Validation of the IMDC Prognostic Model in Patients With Metastatic Renal-Cell Carcinoma Treated With First-Line Axitinib: A Multicenter Retrospective Study.

BACKGROUND: The objective of the study was to validate the characteristics of the International Metastatic Renal-Cell Carcinoma Database Consortium (IMDC) prognostic model in patients treated with first-line axitinib in clinical practice. PATIENTS AND METHODS: We retrospectively evaluated 143 patients with metastatic renal-cell carcinoma who were treated with axitinib as the first-line therapy between October 2008 and February 2019. Overall survival (OS) was evaluated according to the IMDC prognostic model. We investigated the intragroup heterogeneity in the intermediate-risk group and divided these patients according to abnormal C-reactive protein (CRP) levels. An inverse probability of treatment-weighted (IPTW)-adjusted Cox regression analysis was performed to evaluate the effects of the CRP-risk model of OS in the patients in the IMDC intermediate-risk group. RESULTS: A significant difference in OS was observed in patients in the IMDC intermediate- and poor-risk group, although no significant difference was observed between the IMDC favorable- and intermediate-risk group. Significantly shorter prognosis was observed in patients in the IMDC intermediate-risk group who had 2 risk factors and CRP ≥0.3 mg/dL (inter-high group) than in those with 1 risk factor or 2 risk factors with CRP <0.3 mg/dL (inter-low group). IPTW-adjusted Cox regression analysis revealed significant differences in the OS between the inter-low and inter-high groups. CONCLUSION: The IMDC prognostic model was active in patients who received first-line axitinib treatment. The combination of CRP value with the number of positive risk factors in the IMDC model might predict prognosis in patients with IMDC intermediate-risk treated with first-line axitinib.