abo blood groups and prognosis of breast cancer: a case-control study in arak/iran

background: to explore a possible rela!onship among blood groups and the prognosis of breast cancer, this case- control study was carried out in arak city, arak province, iran. materials and methods: one hundred and thirty four pa!ents with breast cancer were inves!gated. abo blood groups were obtained from medical records. mul!variate analyses were performed, including size of tumor, axillary lymph nodes involvement and prognosis of the pa!ents. results: we found that there is a significant rela!onship between the blood type and the size of tumor (p.v=0.035), axillary lymph nodes involvement (p.v=0.001) and the prognosis of the breast cancer (p.v=0.014). conclusion: the blood type of among our pa!ents with breast cancer seems to be a prognos!c factor and the presence of b-an!gen shows associa!on with poor prognosis of breast cancer.