Breast cancer and histocompatibility antigens.

HLA antigens and haplotypes were studied in 50 women with infiltrating ductal carcinoma of the breast, from the Basque provinces and Navarra, and in a comtrol group consisted of 166 healthy persons from the same geographical area. A greater incidence of HLA-B7 and B26 was observed in the breast cancer group if compared with the frequency of occurrence of these antigens in the Spanish population. However, when compared with Navarra-Basque population, no significant differences were observed. The study of the haplotype frequencies in breast cancer showed a greater incidence of the A9, B27 and A10, B14 haplotypes than in the normal population. However, the significance of D values disappeared after making the necessary correction for the number of antigens tested. The major histocompatibility system has a variety of functions which have not yet been documented but that might predispose to disease. It is certainly probable that there will be multiple mechanisms underlying HLA and cancer associations, however so far none of the data available suggest the presence of an immune response gene linked with breast cancer.