Invasive potential of superficial bladder cancer. A study of the relative merits of predictive parameters.

The indirect immunoperoxidase test to detect urothelial cell surface blood group antigens was performed in an attempt to assess the loss of these antigens as a prognostic predictor. In our technique A, B and O(H) blood group specific monoclonal antibodies were used. It was possible to perform the test satisfactorily on histological material from 55 cases which were superficial on presentation; 15 subsequently became invasive. The loss of surface antigens correlated well with histological grade--44.4% of G1, 87.2% of G2 and 94.1% of G3 tumours were antigen-negative. The blood group phenotype of 114 patients was studied. In the group that subsequently became invasive, 14 of 26 (54%) were of blood group A phenotype compared with 37 of 88 (42%) in the non-invasive category. Acetylation studies were performed on 47 cases. In the group that subsequently became invasive, 5 of 10 (50%) had the slow phenotype of the enzyme N-acetyltransferase compared with 13 of 37 (35%) in the group that remained superficial.