Biomarkers defining probability of receiving second-line targeted therapy in metastatic renal cell carcinoma

In order to facilitate long-term treatment decisions, we aimed to define biomarkers defining the probability of receiving second-line (SL) targeted therapy (TT) in patients with metastatic renal cell carcinoma (mRCC) based on their characteristics present at first-line TT initiation. We analysed 152 consecutive mRCC patients treated and used multivariable binominal logistic regression to identify factors contributing to the probability of receiving SL TT. Final model was assessed with bias-corrected indices (Nagelkerke's R² and area under receiver operating characteristic curve [AUC]) and two bootstrap procedures were used for internal validation. Factors associated with the probability of SL TT eligibility were the presence of brain metastases (odds ratio [OR] 0.084, 95% confidence interval [CI] 0.010-0.707), number of metastatic sites (OR 0.740, 95% CI 0.575-0.953 per each site), platelet count (OR 0.971, 95% CI 0.947-0.997, per 10⁴/ml), lactate dehydrogenase level (OR 0.952, 95% CI 0.910-0.997 per 10 units/l), and albumin concentration (OR 1.924, 95% CI 1.057-3.503 per 1 g/dl). We developed on-line calculator that enables practicing clinicians to estimate SL treatment probability ( http://www.r-calc.com ).