Racial Disparity in Colorectal Cancer: The Role of Equal Treatment

BACKGROUND: Racial disparity exists in colorectal cancer outcomes. The reasons for this are multifactorial. OBJECTIVE: The aim of this study was to evaluate the role of equal treatment of blacks and whites in the elimination of racial disparity in colorectal cancer outcomes. DESIGN: A retrospective cohort study of 878 patients with colorectal cancer diagnosed between 1998 and 2008 was done at a University tertiary referral center. Demographic variables including age, sex, and race were abstracted. Tumor-specific variables including American Joint Committee on Cancer stage, anatomic tumor location, vital status, and survival were obtained. Treatment-specific variables including surgery, chemotherapy, radiotherapy, and follow-up were also obtained. Racial differences in these variables were studied and their effect on overall survival was determined by using univariate and multivariate analyses. The findings were then compared with previous data from our institution. SETTING: University tertiary referral center. MAIN OUTCOME MEASURES: The primary outcomes measured were overall survival and cancer-specific mortality. RESULTS: A total of 878 patients met the inclusion criteria, 186 (21.2%) of whom were black. Blacks were significantly younger at diagnosis in comparison with whites, with a median (quartiles) age of 55 years (28-87) compared with 59 years (23-94) (p = 0.0012). Equal proportions of blacks (78.5%) and whites (79.2%) underwent surgery (p = 0.84), similar proportions of blacks (55.4%) and whites (60.8%) received chemotherapy (p = 0.18), and similar proportions of blacks (17.2%) and whites (20.5%) received radiation therapy (p = 0.31). There was no difference in overall survival or cancer-specific mortality between the 2 racial groups. Univariate analysis showed American Joint Committee on Cancer stage and surgery as the only statistically significant factors for overall survival. On multivariate analysis, stage, surgery, and chemotherapy were the only statistically significant factors. Race was not an independent determinant of survival. CONCLUSIONS: There were no differences in overall survival and cancer-related mortality between blacks and whites, and this may have resulted from identical treatment. The previously noted disparities in treatment and overall survival at our institution have disappeared.