Association of blood group a with colorectal cancer prevalence in Croatian population

Purpose: The aim of our study was to investigate the association of ABO phenotypes and genotypes with colorectal cancer prevalence in Croatian population. Methods: Study included 80 patients (51 men) with colorectal cancer and 303 healthy volunteer blood donors (180 men) in the control group. Using the PCR-SSP method, genotyping was performed on 5 main alleles (O1, O2, A1, A2, B), resulting in 15 ABO genotypes. Results: There was no difference in the prevalence of colorectal cancer between men and women. There was no difference in a specific blood group phenotype between patients and healthy controls. However, there was a statistically significant higher odds ratio for individuals to carry blood group A than O in patients with colorectal cancer. There was no significant higher odds ratio for non-O genotypes compared to all genotypes constituting O blood group in patients with colorectal cancer. Conclusion: Our study has shown that there are higher odds for blood group A in colorectal patients than O when compared to healthy controls, suggesting blood group A could be a potential risk factor for colorectal cancer. This is accordant with some previously published studies. Further studies with larger group of patients and controls are needed to confirm this observation.