Clinical trials of adjuvant radiation therapy for breast cancer

Years ago, radiation therapists conducted randomized clinical trials which showed that regional irradiation significantly reduces local recurrence of breast cancer but does not often affect life span. No new findings challenge these conclusions. Controlled trials in general have lost some credibility, however, as it has become more widely recognized that they are very vulnerable to fallacious reasoning and to simple human error. There is serious concern that some physicians may be unwisely abandoning well tested treatment methods because of the premature dissemination of early results of some trials. Still, many important questions remain that can only be answered by clinical trials, some including radiation therapy. This paper suggests that randomization schemes be incorporated into "routine" medical practice, although only after the most careful deliberation, in order to hasten fuller understanding of old therapeutic methods as well as new ones.