Clinical efficacy and prognostic factors for overall survival in Japanese patients with metastatic renal cell cancer treated with sunitinib

Study Type--Therapy (case series). Level of Evidence 4. What's known on the subject? and What does the study add? A randomized prospective phase III clinical trial for systemic treatment-naïve metastatic renal cell cancer (RCC) patients demonstrated the superiority of sunitinib over interferon with an acceptable safety profile. However, a commonly asked question is whether patients with RCC in clinical trials are representative of those with this disease being seen in ordinary clinical practice. To our knowledge, this is the first report of sunitinib for the Japanese patients with metastatic RCC in ordinary clinical practice. The estimated median PFS and OS in this study were 9.3 and 32.2 months, respectively. The application of the MSKCC model distinctly separated OS curves (P<0.001), suggesting that MSKCC prognostic factors might be still valid to predict survival in metastatic RCC in the era of molecular targeted therapy.

Objectives: • To report the treatment efficacy and safety profile of sunitinib for patients with metastatic renal cell carcinoma (RCC) in ordinary clinical practice. • In addition, to investigate the prognostic clinicopathological factors in these patients.

Patients and methods: • The present study consisted of native Japanese patients with metastatic RCC, comprising 29 pretreated and 34 systemic treatment-naïve patients. • Univariate and multivariate analyses were performed by the log-rank test and the Cox proportional hazards model, respectively.

Results: • Estimated median progression-free survival and overall survival (OS) were 9.3 months (95% confidence interval, CI, 5.0-13.7) and 32.2 months (95% CI, 24.4-40.0), respectively. • Among the patients pretreated before sunitinib, two patients were treated with initialized systemic therapy with sorafenib and the remaining 27 were initialized with interferon-α. • The OS from the initial systemic therapy of the patients in pretreated groups was 79.6 months (95% CI, 14.6-144.5). • The application of the Memorial Sloan-Kettering Cancer Center model distinctly separated the OS curves (P < 0.001). • The most common grade 3 adverse events were fatigue (53%), thrombocytopaenia (48%), hand-foot syndrome (16%), anaemia (20%), hypertension (10%) and leucopaenia (9%), although these events were manageable and reversible.

Conclusions: • Sunitinib has a favourable efficacy/safety profile for Japanese metastatic RCC patients in clinical practice. • The estimated median OS was >2 years with acceptable tolerability. • The median OS from the initial systemic therapy of the pretreated patients was >6 years. • Memorial Sloan-Kettering Cancer Center prognostic factors still appear to be valid for predicting survival in metastatic RCC in the era of molecular targeted therapy.