Ovarian cancer is a type of cancer that begins in the ovaries. Women have two ovaries, one on each side of the uterus. The ovaries — each about the size of an almond — produce eggs (ova) as well as the hormones estrogen and progesterone.
Ovarian cancer often goes undetected until it has spread within the pelvis and abdomen. At this late stage, ovarian cancer is more difficult to treat and is frequently fatal. Early-stage ovarian cancer, in which the disease is confined to the ovary, is more likely to be treated successfully.
Surgery and chemotherapy are generally used to treat ovarian cancer.
Signs and symptoms of ovarian cancer may include:
- Abdominal bloating or swelling
- Quickly feeling full when eating
- Weight loss
- Discomfort in the pelvis area
- Changes in bowel habits, such as constipation
- A frequent need to urinate
It’s not clear what causes ovarian cancer.
In general, cancer begins when a genetic mutation turns normal cells into abnormal cancer cells. Cancer cells quickly multiply, forming a mass (tumor). They can invade nearby tissues and break off from an initial tumor to spread elsewhere in the body (metastasize).
Types of ovarian cancer
The type of cell where the cancer begins determines the type of ovarian cancer you have. Ovarian cancer types include:
- Epithelial tumors, which begin in the thin layer of tissue that covers the outside of the ovaries. About 90 percent of ovarian cancers are epithelial tumors.
- Stromal tumors, which begin in the ovarian tissue that contains hormone-producing cells. These tumors are usually diagnosed at an earlier stage than other ovarian tumors. About 7 percent of ovarian tumors are stromal.
- Germ cell tumors, which begin in the egg-producing cells. These rare ovarian cancers tend to occur in younger women.
Certain factors may increase your risk of ovarian cancer:
- Ovarian cancer can occur at any age but is most common in women ages 50 to 60 years.
- Inherited gene mutation. A small percentage of ovarian cancers are caused by an inherited gene mutation. The genes known to increase the risk of ovarian cancer are called breast cancer gene 1 (BRCA1) and breast cancer gene 2 (BRCA2). These genes were originally identified in families with multiple cases of breast cancer, which is how they got their names, but women with these mutations also have a significantly increased risk of ovarian cancer.
The gene mutations that cause Lynch syndrome, which is associated with colon cancer, also increase a woman’s risk of ovarian cancer.
- Estrogen hormone replacement therapy, especially with long-term use and in large doses.
- Age when menstruation started and ended. If you began menstruating before age 12 or underwent menopause after age 52, or both, your risk of ovarian cancer may be higher.
- Never being pregnant.
- Fertility treatment.
- Use of an intrauterine device.
- Polycystic ovary syndrome.
If you have a genetic predisposition to ovarian cancer, your doctor may recommend regular pelvic imaging and blood tests to screen for the disease.
Tests and diagnosis
Your doctor is likely to start with a pelvic examination:
- The outer part of your genitals is carefully inspected.
- The doctor then inserts two gloved fingers into the vagina and simultaneously presses a hand on your abdomen to feel your uterus and ovaries.
- A device (speculum) is inserted into the vagina so that the doctor can visually check for abnormalities.
Your doctor also may recommend:
- Imaging tests, such as ultrasound or CT scans, of your abdomen and pelvis. These tests can help determine the size, shape and structure of your ovaries.
- Blood test, which can detect a protein (CA 125) found on the surface of ovarian cancer cells.
- Surgery to remove a tissue sample and abdominal fluid to confirm a diagnosis of ovarian cancer. Minimally invasive or robotic surgery may be an option. If cancer is discovered, the surgeon may immediately begin surgery to remove as much of the cancer as possible.
Staging ovarian cancer
Your cancer’s stage helps determine your prognosis and your treatment options.
Stages of ovarian cancer include:
- Stage I. Cancer is found in one or both ovaries.
- Stage II. Cancer has spread to other parts of the pelvis.
- Stage III. Cancer has spread to the abdomen.
- Stage IV. Cancer is found outside the abdomen.
Treatments and drugs
Treatment of ovarian cancer usually involves a combination of surgery and chemotherapy.
Treatment generally involves removing both ovaries, the fallopian tubes, the uterus as well as nearby lymph nodes and a fold of fatty abdominal tissue (omentum) where ovarian cancer often spreads. Your surgeon also will remove as much cancer as possible from your abdomen.
Less extensive surgery may be possible if your ovarian cancer was diagnosed at a very early stage. For women with stage I ovarian cancer, surgery may involve removing one ovary and its fallopian tube. This procedure may preserve the ability to have children.
After surgery, you’ll likely be treated with chemotherapy to kill any remaining cancer cells. Chemotherapy drugs can be injected into a vein or directly into the abdominal cavity or both.
Chemotherapy may be used as the initial treatment in some women with advanced ovarian cancer.
There’s no sure way to prevent ovarian cancer. But certain factors are associated with lower risk:
- Use of oral contraceptives, especially for more than 10 years
- Previous pregnancy
- History of breast-feeding
- Daily use of aspirin