Risks and benefits of repeated courses of intravesical bacillus Calmette-Guerin therapy for superficial bladder cancer.

An actuarial analysis of the risks and benefits of repeated courses of intravesical bacillus Calmette-Guerin therapy for superficial bladder cancer was performed for 100 consecutive patients treated for carcinoma in situ (29), prophylaxis against recurrent tumor (51) or residual superficial papillary tumor (21). The risk-to-benefit ratio at entry into bacillus Calmette-Guerin therapy (7 per cent risk of invasive cancer developing, 5 per cent risk of metastases and 77 per cent prospect for status free of tumor) and in patients who had failed only 1 course of bacillus Calmette-Guerin therapy (11 per cent invasive cancer, 14 per cent metastases and 58 per cent free of tumor) were highly favorable. However, among patients who had failed 2 or more courses of bacillus Calmette-Guerin therapy the risks of invasive (30 per cent) or metastatic (50 per cent) cancer developing exceeded the prospects for eradicating the superficial tumor present (20 per cent) with further therapy. The results suggest that patients who have failed 2 courses of bacillus Calmette-Guerin therapy (as given in our treatment protocol) should be considered for alternative treatment.