Carcinoma of the bladder, 5-fluorouracil and the critical role of a placebo. A cooperatie group report. I

Investigators in 12 centers agreed to study patients with invasive carcinoma of the bladder on a double blind basis to determine the effectiveness of 5-FU in treatment. Pairing of patients, repeated examinations designed to detect not only tumor growth but toxicity and other items were provided for in the protocol. Analysis of the data concerning 36 patients, 14 of whom were paired, demonstrated that the placebo patient of the pair responded better in five of seven instances. When pairing was disregarded, tumor growth was at least as great in 5-FU patients. Thus it is clear that 5-FU demonstrated no advantage over the placebo. Further, the placebo played a critical role in the study, for without it the investigators would never have discovered that the basic premise concerning progressive growth of cancer was wrong in these cases. The relatively greater regressions in the placebo patients indicates that carcinoma of the bladder does not grow in a predictable measurable fashion, at least not over a 60-day period.