Colorectal cancer is a common malignant tumor and surgical treatment remains the most important treatment for colorectal cancer. Through the use of anastomoses and the continuous improvement of surgical methods, the surgical outcome of colorectal cancer has been greatly improved. However, the improvement of the therapeutic effect of rectal cancer purely through the improvement of surgical techniques has reached a bottleneck, and it is difficult to improve to a greater extent. More and more researches suggest that only surgery-based comprehensive treatment can further improve the therapeutic effect. Comprehensive treatment for colorectal cancer includes surgery, radiotherapy, chemotherapy, biotargeted therapy, traditional Chinese medicine and other treatments. Today, we will focus on explaining the surgical treatment of rectal cancer for you. Why the most effective treatment for colorectal cancer is surgical resection? Surgery is the most effective treatment for colorectal cancer and the only possible cure for colorectal cancer. For early and middle stage colorectal cancer, radical surgery can completely remove the tumor, two sections of partially normal intestinal tubes together with the surrounding mesentery and lymph nodes within the mesentery, which can completely remove the tumor and achieve good therapeutic effect. Other treatments, whether radiotherapy, chemotherapy or targeted therapy, can only make the tumor shrink down to a lower stage, but cannot completely eliminate the tumor, and the treatment effect is poor. For advanced colorectal cancer, if the tumor can no longer be completely resected, palliative surgeries such as enterostomy or intestinal short-circuit surgery can also be performed to solve the symptoms of obstruction and improve the quality of life of patients. What are the surgical resection methods for colorectal cancer? Surgical treatment for colorectal cancer includes many kinds of surgical methods, which can be broadly classified into the following categories: 1. Local resection Local resection refers to resecting only part or the whole layer of the intestinal wall in the area where the tumor is located, with the cutting edge not less than 2cm away from the tumor, and not dealing with lymph nodes in the mesentery. Local resection includes transanal local resection, transanal endoscopic minimally invasive surgery (TEM) and colonoscopic resection. It is only suitable for T1 stage colorectal cancer, or for patients who cannot tolerate radical surgery such as the elderly and frail. Even for T1 stage colorectal cancer, there is still a 3-5% possibility of lymph node metastasis, and the recurrence rate after surgery is high, so it should be used with caution. Radical resection refers to the complete removal of the tumor and the regional lymph nodes around the intestinal canal that may have metastasis. The scope of resection includes a certain length of intestinal tube including the tumor, and the upper and lower cutting edges of the intestinal tube should not be less than 5.0cm from the tumor; for the lower rectal cancer, the lower cutting edge of more than 1-2cm can be regarded as the safety scope. The resection should also include the corresponding mesentery, and the upper and lower margins and circumferential margins should be free of cancer residues (as shown in the figure: specimen after radical resection of rectal cancer). 3. Combined organ resection Combined organ resection (also known as enlarged radical resection), i.e., on the basis of conventional radical resection, the invaded organs are resected together at the same time. It is suitable for patients whose colorectal cancer has invaded the neighboring organs but still can be radically resected. Palliative resection Palliative resection is suitable for patients with colorectal cancer staged at a late stage, accompanied by invasion of surrounding organs, extensive lymph node metastasis, or accompanied by metastasis of distant organs such as liver, lungs, bones, brain, etc., which can not be completely resected. Currently, surgery is the most effective treatment for colorectal cancer, and it is also the only possible “cure” for colorectal cancer. However, the comprehensive treatment of colorectal cancer includes surgery, radiotherapy, chemotherapy, biotargeted therapy, traditional Chinese medicine and other treatments.