INTRAVESICAL INTERLEUKIN-2 IN T1 PAPILLARY BLADDER-CARCINOMA - REGRESSION OF MARKER LESION IN 8 OF 10 PATIENTS

Purpose: We evaluate the therapeutic effect of intravesical interleuki n-2 (IL-2) on T1 papillary bladder carcinoma after incomplete transure thral resection.Materials and Methods: After incomplete transurethral resection we treated 10 patients in whom the marker lesion was left in place with 3 x 10(6) Chiron units IL-2 in 50 mi. saline plus 0.1% hum an serum albumin. The solution remained in the bladder for 2 hours and it was instilled on 5 consecutive days. The effect of IL-2 treatment on the marker lesion was evaluated by cystoscopy and repeat biopsy of the marker site 2 months after treatment. In addition, the effect on t he recurrence of bladder tumors was studied. Results: At 2 months 8 of the 10 marker lesions (80%) had completely regressed and there were n o tumor cells on repeat biopsy. Four patients remained tumor-free afte r 30 to 54 months. We noted no toxic effects. In 1 patient with a 7-ye ar history of bladder cancer the marker was only partially regressed a fter 2 months. After removal of the marker this patient remained tumor -free at a followup of 54 months. Conclusions: To our knowledge this r eport represents the first study of the effect of IL-2 on marker lesio ns left in place after transurethral resection. The results indicate t hat IL-2 instillations are feasible, and the combination of transureth ral resection and IL-2 instillation may have a powerful antitumor effe ct. The therapeutic effects may not simply be due to intravesical IL-2 , because previous transurethral resection probably caused some influx of infiltrating cells and the marker may have had tumor associated an tigens. Consequently these effects may be due to the interaction of tu mor associated antigens, infiltrating cells and IL-2.