Neoadjuvant Chemotherapy and PD-1 Inhibitor for Locally Advanced Rectal Cancer（CONTROL-01）

Inclusion Criteria: * Be willing and able to provide written informed consent for the trial * Age 18 years or greater * Pathologically proven diagnosis of adenocarcinoma of the rectum * Clinically determined to be stage T3 or T4, N0-N2, and M0 * Be fully active, able to carry on all pre-disease performance without restriction or Restricted in physically strenuous activity. * Contrast-enhanced imaging of the abdomen and chest by CT to exclude distant metastases and provide local tumor stage * Preoperative ECOG status score 0-1 * Preoperative ASA grade I-III * Adequate bone marrow function * Adequate renal and liver function * No active second cancers * Be willing and able to comply with all aspects of the protocol * Women of childbearing potential must have used reliable contraception or have had a pregnancy test result within 7 days prior to enrollment. Be negative and willing to use an adequate method of contraception for the duration of the trial and for 8 weeks after the last administration of the trial drug. * Adequate bone marrow function defined as follows: Absolute neutrophil count (ANC) ≥ 1,200 cells/mm3 Platelets ≥ 100,000 cells/mm3 Hemoglobin ≥ 8.0 g/dl. * Adequate hepatic function within within 28 days before registration on this study:total bilirubin must be ≤ ULN (upper limit of normal) for the lab unless the patient has a bilirubin elevation \> ULN to 1.5 x ULN due to Gilbert\'s disease or similar syndrome involving slow conjugation of bilirubin; and AST and ALT must be ≤3 x ULN for the lab If AST and/or ALT is ≥ ULN but ≤ 3 x ULN, serologic testing for Hepatitis B and C must be performed and results for viral infection must be negative. * Adequate renal function within 28 days before randomization defined as serum creatinine ≤ 1.5 x ULN for the lab or calculated creatinine clearance \> 30 mL/min Exclusion Criteria: * Age less than 18 years * Pregnant or breastfeeding women * Prior invasive malignancy unless disease free for a minimum of three years * Preoperative body temperature ≥ 38°C or concurrent infectious diseases requiring systemic therapy; * Severe mental illness; * Severe abnormal heart, lung and kidney function * History of unstable angina pectoris or myocardial infarction within 6 months; * History of cerebral infarction or cerebral hemorrhage within 6 months; * Patients with abnormal coagulation function; * Have a history of psychotropic drug abuse or have a mental disorder; * Continuous use of glucocorticoids within 1 month (except topical application); * Patient has participated in or is participating in other clinical studies (within 6 months); * According to the judgment of the investigator, it endangers the patient\'s health or affects the experimental results.