Chemo Regimen FAQs: CMF Chemotherapy

 

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.