Table 1. Studies validating robot-assisted surgery for rectal cancer

Study [Ref.]	Design	Diagnosis	Operation	Study arms	Sample size	Conclusion
Baik et al., 2009 [17]	Prospective	Rectal cancer	Low anterior resection	Robot	56	Lower conversion rate and serious complication rate in robot group.
Baik et al., 2009 [17]	Prospective	Rectal cancer	Low anterior resection	Laparoscope	57
Patriti et al., 2009 [18]	Case-matched	Rectal cancer	All rectal resection (LAR, ISR, APR)	Robot	29	Lower conversion rate in robot group, comparable OS and DFS.
Patriti et al., 2009 [18]	Case-matched	Rectal cancer	All rectal resection (LAR, ISR, APR)	Laparoscope	37
Jayne et al., 2017 [19]	RCT	Rectal cancer	All rectal resection (AR, LAR, APR)	Robot	236	Comparable conversion rate, CRM, and sexual/urinary functions.
Jayne et al., 2017 [19]	RCT	Rectal cancer	All rectal resection (AR, LAR, APR)	Laparoscope	230
Kim et al., 2018 [20]	RCT	Rectal cancer	All rectal resection (LAR, APR, Hartmann)	Robot	66	Comparable TME quality, postoperative morbidity, bowel function recovery, QoL.
Kim et al., 2018 [20]	RCT	Rectal cancer	All rectal resection (LAR, APR, Hartmann)	Laparoscope	73
Kim et al., 2017 [21]	Retrospective, PPM	Rectal cancer	All rectal resection	Robot	224	Favorable 5-year OS, CSS, DFS in the robot group.
Kim et al., 2017 [21]	Retrospective, PPM	Rectal cancer	(AR, LAR, ISR, APR)	Laparoscope	224	Favorable 5-year OS, CSS, DFS in the robot group.

LAR, low anterior resection; ISR, intersphincteric resection; APR, abdominoperineal resection; OS, overall survival; DFS, disease-free survival; RCT, randomized controlled trial; AR, anterior resection; CRM, circumferential resection margin; TME, total mesorectal excision; QoL, quality of life; PPM, propensity score matching; CSS, cancer-specific survival.