Once the diagnosis of rectal cancer is clear, surgery is preferred. The presence of the following factors is a contraindication to surgery: 1. If the patient is above 80-90 years old and has serious organ disorders in the heart, lung or brain, and cannot tolerate surgery or anesthesia, radical surgery cannot be performed; 2. If the patient is found to have a large tumor size at the time of consultation, and the adhesion with surrounding tissues is more serious and tumor separation is not possible, the patient needs to be evaluated in detail and consider preoperative radiotherapy first for the chance of surgery.