PBP (Panitumumab beyond Progression)

Interventions: Second-line treatment with FOLFIRI plus panitumumab after failure of the first-line treatment with FOLFOX plus panitumumab for advanced and/or recurrent RAS wild-type colorectal cancer with special reference to the changes in biomarker expression examined by a liquid biopsy and its effect on the refractory tumor Primary outcome(s): 6-month progression-free survival (PFS) rate Study Design: single arm study, open(masking not used), uncontrolled control, single assignment, treatment purpose