Long-term follow-up of the randomized trial on open versus laparoscopic surgery for primary tumor resection in patients with non-curable stage IV colon cancer (JCOG1107).

55 Background: The Japan Clinical Oncology Group (JCOG) 1107 (UMIN-CTR: UMIN000009715) was a non-inferiority phase III trial to compare laparoscopic surgery (LAP) with open surgery (OP) for symptomatic, non-curable stage IV colon cancer, using progression-free survival (PFS) as the primary endpoint based on the intention-to-treat principle. The planned primary analysis confirmed the non-inferiority of the LAP over the OP. Additionally, the present study aimed to compare the LAP and OP using long-term 3-year follow-up data from the JCOG1107. Methods: Eligibility criteria included pathologically proven adenocarcinoma or adenosquamous carcinoma; primary tumor located at the cecum, ascending, transverse, descending, sigmoid, and rectosigmoid colon; primary tumor with bowel stenosis and/or bleeding; and having at least one to three non-curable factors. The sample size was 194 with a power of 70%, one-sided alpha of 5%, and non-inferiority margin of the hazard ratio (HR) of 1.38. Results: In total, 195 patients were randomized (OP 95, LAP 100) between January 2013 and January 2021. OP was performed in 92 and LAP in 98 patients. Postoperative chemotherapy was administered in 82 OP and 86 LAP patients. As the data cut-off date of Feb 2024, 93 (98%) and 100 (100%) PFS event occurred in OP and LAP. The 3-year PFS were 5.3% (95% CI, 2.0-11.0) and 3.0% (0.8-7.8) for OP and LAP arms, respectively (HR: 1.028, 95% confidence interval [CI]: 0.772–1.370; P for non-inferiority = 0.0222). Regarding OS, 87 (92%) and 90 (90%) death occurred in OP and LAP. The 3-year OS were 31.5% (22.5-41.0) and 28.5% (20.0-37.6) for OP and LAP arms, respectively (HR: 1.048; 95% CI: 0.780–1.410). Conclusions: Long-term follow-up data supported the non-inferiority of LAP over OP for primary tumor resection in patients with non-curable stage IV colon cancer. Our study findings indicate that LAP is acceptable as a standard treatment for symptomatic, non-curable stage IV colon cancer. Clinical trial information: UMIN000009715 .