Outcomes of partial nephrectomy for non-metastatic cT2 renal tumors: Results from a Canadian, multi-institutional collaborative
Rahul Bansal1, Ryan Sun1, Frédéric Pouliot2, Ranjeeta Mallick3, Simon Tanguay4, Darrel Drachenberg1, Ricardo A. Rendon5, Alan I. So6, Luke T. Lavallée7, Antonio Finelli8, Lucas Dean9, Anil Kapoor10, Bimal Bhindi11, Lori A. Wood12, Naveen Basappa13, Rodney H. Breau7.
1Section of Urology, Department of Surgery, University of Manitoba, Winnipeg, MB, Canada; 2Division of Urology, Université Laval, Quebec , QC, Canada; 3Ottawa Hospital Research Institute, University of Ottawa, Ottawa, ON, Canada; 4Division of Urology, McGill University, Montreal, QC, Canada; 5Department of Urology, Dalhousie University, Halifax, NS, Canada; 6Department of Urologic Sciences, University of British Columbia, British Columbia, BC, Canada; 7Division of Urology, University of Ottawa, Ottawa, ON, Canada; 8Division of Urology, University of Toronto, Toronto, ON, Canada; 9Division of Urology, University of Alberta, Edmonton, AB, Canada; 10Division of Urology, McMaster University, Hamilton, ON, Canada; 11Section of Urology, University of Calgary, Calgary, AB, Canada; 12Department of Medicine and Urology, Dalhousie University, Halifax, NS, Canada; 13Department of Oncology, University of Alberta, Edmonton, AB, Canada
CKCis database and support staff.
Introduction: The role of partial nephrectomy (PN) is not well-defined for cT2 renal cell carcinoma (RCC) as compared to radical nephrectomy (RN). The aim of this study was to examine oncological outcomes of PN as compared to RN for non-metastatic cT2 RCC.
Methods: The Canadian Kidney Cancer information system was used to define patients who underwent surgery for non-metastatic cT2 RCC from January 2011 to October 2021. Patients with clear-cell, papillary, and chromophobe RCC were included. Other histology, multiple tumors, and hereditary RCC syndrome patients were excluded. Each PN patient was individually matched to RN up to 1:4 depending on the availability of patients based on tumor size (±1 cm), histology, grade (clear-cell and papillary), and necrosis (clear-cell). Matched patients were analyzed as clusters.
Results: A total of 1347 patients were identified and 42 PN patients met study criteria, who were then matched to 145 RN patients. Both groups had similar age, gender, smoking status, body mass index, Charlson comorbidity index score, symptoms at presentation, baseline estimated glomerular filtration rate (eGFR), hemoglobin, and pathological characteristics. PN patients had smaller tumors (7.6 cm, interquartile range [IQR] 7.2, 9.2 vs. 8.5 cm, IQR 7.6, 10.3, p=0.048), had higher likelihood of undergoing open surgery (75% vs. 30%, p<0.0001), less likely received adrenalectomy (0 vs. 21%, p=0.0001), and had higher likelihood of positive surgical margin (PSM) (10% vs. 1%, p=0.025). Median followup was not significantly different in either group (3.7 years, IQR 1.1, 5.4 in PN vs. 2.8 years, IQR 1.2, 5.6 in RN, p=0.79). During the followup period, PN patients had a higher risk of local recurrence (hazard ratio [HR] 4.38, 95% confidence interval [CI] 1.51–12.71), lower risk of metastasis (HR 0.39, 95% CI 0.16–0.95), improved cancer-specific survival (HR 0.65, 95% CI 0.22–1.87) and improved overall survival (HR 0.47, 0.17–1.27) as compared to RN (Figure 1).
Conclusions: In this multi-institutional, Canadian cohort of patients with non-metastatic cT2 RCC undergoing surgery, PN was associated with a higher likelihood of PSM and local recurrence as compared to RN, and a lower risk of distant metastasis, cancer-related death, or death from any cause. Despite individual patient matching, there is likely unadjusted selection bias resulting in superior cancer survival associated with PN.
