Short- and Long-Term Outcomes of Open, Laparoscopic, and Robot-Assisted Surgery for Rectal Cancer.

Background: Robot-assisted surgery has short-term benefits in rectal cancer surgery; however, its long-term advantages remain unclear. This study compared short- and long-term outcomes of open, laparoscopic, and robot-assisted rectal cancer surgeries using large-scale, database-driven evidence.

Methods: Patients (28 711) diagnosed with clinical stages I-III rectal cancer who underwent rectal resection and were registered in the Japanese Medical Data Vision Co. Ltd. database were included. Open rectal resection (ORR), laparoscopic rectal resection (LRR), and robot-assisted rectal resection (RARR) were identified. The primary outcomes were 5-year overall survival (OS) and relapse-free survival (RFS). Secondary outcomes included perioperative outcomes.

Results: After applying overlap weight, the RARR, LRR, and ORR groups had 3635 (15.3%), 17 142 (72.3%), and 2935 (12.4%) patients, respectively. Among the cohort (mean age: 69.5 years), 64.9% were male, and 24.7%, 31.5%, and 43.8% had clinical stages I, II, and III, respectively. The RARR group demonstrated the lowest postoperative complication rate, 30- and 90-day mortality rates, and shortest hospital stay. The RARR group had the highest 5-year OS (95%) and RFS (93%) compared to LRR (OS: 89%, RFS: 86%) and ORR (OS: 81%, RFS: 77%;  < 0.001). Multivariable analysis revealed that RARR was significantly associated with improved OS, whereas higher risks were observed for LRR (hazard ratio [HR]: 2.18, 95% confidence interval [CI]: 1.69-2.81) and ORR (HR: 3.96, 95% CI: 3.03-5.19).

Conclusions: The RARR group demonstrated superior short- and long-term outcomes than the LRR and ORR groups, indicating robot-assisted surgery as a potential new standard treatment for rectal cancer.