Identification of tumor size as the only factor associated with non-diagnostic biopsies in patients with small renal masses

  • Charlie J. Gillis Memorial University
  • Ricardo Rendon Department of Urology, Dalhousie University
  • Landan P. MacDonald Dalhousie University
  • Michael A.S. Jewett University of Toronto
  • Christopher French Memorial University
  • Henry Ajzenberg Queen's University
  • Ashraf Almatar King Fahad Specialist Hospital - Dammam
  • Mohammed Abdolell Dalhousie University
  • Michael Organ Memorial University
Keywords: small renal mass, renal tumor biopsy, non-diagnostic biopsy, renal tumor, classification tree, mass size, CART methodology, biopsy series

Abstract

Introduction: 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.

Methods: 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.

Results: 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).

Conclusions: When evaluating SRMs for diagnostic workup, mass size is the only tumor or patient characteristic associated with a non-diagnostic RTB.

Author Biographies

Ricardo Rendon, Department of Urology, Dalhousie University

Department of Urology, Dalhousie University, Nova Scotia, Canada. 

Landan P. MacDonald, Dalhousie University

School of Medicine, Dalhousie University, Saint John, NB Canada

Michael A.S. Jewett, University of Toronto

Departments of Surgery (Urology) and Surgical Oncology, Princess Margaret Cancer Centre, University Health Network and University of Toronto, Toronto, ON, Canada. 

Christopher French, Memorial University

Department of Urology, Memorial University, St. John's NL, Canada

Henry Ajzenberg, Queen's University

School of Medicine, Queen's University, Kingston ON, Canada. 

Ashraf Almatar, King Fahad Specialist Hospital - Dammam

Department of Urology, King Fahad Specialist Hospital-Dammam, Dammam, Saudi Arabia. 

Mohammed Abdolell, Dalhousie University

Department of Diagnostic Radiology, Dalhousie University, Halifax, NS, Canada. 

Michael Organ, Memorial University

Department of Urology, Memorial University, St. John's NL, Canada. 

Published
2019-09-20
How to Cite
Gillis, C. J., Rendon, R., MacDonald, L. P., Jewett, M. A., French, C., Ajzenberg, H., Almatar, A., Abdolell, M., & Organ, M. (2019). Identification of tumor size as the only factor associated with non-diagnostic biopsies in patients with small renal masses. Canadian Urological Association Journal, 14(5). https://doi.org/10.5489/cuaj.6103
Section
Research Letter