Test Your Knowledge

Ovarian cancer, also called carcinoma of the ovary, is a type of cancer that begins in one or both ovaries. The ovaries are female reproductive organs that produce eggs (ova). They are also the primary source of estrogen and progesterone, the female reproductive hormones. The ovaries are located in the pelvis on both sides of the uterus (womb).

The ovaries contain three distinct types of tissue:

• Germ cells. Cells that produce the ova. Every month from puberty until menopause, women usually produce an egg that travels to the surface of the ovary, where it is shed into their fallopian tube.
  
  
• Stromal cells. Cells that produce the majority of a woman’s estrogen and progesterone.
  
  
• Epithelial cells. Cells that cover the ovaries.

Although ovarian cancer can begin in any of these cells, 85 to 90 percent of cases begin in the epithelial cells, according to the American Cancer Society (ACS).

Normal cells divide, grow and die in an organized manner. Cancer cells continuously multiply until they form a growth or tumor (a mass of excess tissue). This occurs because the DNA, which directs all of the cell’s activities, becomes damaged by any of a variety of factors. In some cases, the cancer cells become invasive, spreading to tissues and organs outside of the ovaries (metastasis). Organs that are most likely to be affected include those of the abdomen, such as the intestines, liver and stomach. However, ovarian cancer can also spread to other organs such as the brain, lungs, breast and lymph nodes.

The ACS estimates that a woman’s chance of getting ovarian cancer in her lifetime is roughly 1 in 71, or 1.5 percent. Approximately 21,650 new cases of ovarian cancer will be diagnosed in 2008 in the United States. However, the incidence rate for ovarian cancer has been declining since 1985. The likelihood of developing ovarian cancer increases with age and about two-thirds of cases are diagnosed in women over age 55. 

According to the ACS, ovarian cancer is the eighth leading cancer among women, excluding non-melanoma skin cancer. The disease ranks fifth among cancer deaths in women and claims more lives than any other female reproductive cancer. In 2008, an estimated 15,520 women will die from ovarian cancer.

If ovarian cancer is diagnosed and treated in its earliest stages, the five-year survival rate is 94 percent, according to the ACS. Only 19 percent of ovarian cancers are detected at an early stage. An estimated 45 percent of women diagnosed with ovarian cancer live longer than five years after the diagnosis.

Many women develop ovarian cysts in their lifetime. These growths form when fluid collects in a sac inside the ovary. A large percentage of ovarian cysts are not cancerous and are a regular part of the ovulation process. Known as functional cysts, these growths usually disappear once the fluid inside the cyst is absorbed by the body. If the growth is large, occurs in childhood or does not disappear, a physician may recommend certain tests. In a small number of cases, ovarian cysts may become cancerous.