Clinical Outcome and Prognostic Factors of Sorafenib in Japanese Patients with Advanced Renal Cell Carcinoma in General Clinical Practice

Objective Effects of sorafenib in general clinical practice, especially those with patients of Asian ethnicity, have been rarely investigated. We assessed efficacy, safety and prognostic factors for progression-free survival in Japanese patients receiving sorafenib for advanced renal cell carcinoma. Methods We performed a retrospective analysis of 159 Japanese patients with renal cell carcinoma. Progression-free survival was estimated by the Kaplan-Meier method. Objective response (per Response Evaluation Criteria in Solid Tumors) and safety were assessed. Cox proportional hazards model was used to identify independent prognostic factors for progression-free survival. Results The median progression-free survival was 9.0 months (95% confidence interval, 7.5-10.6 months). In 142 patients with measurable lesions, the objective response rate was 21.8%, and disease control was achieved in 85 (59.9%) patients. Adverse events of any grade occurred in 152 patients (95.6%). Most common adverse events causing discontinuation or interruption of sorafenib were hand-foot skin reaction (22%), rash (10.7%) and liver dysfunction (10.7%). Dose reduction or therapy interruption due to adverse events was required in 128 patients (80.5%). Univariate and multivariate analysis revealed that favorable prognosis according to Memorial Sloan-Kettering Cancer Center prognostic factors and relative dose intensity during the first month of treatment of ≥50% were significant factors for predicting superior progression-free survival with sorafenib treatment. Conclusions Sorafenib was effective in Japanese patients with advanced renal cell carcinoma in general clinical practice and was tolerated although most patients required dose reduction or interruption of therapy. Future studies should establish new strategies for treatment without sacrificing both efficacy and patient quality of life.