Rectal cancer is a very common type of malignant tumor in the gastrointestinal system. Generally, stage 3 rectal cancer is very serious and belongs to the middle and late stage of rectal cancer, which may not be curable by surgery. If after 4-8 courses of chemotherapy, the tumor can be shrunk and the stage can be reduced, there is still a chance for surgery later, which may have better treatment effect. Generally, if the tumor lesion of rectal cancer is close to the anus, there is no way to preserve the anus, so fistula surgery is needed, and the psychological impact on the patient after the surgery is relatively large. After surgery, rectal cancer also needs to be treated with adjuvant chemotherapy and radiotherapy to prevent local recurrence and distant metastasis. Generally, if stage III rectal cancer can survive for more than three years or five years, it is considered a good treatment effect, but there are many who survive for less than five years.