METHODS
A population-based retrospective cohort study of endometrial cancer patients was conducted in the province of Ontario, Canada. Women with endometrial cancer diagnosed 2009-2017 were identified from the Ontario Cancer Registry, which uses a rapid case ascertainment system to capture all cancer diagnoses in the province based on pathology reports as well as admission and discharge databases, regional cancer treatment reports and death certificates 31, and has undergone rigorous quality analysis as part of a global cancer surveillance project32. All uterine endometrial cancer histologies were included, but uterine sarcomas were excluded. Populations excluded from Ontario’s provincial administrative healthcare databases, including incarcerated persons, Canadian armed forces and Indigenous people living on Reserves whose healthcare is federally funded, were not included in the study population. The timeframe chosen was selected to reflect a period in which stage information began to be systematically entered in the Ontario Cancer Registry, and was cut off to allow for latency in reporting.
The study, using de-identified secondary data analysis, was reviewed and exempted by the Hamilton Health Sciences integrated research ethics board (#7732-C).