Efficacy and Safety of Trifluridine/Tipiracil (TAS-102) Combined With Bevacizumab and Serplulimab in Patients With Metastatic Colorectal Cancer Undergoing Cytoreductive Surgery: A Single-Arm, Single-Center Clinical Study

Inclusion criteria

• Patients who had undergone cytoreductive surgery (CC0-1) for colorectal cancer with peritoneal metastases;
• Patients with extra-peritoneal metastatic lesions that were unlikely to affect prognosis in the short term;
• Patients who had failed standard therapies (disease progression or intolerance to oxaliplatin, irinotecan, fluorouracil, or other chemotherapeutic agents) or for whom no effective treatment options were available;
• Patients with histologically and radiologically confirmed peritoneal metastasis from colorectal cancer, with microsatellite stable (MSS) status as determined by genetic testing;
• Age ≥ 18 years at the time of informed consent;
• Estimated life expectancy > 6 months;
• Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1;
• Adequate function of major organs (cardiac, hepatic, and renal);
• Adequate hematological parameters: absolute neutrophil count (ANC) ≥ 1.5 × 10⁹/L, white blood cell count (WBC) ≥ 3.0 × 10⁹/L, hemoglobin ≥ 10 g/dL, and platelet count ≥ 100 × 10⁹/L;
• Adequate biochemical parameters: total bilirubin ≤ 1.5 × upper limit of normal (ULN); aspartate aminotransferase (AST) and alanine aminotransferase (ALT) ≤ 2.5 × ULN; serum creatinine and blood urea nitrogen (BUN) ≤ 1.5 × ULN;
• Ability to comply with the study protocol and follow-up procedures.

Exclusion criteria

• Refusal to provide informed consent;
• Currently participating in an interventional clinical study, or having received other investigational drugs or devices within 4 weeks prior to enrollment;
• Concurrent malignancy, except for malignancies that have been clinically cured;
• Other severe diseases that, in the investigator's judgment, may affect follow-up compliance or short-term survival;
• Known hypersensitivity to any component of TAS-102, bevacizumab, or serplulimab;
• Uncontrolled brain metastases;
• Active autoimmune disease;
• Pregnant or lactating women;
• History of psychiatric disorders;
• Uncontrolled comorbidities including, but not limited to, active infection, symptomatic congestive heart failure, unstable angina, cardiac arrhythmia, severe coronary artery disease, or cerebrovascular disease, or any other condition deemed by the investigator to render the patient ineligible for enrollment;
• Any other condition that the investigator considers unsuitable for enrollment.