What is the best way to get 5-FU (fluorouracil) (by IV, continuous infusion, or pill)?

Carolyn Vachani, MSN, RN, AOCN
Last Modified: June 30, 2002

Dear OncoLink "Ask The Experts,"
What is the best way to get 5-FU (fluorouracil) (by IV, continuous infusion, or pill)?

Carolyn Vachani, MSN, RN, AOCN, OncoLink's Clinical Trials Coordinator, responds:

This is a difficult question to answer, as the treatment should fit the patient's particular case. For example, an elderly patient may not tolerate certain regimens as well as a younger, healthier patient, or a patient may not have responded to one form of 5-FU, but could respond to another form.

That being said, the oldest, and most tested way to receive 5-FU is by intravenous infusion, usually given over 2 hours. Studies have been testing this form of 5-FU since the 1950's. This is the method most often used in the treatment of stage II and III colon cancers after surgery, and in combination with other medications for stage IV cancer.

Several studies in the treatment of stage IV colon cancer have utilized continuous infusion 5-FU. These studies have reported decreased side effects, and some have reported increased response rates with a small benefit in survival time. This method of giving 5-FU may be used in conjunction with 5-FU by shorter infusion, other chemotherapies, or radiation.

Oral 5-FU is a relatively new treatment available for the treatment of colon cancers. In one study this medication had more responses to treatment then 5-FU infusion, but the time until the cancer returned or progressed was equal in both medications. Because it works differently then the intravenous form, this may be an option for patients who no longer respond to the intravenous form of 5-FU.