Impact of cytoreductive nephrectomy in patients with primary metastatic renal cell carcinoma receiving systemic tyrosine kinase inhibitor therapy: A multicenter retrospective study

Objectives To compare overall survival between patients with metastatic renal cell carcinoma treated by cytoreductive nephrectomy and those not treated by cytoreductive nephrectomy. Methods We retrospectively evaluated 278 patients with metastatic renal cell carcinoma treated with first-line tyrosine kinase inhibitors between January 2008 and November 2019. Patients were divided into two groups: a cytoreductive nephrectomy group (immediate or deferred cytoreductive nephrectomy) and a group who received systemic tyrosine kinase inhibitor therapies alone without cytoreductive nephrectomy (control group). Overall survival comparisons were made in all patients in the control versus the cytoreductive nephrectomy group, the control versus the immediate cytoreductive nephrectomy group, the control versus the deferred cytoreductive nephrectomy group, and the deferred cytoreductive nephrectomy versus the immediate cytoreductive nephrectomy group. Analyses were weighted using the propensity score-based inverse probability of treatment weighting method to adjust for group imbalances. Results The median (range) age of the patients was 65 (59-73) years. Of the 278 patients, 132 and 146 were in the control group and the cytoreductive nephrectomy (immediate, n = 107 and deferred, n = 39) group, respectively. A significant difference was noted between the control and cytoreductive nephrectomy groups in age, clinical stage, International Metastatic Renal Cell Carcinoma Database Consortium risk factors, and the number of metastatic sites. Inverse probability of treatment weighting-adjusted Cox regression analysis showed a significant difference in overall survival between the control and the cytoreductive nephrectomy groups and between the control and the immediate or deferred cytoreductive nephrectomy groups. However, there was no significant difference in overall survival between the immediate and the deferred cytoreductive nephrectomy groups. Conclusions Our findings suggest that metastatic renal cell carcinoma patients undergoing cytoreductive nephrectomy are more likely to have longer overall survival than those who receive tyrosine kinase inhibitor therapy only.