The emergence of RAS mutations in patients with RAS wild-type mCRC receiving cetuximab as first-line treatment: a noninterventional, uncontrolled multicenter study.

"Competing interests The authors declare no competing interests."

"Funding This research was financially supported by Merck Ltd., Taipei, Taiwan, an affiliate of Merck KGaA, Darmstadt, Germany (CrossRef Funder ID: 10.13039/100009945). Merck KGaA, Darmstadt, Germany reviewed the manuscript for medical accuracy only before journal submission. The authors are fully responsible for the content of this manuscript and the views and opinions are described in the publication reflect solely those of the authors."

"Conclusions: We demonstrated that RAS ctDNA status might be a valuable biomarker for detecting early tumour response and predicting benefit to anti-EGFR therapy.: Clinical Trial Registration: NCT03401957 (January 17, 2018).: Ethics approval and consent to participate: The study protocol was approved by the Institutional Review Board of Kaohsiung Medical University Hospital [KMUHIRB-G(II)-20170027], Taipei Veterans General Hospital (reference number: 2017–12-003A), Cathay General Hospital (reference number: CGH-P107013), and National Cheng Kung University Hospital (reference number: A-BR-106-045) and registered at Clinical Trials.gov. (NCT03401957). A statement that the study was performed in accordance with the Declaration of Helsinki. All patients provided written informed consent prior to enrolment."