Analysis of clinical factors for pathological complete response after preoperative neoadjuvant chemoradiotherapy for rectal cancer / 中华放射肿瘤学杂志

ABSTRACT

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 fluorouracilbased 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.