(1) To evaluate the oncological effects of Treatment of low locally advanced rectal cancer with radiotherapy removal TNT plus neoadjuvant therapy TNT plus mode on TRG, Anal sphincter preservation surgery rate / rectal preservation surgery rate, cCR rate, pCR rate and other oncological effects in patients with middle and low LARC; (2) Evaluate the R0 resection rate, LARS score, urination function and sexual function score, local recurrence rate, and 3-year DFS and OS of Treatment of low locally advanced rectal cancer with radiotherapy removal TNT plus neoadjuvant therapy TNT plus mode, resolve the current dispute about the Treatment of low locally advanced rectal cancer with radiotherapy removal TNT plus neoadjuvant therapy TNT treatment mode of LARC, provide a new mode for LARC treatment, and hopefully rewrite the diagnosis and treatment guidelines for rectal cancer.

Inclusion Criteria:

• Aged between 18 and 70;
• Histologically confirmed adenocarcinoma of rectum;
• The distance from the lower edge of the tumor to the anus is ≤ 10cm;
• ECOG score ≤ 1;
• Have not received any anti-tumor treatment before;
• Preoperative abdominal enhanced CT or MRI showed cT4, cN0-2; M0 chest and abdomen CT showed no obvious metastasis. (Note: PET-CT is recommended when small nodules can not be identified by liver or lung CT, and can still be included in the group when considering the possibility of metastasis)
• Hematological indicators and liver and kidney function within 7 days are within the normal range;
• Sign the informed consent form and be able to follow the research and /or follow-up procedures.

Exclusion Criteria:

• Have serious basic diseases, such as heart disease, renal failure, severe liver failure or liver failure, coagulation dysfunction, etc; Postoperative recurrence of colorectal cancer;
• The patient had a history of malignant tumor within 5 years;
• Pregnant or lactating women;
• The patient has a history of adjuvant radiotherapy for other system diseases, and surgical contraindications, so it is not suitable for surgery;
• The patient has had radiotherapy and chemotherapy records before this visit;
• Distant metastasis was found during operation;
• Patients with poor radiotherapy compliance and difficult cooperation;