<qa>  What was the only treatment for Fluorouracil?For many years 5 Fluorouracil FU was the only treatment, but the approval of irinotecan, oxaliplatin, fluoropyrimidines, as well as various monoclonal antibodies targeting VEGF and EGFR growth factors led to the development of a number of different regimens. The ideal combination and sequence of the different agents is still not determined. 