Shifting to first-line regimen after previous failure of irinotecan and oxaliplatin containing chemotherapies in unresectable metastatic colorectal cancer: a retrospective study of case analysis.

Purpose Conventional use of FOLFIRI–FOLFOX or the reverse sequence is the optional regimen in metastatic unresectable colorectal cancer (CRC). We present our experience in chemotherapy (C/T) shifting to first-line regimen after previous failure of irinotecan and oxaliplatin containing regimens.