Hysterectomy-Corrected Uterine Corpus Cancer Incidence Trends and Differences in Relative Survival Reveal Racial Disparities and Rising Rates of Nonendometrioid Cancers

Abstract

Purpose: Uterine corpus cancer incidence rates have been projected to increase, a prediction often attributed to the obesity epidemic. However, correct estimation of these rates requires accounting for hysterectomy prevalence, which varies by race, ethnicity, and region. Here, we evaluated recent trends in hysterectomy-corrected rates by race and ethnicity and histologic subtype and estimated differences in relative survival by race and ethnicity, subtype, and stage.

Methods: We estimated hysterectomy prevalence from the Behavioral Risk Factor Surveillance System. Hysterectomy-corrected age-standardized uterine corpus cancer incidence rates from 2000 to 2015 were calculated from the SEER 18 registries. Incidence rates and trends were estimated separately by race and ethnicity, region, and histologic subtype. Five-year relative survival rates were estimated by race and ethnicity, histologic subtype, and stage.

Results: Hysterectomy-corrected incidence rates of uterine corpus cancer were similar among non-Hispanic whites and blacks and lower among Hispanics and Asians/Pacific Islanders. Endometrioid carcinoma rates were highest in non-Hispanic whites, whereas nonendometrioid carcinoma and sarcoma rates were highest in non-Hispanic blacks. Hysterectomy-corrected uterine corpus cancer incidence increased among non-Hispanic whites from 2003 to 2015 and among non-Hispanic blacks, Hispanics, and Asians/Pacific Islanders from 2000 to 2015. Overall incidence rates among non-Hispanic blacks surpassed those of non-Hispanic whites in 2007. Endometrioid carcinoma rates rose among non-Hispanic blacks, Hispanics, and Asians/Pacific Islanders but were stable among non-Hispanic whites; however, nonendometrioid carcinoma rates rose significantly among all women. Non-Hispanic blacks had the lowest survival rates, irrespective of stage at diagnosis or histologic subtype.

Conclusion: Among all women, rates of nonendometrioid subtypes have been rising rapidly. Our analysis shows profound racial differences and disparities indicated by higher rates of nonendometrioid subtypes and poorer survival among non-Hispanic black women.

FIG 1.

Trends in age-adjusted incidence rates of microscopically confirmed uterine corpus cancer (A) overall and by (B) endometrioid and (C) nonendometrioid subtypes, uncorrected and corrected for hysterectomy prevalence, among US women age 30 to 79 years according to SEER 18 (2000 to 2015). All trends are summarized by a single annual percentage change estimate, with the exception of uncorrected and corrected overall rates, which are summarized by the average annual percentage change; trends for nonendometrioid carcinomas are plotted on a different scale. (*) Significantly different than zero at P < .05.

FIG 2.

Trends in age-adjusted incidence rates of microscopically confirmed uterine corpus cancer by race and ethnicity: (A, B) overall and by (C, D) endometrioid and (E, F) nonendometrioid subtypes, (A, C, E) uncorrected and (B, D, F) corrected for hysterectomy prevalence, among US women age 30 to 79 years according to SEER 18 (2000 to 2015). Uncorrected and corrected rates are shown separately among non-Hispanic whites (+), non-Hispanic blacks (solid square), Hispanics (solid triangle), and non-Hispanic Asians/Pacific Islanders (×). All trends are summarized by a single annual percentage change estimate, with the exception of uncorrected and corrected overall rates among non-Hispanic whites, which are summarized by the average annual percentage change; trends for nonendometrioid carcinomas are plotted on a different scale. (*) Significantly different than zero at P < .05.

FIG 3.

Five-year relative survival for patients with microscopically confirmed uterine corpus cancer age 30 to 79 years by stage at diagnosis and race and ethnicity for (A) endometrioid and (B) nonendometrioid subtypes. Expected survival for patients diagnosed between 2000 and 2014 was estimated with the Ederer II method, and relative survival was calculated by estimating the observed to the expected survival rate using the actuarial method. Error bars indicate standard error.

FIG A1.

Trends in age-adjusted incidence rates of microscopically confirmed uterine corpus sarcomas overall and by race and ethnicity, uncorrected and corrected for hysterectomy prevalence, among US women age 30 to 79 years according to SEER 18 (2000 to 2015). (A) Uncorrected and corrected rates for sarcomas among all women. (B) Uncorrected and (C) corrected rates for non-Hispanic whites (+), non-Hispanic blacks (solid square), Hispanics (solid triangle), and non-Hispanic Asians/Pacific Islanders (×). Annual percentage change estimates are shown next to each respective curve. (*) Significantly different than zero at P < .05.

FIG A2.

Five-year relative survival for patients with microscopically confirmed uterine corpus sarcoma age 30 to 79 years by stage at diagnosis and race and ethnicity. Expected survival for patients diagnosed between 2000 and 2014 was estimated with the Ederer II method, and relative survival was calculated by estimating the observed to the expected survival rate using the actuarial method. Error bars indicate standard error.