Abstract B25: Black-white differences in colorectal cancer screening and incidence over time by age and sex

Abstract

Abstract Introduction: Blacks have the highest colorectal cancer (CRC) burden of any racial/ethnic group and the underlying reason for this disparity has not been fully elucidated. Continued examination of incidence in relation to screening, which is recommended for men and women beginning at age 50 years, may provide valuable insights into these disparities. The present study examined black-white differences in CRC incidence and screening patterns by age and sex over time. Methods: National Health Interview Surveys between 2000-2015 were used to estimate screening prevalence and prevalence ratios (PR) among adults 50 years and older by non-Hispanic white/black race and sex. Data from the SEER were used to estimate age-sex-specific incidence rates from 1992-2013. Results: From 2000 to 2015, CRC screening prevalence in age 50 years and older increased by 69% in whites (from 39.4% to 66.5%) and by 98% in blacks (from 31.1% to 61.4%) on a relative scale. Increases in CRC screening were evident in both men and women. During this time period, black-white differences also narrowed, such that CRC screening in blacks was 19% lower than in whites in 2000 (PR=0.81, 95%CI 0.71,0.92) but only 6% lower in 2015 (PR=0.94, 95%CI 0.88, 1.00). Absolute black-white differences in CRC incidence rates were slightly larger for men than for women (men: 3.0-6.0 versus women: 2.8-5.4 per 100,000) in people 35-49 years old, but decreased overtime in both groups. In 50-79-year-olds, absolute black-white incidence differences were larger for men prior to 2003 (men: 19.8-28.9 versus women: 28.3-33.1 per 100,000) and during 2004-2013 (men: 27.7-53.3 versus women: 20.6-38.7 per 100,000). In 35-49-year-olds, black-white incidence rate ratios (IRR) decreased overtime from 1992-2000 to 2009-2013 in both men (1.47 to 1.19) and women (1.49 to 1.17), but increased in both men (1.06 to 1.38) and women (1.15 to 1.49) for those 50 years and older. Conclusions: Black-white differences in CRC incidence in both absolute and relative terms are greatest in screening-eligible adults and have persisted in recent years whereas absolute differences in incidence in those younger than 50 are relatively small. These patterns may reflect racial gaps in screening uptake. However, disparities in CRC screening prevalence have narrowed in recent years and may portend convergence in CRC incidence rates. Note: This abstract was not presented at the conference. Citation Format: Stacey A. Fedewa, Douglas Corley, Ahmedin Jemal, Rebecca Siegel, Michael Goodman, Chyke Doubeni. Black-white differences in colorectal cancer screening and incidence over time by age and sex. [abstract]. In: Proceedings of the AACR Special Conference on Colorectal Cancer: From Initiation to Outcomes; 2016 Sep 17-20; Tampa, FL. Philadelphia (PA): AACR; Cancer Res 2017;77(3 Suppl):Abstract nr B25.