Ovarian cancer occurs when abnormal cells in the ovaries begin to grow out of control and form a mass, or tumor. The ovaries are two small organs located in the pelvis, one on either side of the uterus. They produce and store eggs. They also make the female hormones estrogen and progesterone.
Ovarian tumors may be either cancer (malignant) or not cancer (benign). Benign tumors do not spread (metastasize). Ovarian cancer can metastasize to other parts of the body.
Types of ovarian cancer
There are three main types of malignant ovarian tumors:
- Epithelial carcinomas start in cells that make up the surface of the ovaries. The majority of women with ovarian cancer have this type.
- Germ cell tumors start in the egg-producing cells. Fewer than two out of 100 ovarian cancers are this type.
- Stromal cell tumors form in cells of the connective tissue that holds the ovaries together and produce female hormones. Stromal cell tumors account for only about one out of 100 ovarian cancers.
The prognosis for women with ovarian cancer depends on a number of factors, including the type of cancer and whether the cancer has spread beyond the ovaries. Age is also a factor. Women who are younger than 65 at the time of diagnosis tend to do better than women older than 65.
Prognosis is often expressed as the survival rate, or how many women live for a certain number of years after diagnosis. For all types of ovarian cancer combined:
- The one-year survival rate is 75 percent. This means 75 out of 100 women are still alive one year after diagnosis.
- The five-year survival rate is 46 percent. This means almost half of women survive five years or longer.
The five-year survival rate is 94 percent if the cancer is found while it is still confined to the ovaries. Sadly, only about 15 percent of cases are diagnosed this early. More than 60 percent of women are diagnosed only after cancer has metastasized to other organs.
Facts about ovarian cancer
- Ovarian cancer accounts for about 3 percent of cancer in women.
- A woman's lifetime risk of ovarian cancer is about one in 71.
- About half of women diagnosed with ovarian cancer are age 60 or older. It is rare in women younger than 40.
- It is more common in white women than in African American women.
Created on 09/03/1999
Updated on 12/08/2010
- American Cancer Society. Cancer facts and figures 2010.
- American Society of Clinical Oncology. Ovarian cancer.
- National Cancer Institute. What you need to know about ovarian cancer.