Abstract: The anti-epidermal growth factor receptor (EGFR) monoclonal antibody cetuximab in combination with chemotherapy is the standard of care in the first-line treatment for RAS wild-type metastatic colorectal cancer (mCRC), and it may also be effective in further lines of therapy. After the first-line cetuximab combined with chemotherapy, it is controversial that cetuximab can be used as maintenance treatment. Progressive disease (PD) occurs when tumors develop resistance to a therapy. Progression after chemotherapy and targeted therapy does not mean that the tumor is resistant to both treatments at the same time. Evidence from multiple studies suggests that patients who experience progression on cetuximab plus chemotherapy have probably developed resistance to the chemotherapeutic agents rather than the biologic component of the regimen and others may regain sensitivity to cetuximab following a chemotherapy switch. It is still inconclusive whether the patients treated with the continuation treatment and rechallenge treatment with cetuximab after having PD on regimens including cetuximab in an earlier treatment line can gain additional clinical benefit. Multiple studies have attempted to identify patients suitable for such a strategy. With this approach, treatment benefit can be extended, adding to established continuum-of-care strategies in patients with mCRC.

Key words: Metastatic colorectal cancer, Cetuximab, Maintenance treatment, Rechallenge