Significance of upfront cytoreductive nephrectomy stratified by IMDC risk for metastatic renal cell carcinoma in targeted therapy era - a multi-institutional retrospective study

Background: This retrospective multicenter study aimed to evaluate the survival benefit of upfront cytoreductive nephrectomy (CN) in metastatic renal cell carcinoma (RCC) patients stratified by International Metastatic RCC Database Consortium (IMDC) risk criteria.

Methods: We reviewed the medical records in the Michinoku Database between 2008 and 2019. Patients who received upfront CN, systemic therapy without CN (no CN) and CN after drug therapy (deferred CN) were analyzed. To exclude selection bias due to patient characteristics, baseline clinical data were adjusted by inverse probability of treatment weighting (IPTW). Overall survival (OS) was compared between upfront CN and non-upfront CN (no CN plus deferred CN). Associations between time-varying covariates including systemic therapies and OS stratified by IMDC risk criteria were analyzed by IPTW-adjusted Cox regression method.

Results: Of 259 patients who fulfilled the selection criteria, 107 were classified in upfront CN and 152 in non-upfront CN group. After IPTW-adjusted analysis, upfront CN showed survival benefit compared to non-upfront CN in patients with IMDC intermediate risk (median OS: 52.5 versus 31.3 months, p < 0.01) and in patients with IMDC poor risk (27.2 versus 11.4 months, p < 0.01). In IPTW-adjusted Cox regression analysis of time-varying covariates, upfront CN was independently associated with OS benefit in patients with IMDC intermediate risk (hazard ratio 0.52, 95% confidence interval 0.29-0.93, p = 0.03) and in patients with IMDC poor risk (0.26, 0.11-0.59, p < 0.01).

Conclusions: Upfront CN may confer survival benefit in RCC patients with IMDC intermediate and poor risk.