Fruquintinib, as a standard treatment for refractory metastatic colorectal cancer (mCRC), has attracted increasing research efforts to explore its innovative strategies in combination with immunotherapy and chemotherapy because of its multi-target mechanism which enhances the sensitivity of the immune system and chemotherapy, aiming to further improve the survival benefits for mCRC patients. Trifluridine/tipiracil (TAS-102) is also a standard treatment for mCRC. This study aims to investigate the safety and effectiveness of the combined use of these two drugs in mCRC.

Inclusion Criteria:

• Histology-confirmed metastatic CRC (mCRC)
• Disease progression on standard therapy with at least two lines of chemotherapy, including fluorouracil, oxaliplatin, and irinotecan with or without biologics such as bevacizumab and cetuximab
• Fruquintinib administered as salvage treatment
• Age: 18-75 years old
• Informed consent

Exclusion Criteria:

• Liver or kidney dysfunction, or other conditions unsuitable for chemotherapy
• Fruquintinib and/or TAS-102 administration as second-line treatment
• Drug administration stopped after less than two cycles

Patients with refractory metastatic colorectal cancer who have undergone third-line or later treatment with a combination of fruquintinib and TAS-102.