Short- and long-term outcomes of robotic-assisted laparoscopic surgery for rectal cancer: results of a single high-volume center in Japan.

PURPOSE: Scientific evidence supporting robotic-assisted laparoscopic surgery (RALS) for rectal cancer remains inconclusive because most previous reports were retrospective case series or case-control studies, with few reports focusing on long-term oncological outcomes with a large volume of patients. The aim of this study was to clarify the short- and long-term outcomes of a large number of consecutive patients with rectal cancer who underwent RALS in a single high-volume center. METHODS: The records of 551 consecutive patients who underwent RALS for rectal adenocarcinoma between December 2011 and March 2017 were examined to reveal the short-term outcomes. The oncological outcomes of the 204 patients who underwent surgery between December 2011 and March 2014 were evaluated. RESULTS: Most patients had tumors located in the lower or mid-rectum (86.0%). Only 7.6% of patients underwent neoadjuvant chemoradiotherapy. Lateral lymph node dissection was performed for 191 patients (34.7%). The median operative time was 257 min, median blood loss was 10 mL, and no transfusions were needed. No conversion to open surgery was necessary. Eighteen patients (3.3%) had Clavien-Dindo grade III postoperative complications. Six patients (1.1%) had positive resection margins. The mean follow-up duration of the 204 patients was 43.6 ± 9.8 (months). The 5-year cancer-specific survival rate for stage I/II/III/IV was 100%/100%/100%/not reached, respectively. The 5-year relapse-free survival rate for stage I/II/III/IV was 93.6%/75.0%/77.6%/ not reached, respectively. The rate of local recurrence was 0.5%. CONCLUSIONS: Our results suggest that RALS is technically feasible for rectal cancer and has good short- and long-term outcomes.