Prognostic nomogram for sunitinib in patients with metastatic renal cell carcinoma

BACKGROUND: In a randomized, phase 3 trial, sunitinib demonstrated superior efficacy over interferon-alfa as first-line therapy in patients with metastatic clear-cell renal cell carcinoma (RCC). On the basis of outcome data from that trial, the authors developed a nomogram for predicting the probability of 12-month progression-free survival for patients who received sunitinib therapy. METHODS: Three-hundred seventy-five patients who received sunitinib in the phase 3 trial were the subject of the current analysis. Nomogram pretreatment predictor variables included corrected serum calcium levels, the number of metastatic sites, hemoglobin levels, prior nephrectomy, the presence of lung and liver metastases, thrombocytosis, Eastern Cooperative Oncology Group performance status, time from diagnosis to treatment, and serum levels of alkaline phosphatase and lactate dehydrogenase. Investigator-assessed progression-free survival was the predicted outcome endpoint. Internal validation of the nomogram consisted of quantification of the discrimination with the concordance index and assessment of calibration. RESULTS: One-hundred seventy-four of 375 patients (46%) who received sunitinib achieved an objective response, and the median progression-free survival was 10.8 months (95% confidence interval, 10.6-12.6 months). A nomogram for predicting the probability of 12-month progression-free survival for patients who received sunitinib therapy was constructed on the basis of a Cox regression model from 11 parameters that were determined before treatment. The concordance index was 0.633. CONCLUSIONS: A nomogram was developed from pretreatment clinical features to predict the probability of achieving 12-month progression-free survival with sunitinib therapy for metastatic clear-cell RCC. The authors concluded that independent validation of the nomogram and additional studies to identify tumor-specific prognostic factors are warranted.