Partial nephrectomy seems to confer a survival benefit relative to radical nephrectomy in metastatic renal cell carcinoma

Objective: Partial nephrectomy (PN) is technically feasible in patients with metastatic renal cell carcinoma (mRCC). We tested the contemporary effect of PN on cancer-specific mortality (CSM), other-cause mortality (OCM) and early postoperative outcomes compared to radical nephrectomy (RN) in mRCC patients. Materials and Methods: In the first part, we identified surgically treated mRCC patients within the SEER database (2004–2013). After propensity-score (PS) matching, cumulative incidence plots and multivariable competing-risks regression (CRR) models were used. In the second part, we identified surgically treated mRCC patients within the NIS database (2004–2013). After PS matching, multivariable logistic regression (MLR) and multivariable Poisson regression (MPR) models were used. Results: Within the SEER database, 217 (4.2%) of 5171 mRCC patients underwent PN. After 4:1 PS matching, multivariable CRR models showed lower OCM rates in PN patients (hazard ratio [HR]: 0.23, p = 0.01). No difference in CSM was reported in PN vs. RN patients (p = 0.08). Within the NIS database, 226 (4.4%) of 5138 patients underwent PN. After 4:1 PS matching, MLR showed lower rates of transfusions (odds ratio [OR]: 0.46, P < 0.001), intraoperative (OR: 0.33, p = 0.02) and miscellaneous surgical complications (OR: 0.42, p = 0.009) in PN vs. RN patients. No difference in overall complications (OR: 1.00, p = 0.9) and in-hospital mortality (OR: 1.2, p = 0.8) was observed. In MPR, PN did not affect LOS (OR: 0.94, p = 0.3). Conclusions: We demonstrate that PN is associated with lower OCM in the setting of mRCC, but not with differences in other examined endpoints. In consequence, PN merits greater consideration in the context of mRCC.