Prognostic Factors in Relation to Racial Disparity in Advanced Colorectal Cancer Survival

Colorectal cancer (CRC) mortality rates are higher in African-American (AA) than European-American (EA) individuals. We studied the role of race and survival in a small set of advanced stage patients. The risk of death was 145% greater among younger AA compared with EA individuals but only 16% greater in older patients. Future studies should examine why the disparity was larger among younger patients. Introduction: Colorectal cancer mortality rates are significantly greater in AA than in EA individuals, and the disparity is worsening. We investigated the relationship between race and metastatic CRC (mCRC) survival in younger and older patients. Patients and Methods: Using data from the Hollings Cancer Center (Charleston, SC), we studied the role of clinical, pathologic, and treatment-related factors on the disparity in survival. We carried out a retrospective cohort study of 82 mCRC patients (26 AA, 56 EA). The data source was medical record data from June 1, 2004 through May 31, 2008 with follow-up through June 30, 2010. Using Kaplan-Meier methods, we generated median survival time according to race and age (< 61, >= 61 years). Cox proportional hazards regression models were used to model the risk of death according to race. Results: The median age was 56.7 years for AA and 61.6 years for EA patients. Compared with EA, median survival in AA patients was 59% worse in younger patients (12.7 vs. 31.0 months) and 29% worse in older patients (11.7 vs. 16.4 months). The risk of death among younger AA compared with EA patients was 2.45 (95% confidence interval [CI], 1.15-5.23) and among older patients was 1.16 (95% CI, 0.49-2.73). Conclusion: Our results highlight the importance of considering younger age, clinical prognostic markers, and tumor phenotypes as potential sources of the disparity in advanced stage CRC.