Blood group antigen expression in bladder tumors: An immunohistochemical study of superficial bladder lesions
Blood group related antigens have been considered tumor markers with potential clinical value in bladder cancer, mainly due to their altered patterns of expression reported for urothelial tumor cells. Deletion of ABH antigens and abnormal levels of Lewis determinants have been reported to frequently occur in bladder transitional cell carcinomas. Moreover, some of these alterations have been associated with clinical outcome. However, the previous studies concerning blood group antigen expression in neoplastic urothelium have been performed using either in appropriate techniques, restricted panels of antibodies detecting these antigens or limited number of patients. We undertook the present study in order to investigate the hypothesis that altered patterns of blood group antigen expression correlate with recurrence or progression in patients with primary superficial bladder tumors. Expression of A, B, H, Le(a), Le(b), Le(x), and Precursor Type 1 chain determinants was evaluated on primary tumor specimens in 124 patients collected from four different institutions, including 51 with nonrecurrent tumors, 54 with recurrent lesions and 19 with disease progression. Antigen expression was examined by immunohistochemistry using a panel of well characterized mouse monoclonal antibodies on deparaffinized tissue sections. The median follow-up for this cohort of patients was 6.7 years. No correlation was observed when comparing altered patterns of ABH expression, Le(a), Le(b) and Precursor determinants in the context of tumor recurrence or progression. However, we observed that enhanced expression of Le(x) is a useful marker for early detection of bladder tumors and may contribute to the stratification of patients with bladder cancer.