Ovarian cancer is the uncontrolled growth of abnormal cells in the ovaries. Ovaries are the female reproductive organs that produce eggs. They also make the hormone estrogen.
Ovarian cancer cells can form in three areas:
- on an ovary's surface
- in an ovary's egg-producing cells
- in tissues within an ovary.
Tumors on the surface of an ovary are the most common.
Ovarian cancer often does not cause any symptoms until it has spread beyond the ovary. Doctors have a hard time detecting the disease during a pelvic exam before this late stage. That’s why ovarian cancer leads to more deaths than any other cancer of the female reproductive system.
Even if the disease has spread, symptoms may be mild and attributed to other problems. Symptoms, such as frequent urination and bloating, are also vague. For these reasons, most ovarian cancers aren't diagnosed until the later stages of the disease. Researchers are trying to develop tests to detect ovarian cancer in its early stages, when it’s more likely to be cured or controlled.
Doctors don’t know exactly what causes ovarian cancer. However, some things increase a woman's risk of the disease. For example, the disease may be inherited. Women who have had a first-degree relative (sister, mother, or daughter) diagnosed with ovarian cancer are at high risk of getting it themselves.
Women who have a relative who has had breast or colon cancer are also at high risk.
Certain groups of women, such as Jewish women of Eastern European descent, are more likely to carry the breast cancer genes BRCA1 and BRCA2. These genes are linked to ovarian cancer. Doctors can test for these genes.
The chances of developing ovarian cancer also increase with age. Most ovarian cancers occur in women over age 50. The highest risk is in women over 60. Women who have never had children are more likely to develop ovarian cancer, too.
Ovarian cancer usually doesn't cause symptoms until it has spread. Even then, the symptoms can be mistaken as signs of another disorder.
Symptoms of ovarian cancer include:
- abdominal discomfort and pain, especially in the lower part of the abdomen
- urinating often
- sudden weight gain or loss
- abnormal vaginal bleeding
Occasionally, a doctor may find signs of early stage ovarian cancer (before the abnormal cells have spread beyond the ovary). For example, the ovary may feel firm and enlarged. A pelvic ultrasound may help diagnose the disease at an early stage. (Ultrasound uses sound waves to create pictures of organs and other structures.) However, the ovaries often look normal in the early stages of disease.
Computed tomography (CT) scans and magnetic resonance imaging (MRI) may help identify a misshapen or enlarged ovary—or show other features that may point to cancer.
The CA-125 blood test can help to confirm ovarian cancer. Women with ovarian cancer often have high levels of the CA-125 protein. The usefulness of this test is limited, however, because noncancerous conditions can also raise CA-125 levels.
The only way to be certain that cancer is present is to have a biopsy. During this test, your doctor removes a small piece of ovarian tissue. He or she then looks at it under a microscope to see if there are cancerous changes.
Ovarian cancer is usually treated with surgery. In most cases, the surgeon removes the ovaries, fallopian tubes, uterus and cervix. She or he may also remove the thin tissue covering the stomach and intestines, as well as nearby lymph nodes.
After surgery, systemic chemotherapy may be needed to kill any remaining cancer cells. It also may be infused directly into the abdomen to try to kill any cancer cells on the lining of the abdomen. Radiation therapy is used less often.
Chemotherapy and radiation therapy kill cancer cells, but they also affect healthy cells. This causes side effects. Side effects depend on the type of treatment and how long it lasts. Side effects may include:
- anemia (a low red blood cell count)
- infection because of a low white blood cell count)
- easy bruising and problems with blood clotting because of a low platelet count
- nausea and vomiting
- hair loss
The likelihood of surviving ovarian cancer depends on how far it has spread. Nearly all women who are diagnosed and treated before the cancer spreads beyond the ovary survive at least five years. But only one-quarter of ovarian cancers are found at this stage.
About three-quarters of all ovarian cancer patients live at least one year after diagnosis. More than half live longer than five years. In general, older women with ovarian cancer have a poorer outlook than younger women.
In some patients, ovarian cancer never goes away completely. In others, the cancer goes away with treatment. However, it can come back. That's why it's important to keep follow-up appointments with your doctor.
Women who take birth control pills cut their risk of ovarian cancer in half, possibly because these drugs prevent ovulation. (Ovulation is the release of an egg from the ovary each month.) The protective effect of the pill is greatest in women who use it for four years or longer. Breast-feeding, which also reduces the number of times a woman ovulates, may trim the risk of ovarian cancer.
Women who know that they carry the BRCA1 or BRCA2 gene might consider having their ovaries removed before cancer develops.
When to call a professional
Check with your doctor if you notice any of these symptoms:
- abdominal discomfort or pain that doesn't go away or gets worse
- unexplained nausea or diarrhea that doesn't go away or gets worse
- frequent urination
- sudden weight gain or loss
- abnormal vaginal bleeding
The symptoms of ovarian cancer are vague and often blamed on other conditions. If you are high risk of ovarian cancer, it’s important to have regular pelvic exams. Watch for symptoms, too. Women at high risk of developing ovarian cancer include those who:
- have specific forms of the breast cancer genes BRCA1 or BRCA2
- have had a first-degree relative (sister, mother, or daughter) diagnosed with ovarian cancer
- have a first degree relative who has had breast or colon cancer.