Medical Author: Melissa Conrad Stöppler, MD
Medical Editor: William C. Shiel Jr., MD, FACP, FACR
Ovarian cancer is the seventh most common cancer in women in the U.S. and the fifth leading cause of cancer deaths in women. Ovarian cancer, like all cancers, results from the uncontrolled growth of a subpopulation of cells within the organ. Ovarian cancer most commonly arises from the lining (epithelial) cells on the surface of the ovary, but cancers derived from the supporting tissue (stroma) and the egg-producing germ cells can also occur. Ovarian cancer frequently has no symptoms until the cancer has spread extensively.
Doctors examined patient survey responses from over 400 women with ovarian cancer and over 2,100 healthy women who were participants in the Canadian National Enhanced Cancer Surveillance System (NECSS) to study the role of physical activity and the risk of developing ovarian cancer. The study showed that women who reported moderate levels of recreational physical activity (but not vigorous activity) or who held jobs that required moderate or strenuous physical activity had a reduced risk for development of ovarian cancer when compared to sedentary women.
This study is important because it demonstrates that lifestyle modification has the potential to reduce a woman's chances of developing ovarian cancer. The reasons for the reduction in ovarian cancer risk are not clear; however, the authors of the study note that potential alterations in hormone and growth factor levels, enhancement of the immune system, and/or the reduction in obesity associated with moderate exercise may be responsible for the effect. Physical activity is also known to be of benefit in reducing the incidence of breast and colon cancer.
For more information about risk factors for ovarian cancer, see the article "Ovarian Cancer: Assessing Your Risk Factors."
Reference: "Physical Activity and the Risk of Ovarian Cancer: A Case-Control Study in Canada," Sai Yi Pan, Anne-Marie Ugnat, Yang Mao, and The Canadian Cancer Registries Epidemiology Research Group," International Journal of Cancer; Published Online: May 16, 2005 (DOI: 10.1002/ijc.21157).