Postoperative Chemotherapy With/Without Radiotherapy and Immunotherapy for Colorectal Liver Metastases With High Risk of Locally Recurrence

This study is a randomized controlled phase II trial to evaluate the efficacy of the combination of stereotactic body radiation therapy (SBRT) and immunotherapy with postoperative chemotherapy in colorectal cancer liver metastasis (CRLM) patients with high risk of locally recurrence. Researchers will compare the combination therapy with the postoperative chemotherapy alone to see if postoperative chemotherapy plus SBRT and immunotherapy can further reduce the risk of recurrence and metastasis after surgery.

40-50% of colorectal cancer patients have metastases at the time of diagnosis, of which liver metastases are the most common. Surgical resection is the most likely cure for CRLM patients, however, more than 50% of patients will experience recurrence within 2 years after resection of liver metastases. SBRT can be an effective and safe treatment modality, which can not only provide better local control of metastatic lesions, but also has a sensitizing immunotherapeutic effect. SBRT can effectively synergize with anti-PD-1/PD-L1 antibodies to activate the immune microenvironment of CRLM patients and improve survival. However, in CRLM patients after surgery, whether combining SBRT, immunotherapy and adjuvant chemotherapy results in better survival than chemotherapy alone, the evidence is insufficient.