Effective Study of Preoperative Short-course Radiotherapy for the Advanced Resectable Rectal Cancer

The local recurrence of rectal cancer is one of the main problem that fail the treatment. The preoperative neoadjuvant (chemo)radiotherapy has been confirmed to reduce the local recurrence rate,especially in the advanced rectal cancer. However the local recurrence rate is low about 10-20% totally,and the integrity of the mesorectum after the operation and circumferential resection margin(CRM) are the most critical factor for the local recurrence.So that, the advanced rectal cancer patients with negative CRM and had a complete mesorectum excision,may not benefit from the neoadjuvant radiation.This trial was mainly focus on the resectable advanced rectal cancer patients whose preoperative stage was cT3/N+. These patients will be divided into the lower risk group and higher risk group according the preoperative CT,Endoscopic ultrasound, and MRI,and carrying out randomized trial in the two groups respectively.The purpose of this trial is to confirm whether the preoperative radiotherapy is necessary for all the advanced rectal cancer patients,identify the reason of the local recurrence,and finally help the making of the treatment decision for the advanced resectable rectal cancer.