Abstract B70: Colorectal cancer-related disparities according to rurality, socioeconomic status, and race.
Authors: Hines Robert B. , Mohamadi Asal , Markossian Talar W. 
Published: August 2014

Background: The goal of the current study was to assess colorectal cancer (CRC)-related disparities according to geographic residency status, area-level socioeconomic status, and race (African American vs. white). Although numerous scientific endeavors have taken place to address the issue of cancer-related health disparities, especially racial disparities, less have focused on socioeconomic status and fewer still, disparities according to geographic residency (i.e., rural, suburban, urban). The health promoting effect that was once associated with rural living has diminished and, in fact, reversed for many health outcomes including cancer. However, of the studies of cancer outcomes that have been conducted according to geographic residency status, the findings have been mixed.

Methods: This study utilized cross-sectional and longitudinal data from the Georgia Comprehensive Cancer Registry on all incident cases of colorectal cancer diagnosed in the state for the years 2000-2009. In addition to individual-level predictors, census tract (CT)-level designation of socioeconomic status (upper-middle, lower-middle, and low) and geographic residency status was obtained by matching with Census 2000 data. The outcomes of interest were the odds of late stage disease at diagnosis, the odds of receiving treatment, and all-cause 5-year survival following diagnosis.

Results: African Americans [OR, 1.21; 95% confidence interval (CI), 1.14-1.29] and, to a lesser degree, residents of lower-middle SES CTs (OR, 1.07; 95% CI, 1.00-1.14) experienced an increased odds of being diagnosed with a late stage tumor. For colon cancer, African Americans (OR, 0.74; 95% CI, 0.64-0.87) and those of lower-middle (OR, 0.77; 95% CI, 0.64-0.91) and low SES CTs (OR, 0.76; 95% CI, 0.62-0.92) had a decreased odds of receiving surgery while suburban residency (OR, 1.17; 95% CI, 0.99-1.39) was positively associated with receiving surgery. Rural residency (OR, 0.82; 95% CI, 0.71-0.96) and living in low SES CTs (OR, 0.85; 95% CI, 0.73-0.98) were associated with decreased odds of receiving chemotherapy. For rectal cancer, low SES residents (OR, 0.68; 95% CI, 0.52-0.87) were at a decreased odds of receiving surgery while suburban residency (OR, 1.15; 95% CI, 0.99-1.33) was positively associated with receiving radiotherapy. For colon and rectal cancer, African Americans {[colon: hazard ratio (HR), 1.13; 95% CI, 1.07-1.22] [rectum HR, 1.12; 95% CI, 0.99-1.26]} and those living in lower-middle [(colon: HR, 1.10; 95% CI, 1.03-1.19) (rectum HR, 1.25; 95% CI, 1.11-1.40)] and low SES CTs [(colon: HR, 1.24; 95% CI, 1.14-1.35) (rectum HR, 1.29; 95% CI, 1.11-1.50)] experienced an increased risk of death following diagnosis. Rural residency [(colon: HR, 1.10; 95% CI, 1.02-1.18) (rectum HR, 1.20; 95% CI, 1.07-1.36)] was associated with an unadjusted increased risk of death, but this effect was completely explained after adjustment for SES.

Summary: In this study, we found significant disparities in colorectal cancer outcomes according to geographic residency, census tract-level SES, and race. These findings highlight progress that has been made, but also indicate the importance of continuing to pursue policies and interventions to eliminate health disparities according to geographic residency status, SES, and race.

Citation Format: Robert B. Hines, Asal Mohamadi, Talar W. Markossian. Colorectal cancer-related disparities according to rurality, socioeconomic status, and race. [abstract]. In: Proceedings of the Fifth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2012 Oct 27-30; San Diego, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2012;21(10 Suppl):Abstract nr B70.