Racial differences in colorectal cancer survival in the Detroit Metropolitan Area

Abstract

Background: Colorectal carcinoma is the second most common cause of cancer death with African Americans having lower survival compared with White Americans. The purpose of this study was to investigate the effect of demographics, clinical factors, and socioeconomic status (SES) on racial disparities in colorectal cancer survival in the Detroit Metropolitan Area.

Methods: The study population included 9078 individuals with primary invasive colorectal cancer identified between 1988 and 1992 through the Surveillance, Epidemiology, and End Results (SEER) program. Demographics, clinical information, and survival were obtained through SEER. SES was categorized using occupation, educational level, and poverty status at the census tract level. Kaplan-Meier survival curves and Cox proportional hazards regression were used to compare overall survival by race.

Results: African Americans were more likely to be diagnosed with stage IV disease (P < .001), and to reside within poor census tracts (P < .001) compared with White Americans. Unadjusted analysis showed that African Americans had a significantly higher risk of death compared with their White American counterparts (hazards ratio [HR], 1.13; 95% confidence interval [CI], 1.07-1.20). After adjusting for age, marital status, sex, SES group, TNM stage, and treatment, race was no longer significantly associated with overall survival (HR, 1.00; 95% CI, 0.92-1.09). Similar results were seen with colorectal cancer-specific survival.

Conclusions: Racial disparities in colorectal cancer survival dissipate after adjusting for other demographic and clinical factors. These results can potentially affect medical guidelines regarding screening and treatment, and possibly influence public health policies that can have a positive impact on equalizing racial differences in access to care.