occurs only in one or both ovaries (or
fallopian tubes).
Stage II: The cancer has spread to the uterus, or nearby
tissues within the pelvis (which contains the internal reproductive organs,
bladder, and rectum).
Stage III: The cancer has spread outside the pelvis to lymph
nodes and/or to other parts of the abdomen (such as the surface of the liver or
spleen).
Stage IV: The cancer has spread outside the pelvis (for
example, to the lung).
Prognosis of Ovarian Cancer
The prognosis for women with ovarian cancer is based on the
stage. The percentages of women who are alive 5 years after diagnosis and
treatment (5-year survival rate) are
Stage I: 85 to 95%
Stage II: 70 to 78%
Stage III: 40 to 60%
Stage IV: 15 to 20%
The prognosis is worse when the cancer is more aggressive or
when surgery cannot remove all visibly abnormal tissue. Cancer recurs in about
70% of women who have had stage III or IV cancer.
Prevention of Ovarian Cancer
Some experts believe that if ovarian or breast cancer runs in the family, women should be tested for genetic abnormalities. If first- or second-degree relatives have such cancers, particularly among Ashkenazi Jewish families, women should discuss genetic testing for BRCA abnormalities with their doctors.
Women with certain BRCA gene mutations may be offered the option of having both ovaries and fallopian tubes removed after they no longer wish to bear children, even when no cancer is present. This approach eliminates the risk of ovarian cancer and reduces the risk of breast cancer. More information is available from the National Cancer Institute Cancer Information Service (1-800-4-CANCER) and the Foundation for Women's Cancer.
Did You Know...
If women have first- or second-degree relatives with ovarian
or breast cancer, they should ask their doctor about genetic testing for BRCA
abnormalities.
Treatment of Ovarian Cancer
Usually removal of ovaries, fallopian tubes, and uterus
Removal of all tissue that appears affected (cytoreductive
surgery)
Usually chemotherapy
The extent of surgery depends on the type of ovarian cancer
and the stage.
For most ovarian cancers, treatment involves removing the
ovaries and fallopian tubes (salpingo-oophorectomy) and the uterus
(hysterectomy). Laparoscopic surgery or robotic-assisted laparoscopic surgery
may be used.
When cancer has spread beyond the ovary, nearby lymph nodes
and surrounding structures that the cancer typically spreads to are also
removed. This approach aims to remove all visible cancer.
If a woman has stage I cancer that affects only one ovary
and she wishes to become pregnant, doctors may remove only the affected ovary
and fallopian tube.
For more advanced cancers that have spread to other parts of
the body, doctors usually remove as much of the cancer as possible to prolong
survival. This type of surgery is called cytoreductive surgery. However,
depending on where the cancer has spread and how much cancer is present, women
may be treated with chemotherapy instead of or before and after surgery.
After surgery, most women with less aggressive stage I
epithelial carcinomas require no further treatment. For other stage I cancers
or for more advanced cancers, chemotherapy may be used to destroy any small
areas of cancer that may remain. Typically, chemotherapy consists of paclitaxel
combined with carboplatin.
Most women with germ cell tumors can be cured with removal
of the one affected ovary and fallopian tube plus combination chemotherapy,
usually with bleomycin, cisplatin, and etoposide. Radiation therapy is rarely
used.
Advanced ovarian cancer usually recurs. So after
chemotherapy, doctors typically measure levels of cancer markers (such as CA
125). Cancer marker levels that remain high usually mean that some of the tumor
remains.
If the cancer recurs after chemotherapy appeared to be
effective, chemotherapy is repeated. Many different chemotherapy drugs or
combinations of drugs may be used.