手术期化疗（IOC）对结直肠癌（CRC）患者的长期生存影响仍不清楚。在本研究中，我们评估了5-氟尿嘧啶钙叶酸联合手术期输注对根治性切除手术后CRC患者生存的独立影响。招募了1820名患者，其中1263名接受了IOC，557名未接受。收集了临床和人口统计数据，包括总体生存期（OS）、临床病理特征和治疗策略。使用多重Cox比例风险模型确定了与IOC相关的死亡风险因素。开发回归模型分析IOC的独立效应。比例风险回归分析显示IOC（危险比[HR]=0.53，95％置信区间[CI][0.43，0.65]，P ＜ 0.001）是患者生存的保护因素。IOC组的平均生存时间为82.50（95％CI [80.52，84.49]）个月，非IOC组为71.21（95％CI [67.92，74.50]）个月。IOC治疗患者的OS显著高于非IOC治疗患者（P ＜ 0.001，log-rank检验）。进一步分析显示，IOC在未经调整的模型（HR=0.53，95％CI [0.43，0.65]，P ＜ 0.001）、模型2（调整年龄和性别，HR=0.52，95％CI [0.43，0.64]，P ＜ 0.001）和模型3（调整所有因素，95％CI 0.71 [0.55，0.90]，P = 0.006）中降低了CRC患者的死亡风险。亚组分析显示，在预手术放疗（HR=0.55，95％CI [0.45，0.68]）或预手术化疗（HR=0.54，95％CI [0.44，0.66]）的情况下，IOC对于II期（HR=0.46，95％CI [0.31，0.67]）或III期疾病（HR=0.59，95％CI [0.45，0.76]）患者的生存影响HR较低。IOC是影响CRC患者生存的独立因素。它提高了根治手术后II、III期CRC患者的OS。chictr.org.cn，ChiCTR 2100043775。中国医师协会版权所有，由沃尔特斯·克鲁尔公司在CC-BY-NC-ND许可下制作。

The effect of intra-operative chemotherapy (IOC) on the long-term survival of patients with colorectal cancer (CRC) remains unclear. In this study, we evaluated the independent effect of intra-operative infusion of 5-fluorouracil in combination with calcium folinate on the survival of CRC patients following radical resection.1820 patients were recruited, and 1263 received IOC and 557 did not. Clinical and demographic data were collected, including overall survival (OS), clinicopathological features, and treatment strategies. Risk factors for IOC-related deaths were identified using multivariate Cox proportional hazards models. A regression model was developed to analyze the independent effects of IOC.Proportional hazard regression analysis showed that IOC (hazard ratio [HR]=0.53, 95% confidence intervals [CI] [0.43, 0.65], P < 0.001) was a protective factor for the survival of patients. The mean survival time in IOC group was 82.50 (95% CI [80.52, 84.49]) months, and 71.21 (95% CI [67.92, 74.50]) months in non-IOC group. The OS in IOC-treated patients were significantly higher than non-IOC-treated patients (P < 0.001, log-rank test). Further analysis revealed that IOC decreased the risk of death in patients with CRC in a non-adjusted model (HR=0.53, 95% CI [0.43, 0.65], P < 0.001), model 2 (adjusted for age and gender, HR=0.52, 95% CI [0.43, 0.64], P < 0.001), and model 3 (adjusted for all factors, 95% CI 0.71 [0.55, 0.90], P = 0.006). The subgroup analysis showed that the HR for the effect of IOC on survival was lower in patients with stage II (HR = 0.46, 95% CI [0.31, 0.67]) or III disease (HR=0.59, 95% CI [0.45, 0.76]), regardless of pre-operative radiotherapy (HR=0.55, 95% CI [0.45, 0.68]) or pre-operative chemotherapy (HR=0.54, 95% CI [0.44, 0.66]).IOC is an independent factor that influences the survival of CRC patients. It improved the OS of patients with stages II and III CRC after radical surgery.chictr.org.cn, ChiCTR 2100043775.Copyright © 2023 The Chinese Medical Association, produced by Wolters Kluwer, Inc. under the CC-BY-NC-ND license.