Long-term oncological outcomes of robotic versus laparoscopic total mesorectal excision of mid-low rectal cancer following neoadjuvant chemoradiation therapy

Purpose The use of robotic surgery and neoadjuvant chemoradiation therapy (CRT) for rectal cancer is increasing steadily worldwide. However, there are insufficient data on long-term outcomes of robotic surgery in this clinical setting. The aim of this study was to compare the 5-year oncological outcomes of laparoscopic vs. robotic total mesorectal excision for mid-low rectal cancer after neoadjuvant CRT. Materials and methods One hundred thirty-eight patients who underwent robotic (n = 74) or laparoscopic (n = 64) resections between January 2006 and December 2010 for mid and low rectal cancer after neoadjuvant CRT were identified from a prospective database. The long-term oncological outcomes of these patients were analyzed using prospective follow-up data. Results The median follow-up period was 56.1 +/- 16.6 months (range 11-101). The 5-year overall survival (OS) rate of the laparoscopic and robotic groups was 93.3 and 90.0 %, respectively, (p = 0424). The 5-year disease-free survival (DFS) rate was 76.0 % (laparoscopic) vs. 76.8 % (robotic) (p = 0.834). In a subgroup analysis according to the yp-stage (complete pathologic response, yp-stage I, yp-stage II, or yp-stage III), the between-group oncological outcomes were not significantly different. The local recurrence rate was 6.3 % (laparoscopic, n = 4) vs. 2.7 % (robotic, n = 2) (p = 0.308). The systemic recurrence rate was 15.6 % (laparoscopic, n = 10) vs. 18.9 % (robotic, n = 14) (p = 0.644). All recurrences occurred within less than 36 months in both groups. The median period of recurrence was 14.2 months. Conclusion Robotic surgery for rectal cancer after neoadjuvant CRT can be performed safely, with long-term oncological outcomes comparable to those obtained with laparoscopic surgery. More large-scale studies and long-term follow-up data are needed.