A National Study of the Rate of Benign Pathology After Partial Nephrectomy for T1 Renal Cell Carcinoma: Should We Be Satisfied?

Objectives: To determine the rate of benign pathology in cT1 tumors following partial nephrectomy in the Netherlands, thereby evaluating the rate of overtreatment. Methods: Data were collected from a nationwide database containing histopathology of resected renal tissue from 2014 to 2022. Patients who underwent partial nephrectomy for suspected RCC staged T1a-b were extracted for analysis. Data are shown in percentages, and multivariable logistic regression was performed to determine predictive factors for benign pathology. Results: 3409 cases were analyzed, of which 403 (12%) were benign and 3006 (88%) malignant. Subtype analysis showed 2126 (62%) cases of clear-cell RCC, followed by 604 (18%) of papillary RCC and 344 (10%) oncocytomas. Mean age was 63 years among patients with malignant pathology versus 65 years for patients with benign lesions (p < 0.001). Mean tumor size was 3.2 cm for malignant pathology and 2.9 cm for benign (p < 0.001). The rates of benign and malignant pathology did not change between 2014 and 2022 (p = 0.377). Multivariable regression showed age ≥ 65 years (65-79 years [OR 1.881, p = 0.002], ≥ 80 years [OR 3.642, p < 0.001]) and tumor size (OR 0.793, p < 0.001) as predictors for benign pathology. The main limitation of this study is that we do not know the biopsy rate of our cohort. Conclusion: This study reports a low rate of 12% benign pathology after partial nephrectomy in the Netherlands. It remains debatable whether these rates are acceptable, or if renal tumor biopsies should be utilized more frequently to reduce overtreatment.

Cancers. 2024 Oct 17*** epublish ***

Luna van den Brink, Tess Debelle, Lieke Gietelink, Niels Graafland, Annebeth Ruiter, Axel Bex, Harrie P Beerlage, R Jeroen A van Moorselaar, Brunolf Lagerveld, Patricia Zondervan

Department of Urology, Amsterdam UMC, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands., Department of Urology, Amsterdam UMC, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands., Department of Urology, Spaarne Gasthuis, 2035 RC Haarlem, The Netherlands., Department of Urology, Netherlands Cancer Institute (NKI), 1066 CX Amsterdam, The Netherlands., Department of Urology, OLVG, 1091 AC Amsterdam, The Netherlands.