Oncology/endocrineRacial disparity in colorectal cancer: the role of ABO blood group

BackgroundWe tested the hypothesis that racial differences that exist in the distribution of ABO blood type would partially explain the racial disparity in overall survival seen in colorectal cancer.Methodsretrospective analysis of the cancer registry of a university hospital for patients treated for colorectal cancer between 1996 and 2008. Demographic, tumor-specific, and treatment-specific variables were abstracted. We also obtained ABO blood group data. The primary end point was overall survival. We divided patients into two groups based on where they underwent surgery: the University of Arkansas for Medical Sciences (UAMS) or outside facilities.ResultsOf 833 patients, 182 (21.8%) were black. There was no difference in overall survival between blacks and whites for the entire group (P = 0.61). There was a statistically significant difference in overall survival between patients at the UAMS and outside facilities (P < 0.0001). For the outside facilities group, there was a statistically significant difference in overall survival between blacks and whites (hazard ratio, CI: 1.48 [1.06-2.00]; P = 0.012); no race difference existed for the UAMS group. The ABO blood group had no effect on overall survival. On stage-stratified univariate and multivariate analyses, chemotherapy and surgery were the only statistically significant determinants of survival.ConclusionsIn this study, racial differences in ABO blood group distribution had no effect on overall survival.