Does endometriosis increase cancer risk?

Ask the doctors

Q. I have endometriosis, and I recently heard that it might increase my risk of certain cancers. Is this true?

A. Researchers have linked endometriosis, an often painful condition that causes endometrial-like tissue to grow outside the uterus, to a higher risk of two types of ovarian cancer — endometrioid and clear-cell subtypes. That said, even though your risk of these cancers may be higher than that of the average woman who doesn't have endometriosis, your chances of developing one of these cancers is still very small — less than 1%.