The Study: That’s because of increased rates of obesity and estrogen exposure, right? That would be a good hypothesis if the rise was being driven by the more common, estrogen-related endometrioid histology. This SEER analysis challenges that assumption using data from 2000 to 2015 to characterize the rates of both endometrioid and non-endometrioid uterine malignancies by race and ethnicity. Importantly, the authors correct for hysterectomy rates by the regional source of the SEER data because surgical practice variations across the U.S. can bias the rates of incidental cancer diagnoses. From 2000 to 2015, the average rate of hysterectomy was 25%, ranging from ~30% for blacks to ~15% for Asians, with a gradual decline in hysterectomies over time. Correcting for hysterectomy rate resulted in a large 59% relative increase in the observed incidence of uterine cancer. Overall, the rates of endometrial cancer saw an absolute increase of 1% per year with even higher increases among non-whites. Around 2007, the rate among blacks actually surpassed that of whites. Most interesting, while diagnoses of endometrioid histology remained stable, non-endometrioid histologies rose significantly among all races, by roughly 3% per year, again even higher among non-whites.
Bottom Line: Hysterectomy-corrected rates of endometrial cancer are rising in the U.S. as a result of significant increases in rates of more aggressive, non-endometrioid histologies primarily among non-white women. | Clarke, J Clin Oncol 2019