[Evaluation of preoperative radiotherapy or chemoradiotherapy in sphincter preservation for locally advanced middle-low rectal cancer].

Objective: To investigate the effect of preoperative radiotherapy or chemoradiotherapy on the sphincter preservation and local tumor control as well as survival for the patient with locally advanced middle-low rectal cancer.

Methods: 121 locally advanced middle-low rectal cancer patients were treated with preoperative radiotherapy or chemoradiotherapy followed by surgery after rest of 4 to 6 weeks. 103 of these patients who underwent radical surgery were finally included in this study. The irradiation regimen was: 40 Gy/4 - 5 weeks, whereas 57 of these 103 patients received concurrent chemotherapy of 5-Fu or Xeloda. Sphincter-preserving surgery was performed in 59 patients and abdominoperineal resection in 44 patients. The survival was estimated by Kaplan-Meier model, and the differences between groups were compared using Log rank test. Multivariate analysis was performed by Cox's model.

Results: Ten patients (9.7%) achieved a complete pathological response (pCR) to preoperative radiotherapy or chemoradiotherapy. The sphincter preservation rate was 57.3%. The 3-year overall survival (OS) and disease free survival (DFS) was 66.3% and 59.5%, respectively. Univariate analysis showed that pCR and postoperative pTNM stage were prognostic factors affecting survival, whereas, only pTNM stage was an independent prognostic factor (P = 0.003) by multivariate analysis.

Conclusion: Neoadjuvant preoperative radiotherapy and chemoradiotherapy is effective in local tumor control and improving survival for locally advanced middle-low rectal cancer, which can raise the rate of sphincter-preserving surgery, and achieve comparable result to abdominoperineal resection.