Abstract

Background Previous prognostic models for second-line systemic therapy in patients with metastatic renal cell carcinoma have not been studied in the setting of targeted therapy. We sought to validate the International Metastatic Renal Cell Carcinoma Database Consortium (IMDC) model in patients with metastatic renal cell carcinoma receiving next-line targeted therapy after progression on first-line targeted therapy. Methods In this population-based study, we analysed patients who received second-line targeted therapy for metastatic renal cell carcinoma at 19 centres in Canada, USA, Greece, Japan, Singapore, South Korea, and Denmark. The primary endpoint was overall survival since the initiation of second-line therapy. We compared the prognostic performance of the IMDC model with the three-factor MSKCC model used for previously treated patients for overall survival since the start of second-line targeted therapy. Findings Between Jan 1, 2005, and Nov 30, 2012, we included 1021 patients treated with second-line targeted therapy. Median overall survival since the start of second-line targeted therapy was 12·5 months (95% CI 11·3–14·3). Five of six predefined factors in the IMDC model (anaemia, thrombocytosis, neutrophilia, Karnofsky performance status [KPS] <80, and <1 year from diagnosis to first-line targeted therapy) were independent predictors of poor overall survival on multivariable analysis. The concordance index using all six prognostic factors (ie, also including hypercalcaemia) was 0·70 (95% CI 0·67–0·72) with the IMDC model and was 0·66 (95% CI 0·64–0·68) with the three-factor MSKCC model. When patients were divided into three risk categories using IMDC criteria, median overall survival was 35·3 months (95% CI 28·3–47·8) in the favourable risk group (n=76), 16·6 months (14·9–17·9) in the intermediate risk group (n=529), and 5·4 months (4·7–6·8) in the poor risk group (n=261). Interpretation The IMDC prognostic model can be applied to patients previously treated with targeted therapy, in addition to previously validated populations in first-line targeted therapy. The IMDC prognostic model in the second-line targeted therapy setting has an improved prognostic performance and is applicable to a more contemporary patient cohort than that of the three-factor MSKCC model. Funding DF/HCC Kidney Cancer SPORE P50 CA101942-01, Kidney Cancer Research Network of Canada, Canadian Institute for Health Research, Trust Family, Loker Pinard, Michael Brigham, and Gerald DeWulf.