Prognostic outcome in patients treated with tyrosine kinase inhibitors as first-line molecular-targeted therapy for metastatic renal cell carcinoma: Experience in real-world clinical practice in Japan

The aim of this study was to evaluate the oncological efficacy of tyrosine kinase inhibitors (TKIs) as first-line molecular-targeted therapy for Japanese patients with metastatic renal cell carcinoma (mRCC) in a routine clinical setting. This study included a total of 271 consecutive Japanese patients with TKI-naive mRCC, including 172 patients who received sorafenib and 99 who received sunitinib for >= 2 months as a first-line molecular-targeted agent. The prognostic outcomes of these patients were retrospectively assessed. During the observation period (median, 19 months), 126 patients (46.5%) succumbed to the disease and the median overall survival (OS) for the entire cohort was 33.1 months. The univariate analysis identified the Memorial Sloan-Kettering Cancer Center (MSKCC) classification, C-reactive protein (CRP) level, lymph node metastasis, bone metastasis, liver metastasis, histological subtype and sarcomatoid characteristics as significant predictors of OS. Of these factors, only the MSKCC classification, CRP level and liver metastasis were found to be independently associated with OS in the multivariate analysis. Furthermore, there were significant differences in OS according to the positivity for these 3 independent risk factors (i.e., negative for all factors vs. positive for a single factor vs. positive for 2 or 3 factors). These findings suggest that the introduction of TKIs as first-line molecular-targeted agents resulted in favorable cancer control outcomes in Japanese mRCC patients and that the prognosis of these patients may be stratified by 3 potential parameters, including the MSKCC classification, CRP level and liver metastasis.