brief summary：Currently the overall 5-year survival rate for patients with colorectal liver metastases CRLM is still less than 20 Surgery-based local treatment can achieve no evidence of disease NED i

The study aims to investigate the effectiveness and safety of fruquintinib as a maintenance treatment for advanced colorectal cancer (CRC) patients who have completed adjuvant chemotherapy and achieved no evidence of disease (NED). The current 5-year survival rate for patients with colorectal liver metastases (CRLM) is less than 20%, and even after achieving NED, over 60% of patients experience recurrence. The study proposes that further anti-tumor maintenance treatment with fruquintinib may reduce the recurrence rate and prolong the time to recurrence and metastasis for these patients. Fruquintinib is a highly selective anti-angiogenesis inhibitor that has shown promising anti-tumor efficacy and manageable side effects. The study aims to explore the clinical efficacy and safety of fruquintinib as a maintenance treatment for advanced CRC patients with NED.