Breast cancer incidence in Greek women in relation to ABO blood groups and Rh factor

AIM: To investigate the correlation between breast cancer in Greek women and ABO blood groups. MATERIAL-METHODS: In 166 female patients with breast cancer factors such as blood group, histological type, family history, presence or absence of nodal and/or distant metastases were examined. These patients had similar demographic, clinical, surgical, immunohistochemical, laboratory, and follow-up data and this group is representative of general population of women in Greece. RESULTS: The ductal type of breast cancer was differentially distributed in blood groups Rh (+) (P ≤ 0.001). In patients with A (+) blood group the ductal type of breast cancer was present in 49.6% of cases, in relation to the other blood groups and in AB blood group the same type occurred rarely (3.6%). Rh (+) women with positive family history were more often found in A blood group. The relative risk of metastasis in Rh (-) patients was 4.2 times higher than that in Rh (+) patients. Among Rh (+) patients, the relative risk of metastasis was 1.29 times higher in A blood group than in other blood groups. CONCLUSION: Blood group A is often associated with ductal breast cancer (49.6%), in contrast to the other blood groups and particularly to blood group AB (3.6%). Blood group A and, particularly, A (-) has the worst prognosis of all.