Lewis a antigen in transitional cell tumors of the urinary bladder.

The failure of A,B,H antigens as prognostic parameters in noninvasive bladder cancer of blood group O individuals, who constitute 44% of the population, encouraged the evaluation of the closely related Lewis a antigen. Ninety-three tumors of the urinary bladder were stained employing the Tween 20 (Merck)-modified immunoperoxidase staining technique and serial dilution of monoclonal anti-Lewis a antibodies. On the basis of recent findings in non-neoplastic ureter urothelium of erythrocyte Lea+b-, Lea-b+, and Lea-b- individuals, alterations in tumors, except eight from Lea-b- individuals, were quantified on a scale from 0 (normal) to 3 (total loss). Scores were related to the pathologic stage and grade (P less than 0.01), and, in stage Pa tumors, to the clinical course: recurrence rate (P less than 0.10), stroma invasive recurrence, and/or papillomatosis (P less than 0.05). Although further studies are needed the current study points to Lewis a antigen determination as an advantageous prognostic tool in stage Pa tumors of the urinary bladder of Lea-b+ and Lea+b- individuals, who, together, constitute 94% of the population.