[Idea of Treatment Method for Upper and Lower Rectal Cancer Avoiding Irradiation to Internal and External Sphincter]

Preoperative chemoradiotherapy(CRT)followed by total mesorectal excision(TME)is used for locally advanced rectal cancer, but it can induce postoperative anorectal function. The primary objective of this study is to confirm the efficacy and safety of preoperative CRT and TME without irradiation to the internal and external sphincter muscles.

Patients were eligible for this study if they met the following inclusion criteria: histologically proven rectal cancer, clinical T3T4N0-2 disease, and a distance between anal margin of tumor and the rental line is more than 2 cm. Twelve patients who underwent preoperative CRT and TME between 2013 and 2017 were enrolled. The primary endpoint was completion rate of sphincter-preserving surgery.

All patients completed preoperative CRT without Grade 3 or higher adverse effect. Sphincter-preserving surgery was performed in all cases. The 5-year disease-free survival rate was 46.7%, and the local recurrence-free survival rate was 75%, and the overall survival rate was 90.9%.

It is suggested that preoperative CRT and TME without irradiation to the internal and external sphincter muscles is effective and safe therapy for locally advanced rectal cancer.