摘要目的：分析与局部晚期直肠癌患者术前放化疗后达pCR相关的临床因素。方法搜集2005—2012年间经活检证实并neo?CRT （放疗采用3DCRT、VMAT）及根治性切除的临床资料完整的局部晚期直肠癌297例，采用Logistic回归模型多因素分析年龄、性别、肿瘤距肛门距离、疗前血清CEA水平、疗前血红蛋白、cT 分期、cN 分期与 pCR 是否相关。结果全组疗后达 pCR 者78例（26?7％），T1—T3期者达42例（34?4％），T4期者达37例（21?1％）。疗前CEA≤5?33 ng／ml疗后达pCR者55例（36?4％），CEA＞5?33 ng／ml仅24例（16?4％）。单因素分析年龄、性别、肿瘤距肛门距离、疗前是否贫血和cN分期与pCR无关。多因素分析cT1—T3期、疗前CEA≤5?33 ng／ml是影响局部晚期直肠癌neo?CRT后是否达pCR的影响因素（ P＝0?031、0?000）。结论临床分期、疗前血清CEA水平是影响局部晚期直肠癌neo?CRT后是否达pCR的影响因素；疗前血清CEA水平可作为局部晚期直肠癌neo?CRT后是否达pCR的筛选指标之一。

abstractsObjective To analyze the clinical factors for pathologic complete response ( pCR) after preoperative neoadjuvant chemoradiotherapy ( neo?CRT) for locally advanced rectal cancer. Methods From 2005 to 2012, 297 patients with locally advanced rectal cancer and complete clinical data were enrolled as subjects. Those patients were diagnosed with biopsy and treated with neo?CRT ( radiotherapy by 3?dimonsional conformal radiotherapy or volumetric?modulated arc therapy) followed by radical surgery. The logistic regression model was used for the multivariate analyses of the correlation of pCR with age, gender, distance between tumor and the anal verge, serum level of carcinoembryonic antigen ( CEA ) before treatment, hemoglobin level before treatment, cT staging, and cN staging. Results In all patients, 78 ( 26?7%) patients had pCR after treatment. The numbers of patients with pCR were 42( 34?4%) in patients with stage T1?T3 disease and 37(21?1%) in patients with stage T4 disease. In the patients with serum CEA levels no higher than 5?33 ng/ml, 55(36?4%) had pCR after treatment, while in the patients with serum CEA levels higher than 5?33 ng/ml, only 24( 16?4%) had pCR. The univariate analysis revealed that age, gender, distance between tumor and the anal verge, anemia before treatment, or cN staging were not related to pCR. The multivariate analysis showed that stage cT1?T3 and a serum CEA level no higher than 5?33 ng/ml before treatment were influencing factors for pCR after neo?CRT for locally advanced rectal cancer ( P=0?031,P=0?000) . Conclusions The clinical staging and the serum CEA level before treatment are influencing factors for pCR after neo?CRT for locally advanced rectal cancer. The serum CEA level before treatment can be considered as a predictor of pCR after neo?CRT for locally advanced rectal cancer.