Association between cytoreductive nephrectomy and survival among patients with metastatic renal cell carcinoma receiving modern therapies: a systematic review and meta-analysis examining effect modification according to systemic therapy approach.

Purpose: Cytoreductive nephrectomy (CN) has played a role in treatment of metastatic renal cell carcinoma (mRCC) since trials demonstrated a survival benefit in patients receiving CN with interferon. With the publication of CARMENA, it became clear that the value of CN may depend on the co-therapy administered. We sought to assess the benefit of CN in the era of modern immunotherapy (IO).
Methods: We performed a systematic review to identify studies assessing CN in patients receiving TT or IO. We extracted multivariable-adjusted hazard ratios for the association between CN and overall survival (OS) and performed random effects meta-analysis. We tested for effect modification by systemic therapy approach on the association between CN and OS by pooling the difference in logHR associated with CN for patients treated with TT versus IO.
Results: We identified three comparisons assessing CN in patients receiving TT or IO. Pooled analysis indicated improved survival with CN in both the TT (2 cohorts, pooled HR: 0.52, 95% CI 0.46-0.59; I ²  = 80%) and IO era (2 cohorts; pooled HR: 0.28, 95% CI 0.16-0.49; I ²  = 21%), with a stronger association in the IO era (p = 0.01; I ²  = 0%).
Conclusion: In observational datasets, we observed a larger survival benefit to CN in patients treated with IO-based regimens versus those treated with TT-based regimens. While the role of CN for patients receiving TT has recently been questioned, this suggests that the results of CARMENA do not necessarily preclude a benefit to CN when combined with IO-based regimens.