Epithelial blood group antigens in human carcinomas of the distal colon: further studies on their pathologic significance.

Blood group antigen content of human carcinomas located in the distal large bowel (descending colon, sigmoid colon, and rectum) was determined by the specific red cell adherence reaction and was compared to several morphologic features of prognostic significance, e.g., differentiation, extent of tumor spread, peritumoral lymphoplasmocytic infiltration, and growth patterns. About 50% of the carcinomas expressed blood group antigens in either diffuse or patchy distribution. Classification of tumors according to the extent of local spread revealed that 60% of Dukes stage A tumors were blood group antigen-negative, whereas 58% of those in Dukes stage B were positive. Dukes stage C lesions had an intermediate position, and this limits the prognostic usefulness of blood group antigen determinations. No significant correlations were found between blood group antigenicity and the degree of histologic differentiation, the degree of peritumoral lymphoplasmocytic infiltration, and the mode of tumor growth.