T-antigen. A prognostic indicator of high recurrence index in transitional carcinoma of the bladder.

Forty biopsies from 36 patients with bladder tumors were tested for T-antigen (TAg) expression on tumor cells on sections untreated or treated with neuraminidase; a 37.5% of tumors showed abnormal expression of TAg either as an aberrant expression, or absence of this antigen after removing sialic acid. These changes were not well correlated with histologic signs of anaplasia or infiltration, nor with other biologic properties of tumor cells such as the expression of blood group antigens (ABH). However, a practical utility of TAg in the study of bladder tumors, is suggested by the analysis of those biopsies with low-grade low-stage tumors, on which the abnormal expression of TAg was more discriminatory than the ABH changes in defining those patients suffering tumors with a particular aggressiveness. Circulating antibody titer was also investigated in 20 patients but all of them displayed titers in the normal range, with independence of the results observed in their corresponding bladder biopsies.