Posters 9: Kidney, Penis and Testis Cancer

Monday July 01, 2019 from 07:30 to 09:00

Room: QCCC - 206 A

MP-9.2 Renal biopsy – When will it change management?

Douglas C. Cheung, Canada

University of Toronto


Renal biopsy: When will it change management?

Douglas C. Cheung1, Patrick Richard2, Diana E. Magee1, Luke T. Lavallée3, Frédéric Pouliot4, Maria Komisarenko1, Lisa Martin1, Jean-Baptiste Lattouf5, Shabbir M. Alibhai6, Murray Krahn6, Antonio Finelli1.

1Urology, University of Toronto, Toronto, ON, Canada; 2Urology, Université de Sherbrooke, Sherbrooke, QC, Canada; 3Urology, University of Ottawa, Ottawa, ON, Canada; 4Urology, Université Laval, Québec City, QC, Canada; 5Urology, Centre Hospitalier de l'Université de Montréal, Montréal, QC, Canada; 6Internal Medicine, University of Toronto, Toronto, ON, Canada

Introduction: Despite strong safety and accuracy data, renal biopsy use remains low. Proponents of no-biopsy argue that it would not change management since biopsy cohorts in existing studies may not be representative of those progressing to treatment. In a multi-institutional nephrectomy (treatment) cohort, we perform a cost-effectiveness analysis of renal biopsy to alter management in patients who have (would have) undergone intervention.

Methods: We completed a decision analysis populated by a multi-institutional, multi-provincial Canadian cohort from 2013–2015 (Fig. 1, TreeAgePro software). Outcomes and cost data were compared against reference literature values for generalizability to other jurisdictions. Non-diagnostic biopsies were re-biopsied once. Given our low event rate and risk of bias, literature rates were used for false negative and false positive biopsy rates.

Results: Of 542 patients, 192 (35%) received preoperative biopsy and 58 (10.7%) had benign disease on nephrectomy pathology. Fourteen (7.3%) had discordant pathology between biopsy and nephrectomy; however, many of these would not have altered management (renal cell carcinoma subtype misclassification). Seven (3.6%) were non-diagnostic. Using final pathology as gold standard and accounting for biopsy accuracy, we found a number needed to biopsy (NNTB) of 10.4 biopsies per nephrectomy avoided. Results were most sensitive to parameter uncertainty around probability of benign disease, cost of surgery and of biopsy. After 50 000 simulations, biopsy was cost-saving ($11 933 vs. $12 416, threshold 6.9% likelihood of preoperative benign disease). In subanalysis of non-biopsy centres (16% benign disease), cost savings increased and NNTB fell to 7.0.

Conclusions: Even prior to incorporating quality of life benefits from avoiding unnecessary operating rooms and surgical complications, we demonstrate the clinical and cost-effectiveness of incorporating renal biopsy as a useful preoperative planning tool.

© 2019 CUA 74th Annual Meeting