FAC: Fluorouracil, Adriamycin, and cyclophosphamide


FAC (Fluorouracil, Adriamycin, and Cytoxan) is a chemotherapy regimen sometimes given for localized breast cancers with a relatively high risk for recurrence. It is a combination of three chemotherapy medicines:

FAC uses the same medicines as the combination CAF, but has different doses and schedules.


How FAC works

Each medicine attacks the cancer cells in a different way:

  • Fluorouracil stops cells from making and fixing DNA. This causes the cells to die when they try to divide.
  • Doxorubicin stops DNA production and interferes with the enzymes that repair DNA.
  • Cyclophosphamide stops cancer cells from reproducing.

Who gets FAC

Doctors typically use FAC to treat HER2-negative breast cancers, regardless of whether the cancer traveled to the lymph nodes. Sometimes, it's used instead of AC chemotherapy.

You and your doctor will discuss the best chemotherapy treatment for your situation.


How FAC is given

  • FAC is usually given in six 3-week cycles.
  • All three medicines are given together, by vein, on the first day of treatment
  • Fluorouracil is given by itself one week later, followed by a 2-week rest period off of all chemotherapy.
  • The entire course of treatment lasts about 18 weeks.

Side effects and things to remember

Different medicines have different side effects. You may not have every side effect related to each medicine of the combination. Side effects of FAC may include:

Rare side effects may include increased risk of leukemia, a blood cancer, and heart failure.

Before starting FAC, be sure to tell your doctor about any medicines you are taking, including vitamins, herbal supplements, and over-the-counter medicines, to make sure they won’t interfere with your chemotherapy treatment.

You should avoid becoming pregnant while you are receiving FAC. Tell your doctor right away if you become pregnant while you are undergoing treatment.

Be sure to talk to your doctor or nurse about all your side effects so that they can help you manage them. You can also go to our section on Side effects for more information.


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Reviewed and updated: October 7, 2019

Reviewed by: Sarah Mougalian, MD


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