As greater numbers of small renal masses (SRMs) are discovered incidentally, renal tumor biopsy (RTB) is an increasingly recognized step for the management of these lesions, ideally for the prevention of surgical overtreatment for benign disease. While the diagnosis can often be obtained preoperatively by RTB, indeterminate results create greater difficulty for patients and clinicians. This study examines a series of RTBs, identifying the portion of these that were able to yield a diagnosis, and correlates patient factors, including RENAL and PADUA scoring, with the outcome of a non-diagnostic result.
Patients were identified as having undergone RTB at the Princess Margaret Cancer Centre in Ontario, Canada, between January 2000 and December 2009. Data was compiled from these 423 patients and analyzed using CART methodology to determine the level of association between various patient and tumor factors and the outcome of a non-diagnostic biopsy. Tumor size was further used to develop a classification tree to describe the prediction of a non- diagnostic biopsy.
Of these 423 patients undergoing RTB, 66 (16%) resulted in a non-diagnostic biopsy. The only patient or tumor factor that was found to be associated with a non-diagnostic outcome was mass size, where small masses (<1.28 cm diameter) were found to have a 38% chance of being non-diagnostic, compared with a 13% chance in those tumors >1.28 cm diameter (86% accuracy, 95% confidence interval [CI] 0.82-0.89).
When evaluating SRMs for diagnostic workup, mass size is the only tumor or patient characteristic associated with a non-diagnostic RTB.
Canadian Urological Association journal = Journal de l'Association des urologues du Canada. 2019 Nov 29 [Epub ahead of print]
Charlie J Gillis, Ricardo Rendon, Landan P MacDonald, Michael A S Jewett, Christopher French, Henry Ajzenberg, Ashraf Almatar, Mohammed Abdolell, Michael Organ
Facultyof Medicine, Memorial University, St. John's NL, Canada., Department of Urology, Dalhousie University, Halifax, NS, Canada., School of Medicine, Dalhousie University, Saint John, NB, Canada., Departments of Surgery (Urology) and Surgical Oncology, Princess Margaret Cancer Centre, University Health Network and University of Toronto, Toronto, ON, Canada., Department of Urology, Memorial University, St. John's NL, Canada., School of Medicine, Queen's University, Kingston ON, Canada., Department of Urology, King Fahad Specialist Hospital- Dammam, Dammam, Saudi Arabia., Department of Diagnostic Radiology, Dalhousie University, Halifax, NS, Canada.