In this retrospective analysis, patients with RAS and BRAF mCRC admitted to the Department of Medical Oncology, Huizhou Municipal Central Hospital, from January 2016 to October 2020 were enrolled and treated with cetuximab plus FOLFIRI as an initial therapy....The median PFS after maintenance treatment in observation group (9.5 months, [95% CI=6.4-12.6]), was significantly better than the control group (7.3 month, [95% CI=5.8-8.8]).