Fluoropyrimidine (5-fluorouracil [5-FU] is the oldest chemotherapy drug for colon cancer and it is usually given with leucovorin [LV]. , It has a long history of its use for colorectal metastatic cancer and support from many older papers.
Unfortunately, the issue ofweekly versus every three weeks schedule for 5FU.leukovorin has not been resolved, and with the appearance of many new drugs, has receded into the past and is no longer of actual importance to a significant number of patients. Older evidence from phase II trials suggests that weekly 5-fluorouracil and leucovorin have lower toxicity.
The FDA has not weigned in on the schedule. The indication states that Fluorouracil is effective in the palliative management of carcinoma of the colon, rectum, breast, stomach and pancreas.
For Professional version see here