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.
Early-stage ovarian cancer rarely causes any symptoms. Advanced-stage ovarian cancer may cause few and nonspecific symptoms that are often mistaken for more common benign conditions, such as constipation or irritable bowel.
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
When to see a doctor
Make an appointment with your doctor if you have any signs or symptoms that worry you.
If you have a family history of ovarian cancer or breast cancer, talk to your doctor about your risk of ovarian cancer. Your doctor may refer you to a genetic counselor to discuss testing for certain gene mutations that increase your risk of breast and ovarian cancers. Only a small number of women are found to have genetic mutations that can lead to ovarian cancer.
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:
- Age. 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.
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