Biopsy Cell Cycle Proliferation Score Predicts Adverse Surgical Pathology in Localized Renal Cell Carcinoma

Active surveillance (AS) is an accepted management strategy for some patients with renal cell carcinoma, but limited tools are available to identify optimal AS candidates. While renal mass biopsy provides diagnostic information, risk stratification based on biopsy is limited. In a retrospective, multi-institutional cohort that underwent renal mass biopsy followed by surgery, we assessed the ability of the cell cycle proliferation (CCP) score from clinical biopsy specimens to predict adverse surgical pathology (ie, grade 3-4, pT stage >= 3, metastasis at surgery, or papillary type II). Of 202 patients, 98 (49%) had adverse surgical pathology. When added to a baseline model including age, sex, race, lesion size, biopsy grade, and histology, CCP score was significantly associated with adverse pathology when modeled as a binary (odds ratio [OR]: 2.44 for CCP score >0, p = 0.02) and a continuous (OR: 1.72 per one unit increase, p = 0.04) variable. Discriminative performance measured by the area under the curve (AUC) improved from 0.73 in the baseline model to 0.75 and 0.76 in models including the CCP score. In the subgroup of patients with nephrectomy CCP score available (n = 67), the biopsy-based model outperformed the nephrectomy-based model (AUC 0.78 vs 0.75). These data support prospective assessment of biopsy CCP score to confirm clinical validity and assess potential utility in AS-eligible patients. Patient summary: In patients with localized renal cell carcinoma who underwent renal mass biopsy followed by surgery, the cell cycle proliferation score from clinical biopsy specimens could predict adverse surgical pathology. (C) 2020 European Association of Urology. Published by Elsevier B.V. All rights reserved.