Chemo Regimen FAQs: CMF Chemotherapy

Patient Expert

Q. 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?

A. CMF is an acronym for the three-drug "cocktail" you'll be getting. This particular combination is unusual in that it's been found effective for women with both node-negative, and node-positive breast cancer.

First off, here're the names of the drugs that make up the acronym: cyclophosphamide (Cytoxan); methotrexate (Amethopterin, Mexate, Folex); and fluorouracil (5FU). Don't bother committing this to memory; it's enough to know that you're getting "CMF."

How do these three drugs work together to kill cancer? Basically, each attacks your cancer cells in a slightly different way. "C" attaches itself to the cancer cell's DNA, which then gets tangled up and is unable to replicate itself (sneaky!). "M" prevents cells from using folic acid, a vitamin that's critical for their growth and development; without it, they die. And "F" is made up of molecules that look very much like the molecules in normal cells, but they're structured slightly differently; this very small difference is enough to keep cells from functioning properly, once "F" makes its way into them. And when cells can't function, they die.

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

A. Delivery methods and schedules vary, as the pharmacology is constantly changing. That said, CMF is usually given intravenously, via a drip into your hand or arm. You'll receive the drugs on the first day of treatment, then again 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 you about five to six and a half months, start to finish, barring any complications that slow down the process.

There are other ways of receiving CMF, mostly involving variations in timing. Occasionally, "C" 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 exactly the schedule you'll be following.

The CMF treatment itself will probably take between 2 and 3 hours. Add to that the ride to and from the hospital, the blood tests before (to make sure your white cells are up to the battle), and the inevitable waiting around, and you're looking at half a day each time. Bring stuff to distract or amuse yourself: books, knitting, a friend or family member. You don't want to just sit around and twiddle your thumbs the whole time.

Q. You mentioned complications to CMF chemo...

A. Each time you begin CMF treatment, you'll have blood drawn first. One of chemo's side effects is lowering your white blood cell count; i.e., killing off some of the cells that help fight infection. If your doctor decides your white cell count isn't high enough to keep you healthy, he or she will delay your next chemo until your white cells have built themselves back up to an acceptable level.

Q. OK, what about side effects? Hate to ask, want to know...

A. Thankfully, the side effects of CMF aren't QUITE as troublesome as those of other chemotherapy treatments. Here's what you might expect:

  • Hair loss: Hooray! You probably won't lose your hair, a rarity in breast cancer chemotherapy. CMF may thin your hair, but only rarely does it cause complete hair loss. Hair loss is more of a problem if you take "C" orally, rather than by injection; but still, you should retain a good deal of your hair. Congratulations!

  • Unpleasant taste in your mouth. Have you heard anyone mention "tin-can mouth"? You may develop a metallic taste in your mouth; not much you can do about this CMF side effect. Don't eat spicy foods in an attempt to "drown out" the metallic taste; it won't work, and may give you mouth sores. Speaking of...

  • Mouth and throat sores: These feel like a series of cold sores inside your mouth and partway down your throat. Obviously, it makes eating a pain-literally. Try chewing on ice chips the first five to ten minutes of each CMF treatment; some women have reported success with this method of preventing sores. If sores develop, ask for medication from your doctor. They have stuff that can help. Oh, and don't use harsh mouthwash or eat spicy foods when you have mouth sores; either of those will exacerbate the situation.

  • Nausea/vomiting/diarrhea: All three of these are a possibility with CMF. The good news is, this unpleasant side effect is much, MUCH better controlled than it used to be, via medication. So don't listen to anyone's awful stores about when they had chemo 5 years ago and how sick they were! TIMES HAVE CHANGED.

You'll probably get some anti-nausea drugs right along with your treatment, plus some to take home, just in case. If you feel nauseous, and you've taken your medication, don't suffer in silence! Call the doctor and get a prescription for something else. There are all kinds of anti-nausea drugs they can try; it's not one-size-fits-all. They'll keep trying till they find what works best for you.

  • Irritated eyes/stuffy nose: Your nose may feel a bit stuffy as you receive the drugs. And afterwards, your eyes may feel sore, they may burn, 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: "C" will possibly cause some bladder irritation, which may feel like a mild bladder infection. Drink plenty of fluids; 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 in fact 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 age: 80% of 45-year-old women will be permanently infertile (menopausal); while only 20% of 35-year-old women will remain infertile.

  • Fatigue: This is pretty much a given with any kind of chemo. You're losing a fair number of red blood cells, the cells that carry oxygen around your body. You'll find it harder than usual to do just about anything, from getting out of bed in the morning to climbing a flight of stairs to simply doing the dishes. Be good to yourself; rest when you need to. On the other hand, don't just lie around constantly; exercise, even if it's only a short walk around the yard, will make you feel better.

  • Susceptibility to infection: Like your red blood cells, some of your white blood cells will be destroyed, too. These are the cells that fight off infections, so be extra-careful; act like it's the height of flu season. Wash your hands, avoid crowds, stay away from sick people... If you get sick during chemo, you're likely to get REALLY sick, perhaps even require hospitalization. So take extra precautions; 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 "F." You'll be more likely than usual to get a sunburn, so wear a hat, slather on the sunblock, and just plain stay out of the sun as much as possible.

  • Weight gain. GRRRRRR! Wouldn't you know you're having one of the few chemo treatments that can actually promote weight gain? Don't try to starve yourself, or even to diet, during chemo; you need to stay healthy. So eat right: low fat, lots of fruits and vegetables, plenty of fluids. Don't worry, you can work on taking the weight off, if you do gain, once you're through with treatment.

  • Chemo brain: This rather disheartening side effect is experienced by many women as they go through chemo. And in about 15 percent of women, it lingers for years. Imagine your brain is a blackboard: chemo-brain is the eraser. Short-term memory loss and difficulty concentrating are its main characteristics. You may forget your best friend's name, your own phone number, or which way to turn a doorknob... any number of heretofore simple tasks are made more difficult, simply because you've (temporarily, hopefully) lost some short-term memory. Until very recently, this side effect wasn't officially recognized, nor taken seriously. But now, as more and more women experience it, researchers are trying to figure out just what's going on, and how to provide relief. If you do run up against chemo-brain, try not to stress; if it doesn't disappear pretty quickly once you finish chemo, it should lessen over time.

That wraps up the main possibilities. Remember: you'll follow your own path. You may experience none of this (lucky you!); you may have some personal side effects of your very own, ones not listed here. The most important thing to remember: let your doctor or chemo nurse know how and what you're feeling. They want you to feel better, and they'll work with you towards that goal. Repeat after me: I will not suffer in silence! Best of luck.