Abstract B137: Colorectal cancer mortality and disparities in America’s 30 most populous cities
Authors: Silva Abigail , Sayad Nazia , De Maio Fernando , Benjamins Maureen 
Published: September 2020

Abstract
Background: In the U.S., colorectal cancer (CRC) is the 2nd leading cause of cancer deaths and Blacks have a 40% higher CRC mortality rate compared to Whites. Reduction in CRC mortality and racial disparities may be achieved, in part, by addressing modifiable factors (e.g. smoking, overweight/obesity, cancer screening availability/uptake, treatment access) and coordinating efforts by civil societies, policy makers, and community leaders. Implementing programs and policy changes at the city level may be the most effective strategy for the U.S. because over 80% of invasive cancer cases occur within urban areas. The purpose of the present analysis is to calculate (and rank) overall and race-specific CRC mortality rates as well as measures of disparities for the 30 biggest U.S. cities. Methods: The 2013-2017 National Center for Health Statistics mortality data and 2013-2017 American Community Survey 5-year population estimates were used to compute the overall, non-Hispanic (nH) Black, and nH White average annual CRC mortality rates for the U.S. and the 30 most populous cities. The rates were age-adjusted using the 2000 standard U.S. population. The Black and White CRC mortality rates were used to calculate rate ratios (RR) and rate differences (RD) and their respective 95% confidence intervals (CIs). In addition, the number of excess deaths due to the racial disparity in CRC mortality was ascertained. Results: The estimated annual CRC mortality rate for the U.S. was 14.3 per 100,000 total population. The city-level rates ranged from a low of 10.6 (San Jose) to a high of 31.1 (Las Vegas). Nationally, the Black rate was 43% higher than the White rate (95% CI: 1.41-1.44) with a RD of 6.27 per 100,000 population. Racial disparities were found in 25 of the 30 cities. Among those with a disparity, Philadelphia had the lowest level (RR=1.21; 95% CI 1.08-1.35, RD=3.55; 95% CI: 1.46-5.63) while Washington DC had the highest (RR=2.60; 95% CI 2.04-3.30, RD=13.65; 95% CI: 10.76-16.54). In the U.S., the yearly number of excess Black CRC deaths was 2,252. Across the 25 cities with a disparity, Seattle and Portland fared the best while Chicago fared the worst in terms of excess deaths (3 versus 96, respectively). Even among the 12 cities with a lower CRC mortality rate than that of the U.S., 7 had a greater level of disparity (RR&gt;1.43) than the nation. However, some cities like San Diego, New York, Boston, and Oklahoma City fared well in terms of the overall CRC mortality rates and level of disparity. Conclusion: To our knowledge, this study is the first to illustrate the substantial variability in CRC mortality disparities across a sample of urban cities. Local level data helps identify cities that may need the most support and offers examples of model cities. City-level information can be used to assist city officials, public health professionals, cancer control agencies, and other organizations to make real, evidence-based changes in policies, services, and funding.
Citation Format: Abigail Silva, Nazia Sayad, Fernando De Maio, Maureen Benjamins. Colorectal cancer mortality and disparities in America’s 30 most populous cities [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr B137.