Clinical efficacy and prognostic factors of tumor progression in Japanese patients with advanced renal cell carcinoma treated with sorafenib

Objective: Result of clinical trial for registration purpose is often difficult to generalize because of its limited population in number and inclusion criteria. Methods: To understand the efficacy of sorafenib under daily medical practice, we retrospectively investigated therapeutic outcomes of 175 Japanese patients with advanced renal cell carcinoma treated with sorafenib at 15 centers. Results: The objective response rate and disease control rate were 15.4 and 77.1%, respectively, being similar to those in the Phase II study in Japanese patients (19.4 and 73.6 months). Any tumor shrinkage was observed with 53% of patients, while tumor control without growth was in 61%. Lung lesions were more sensitive to sorafenib than other lesions, in terms of any tumor shrinkage (54%) and the extent of maximal shrinkage, while tumor control was better in lymph node metastases (77%) than in lung (69%). Liver was worse in any tumor shrinkage (35%), tumor control (55%) and the extent of tumor growth. Slightly, shorter median overall survival of 21.1 months compared with Phase II clinical trial (25.3 months) is likely to be attributable to different patient population, because median overall survival was improved to 26.4 months when the population was matched to that in Phase II trial. Univariate and multivariate analyses identified prognostic factors for worse overall survival, including intermediate and poor Memorial Sloan-Kettering Cancer Center risk, Eastern Cooperative Oncology Group performance status ≥1, the presence of non-clear cell component and the presence of liver metastasis.Conclusions: In conclusion, the present study confirmed the efficacy of sorafenib in the real-world setting on advanced renal cell carcinoma.