Female reproductive system

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.

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, though doctors have identified factors that can increase the risk of the disease.

In general, cancer begins when a cell develops errors (mutations) in its DNA. The mutations tell the cell to grow and multiply quickly, creating a mass (tumor) of abnormal cells. The abnormal cells continue living when healthy cells would die. 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.

Factors that can increase your risk of ovarian cancer include:

• Older age. Ovarian cancer can occur at any age but is most common in women ages 50 to 60 years.
• Inherited gene mutations. A small percentage of ovarian cancers are caused by gene mutations you inherit from your parents. 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 also increase the risk of breast cancer.

Other gene mutations, including those associated with Lynch syndrome, are known to increase the risk of ovarian cancer.

• Family history of ovarian cancer. People with two or more close relatives with ovarian cancer have an increased risk of the disease.
• Estrogen hormone replacement therapy, especially with long-term use and in large doses.
• Age when menstruation started and ended. Beginning menstruation at an early age or starting menopause at a later age, or both, may increase the risk of ovarian cancer.