Women who have a history of endometriosis may be at risk of certain types of ovarian cancer, suggests a new study in The Lancet Oncology. Endometriosis occurs when cells from the lining of the uterus grow in other parts of the body a relatively common condition that occurs in about 10 percent of women during their childbearing years. It can lead to pain, difficulties conceiving, and irregular bleeding.
Led by Dr. Celeste Leigh Pearce at the University of Southern California, researchers used data from over 23,000 women, obtained from the Ovarian Cancer Association Consortium. They found that women who had endometriosis were three times more likely to develop clear-cell ovarian cancer and had double the risk of endometrioid tumors. Our data, taken with the other published data on the link between ovarian cancer and endometriosis, strongly suggests a causal relationship, says Dr. Pearce.
Ovarian cancer was diagnosed in an estimated 22,000 women in the U.S. in 2011 and causes about 15,000 deaths each year, although clear-cell ovarian cancer accounts for just under 5 percent of all ovarian cancer cases. While the large majority of women with endometriosis will never develop ovarian cancer, the study authors note that this is still a link that doctors and patients should be aware of.
Since endometriosis is not uncommon, this study suggests that women and their doctors need to be aware that the condition seems to confer a higher risk, notes ACSH's Dr. Gilbert Ross. Women with endometriosis would be good candidates for screening for ovarian cancer.
