Cancer of the ovary (ovarian cancer) is the ninth most common cancer in women in the U.S. with almost 22,000 women newly diagnosed each year. Ovarian cancer is the fifth leading cause of cancer deaths in women. It frequently does not result in symptoms until the cancer has spread extensively beyond the ovary.
Ovarian cancer actually represents a group of different tumors that arise from diverse types of tissue contained within the ovary. The most common type of ovarian cancer arises from the epithelial cells (the outside layer of cells) of the surface of the ovary. Other, rare types of ovarian cancer develop from the egg-forming germ cells or from the supporting tissue (stroma) of the organ. Benign (noncancerous) tumors and cysts are also found in the ovary and are much more common than ovarian cancers.
The majority of ovarian cancers are diagnosed late, after the cancers have spread. Only about 20% of women are diagnosed early, when the disease may be most curable. There is no definitive screening test for early ovarian cancer. Regular pelvic examinations, sometimes supplemented by ultrasound examinations or blood tests for cancer-related markers, have been routinely used for ovarian cancer screening, but none of these tests are specifically able to detect ovarian cancer. Traditionally, it was believed that ovarian cancer does not produce any characteristic symptoms until the tumor is widespread, and that early symptoms of ovarian cancer were not recognizable.
However, in June 2007, the American Cancer Society, along with other medical societies including the Gynecologic Cancer Foundation and the Society of Gynecologic Oncologists, released a consensus statement about possible early symptoms of ovarian cancer. This statement was based on research suggesting that some of the early symptoms of ovarian cancer can, in fact, be recognized. In particular, possible early ovarian cancer symptoms include the following:
The researchers note that women who have these problems should see a gynecologist for cancer screening if these problems are new, if the symptoms are severe, and if they have been present continuously for over two to three weeks.
It is important for women to remember that these symptoms do not necessarily mean that a woman has ovarian cancer, as many other common and harmless conditions can produce similar symptoms. Moreover, other causes for these symptoms are far more common than ovarian cancer and, for example, include irritable bowel syndrome and urinary tract infection. Women may also experience some of these symptoms in the premenstrual phase of their monthly cycle.
Doctors do not know exactly what causes ovarian cancer. However, some factors and conditions may increase a woman's risk of developing this condition. The following are risk factors for the development of ovarian cancer:
- A family history of ovarian cancer: Women who have one or more close relatives with the disease have an increased risk of developing ovarian cancer. Certain genes, such as the BRCA 1 and 2 genes, are inherited and result in a high risk for development of ovarian cancer.
- A family history of breast or colon cancer also confers an increased risk for the development of ovarian cancer.
- Age: Women over 50 are more likely than younger women to get ovarian cancer, and the risk is even greater after age 60. About 50% of ovarian cancers occur in women over 60 years of age.
- Childbearing and menstruation: Women who have never given birth have a greater risk of developing ovarian cancer than women who have had children. In fact, the number of childbirths correlates directly with a decrease in risk for developing ovarian cancer. The likely explanation for this risk factor seems to be related to the number of menstrual periods a women has had in her lifetime. Those who began menstruating early (before age 12), had no children, had their first child after age 30, and/or experienced menopause after age 50 have a greater chance of developing ovarian cancer than the general population.
- Medications: Some studies show that women who have taken fertility drugs, or hormone therapy after menopause, may have a slightly increased risk of developing ovarian cancer. The use of oral contraceptive pills, on the other hand, seems to decrease a women's chance of getting the disease.
- The American Cancer society reports that obese women have a higher rate of death from ovarian cancer than women of normal weight.
- Talcum powder use: Some studies report a slightly elevated risk of ovarian cancer in women who regularly apply talcum powder to the genital area. A similar risk has not been reported for cornstarch powders.
The lifetime risk for development of ovarian cancer is less than 2% among the general population. If you have a family history of ovarian cancer or other types of cancer, your doctor can help you decide whether genetic testing or other cancer screening procedures might be appropriate for you.
For more in-depth information, please read the following articles:
- Ovarian cancer
- CA 125 (test for ovarian cancer)
United States. American Cancer Society. "Ovarian Cancer." July 18, 2011. <http://www.cancer.org/Cancer/OvarianCancer/DetailedGuide/ovarian-cancer-key-statistics>.
United States. National Cancer Institute. "Ovarian Cancer." July 17, 2006. <http://www.cancer.gov/cancertopics/types/ovarian>.