Interaction between ABO and rhesus blood groups, the site of origin of gastric cancers, and the age and sex of the patient.

ABO and Rhesus blood group data have been examined for 1,680 patients treated for gastric cancer in four London hospitals. The risk of developing gastric cancer was estimated to be 16% higher for group A subjects than for group O subjects, in close agreement with many previous reports throughout the world. More detailed analysis failed to support the suggestion that there was any special correlation between either ABO or Rhesus blood groups and the site of origin of the tumour within the stomach or the sex or age of the patient. Male predominance among the patients was noted to be greater at ages 40-69 years than at other ages and greater for tumours of the upper two thirds of the stomach than for tumours that arose distally.