Efficacy of sorafenib on metastatic renal cell carcinoma in Asian patients: Results from a multicenter study

BACKGROUND: The effects of sorafenib in the treatment of advanced renal cell carcinoma (RCC) have been confirmed in an international collaborative phase III trial. This study aims to confirm similar efficacy and treatment-induced toxicities of sorafenib in the treatment of metastatic RCC in ethnic Chinese patients. METHODS: Ninety-eight consecutive and non-selected patients with pathologically confirmed metastatic RCC were treated according to an institutional treatment protocol. All patients were treated with 400 mg of sorafenib orally twice daily on a continuous basis until disease progression or intolerance to treatment occurred. Dose reduction to 400 mg once daily was required if grade 3 or 4 toxicities occurred. All patients except for 7 received nephrectomy in the course of their disease. All patients were assessed for tumor response, progression-free survival (PFS), overall survival (OS), and treatment-induced toxicities. RESULTS: The median follow-up time was 76 weeks (range 2–296 weeks) for the entire group of patients. Radiologically confirmed complete response (CR), partial response (PR), stable disease (SD) of more than 4 months, and disease progression as best objective responses were observed in 1 (1%), 23 (23.5%), 62 (63.3%), and 12 (12.2%) patients, respectively. The tumor control rate (CR+PR+SD of >4 months) was 87.8%. The 1-year estimated PFS and OS were 58.4% and 64.6%, respectively. The median progression-free survival (PFS) time was 60 weeks (95% CI 41–79); and the median overall survival (OS) time was not reached with a follow-up of 76 weeks. Reduction of sorafenib dose was required in 26 patients who developed grade 3 or 4 treatment-cause adverse-effects. An additional 9 patients discontinued sorafenib treatment due to severe adverse-effects. No grade 5 toxicity occurred. Multivariate analysis revealed that independent predictive factors for tumor response to sorafenib treatment included ECOG status, presence of lymph node metastasis, and nephrectomy prior to the development of metastasis. CONCLUSION: Sorafenib produced an 87.8% disease control rate for metastatic renal cell carcinoma in Chinese patients, with acceptable rates of toxicity. The medication dosed at 400 mg twice daily is both efficacious and safe in the treatment of metastatic renal cell carcinoma in Chinese patients.