Oncological outcomes of minimally invasive partial versus minimally invasive radical nephrectomy for cT1-2/N0/M0 clear cell renal cell carcinoma: a propensity score-matched analysis.

PURPOSE: To compare the oncologic outcomes of partial nephrectomy (PN) and radical nephrectomy (RN) for cT1-2/N0 renal tumors and pathologically confirmed pT1-pT3a-pNx clear cell (cc)-renal cell carcinoma (RCC). Few studies compared the oncologic outcomes of PN and RN for renal tumors >7 cm.

METHODS: A prospective "renal cancer" database was queried for cT<3-cN0-cM0 and pT1a-pT3a-pNx cc-RCC. Out of 1650 cases treated between 2001 and 2013, 921 were cc-RCC and 666 met inclusion criteria, 232 of which treated with minimally invasive RN and 434 with MIPN. A 1:1 propensity score-matched (PSM) analysis was employed to minimize the selection bias of non-random assignment of patients to PN as opposed to RN. Kaplan-Meier method was used to compare the oncologic outcomes of the PSM cohorts. Survival rates were computed at 2, 5, and 10 years after surgery, and the log-rank test was applied to assess statistical significance between the two PSM groups.

RESULTS: RN tumors were significantly larger (p < 0.001), with higher pT stages (p < 0.001), higher Fuhrman grades (p = 0.002) and a more frequent sarcomatoid differentiation (p = 0.04). After applying the PSM analysis, the two cohorts of 155 RN and 155 PN cases did not differ for all clinical and pathologic covariates (all p ≥ 0.32). PN and RN cohorts displayed comparable 5-year metastasis-free survival (88.9 vs 89.9 %, p = 0.811), local recurrence-free survival (94.2 vs 95.9 %, p = 0.283), overall survival (94.5 vs 96.8 %, p = 0.419) and cancer-specific survival (96 vs 98.6 %, p = 0.907) rates.

CONCLUSIONS: PN and RN for patients with cc-RCC larger than 7 cm provided equivalent oncologic outcomes. Safety and reproducibility of our findings should be further investigated in larger multicentric cohorts.