efficacy and safety of sbrt followed by tislelizumab plus cetuximab and irinotecan in patients with previously treated ras wild-type advanced refractory colorectal cancer

Conditions: Colorectal Cancer

Summary: to evaluate the efficacy and safety of sbrt followed by tislelizumab plus cetuximab and irinotecan in patients with previously treated ras wild-type advanced refractory colorectal cancer


Eligibility criteria:
inclusion criteria: * aged 18-75 years * physical condition score (ecog ps) of the eastern cancer cooperative group (usa) 0 or 1; * colorectal cancer diagnosed histologically and/or cytologically has metastases or relapses that are not curable by surgery * have received first - and second-line systemic antitumor therapy for mcrc (chemotherapy drugs may include fluorouracil, oxaliplatin, irinotecan, e.g. xelox, folfox, folfiri, folfoxiri, xeliri; can be combined with or without targeted drugs, such as cetuximab, bevacizumab);and disease progression after second-line treatment; * evaluation of lung or liver metastases can be evaluated, with stereotactic radiotherapy maneuverability; * at least one measurable lesion as defined in recist version 1.1; * fertile patients must be willing to take effective pregnancy avoidance measures during the study period and ≥120 days after the last dose; female patients with negative urine or serum pregnancy test results within 7 days or less before the first administration of the study drug; * have fully understood this study and voluntarily signed informed consent. * adequate organ and bone marrow function, meeting the following definitions: 1. blood routine (no blood transfusion, no granulocyte colony stimulating factor \[g-csf\], no other drug correction within 14 days before treatment);absolute count of neutrophils (anc) ≥1.5×109/l;hemoglobin (hb) ≥9.0 g/dl;platelet count (plt) ≥80×109/l; 2. blood biochemistry, serum creatinine (cr) ≤ 1.5× upper limit of normal (uln) or creatinine clearance ≥60 ml/min;serum albumin ≥2.8g/dl, for patients with poor nutritional status before neoadjuvant therapy, patients who met the requirements through parenteral nutrition could also be included in the group;total bilirubin (tbil) ≤ 1.5×uln;aspartate aminotransferase (ast) or alanine aminotransferase (alt) level ≤2.5×uln; exclusion criteria: * 1. pregnant or lactating women; * patients with a known history of allergy to any investigative drug, similar drug or excipient; * patients with risk of massive gastrointestinal bleeding or gastrointestinal obstruction; * patients with a history of thromboembolism, except thrombosis caused by picc; * there are patients with active infection; * patients with unmanageable hypertension (systolic blood pressure ≥160 mmhg and diastolic blood pressure ≥90mmhg); * patients with brain metastases with clinical symptoms or imaging evidence; * contraindications exist in treatment with other chronic diseases; * patients with a history of immunotherapy-related myocarditis, pneumonia, colitis, hepatitis, nephritis, etc., with current ae ≥ grade 2; * according to the evaluation criteria of nci ctcae version 5.0, there are patients with all kinds of toxicities ≥ grade 2 due to previous treatment; * other conditions that the researchers determined were not suitable for inclusion in the study. * received any antitumor therapy and participated in other clinical studies within 4 weeks before enrollment.