直肠癌新辅助放化疗后病理完全缓解的临床因素分析

Analysis of clinical factors for pathological complete response after preoperative neoadjuvant chemoradiotherapy for rectal cancer

目的评估影响直肠癌新辅助放化疗后pCR的临床因素。方法回顾分析2009—2012年间接受新辅助放化疗随后行根治性手术的116例直肠癌患者临床资料。所有患者术前接受盆腔调强放疗50Gy分25次，同期氟尿嘧啶为基础化疗，完成治疗休息4～8周后行根治性手术。应用Logistic法分析影响pCR和非pCR的临床因素。结果共20例患者经新辅助放化疗后达pCR，pCR率为17．2％。单因素分析表明肿瘤侵犯直肠管腔周径范围达75％以上（全周肿瘤）、治疗前血清CEA水平、T分期、N分期、肛缘距离、分化程度、肿瘤最大直径与直肠癌新辅助放化疗后肿瘤pCR水平相关。多因素分析结果显示全周肿瘤、治疗前血清CEA水平和T分期是影响放化疗后肿瘤pCR预测因素。结论非全周肿瘤、低CEA水平和早T分期等治疗前临床因素可能是获得pCR的重要决定因素。

Objective To evaluate the clinical factors associated with pathological complete response （pCR） after preoperative neoadjuvant chemoradiotherapy for rectal cancer. Methods A retrospective analysis was performed on the clinical data of 116 patients with rectal cancer, who underwent neoadjuvant chemoradiotherapy followed by radical surgery from January 2009 to December 2012. All patients received pelvic intensity-modulated radiotherapy （50 Gy/25 fractions） with concurrent fluorouracil- based chemotherapy and then underwent radical surgery 4--8 weeks later. The clinical factors associated with pCR or non-pCR were analyzed by Logistic regression. Results Of the 116 patients, 20 （ 17.2% ） achieved a pCR after neoadjuvant chemoradiotherapy. The univariate analysis showed that percentage of circumference of the rectal tube invaded by the tumor, preoperative serum carcinoembryonic antigen （CEA） level, T stage, N stage, distance from the anal verge, degree of tumor differentiation, and maximum tumor diameter were associated with pCR or non-pCR after neoadjuvant chemoradiotherapy for rectal cancer. The multivariate analysis revealed that percentage of circumference of the rectal tube invaded by the tumor, preoperative serum CEA level, and T stage were predictive factors for pCR or non-pCR after neoadjuvant chemoradiotherapy for rectal cancer. Conclusions Non-circumferential tumor （ percentage of circumference of the rectal tube invaded by the tumor 〈75% ）, low CEA level, and early T stage before treatment may be associated with pCR after neoadjuvant chemoradiotherapy for rectal cancer.