目的： 分析接受新辅助放化疗（nCRT）后行腹腔镜直肠癌根治术的病人中实现病理完全缓解（pCR）的肿瘤特征以及肿瘤预后情况。方法： 回顾性收集2017年1月至2024年1月在仁济医院接受nCRT治疗的局部进展期直肠癌（LARC）病人的临床病理资料。分析影响实现pCR的因素，并比较pCR组与non-pCR组病人预后情况。结果： 单因素分析、多因素Logistic回归分析以及受试者工作特征（ROC）曲线分析显示，肿瘤长径<5 cm（截断值为5.24 cm）和基线癌胚抗原(CEA)<5 μg/L（截断值为5.33 μg/L）是nCRT后实现pCR的独立预测因素。预后生存分析表明，pCR组和non-pCR组的3年总生存（OS）率分别为92.86%和82.46%（P=0.193)，3年无病生存（DFS）率分别为85.71%和70.18%（P=0.141)，差异均无统计学意义。结论： 肿瘤长径以及基线CEA可作为LARC病人nCRT后实现pCR的独立预测因素。此外，pCR组3年OS和DFS与non-pCR组差异无统计学意义。

Objective To analyze the tumor characteristics associated with achieving pathological complete response(pCR) and tumor prognosis in the patients undergoing laparoscopic rectal cancer surgery after neoadjuvant chemoradiotherapy(nCRT). Methods A retrospective review was conducted on clinical and pathological data of locally advanced rectal cancer(LARC) patients who underwent nCRT at Renji Hospital from January 2017 to January 2024. Factors influencing the achievement of pCR were analyzed, and the patients prognosis of pCR group and non-pCR group was compared. Results Univariate analysis, multivariate Logistic regression analysis, and receiver operating characteristic (ROC) curve analysis showed that tumor length less than 5 cm(cutoff value 5.24 cm) and baseline carcinoembryonic antigen(CEA) less than 5 μg/L(cutoff value 5.33 μg/L) were independent predictors of achieving pCR after nCRT in LARC patients. Prognostic survival analysis showed that the 3-year overall survival(OS) rate for pCR group and non-pCR group were 92.86% and 82.46%, respectively (P=0.193), and the 3-year disease-free survival (DFS) rate were 85.71% and 70.18%, respectively (P=0.141), with no statistically significant differences between the two groups. Conclusions Tumor length and baseline CEA level are independent predictors for achieving pCR after nCRT in LARC patients. Additionally, there were no statistically significant differences in 3-year OS and DFS between pCR group and non-pCR group.