Correlative studies on antigenicity of pancreatic cancer and blood group types.

Blood group-related antigenicity in 14 pancreatic cancer patients was examined by immunohistological method using monoclonal antibodies (MoAbs) against A, B, H, Lea, Leb, and CA 19-9 and compared with the phenotypic expression of the individuals' blood groups. MoAb-A reacted strongly with tumor tissue in four of five blood group A patients. Two of two patients with blood type B showed a weak, focal reactivity of their cancer with MoAb-B. H antigen was found in four of five patients from blood group A, while it was present in only one blood group O person and absent in B-type individuals. B antigen was inappropriately expressed in one person with type A blood and in two with type O. Lea antigen was expressed in all but two tumor tissues and Leb antigen in all tumorous tissues, irrespective of Le blood group status. MoAb 19-9 reacted with 11 of 14 cases.