Do we know (or just believe) that partial nephrectomy leads to better survival than radical nephrectomy for renal cancer?

Abstract

Partial nephrectomy (PN) has become the gold standard for treating small renal masses amenable to such an approach. Surprisingly, the single randomized controlled trial of PN versus radical nephrectomy (RN) indicated an overall survival benefit for RN over PN. Recent studies have shed light on this discordance, and this review will attempt to discern what is known at present. Multiple retrospective observational studies have demonstrated superior outcomes with PN compared with RN. Whether the observed survival benefit with PN is the result of renal functional advantages or the result of selection bias and other unmeasured variables is up for discussion. A meta-analysis of 21 studies including the EORTC 30904 found a 19 % reduction in all-cause mortality (p = 0.0001) and 29 % reduction in cancer-specific mortality (p = 0.0002) with PN versus RN. Recent analysis of SEER-Medicare data revealed that patients undergoing RN had similar survival when compared with non-cancer controls, further supporting concerns about selection biases in prior observational series. Although PN is clearly of benefit for those likely to experience end-stage renal disease with RN, a survival benefit with PN in the elective setting is not proven at present. While experts may still believe PN to improve survival for these patients, the only level I evidence in the field would suggest otherwise, and selection bias is undoubtedly responsible for a significant part of the improved survival observed in retrospective studies. Given recent evidence, any further push to limit the role of RN should be tempered until we know PN is indeed superior.