The variability of blood group antigens in gastric carcinoma as demonstrated by the immunoperoxidase technique.

In this study the immunoperoxidase technique was used to demonstrate the blood group antigens A, B and H in normal gastric mucosa and primary and metastatic gastric carcinomas. No clear relationship between tumour differentiation and preservation of blood group antigens was found. In some well differentiated tumours there was a marked loss of blood group substance, whereas in other poorly differentiated tumours, both primary and metastatic, it was easily detectable. In some tumours an inverse relationship between A or B and H activity was noted. This observation is consistent with the theory that in some malignant cells there is a blocking of the normal step-by-step elongation of the carbohydrate portion of blood group substances.