Endometriosis is a medical condition characterized by growth of tissue that normally lines inside the uterus, the endometrium, but outside the uterus. It attacks the female reproductive system, causing pain and infertility. The tissue affected by endometriosis is usually called endometrial patches, implants, nodules or lesions, and it usually grows in the pelvic cavity, including on or under the ovaries, on the fallopian tubes, behind the uterus, on the tissues that hold the uterus in place, on the bowels or bladder, and in rare cases on the lungs or in other parts of the body.

The estimates from the National Institutes of Health (NIH) indicate that six to ten percent of women who are of reproductive age suffer from endometriosis, the equivalent to five million people in the United States alone. Despite the fact that the disease is more common among women in their 30s and 40s, it can affect any woman. Factors that increase the risk of suffering from endometriosis include having the disease in the family, having first menstruation before the age of 11, short monthly cycles, and heavy menstrual cycles that last more than seven days. On the other hand, pregnancy, starting menstruation late in adolescence, regular exercise of more than four hours a week, and a low amount of body fat decrease its risk.

Increased Risk of Cancer in Endometriosis Patients

Despite the fact that endometriosis and cancer are two separated diseases, there is evidence that suffering from endometriosis increases the risk of developing cancer later in life, in particular ovarian cancer. The relation between the two is not fully understood, but there is one hypothesis. Since endometriosis is the reason for infertility in 50% of women who cannot conceive, the explanation may have something to do with the lack of having children. Conceiving and giving birth is known to offer some protection against ovarian cancer.

On the other hand, it is also known that suffering from endometriosis does not increase vigilance of the reproductive system, which could improve early detection and diagnosis. In addition to ovarian cancer, other cancers that may be more likely in patients with endometriosis include lymphoma and breast cancer, but the development of cancer tend occur later in patients’ lives, according to the Endometriosis Foundation of America.

Research on the Risk of Endometriosis and Cancer

One of the most prominent investigators in the field of endometriosis and cancer is Louise Brinton, PhD, Chief of the Hormonal and Reproductive Epidemiology branch at the National Cancer Institute, who also collaborates with the Endometriosis Foundation of America. During an average follow-up of more than 11 years, the scientist discovered that the risk for cancer among women with endometriosis was elevated by 90% for ovarian cancer, 40% for hematopoietic cancer (primarily non-Hodgkin’s lymphoma), and 30% for breast cancer.

In addition, having a longer history of endometriosis and being diagnosed at a younger age increased the risk of endometriosis and cancer, while women whose site of origin of endometriosis was the ovary had a particularly high risk for ovarian cancer. The investigator Anna-Sofia Melin also focused on the topic and corroborated the results of the first research. Roberta B. Ness and colleagues concluded that the probability of developing ovarian cancer for women with endometriosis was 50% higher, and even higher for determined types of ovarian cancer.

Note: Endometriosis News is strictly a news and information website about the disease. It does not provide medical advice, diagnosis or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.