Comparative risk-adjusted mortality outcomes after primary surgery, radiotherapy, or androgen-deprivation therapy for localized prostate cancer


I read with great interest the article by Cooperberg and co-workers1 studying survival rates in differently treated men with early prostate cancer. In this study, patients who underwent radical prostatectomy had a substantially decreased disease-specific mortality, particularly in the higher-risk groups, compared with those who were selected for radiation therapy or conservative management.1 Unlike Cooperberg et al., I do not consider it unlikely that unmeasured confounding, at least in part, accounted for the observed differences. It is conceivable that patients with a particularly adverse profile within the same risk category might have preferably been referred to external-beam radiotherapy, thus putting this treatment modality at a disadvantage. It is questionable whether this phenomenon is adequately covered by conventional prognostic factors because subjective clinical judgment is included. Selection in favor of surgery is a problem when different treatments for early prostate cancer are compared.2, 3 Even careful risk adjustment will hardly be able to eliminate this effect completely.3, 4 Otherwise, it would be difficult to justify randomized trials comparing radical prostatectomy and external-beam radiotherapy in this setting that the authors rightly called for.1