EFFECT OF INTRAVESICAL THIO-TEPA ON NORMAL AND TUMOR UROTHELIUM

Intravesical thio-tepa instillations for 55 patients with superficial transitional cell carcinoma were evaluated prospectively in the treatment of residual disease (therapeutic) and the prevention of recurrence (prophylactic). The over-all response rate to therapeutic thio-tepa was 56%, with toxicity observed in 26% of the cases. Patients with microscopic residual tumor showed better response and less toxicity than those with gross residual tumor. Prophylactic thio-tepa had no effect in lowering recurrence rates. Examination of pre-treatment and post-treatment biopsies showed no worsening of atypia and no correlation between improvement in atypia and gross tumor response. A characteristic post-treatment thio-tepa effect was observed in non-tumorous urothelium but not in tumor biopsies. The differentiation of such thio-tepa effect cells from pre-malignant atypical cells is discussed.