Survival benefit of partial nephrectomy: Reconciling experimental and observational data.

Given recent epidemiological and practice trends, small kidney cancers are poised to become a focus of modern-day surgical care provided by urologists and urologic oncologists. For the past decade, partial nephrectomy has been viewed as preferable to radical nephrectomy for the treatment of many patients with early-stage kidney cancer, partly because observational studies suggest a survival benefit with nephron sparing. More recently, European Organisation for Research and Treatment of Cancer 30904--a phase 3 randomized control trial--demonstrated better survival for patients treated with radical vs. partial nephrectomy. Shortly thereafter, an instrumental variable analysis reported a survival advantage with partial nephrectomy. Although seemingly contradictory, these studies are potentially reconcilable when considering methodological differences and other empiric work.