Chemo Regimen FAQs: CAF or FAC Chemotherapy

Patient Expert

Question: I was hoping to avoid it, but no such luck: I have to have chemotherapy. What's this CMF the doctor says I'll be having?

Answer: CMF is an acronym for the three-drug "cocktail" you'll be getting. The three drugs are cyclophosphamide (Cytoxan); methotrexate (Amethopterin, Mexate, Folex); and fluorouracil (5FU). This particular combination is unusual in that it's been found to be effective for women with both node-negative, and node-positive breast cancer.

Each drug attacks your cancer cells in a slightly different way. Cyclophosphamide attaches itself to the cancer cell's DNA and causes it to get tangled up and unable to replicate itself . Methotrexate prevents cells from using folic acid, a vitamin that's critical for their growth and development. And fluorouracil is made up of molecules that look very much like the molecules in normal cells except they're structured slightly differently so that they keep cancer cells from functioning properly. When cells can't function, they die.

Question: OK, what's the schedule? How many times, and how often, will I get CMF treatment?

Answer: Delivery methods and schedules vary as the pharmacology is constantly changing. CMF is usually given intravenously though, via a drip into your hand or arm. After the first day of treatment, you’ll come back for another eight days later, then wait for three weeks. This is known as one cycle. The CMF cycle will be repeated six to eight times, so it’ll take between five to six and a half months to finish the entire treatment, barring any complications that may slow down the process.

There are other ways of receiving CMF. Occasionally, Cyclophosphamide is given orally rather than intravenously. And sometimes the drugs are administered all together once every three weeks for eight to twelve cycles. Your doctor will fill you in on what kind of schedule you'll be following.

The CMF treatment itself will probably take between 2 and 3 hours. So bring a book, a friend or something to help pass the time. You don't want to just sit around and twiddle your thumbs the whole time.

Question: You mentioned complications to CMF chemo...

Answer. Each time you begin CMF treatment, you'll have blood drawn prior. A side effect of chemo is a lower white blood cell count. These are the cells that help fight infection. So if your doctor decides your white cell count isn't high enough, your next chemo will be delayed until they’ve built themselves back up to an acceptable level.

Question: What about side effects? Hate to ask, but I want to know...

Answer: Thankfully, the side effects of CMF aren't as severe as other chemotherapy treatments. Here's what you might expect:

  • Hair loss – While CMF may thin your hair, rarely does it cause complete hair loss. Hair loss can be a problem if you take "C" orally, but you should still retain a good deal of your hair.
  • Unpleasant taste in your mouth - You may develop a metallic taste in your mout and there’s not much you can do about it. So don't eat spicy foods to try and "drown out" the metallic taste. It won't work and may give you mouth sores.
  • Mouth and throat sores – It can feel like a series of cold sores inside your mouth and partially along your throat. Obviously, it makes eating a pain so try chewing on ice chips the first five to ten minutes of each treatment. Some women have reported success in using this method to prevent sores. But if sores do develop, ask for medication from your doctor. Also remember to not use harsh mouthwash or eat spicy foods when you have mouth sores since this can exacerbate the situation.
  • Nausea/vomiting/diarrhea - All three of these are a possibility with CMF. The good news is there are now better ways to manage this unpleasant side effect using medication than it used to be in previous years. So don’t worry to much when you hear awful stories from the past about and how sick people felt when undergoing chemo. Times have changed.

You'll probably get some anti-nausea drugs along with your treatment as well as some to take home, just in case. And if you still feel nauseous despite taking your medication, call the doctor and get a prescription for something else. There are all kinds of anti-nausea drugs they can try. They'll keep trying until they find what works best for you.

  • Irritated eyes/stuffy nose - Your nose may feel a bit stuffy as you receive the drugs. Afterward, your eyes may feel sore or as if they’re burning or they may feel "gritty." Try using "artificial tears" eye drops before going to bed at night. Also, you may find you can't wear contacts during treatment.
  • Bladder irritation - Cyclophosphamide will possibly cause some bladder irritation that may feel like a mild bladder infection. Drink plenty of fluids as this will help allay the discomfort. And mention to your doctor that you're feeling uncomfortable. He or she may want to check to make sure you don't have a bladder infection.
  • Loss of fertility - Your ovaries will stop releasing eggs while you're having treatment. Whether or not you get your period back once you're done depends a lot on your age. Eighty percent of 45-year-old women will be permanently infertile while only 20% of 35-year-old women will be menopausal.
  • Fatigue – Chemo causes you to lose a fair number of red blood cells that carry oxygen around your body. You'll find it harder than usual to do just about anything, whether it’s getting out of bed in the morning to climbing a flight of stairs. Don’t overexert yourself and rest when you need to. At the same time, it’s better to do some exercise, even if it's only a short walk around the yard. It will make you feel better.
  • Susceptibility to infection - The treatment destroys some of your white blood cells that fight off infections. This means if you get sick during chemo, you're likely to get really sick and perhaps even require hospitalization. So be extra-careful and wash your hands, avoid crowds and stay away from sick people. It’s probably not a good idea to go shopping at the mall, work out at the gym or go swimming in a public pool.
  • Susceptibility to sunburn - This is a special side effect of fluorouracil. Since you'll be more likely to get a sunburn, wear a hat, slather on the sunblock and try to stay out of the sun as much as possible.
  • Weight gain – It’s not a pleasant side effect, but don't try to diet or starve yourself during chemo. You need to stay healthy so make sure to eat right and include low fat foods, lots of fruits and vegetables and plenty of fluids. Don't worry, you can work on taking the weight off once you're through with treatment.
  • Chemo brain - Many women experience this side effect as they go through chemo. For about 15 percent of women, it lingers for years. If you can imagine your brain is a blackboard, chemo-brain is like the eraser. Symptoms include short-term memory loss and difficulty concentrating.

Until very recently, this side effect wasn't officially recognized nor taken seriously. Researchers are now trying to understand it and figure out ways to provide relief. If you do run up against chemo-brain, try not to stress as it should lessen over time.

As with any side effect, the most important thing to do is to let your doctor or chemo nurse know how and what you're feeling. They want you to feel better and will work with you towards that goal.

Breast cancer survivor and award-winning author PJ Hamel, a long-time contributor to the HealthCentral community, counsels women with breast cancer through the volunteer program at her local hospital. She founded and manages a large and active online survivor support network.