RAS Mutations in ctDNA and Anti-EGFR reINTROduction in mCRC (RASINTRO)

Some data have suggested a clinical survival benefit related to the reintroduction of anti-EGFRs therapy in patients with metastatic colorectal cancer (mCRC). Based on resistance mechanisms related to the development of resistant clones, the investigators could assume that patients who benefited most from the reintroduction of anti-EGFRs were those who, through interval chemotherapy, had no longer mutated RAS clone in plasma that appeared during the progression with the first anti-EGFR treatment. Conversely, those who did not benefit from this therapy were probably patients who had mutated RAS clones circulating at the time of reintroduction of anti-EGFRs. To support this hypothesis, investigators propose to evaluate the correlation between the eventual presence of RAS mutations in circulating blood and the efficacy of an anti-EGFR therapy reintroduction in patients with mCRC.