摘要
BACKGROUND Metastatic colorectal cancer(mCRC)treatment has been evolving and increasingly driven by tumor biology and gene expression analysis.Rechallenge with epidermal growth factor receptor(EGFR)inhibitors(anti-EGFR)represents a promising strategy for patients with RAS wild-type(RAS-wt)mCRC and circulating tumor DNA has emerged as a potential selection strategy.Herein,we report the case of a RAS-wt mCRC patient who had a successful response to cetuximab rechallenge.CASE SUMMARY Our patient was diagnosed with stage IV RAS-wt,microsatellite-stable rectosigmoid junction adenocarcinoma.He was started on first-line treatment with FOLFIRI and cetuximab and achieved partial response,allowing for a left hepatectomy(R0),followed by post-operative chemotherapy and an anterior resection;progression-free survival(PFS)of 16 months was obtained.Due to hepatic and nodal relapse,second-line treatment with FOLFOX and bevacizumab was started with partial response;metastasectomy was performed(R0),achieving a PFS of 11 months.After a 15 months anti-EGFR-free interval,FOLFIRI and cetuximab were reintroduced upon disease progression,again with partial response and a PFS of 16 months.Following extensive hepatic relapse,cetuximab was reintroduced and a marked clinical and analytical improvement was seen,after only one cycle.RASwt status was confirmed on circulating tumor DNA.The patient’s overall survival exceeded 5 years.CONCLUSION Our case provides real-world data to support cetuximab rechallenge in later lines of RAS-wt mCRC treatment.
