Endoscopic Resection of Stage T1 Colorectal Adenocarcinoma Followed by Surgical Intervention: a Single-center Retrospective Study.

Background: Domestic and international guidelines recommend endoscopic resection for stage T1 colorectal adenocarcinoma with indications. However, completion surgery remains imperative for patients exhibiting high-risk factors subsequent to endoscopic procedures.

Objective: To investigate the evidence, pathological features, and surgical outcomes of completion surgery in patients with T1 colorectal adenocarcinoma following endoscopic resection.

Methods: We retrospectively collect data on the clinical features and treatment outcomes of patients with stage T1 colorectal adenocarcinoma who underwent endoscopic resection followed by surgical resection and those who initially completed surgical intervention at Peking University International Hospital between January 2019 and October 2022, with the aim of assessing the necessity and feasibility of surgical intervention.

Results: Seventeen patients (Group A) with high-risk factors following endoscopic procedure, especially with deep submucosal invasion and vascular or lymphatic invasion, experienced further surgical resection. The median interval between endoscopic resection and completion surgery was 23.71 days ± 15.89. Sixteen patients (Group B) underwent radical resection without any prior interventions. The surgical approach involves integration of laparoscopy and colonoscopy for precise localization and quantitative diagnosis, followed by radical surgery. The two groups demonstrated significant differences statistically with reference to tumor diameter (1.65 cm ± 0.77 vs 3.36 cm ± 1.39, P = 0.000) and the attainment of standard lymph node count (cases of detected lymph nodes larger than or equal to 12, 5 vs 12, P = 0.015). Postoperative complications and hospital stay manifested no significant disparity statistically in two groups. Patients who underwent completion surgery had no inferior outcomes compared with those who underwent direct surgery in terms of 5-year disease-free survival (Log rank test: P = 0.083, Breslow test: P = 0.089). The two groups also exhibited no significant differences statistically in the context of overall survival (Log rank test: P = 0.652, Breslow test: P = 0.758).

Conclusion: Completion surgery is a safe and feasible treatment option for T1 colorectal adenocarcinoma patients with high-risk factors, particularly those with deep submucosal invasion and vascular or lymphatic invasion following endoscopic treatment. Furthermore, subsequent treatment should be chosen based on a comprehensive analysis of the patient's history of abdominal surgery, willingness, and pathological features.