Somatic mutations as preoperative predictors of metastases in patients with localized clear cell renal cell carcinoma - An exploratory analysis.

OBJECTIVE: Recurrent genomic alterations in clear cell renal cell carcinoma (ccRCC) have been associated with treatment outcomes; however, current preoperative predictive models do not include known genetic predictors. We aimed to explore the value of common somatic mutations in the preoperative prediction of metastatic disease among patients treated for localized ccRCC. MATERIALS AND METHODS: After obtaining institutional review board approval, data of 254 patients with localized ccRCC treated between 2005 and 2015 who underwent genetic sequencing was collected. The mutation status of VHL, PBRM1, SETD2, BAP1 and KDM5C were evaluated in the nephrectomy tumor specimen, which served as a proxy for biopsy mutation status. The Raj et al. preoperative nomogram was used to predict the 12-year metastatic free probability (MFP). The study outcome was MFP; the relationship between MFP and mutation status was evaluated with Cox-regression models adjusting for the preoperative nomogram variables (age, gender, incidental presentation, lymphadenopathy, necrosis, and size). RESULTS: The study cohort included 188 males (74%) and 66 females (26%) with a median age of 58 years. VHL mutations were present in 152/254 patients (60%), PBRM1 in 91/254 (36%), SETD2 in 32/254 (13%), BAP1 in 19/254 (8%), and KDM5C in 19/254 (8%). Median follow-up for survivors was 8.1 years. Estimated 12-year MFP was 70% (95% CI: 63%-75%). On univariable analysis SETD2 (HR: 3.30), BAP1 (HR: 2.44) and PBRM1 (HR: 1.78) were significantly associated with a higher risk of metastases. After adjusting for known preoperative predictors in the existing nomogram, SETD2 mutations remained associated with a higher rate of metastases after nephrectomy (HR: 2.09, 95% CI: 1.19-3.67, P = 0.011). CONCLUSION: In the current exploratory analysis, SETD2 mutations were significant predictors of MFP among patients treated for localized ccRCC. Our findings support future studies evaluating genetic alterations in preoperative renal biopsy samples as potential predictors of treatment outcome.

Preoperative nomogram predicting 12-year probability of metastatic renal cancer - evaluation in a contemporary cohort.

OBJECTIVES: Preoperative models, based on patient and tumor characteristics, predict risk for adverse outcomes after nephrectomy. Changes in renal tumor characteristics over the last decades, warrant further evaluation using contemporary cohorts. We aimed to validate a previously published preoperative nomogram predicting 12-year metastasis-free probability after nephrectomy for localized renal tumors in a contemporary cohort. PATIENTS AND METHODS: After obtaining institutional review board approval, data of 1,760 patients who underwent nephrectomy for a localized renal mass between 2005 and 2011 were reviewed. Preoperative images were evaluated for the presence of tumor necrosis, lymphadenopathy, and tumor size. The study outcome was metastatic-free probability. Model discrimination was assessed with Gönen and Heller's concordance probability estimate, and calibration was evaluated. RESULTS: The cohort included 1,102 male and 658 female patients with a median age of 60 years. Most patients presented incidentally (84%). On imaging, 3% had evidence of lymphadenopathy, 55% had necrosis and median tumor diameter was 3.7 cm (interquartile range [IQR]: 2.5, 5.5). Median follow-up in non-metastatic patients was 7.7 years (IQR: 5.3, 9.7). Estimated 12-year metastatic-free probability was 88% (86%-90%). The model showed strong discrimination (concordance probability estimate [CPE]: 0.77), and fair calibration. The time-dependent receiver operating characteristic (ROC) curves showed strong discrimination at all-time points and the area under the curve (AUC) for year 12 was 0.83 (95% Confidence Interval: 0.78-0.89). CONCLUSIONS: We validated the preoperative nomogram of 12-year metastasis-free probability in a contemporary cohort despite different tumor characteristics. Future studies should evaluate the role of preoperative risk stratification in patient selection for neoadjuvant treatment.