14. IMPACTS OF ADDITIONAL CYCLES OF NEOADJUVANT IMMUNOCHEMOTHERAPY ON ESOPHAGECTOMY IN ESOPHAGEAL SQUAMOUS CELL CARCINOMA

The aim of this study is to explore the pathological characteristics and safety of esophagectomy after different cycles of neoadjuvant immunochemotherapy for esophageal squamous cell carcinoma (ESCC). We prospectively collected patients who underwent neoadjuvant immunochemotherapy combined with esophagectomy from two institutes between 2019 and 2022. The primary outcome was defined as pathological complete response (PCR), and the secondary outcomes were defined as the incidence of postoperative complications. The most commonly used checkpoint inhibitor was camrelizumab. A total of 152 enrolled patients underwent esophagectomy, with 9 of 119 patients (7.6%) in the 2-cycle group undergoing thoracotomy and 2 patients of 33 patients (6.1%) in the >2-cycle group converting to thoracotomy. Twenty-three patients in the 2-cycle group and 6 patients in the >2-cycle group achieved PCR, there was no statistically significant difference between the two groups (19.3% vs. 18.2%; P = 0.882). The N0 rate (57.1% vs. 51.5%; P = 0.565) and lymph node ratio (6% vs. 6%; P = 0.489) were similar between the two groups. The most common postoperative complication was pneumonia, there were no significant differences in postoperative complications between the two groups. This study indicated that although additional cycles of neoadjuvant immunochemotherapy had no significant effect on the feasibility and safety of esophagectomy, 2-cycle of treatment is enough when considering pathological complete response rate.