Is Robotic Surgery Beneficial for Rectal Cancer Patients with Unfavorable Characteristic After Neoadjuvant Chemoradiotherapy?

Background: The objective of this study was to compare long-term oncologic outcomes of robot and laparoscopic surgeries for patients with advanced rectal cancer who underwent neoadjuvant chemoradiotherapy (nCRT) followed by radical resection. Methods: This study analyzed 3240 rectal cancer patients who underwent radical surgery from 2008 to 2019. Among them, 1204 patients who received nCRT (robotic, n = 316; laparoscopic, n = 888) were analyzed. The oncological outcome according to the number of unfavorable factors (male, body mass index ≥ 25, receiving CCRT) present in patients also was analyzed. We used 1:1 propensity score matching (PSM) to adjust for potential baseline confounders between groups. Results: After PSM, two groups showed similar demographics and pathological results. After PSM analysis, the robotic group showed higher 5-year disease-free survival (DFS) and local recurrence-free survival rates than the laparoscopic group, whereas 5-year overall survival and distant recurrence-free survival rates were similar between the two groups. In addition, by comparing survival rates for each yp stage, it was found 5-year DFS and local recurrence-free survival of the robotic group in yp stage III were significantly higher than those of the laparoscopic group. Five-year DFS was conducted according to the number of unfavorable factors (male, body mass index ≥ 25 kg/m², and undergoing nCRT) as a subgroup analysis. In patients with all three unfavorable factors, the robotic group showed significantly higher DFS than the laparoscopic group. Conclusions: Robotic approach for rectal cancer after nCRT, especially for patients with yp stage III and unfavorable factors, have the advantage of improving oncologic outcomes even for surgeons specializing in colorectal cancer.