Nearly 60 years old, Li has always been strong and healthy, and has never served his age. This year, he went to the hospital for a checkup because of a stool problem, and the doctor informed him that he had rectal cancer. When discussing the treatment plan with the doctor, he was told that he had to undergo radiotherapy and chemotherapy for a period of time before he could have surgery. Old Li is full of doubts, the same ward Zhang hospitalized directly after the surgery, now waiting for the surgery after chemotherapy, why do you still need radiation and chemotherapy before surgery? This is not to suffer more? Bai Zhigang, Department of General Surgery, Beijing Friendship Hospital What is the purpose of radiotherapy and chemotherapy before rectal cancer surgery? Radiotherapy is to act directly on the tumor lesion through radiation, and the combination of chemotherapy at this time is to increase the sensitivity of radiotherapy and kill the tumor cells more effectively. There are two main purposes of preoperative radiotherapy: 1) to reduce the tumor stage, shrink the tumor volume, and make the inoperable patients reach the operable standard; 2) to improve the rate of anus preservation. The recognized anal preservation surgery requires the lower edge of the tumor to be at least 5-7cm away from the anal dentate line. When the tumor becomes smaller, its lower edge will move upward relatively, so the surgery can remove the tumor cleanly while preserving the patient’s anus and improving the patient’s survival quality. Although the patient will suffer a little before the surgery, the long-term survival quality of the patient will be much improved. Pre-operative radiotherapy is suitable for people Why does Lao Li need radiotherapy but Lao Zhang does not? It is because preoperative radiotherapy for rectal cancer has its own adaptation group. The staging of rectal cancer is relatively complicated, the depth of tumor infiltration, the presence or absence of lymph node metastasis, distant organ metastasis and so on. Simply speaking, rectal cancer is divided into 4 stages. The later the stage, the deeper the tumor invades the tissues and the greater the possibility of lymph node or distant organ metastasis. For patients with stage 1 and part of stage 2 without lymph node metastasis, the tumor only invades the superficial layer of rectum, so surgery can completely remove the tumor and the chance of future recurrence and metastasis is low, so preoperative radiotherapy is not needed. For patients with stage 3 and some stage 2 rectal cancer, the tumor has invaded deeper tissues or has lymph node metastasis, which may be inoperable or the postoperative survival quality is not high, so these patients need preoperative radiotherapy. Lao Li is a stage 3 patient with lymph node metastasis, while his patient Zhang is a stage 2 rectal cancer patient with no lymph node metastasis, so their treatment modalities are different. stage 4 patients have metastasis to other organs, and whether to have preoperative radiotherapy or chemotherapy needs to consider a variety of factors. With different staging, treatment modalities are different and individualized treatment of tumor is important. Figure 2 Staging of rectal cancer As patients’ demand for anal preservation increases, the application of anal preservation surgery is becoming more and more widespread, and the indications are gradually expanding, and more patients want to do preoperative radiotherapy and chemotherapy for more chances of anal preservation. However, whether to perform preoperative radiotherapy or not, doctors will consider various aspects such as tumor nature, staging, whether to preserve anus and patient factors, etc., and cannot blindly perform preoperative radiotherapy.