Every cancer and patient is different. Use what works for you. Some it is 5FU and others Folfuri.
Listen to your own response to the treatment issued by your oncologist and adjust if and when needed. As long as you are getting the advice from a major cancer center, you will be following the most recent practices, and will be able to be nimble in your changes in treatment when needed.
It looks like you are being treated in NYC at Sloan Kettering, so that is a great place to start!
All the best for 2018, and your journey forward.
D/H 47 years old, 10/2014, Stage IV M/CRC, nodes 12/15, para-aortic, 5 cm sigmoid resection, positive Virchow. KRAS mut, MSS, Highly Differentiated, Lynch Neg, 5FU/LV and Avastin 1 YR (Oxi for 5 months), Zeloda/Bev since 01/2016. 02/2019 recurrence para-nodes, back to 5FU/LV Oxy/Bev. It is working again. "...Perseverance is not a long race; it is many short races one after the other."-Walter Elliot