Extended Follow-Up of Robot-Assisted Partial Nephrectomy for Renal Hilar Tumor: A Prospective Multi-Institutional Study (ROBOHIT Trial)

Objectives: We aimed to evaluate the long-term oncological and functional outcomes after robot-assisted partial nephrectomy (RAPN) for renal hilar tumors. Methods: A total of 22 academic hospitals in Japan participated in a prospective, multicenter, single-arm, open-label trial with a 2-year enrollment period. After undergoing RAPN, 105 patients with clinical T1 renal hilar tumors were followed up for 5 years and evaluated. Recurrence-free survival, overall survival, and trends of renal function were set as oncological and functional outcomes. Results: Five-year overall survival and recurrence-free survival were 98.0% and 89.2%, respectively. Mean estimated glomerular filtration rates (eGFRs) were 69.031 mL/min preoperatively, and were 59.374, 58.334, 58.221, 56.975, and 59.602 mL/min at 1, 2, 3, 4, and 5 years after surgery, respectively. While eGFR was significantly lower than the preoperative one at all points (p < 0.001), eGFRs at 1 and 5 years after surgery did not differ significantly (p = 0.793). Conclusion: After long-term follow-up, RAPN for clinical T1 renal hilar tumors continues to provide functional and oncological outcomes equivalent to those in the perioperative period. Trial Registration: The study protocol was registered in the Japan Registry of Clinical Trials (jRCT1052190005, UMIN000023968).