Is routine use of renal tumor biopsy associated with lower rates of benign histology following nephrectomy for small renal masses?

Renal tumor biopsies (RTBs) have been proposed as a management alternative to avoid treatment of benign or low-risk small renal masses (SRMs). However, many urologists are reluctant to recommend RTB because they feel its result frequently will not impact management. Our primary objective was to evaluate if centers that routinely favor RTB (FRB) have lower rates of benign histology after surgery than centers that use a selective RTB approach (SRB).

This was a retrospective multicenter study of patients who underwent a partial or radical nephrectomy for a lesion suspicious for localised RCC and measuring ≤4cm (cT1a and pT1a or pT3a) between 2013 and 2015. A logistic regression model was used to examine whether the odds of obtaining a benign tumor following surgery differed between FRB centers and SRB centers.

542 SRMs in 516 patients were included in the study. The rate of histologically benign tumors after surgery was 11%. This rate was significantly lower at FRB than SRB centers (5% vs. 16%;p<0.001). On multivariable analysis, older age, smaller tumors and SRB centers were all significantly associated with greater odds of finding a histologically benign tumor following surgery. Compared to FRB centers, the odds finding a benign tumor at surgery was 4 times more likely at SRB centers (OR 4.1,95%CI:1.9-8.3).

Routine use of RTB reduces surgery for benign tumors and the potential for short and long-term morbidity associated with these procedures. This study suggests that routine RTB may be a valuable tool to decrease overtreatment of SRMs.

The Journal of urology. 2018 Apr 10 [Epub ahead of print]

Patrick O Richard, Luke T Lavallée, Frederic Pouliot, Maria Komisarenko, Lisa Martin, Jean-Baptiste Latouff, Antonio Finelli

Division of Urology, Department of Surgery, Centre Hospitalier Universitaire de Sherbrooke, Centre de recherche du CHUS and the University of Sherbrooke. Electronic address: ., Division of Urology, Department of Surgery, The Ottawa Hospital, Ottawa Hospital Research Institute and University of Ottawa., Division of Urology, Department of Surgery, CHU de Québec, CHU de Québec Research Center, Université de Laval., Division of Urology, Departments of Surgery, Princess Margaret Cancer Centre, University Health Network and the University of Toronto., Division of Urology, Department of Surgery, Centre Hospitalier Universitaire de Montreal, University of Montreal.