Blood group distribution in women with ovarian cancer

The distribution of ABO blood groups and Rh factor was studied in 1930 patients treated at Radiumhemmet for ovarian tumour in the period 1958-1973. The tumour was malignant in 1732 cases and of borderline malignancy in 198. A predominance of blood group A at the expense of group O emerged when the series was compared with findings in 24 120 healthy conscripts. In the present series, the disparity between the frequencies of blood groups A and O appeared to increase the risk of ovarian carcinoma by 19%. The frequencies of blood groups among various histological subgroups are discussed.