Classification tree for the prediction of malignant disease and the prediction of non-diagnostic biopsies in patients with small renal masses

  • Michael Organ Department of Urology, Memorial University, St. John's, Newfoundland, Canada
  • Landan P. MacDonald School of Medicine, Dalhousie University, Saint John, New Brunswick, Canada
  • Michael A.S. Jewett Departments of Surgery (Urology) and Surgical Oncology, Princess Margaret Cancer Centre, University Health Network and University of Toronto, Toronto, Ontario, Canada
  • Henry Ajzenberg School of Medicine, Queen's University, Kingston, Ontario, Canada
  • Ashraf Almatar Department of Urology, King Fahad Specialist Hospital-Dammam, Dammam, Saudi Arabia
  • Mohamed Abdolell Department of Diagnostic Radiology, Dalhousie University, Halifax, Nova Scotia, Canada
  • Matthew R. Acker Department of Urology, Dalhousie University, Saint John, New Brunswick, Canada
  • Ricardo Rendon Department of Urology, Dalhousie University, Halifax, Nova Scotia, Canada
Keywords: small renal masses, classification tree

Abstract

Introduction: Preoperative prediction of benign vs. malignant small renal masses (SRMs) remains a challenge. This study: 1) validates our previously published classification tree (CT) with an external cohort; 2) creates a new CT with the combined cohort; and 3) evaluates the RENAL and PADUA scoring systems for prediction of malignancy.

Methods: This study includes a total of 818 patients with renal masses; 395 underwent surgical resection and 423 underwent biopsy. A CT to predict benign disease was developed using patient and tumour characteristics from the 709 eligible participants. Our CT is based on four parameters: tumour volume, symptoms, gender, and symptomatology. CART modelling was also used to determine if RENAL and PADUA scoring could predict malignancy.

Results: When externally validated with the surgical cohort, the predictive accuracy of the old CT dropped. However, by combining the cohorts and creating a new CT, the predictive accuracy increased from 74% to 87% (95% confidence interval 0.84–0.89). RENAL and PADUA score alone were not predictive of malignancy. One limitation was the lack of available histological data from the biopsy series.

Conclusions: The validated old CT and new combined-cohort CT have a predictive value greater than currently published nomograms and single-biopsy cohorts. Overall, RENAL and PADUA scores were not able to predict malignancy.

Published
2018-09-25
How to Cite
Organ, M., MacDonald, L. P., Jewett, M. A., Ajzenberg, H., Almatar, A., Abdolell, M., Acker, M. R., & Rendon, R. (2018). Classification tree for the prediction of malignant disease and the prediction of non-diagnostic biopsies in patients with small renal masses. Canadian Urological Association Journal, 13(4). https://doi.org/10.5489/cuaj.5196
Section
Original Research