OBJECTIVE: ABO Blood groups play an important biological role in the immunological system. Studies have reported a strong relationship between ABO and Rhesus (Rh) blood types with various cancers; however, results are contrasting. This study encompasses epidemiology of breast cancer patients in north-eastern Uttar Pradesh region and also investigates the distribution of ABO and Rh blood antigens among breast cancer patients.

PATIENTS AND METHODS: A total of 187 breast cancer patients and 209 controls were enrolled in the study. Blood group, Rh factor, histological type, and different clinicopathological parameters were recorded. The frequencies of the ABO blood group among both the groups were evaluated and compared with different clinical parameters.

RESULTS: Frequency of blood group B (40.6%) was comparatively higher in breast cancer patients than other groups (A – 22.5%, AB – 6.4%, O – 30.5%), and the distribution of blood group among cases and controls did not differ significantly. Blood group B (n=53; 69.7%) has been found to be higher in grade II differentiation of breast cancer, but the difference was not significant. Moreover, we did not find any association of blood group with any of the receptor status.

CONCLUSIONS: Results suggested that blood group B was found to be higher in breast cancer patients, but it did not show any significant role. In addition, we did not find any association between Rh factor and breast cancer. Study findings have shown that breast cancer type, grade, stage, age of menarche (AOM), and hormonal status showed no significant associations with ABO blood group. However, further studies with larger number of patients are needed to clearly establish the role of ABO/Rh blood groups as a prognostic factor in breast cancer patients.