Transperitoneal Robot-assisted Partial Nephrectomy with Minimum Follow-up of 5 Years: Oncological and Functional Outcomes from a Single Institution

Abstract

BackgroundRobot-assisted partial nephrectomy (RAPN) is an established, minimally invasive nephron-sparing technique with excellent perioperative and intermediate oncological outcomes. However, long-term oncological outcomes have not been reported to date. ObjectiveTo report oncological and functional outcomes of RAPN among patients with minimum follow-up of 5 yr. Design, setting, and participantsData for consecutive patients undergoing RAPN since October 2006 were extracted from a prospectively-maintained institutional PN database. Patients with benign tumors, genetic mutations, prior radical or ipsilateral PN, and those with follow-up of <5 yr were excluded. InterventionTransperitoneal RAPN for renal cell carcinoma (RCC). Outcomes measurements and statistical analysisDemographic, perioperative, postoperative, functional, and oncological data were evaluated. A linear random-effects model was used to estimate the effect of follow-up duration on the estimated glomerular filtration rate (eGFR) after adjustment for potential confounders. Univariable competing-risks regression analyses were performed to evaluate the hazard ratio (HR) for cancer-related events for the variables of interest. Results and limitationsA total of 278 RAPNs for RCC were included. eGFR was significantly lower at follow-up time points than at baseline. At last follow-up (median 46 mo, interquartile range 30–58) the mean eGFR difference was −10.6ml/min (95% confidence interval −12.56 to −8.66; p < 0.0001). There were 28 deaths (10.1%) in the cohort during the follow-up period, of which five (1.8%) were related to metastatic RCC. The 5-yr and 7-yr cumulative incidence of RCC deaths was 1.80% at both 5 and 7 yr, while the cumulative incidence of local recurrence was 3.61% and 4.16%, and that of metastasis was 3.24% and 4.57% at 5 and 7 yr, respectively. Univariable competing-risks regression revealed that higher Fuhrman grade (HR 8.76; p = 0.051), larger tumor size (HR 1.67; p < 0.0001), and tumor necrosis (HR 16.73; p = 0.0019) were independent predictors of RCC death. The retrospective design and potential selection bias due to patient selection in the early RAPN experience may limit the generalizability of the findings. ConclusionsThis is the first study reporting minimum oncological follow-up of 5 yr after RAPN. The results demonstrate excellent long-term oncological outcomes after RAPN in a selected cohort of patients. Our data confirm that the renal functional deterioration after RAPN remains stable over time after the early postoperative decrease. Patient summaryRobot-assisted partial nephrectomy is being more widely used as a standard treatment for small localized renal cell carcinomas. This study reveals excellent long-term cancer control for both local recurrences and distant metastases. Renal function is stable after an initial postoperative deterioration.