Abstract B48: Racial differences in colorectal cancer survival in the Detroit metropolitan area

Introduction: Colorectal carcinoma (CRC) is the third most frequently diagnosed malignancy and the second most common cause of cancer death with African Americans (AA) having lower overall survival compared to white Americans (WA). The purpose of this study was to investigate the effects of demographics, clinical factors and socioeconomic status (SES) on CRC survival disparities between AA and WA in the Detroit metropolitan area.

Methods: 9,420 individuals were identified with primary CRC between 1988 and 1992. Surveillance, Epidemiology, and End Results (SEER) categorizations were used to define demographic and clinical variables. Since individual SES data are not available in SEER, we used US Census data to create a “SES group” variable based on population based information on occupation, poverty status and educational attainment in each individual's census tract at the time of diagnosis. Kaplan-Meier survival analysis and Cox proportional hazards regression were used to compare overall survival between the two races.

Results: AA were more likely to be diagnosed with distant disease than WA (p < 0.001) and to reside within a poor census tract (p < 0.001). Unadjusted analysis showed that AA had a significantly higher risk of death compared to their WA counterparts (HR 1.12; 95% CI: 1.06−1.18). After adjusting for age, marital status, gender, SES group, SEER stage, and treatment, race was no longer significantly associated with survival (HR 1.01; 95% CI: 0.93−1.09).

Conclusions: Factors that affect access to medical care appeared to have a more important influence than race on the overall survival of men and women with CRC in the Detroit metropolitan area.