Clinical impact of early response to first‐line VEGFR‐TKI in patients with metastatic renal cell carcinoma on survival: A multi‐institutional retrospective study

It remains unknown whether the early response to vascular endothelial growth factor receptor tyrosine kinase inhibitor (VEGFR‐TKI) management in malignancies links to long‐term survival. The objective of this study was to investigate the survival rates and predictive factors of early response in patients with metastatic renal cell carcinoma (mRCC) managed by VEGFR‐TKIs. From Jan. 2008 to Oct. 2018, 496 patients were treated with VEGFR‐TKIs as first‐line treatment at the eight Japanese hospitals (Michinoku RCC). Early cessation was defined as VEGFR‐TKIs being given up within 3 months after their initiation. The number of patients in early cessation VEGFR‐TKIs (Cohort I) was 173 (34.9%), and in long‐term use (Cohort II) was 323 (65.1%). The cancer‐specific survival (CSS) and overall survival (OS) were better in Cohort II. IMDC Poor‐risk was at risk of early cessation of a first‐line VEGFR‐TKI. Axitinib was the most preferred drug for long‐term treatment. On closer examination, both Cohort I and II were divided into two groups, the patients ceased VEGFR‐TKI due to adverse events (Group A [67 from Cohort I] and Group C [51 from Cohort II]) and disease progression (Group B [106 from Cohort I] and Group D [272 from Cohort II]). Despite that the cessation was adverse events, CSS and OS in Group A were worse than both Group C and D. Axitinib was administered with the safer profile. IMDC Poor risk was the risk factor for the early disease progression. Managing early adverse events may contribute to a better prognosis in mRCC patients treated VEGFR‐TKIs.