Ovarian Cancer

• Ovarian cancer may not cause symptoms until it is large or has spread.
• If doctors suspect ovarian cancer, ultrasonography, magnetic resonance imaging, or computed tomography is 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.

Factors that increase the risk of ovarian cancer include the following:

• Being older (the most important)
• Not having any children
• Having a first child late in life
• Starting menstruating early
• Having menopause late
• Having had or having a family member who had cancer of the uterus, breast, or large intestine (colon)

The risk of ovarian cancer is higher in developed countries because the diet tends to be high in fat. Use of oral contraceptives significantly decreases risk.

About 5 to 10% of cases are related to the BRCA gene, which is also involved in some breast cancers. In these cases, ovarian and breast cancer tends to run in families. This abnormal gene is most common among Ashkenazi Jewish women.

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 at least 80%. 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 are much more common among women younger than 30. Sometimes cancers from other parts of the body spread to the ovaries.

Ovarian cancer can spread directly to the surrounding area and through the lymphatic system to other parts of the pelvis and abdomen. It can also spread through the bloodstream, eventually appearing in distant parts of the body, mainly the liver and lungs.

Symptoms

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 (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. 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 hyperthyroidism.

Diagnosis

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, ultrasonography is done first. Sometimes computed tomography (CT) or magnetic resonance imaging (MRI) is used to help distinguish an ovarian cyst from a 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, the ovaries are examined using a thin, flexible viewing tube (laparoscope) inserted through a small incision just below the navel. Also, tissue samples are removed using instruments threaded through the laparoscope and examined (biopsied). In addition, 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 marker levels alone do not confirm the diagnosis of cancer, but when combined with other information, they can help confirm it.

If fluid has accumulated in the abdomen, it can be drawn out (aspirated) through a needle and tested to determine whether cancer cells are present.

If doctors suspect advanced cancer or cancer is confirmed, they make an incision in the abdomen to obtain a tissue sample. At the same time, they remove as much of the cancer as possible and determine how far the cancer has spread (its stage).

Prognosis

The prognosis is based on the stage (see Cancers of the Female Reproductive System: Staging Cancers of the Female Reproductive System*). The percentages of women who are alive 5 years after diagnosis and treatment are

• Stage I: 70 to 100%
• Stage II: 50 to 70%
• Stage III: 20 to 50%
• Stage IV: 10 to 20%

The prognosis is worse when the cancer is more aggressive or when surgery cannot remove all visibly abnormal tissue. Cancer recurs in 70% of women who have had stage III or IV cancer.

Prevention

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 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. These women should be evaluated by a gynecologist who specializes in cancer (gynecologic oncologist). More information is available from the National Cancer Institute Cancer Information Service (1-800-4-CANCER) and the Women's Cancer Network (WCN) web site (www.wcn.org).

Treatment

The extent of surgery depends on the type of ovarian cancer and the stage. For most cancers, the ovaries, fallopian tubes, and uterus are removed. When cancer has spread beyond the ovary, nearby lymph nodes and surrounding structures that the cancer typically spreads to are also removed. 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, removing as much of the cancer as possible prolongs survival.

After surgery, most women with stage I epithelial carcinomas usually 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 Some Trade Names
ABRAXANETAXOL
combined with carboplatin Some Trade Names
PARAPLATIN
, given 6 times. 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 Some Trade Names
BLENOXANE
, cisplatin Some Trade Names
PLATINOL
, and etoposide Some Trade Names
VEPESID
. Radiation therapy is rarely used.

Advanced ovarian cancer usually recurs. So after chemotherapy, doctors typically measure levels of cancer markers. If the cancer recurs, chemotherapy (using drugs such as carboplatin Some Trade Names
PARAPLATIN
, doxorubicin Some Trade Names
DOXIL
, etoposide Some Trade Names
VEPESID
, gemcitabine Some Trade Names
GEMZAR
, paclitaxel Some Trade Names
ABRAXANETAXOL
, or topotecan Some Trade Names
HYCAMTIN
) is given.

What Is an Ovarian Cyst? An ovarian cyst is a fluid-filled sac in or on an ovary. Such cysts are relatively common. Most are noncancerous and disappear on their own. Cancerous cysts are more likely to occur in women older than 40. Most noncancerous ovarian cysts do not cause symptoms. However, some cause pressure, aching, or a feeling of heaviness in the abdomen. Pain may be felt during sexual intercourse. If a cyst ruptures or becomes twisted, severe stabbing pain is felt in the abdomen. The pain may be accompanied by nausea and fever. Some cysts produce hormones that affect menstrual periods. As a result, periods may be irregular or heavier than normal. In postmenopausal women, such cysts may cause vaginal bleeding. Women who have any of these symptoms should see a doctor. Doctors may find a cyst during a routine pelvic examination or occasionally suspect it based on symptoms. A pregnancy test is done to exclude that possibility. An ultrasound device may be inserted through the vagina into the uterus (transvaginal ultrasonography) to confirm the diagnosis. If the cyst appears to be noncancerous, a woman may be asked to return periodically for pelvic examinations as long as the cyst remains. If the cyst could be cancerous, computed tomography (CT) or magnetic resonance imaging (MRI) may be done. If cancer still seems possible, the ovaries may be examined through a laparoscope, inserted through a small incision just below the navel. Blood tests can help confirm or rule out cancer. For noncancerous cysts, no treatment is necessary. But if a cyst is larger than about 2 inches (5 centimeters) and persists, it may need to be removed. If cancer cannot be ruled out, the ovary is removed. Cancerous cysts plus the affected ovary and fallopian tube are removed. Surgery may be done through a laparoscope (with only a small incision) or a larger incision in the abdomen.