What Is Ovarian Cancer?
Ovarian cancer is a malignancy of the ovaries, the female sex organs that produce eggs and make the hormones estrogen and progesterone. Treatments for ovarian cancer are improving, and the best outcomes are always seen when the cancer is found early.
Symptoms of Ovarian Cancer
Ovarian cancer may not produce symptoms, particularly in the early stages. However, when symptoms do occur, they include abdominal bloating or a feeling of pressure, abdominal or pelvic pain, frequent urination, and feeling full quickly when eating. These symptoms, of course, occur with many different conditions and are not specific to cancer. You should discuss these symptoms with your doctor if they occur frequently and persist for more than a few weeks.
Risk Factor: Family History
Family history of ovarian cancer is a risk factor; a woman has a higher chance of developing it if a close relative has had ovarian, breast, or colon cancer. Inherited gene mutations, including the BRCA1 and BRCA2 mutations linked to breast cancer, are responsible for about 10% of ovarian cancers. Talk to you doctor if you have a strong family history of these cancers to determine if closer medical observation may be helpful.
Risk Factor: Age
Age is the strongest risk factor for ovarian cancer. It is much more common after menopause, and using hormone therapy may increase a woman’s risk. This risk appears strongest in those who take estrogen therapy without progesterone for at least 5-10 years. It is not known whether taking estrogen and progesterone in combination also increases risk.
Risk Factor: Obesity
Obesity is also a risk factor for ovarian cancer; obese women have both a higher risk of developing ovarian cancer and higher death rates from this cancer than non-obese women. The risk seems to correlate with weight, so the heaviest women have the highest risk.
Two ways to screen for ovarian cancer in its early stages are ultrasound of the ovaries and measurement of levels of a protein called CA-125 in the blood. Neither of these methods has been shown to save lives when used to test women of average risk. Therefore, screening is currently recommended only for women at higher risk.
Diagnosing Ovarian Cancer
Imaging tests like CT, MRI, or ultrasound can reveal an ovarian mass, but only a sampling of the tissue (biopsy) can determine whether the mass is cancerous. A biopsy is analyzed in a laboratory to determine whether or not the ovarian mass biopsied is due to cancer.
Stages of Ovarian Cancer
Staging of ovarian cancer refers to the extent to which it has spread to other organs or tissues. This is typically evaluated during surgery. Stages of ovarian cancer are as follows:
Stage I: The cancer is limited to the ovaries
Stage II: The cancer has spread to the uterus or other pelvic organs
Stage III: The cancer has spread to lymph nodes or lining tissues of the abdomen
Stage IV: The cancer has spread to distant sites, like the liver or lungs
Types of Ovarian Cancer
There are different kinds of ovarian cancer, depending on the type of cell within the ovary that gave rise to the cancer. The large majority of ovarian cancers are epithelial cancers, or carcinomas. These cancers begin in the cells that line the surface of the ovary. Sometimes, tumors of these cells are not clearly cancerous but still display some suspicious features. These are called tumors of low malignant potential (LMP) and are less dangerous than other kinds of ovarian cancer.
Ovarian Cancer Survival Rates
Five-year survival rates for ovarian cancer range widely, from 18% to 89%, depending on the stage of the cancer when it was diagnosed. However, these odds were based on women diagnosed from 1988 to 2001, and treatments are constantly improving, so the odds may be better for women diagnosed today. For LMP tumors, five-year survival rates range from 77 to 99%.
Ovarian Cancer Surgery
Surgery is not only used to diagnose and stage ovarian cancer, but it is also used as a first step in treatment. Surgery to remove as much of the tumor as possible is typically carried out. It is usually necessary to remove the uterus as well as the fallopian tubes, the unaffected ovary, the omentum, and any other deposits visible and over 2 cm in size if possible to thereby both debulk and stage the ovarian cancer. Biopsies are also usually also done of sites where ovarian cancer is likely to be spread even if it is not visible.
Chemotherapy is typically given after surgery for all stages of ovarian cancer. Chemotherapy drugs are usually given intravenously, or administered directly into the abdominal cavity (intraperitoneal chemotherapy). Newer medications have made such treatment more tolerable than in the past. It is often highly effective, especially if the ovarian cancer has been well debulked. Women with LMP tumors often do not require chemotherapy after surgery unless the surgical findings were initially of concern or tumors grow back.
New therapies for ovarian cancer may be directed at blocking tumor growth by interfering with the formation of blood vessels to supply the tumor. The process of blood vessel formation is known as angiogenesis. The drug Avastin works by blocking angiogenesis, causing tumors to shrink or stop growing. Avastin is used in some other cancers, and it is currently being tested in ovarian cancer.
After Treatment: Early Menopause
If women have both ovaries removed, this triggers menopause if they are still menstruating. The resultant drop in hormone production when the ovaries are removed can elevate a woman’s risk for other conditions like osteoporosis. Regular follow-up care is important after all treatment for ovarian cancer.
After Treatment: Moving On
After treatment, women may find that it takes a long time to regain their energy. Fatigue is common after cancer treatment. A gentle exercise program is a very effective way to restore energy and well-being. Your doctor can help you determine what activities are best for you.
Risk Reducer: Pregnancy
Women who have never given birth are more likely to develop ovarian cancer than those who have biological children. The risk seems to decrease with every pregnancy. Breastfeeding may also decrease risk.
Risk Reducer: ‘The Pill’
Women who have taken birth control pills have a lower risk of ovarian cancer. Taking the pill for at least five years reduces a women’s risk by about 50%. Birth control pills and pregnancy both stop ovulation, and some researchers think that less frequent ovulation lowers the risk of ovarian cancer.
Risk Reducer: Tubal Ligation
Tubal ligation (having your tubes tied) or having a hysterectomy while leaving the ovaries intact may both offer some protection against ovarian cancer.
Risk Reducer: Removing the Ovaries
Removal of the ovaries is an option for women with genetic mutations that increase their cancer risk. This option can also be considered for women over 40 who are undergoing a hysterectomy.
Risk Reducer: Low-Fat Diet
No definitive dietary changes have been shown to prevent ovarian cancer. Nevertheless, a study showed that women who consumed a low-fat diet for at least 4 years had a lower risk of ovarian cancer. Other studies showed that ovarian cancer may be less common in women who consume a lot of vegetables. More studies are needed to clarify any relationship between diet and ovarian cancer.
Reviewed by Jay B. Zatzkin, MD