Assessing endometrial cancer risk among US women: long-term trends using hysterectomy-adjusted analysis

Abstract

Commonly reported incidence rates for endometrial cancer fail to take into account both the large number of hysterectomies performed each year and the dynamic change in hysterectomy rate over the past decade. Large racial differences in premenopausal hysterectomy rates between Black and White women in the United States likely affect calculation of race-based risk. The objectives of the study were to determine how the long-term trends in Black-White differences in endometrial cancer incidence and histology type have changed over time for women at risk. Using longitudinal Surveillance, Epidemiology, and End Results data from 1997 to 2014 and state-level hysterectomy prevalence from the Behavioral Risk Factor Surveillance System, we calculated hysterectomy-adjusted incidence rates of endometrial cancer and the proportion of high vs low-risk endometrial cancer, by race, over time. In women older than 50 years who have not had a hysterectomy, endometrial cancer incidence is 87 per 100,000 from 1997 to 2014. Among White women endometrial cancer incidence changed from 102 (1997-2001) to 86 (2012-2014) cases per 100,000, with a nonsignificant decreasing linear trend (adjusted risk ratio, 0.95; 95% confidence interval, 0.91-1.00; p=0.05). In contrast, incidence for Black women was 88 (1997-2001), 101 (2002-2006), 100 (2007-2011), and 102 (2012-2014) cases per 100,000 with no decreasing trend (adjusted risk ratio, 1.02; 95% confidence interval, 0.96-1.10, P= .449). High-risk histology increased among both groups (White: adjusted risk ratio, 1.06; 95% confidence interval, 1.01-1.11; P= .015; Black: adjusted risk ratio, 1.06; 95% confidence interval, 1.02-1.10, P= .007). Racial difference in the proportion of high-risk disease remained stable. Updated hysterectomy-adjusted incidence demonstrates that endometrial cancer is the second most common cancer among women older than 50 years with a uterus and that endometrial cancer has been more common among Black women compared with White women in the United States since 2002. A clinical approach of proactive communication and routine screening for early symptoms in the perimenopausal and menopausal years, especially among Black women, is warranted. These findings can also inform equitable distribution of research funding for endometrial cancer and serve to promote public awareness of this common cancer.