Grant: Project Grant

Endometriosis is a common chronic condition characterized by lesions resembling uterine tissue found outside the uterus. It affects 10% of women (and other people with uteruses) and carries a 2 to 4-fold increased risk of two types of ovarian cancer, herein referred to as endometriosis-associated ovarian cancer. Research examining endometriosis-associated ovarian cancer has historically relied on a self-reported or clinical diagnosis of endometriosis, however the best diagnostic test for endometriosis is a pathologic diagnosis, made under a microscope. We do not have enough information on how common endometriosis treatments impact risk for endometriosis-associated ovarian cancer. There is also a suggestion that endometriosis will take on atypical features, which can be identified by specialized gynecologic pathologists in the laboratory, prior to becoming cancer. However, this diagnosis differs across different pathologists, thus we need an objective way to identify endometriosis that is likely to become cancer. If we can identify objective tests that will indicate when endometriosis is likely to become cancer, we can intervene before cancer ever develops. We have built a unique dataset that includes all people with pathologically confirmed endometriosis in the Vancouver Coastal Health Authority in British Columbia, Canada (population ~1 million). These data have been linked with population-based administrative datasets in British Columbia, Canada, which includes all treatments received in the universal health care system in the province. We propose to use these data to reassess the association between endometriosis and ovarian cancer, to determine how the surgical and hormonal treatments for endometriosis influence risk for endometriosis-associated ovarian cancer, and to determine whether we can identify objective markers in endometriosis that later developed into cancer that are not present in endometriosis that never developed into cancer.