This information is about a chemotherapy treatment for breast cancer called CMF.
The drugs that are used
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CMF is named after the initials of the chemotherapy drugs used, which are:
Throughout this fact sheet we'll refer to fluorouracil by its more common name 5FU.
How treatment is given
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CMF treatment can usually be given to you as a day patient. Before you start treatment, you'll need to have a blood test on the same day or a few days beforehand. You'll also be seen by a doctor, specialist nurse or pharmacist. If the results of your blood test are normal, the pharmacy will prepare your chemotherapy drugs. This may take a couple of hours.
The nurse will insert a thin, flexible tube (cannula) into a vein in your hand or arm. You may find this uncomfortable or a little painful, but it shouldn't take long. Some people have their chemotherapy given through a thin, plastic tube that is inserted under the skin and into a vein near the collarbone (central line) or passed through a vein in the crook of their arm (PICC line). Your doctor or nurse will explain more about this to you.
You'll be given some anti-sickness (anti-emetic) drugs. These are usually given by injection through the cannula, central line or PICC line, which is connected to a drip (infusion). Some anti-sickness medicines may be given as tablets.
The chemotherapy drugs are then given separately:
Cyclophosphamide (a colourless fluid) is given as an infusion. The cyclophosphamide can also be given as a course of pink or white tablets over two weeks – see Schedule A.
Methotrexate (a yellow fluid) is given as an injection along with an infusion of salt water (saline) into your cannula.
5FU (a colourless fluid) is given as an injection in the same way.
This will usually take up to an hour.
Although the cyclophosphamide is often given first, the order in which the drugs are given won't alter their effectiveness.
If you're being treated as a day patient, you can go home when it is finished. The cannula will be removed before you go. If you have a central or PICC line it will usually stay in place ready for the next cycle of your chemotherapy. You'll be shown how to look after the line.
You'll be given a supply of anti-sickness drugs to take home with you. It's important to take these as directed by your doctor even if you aren't feeling sick. This is because some anti-sickness drugs are much better at preventing sickness than stopping it once it starts.
How often treatment is given
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CMF chemotherapy can be given in different ways. Your doctor may use the word 'regimen' (eg the CMF regimen) when talking about your chemotherapy. This refers to the whole plan or schedule of your particular chemotherapy treatment.
Below are descriptions of four different schedules for giving CMF. You can ask your doctor or nurse to explain which one you're having.
On the first day of your treatment (day one), you'll be given injections of methotrexate and 5FU as described. You'll also start taking cyclophosphamide tablets (which you take for two weeks). One week later (day eight) you'll be given methotrexate and 5FU again.
When you finish your cyclophosphamide tablets (a week after your last injections), you'll have a rest period with no chemotherapy for two weeks. This completes what is called a cycle of your chemotherapy.
You'll start the next cycle of your treatment after the rest period, which will be four weeks after your first injection.
On the first day of your treatment you'll be given all three drugs (cyclophosphamide, methotrexate and 5FU) by infusion and injection. One week later (day eight), you'll be given methotrexate and 5FU again. After this you'll have a rest period with no chemotherapy for the next two weeks. This completes a cycle of your treatment.
You'll start the next cycle of your treatment after the rest period, which will be three weeks after your first injection.
On the first day of your treatment you'll be given all three drugs (cyclophosphamide, methotrexate and 5FU) by infusion and injection. After this you'll have a rest period, with no chemotherapy for the next three weeks. This completes a cycle of your treatment. After the rest period, the same drugs will be given to you again, beginning the next cycle of your treatment.
You'll be given cyclophosphamide, methotrexate and 5FU by infusion and injection on the first day of your treatment. This will be repeated one week later. After this you'll have a rest period, with no chemotherapy for the next two weeks, before starting your next cycle of treatment.
The above schedules are all usually given 4–6 times over a period of 3–6 months. This makes up a course of treatment.
Each person’s reaction to chemotherapy is different. Some people have very few side effects while others may experience more. The side effects described here won't affect everyone who has CMF chemotherapy.
We have outlined the most common side effects but haven't included those that are rare and unlikely to affect you. If you notice any effects that aren't listed here, discuss them with your doctor, chemotherapy nurse or pharmacist.
Risk of infection
CMF can reduce the number of white blood cells, which help fight infection. White blood cells are produced by the bone marrow. If the number of your white blood cells is low you'll be more prone to infections. A low white blood cell count is called neutropenia.
Neutropenia begins seven days after treatment, and your resistance to infection is usually at its lowest 10–14 days after chemotherapy. The number of your white blood cells will then increase steadily and usually return to normal before your next cycle of chemotherapy is due.
Contact your doctor or the hospital straight away if:
your temperature goes above 38°C (100.4°F)
you suddenly feel unwell even with a normal temperature.
You'll have a blood test before having more chemotherapy to check the number of white blood cells. Occasionally, your treatment may need to be delayed if the number of your blood cells (blood count) is still low.
Bruising or bleeding
CMF can reduce the production of platelets, which help the blood to clot. Tell your doctor if you have any unexplained bruising or bleeding, such as nosebleeds, bleeding gums, blood spots or rashes on the skin. You may need to have a platelet transfusion if your platelet count is low.
CMF can reduce the number of red blood cells, which carry oxygen around the body. A low red blood cell count is called anaemia. This may make you feel tired and breathless. Tell your doctor or nurse if you have these symptoms. You may need to have a blood transfusion if the number of red blood cells becomes too low.
Feeling tired is a common side effect of chemotherapy, especially towards the end of treatment and for some weeks after it’s over. It’s important to try to pace yourself and get as much rest as you need. Try to balance this with some gentle exercise, such as short walks, which will help. If tiredness is making you feel sleepy, don’t drive or operate machinery.
Feeling sick (nausea) or being sick (vomiting)
Your doctor can prescribe very effective anti-sickness (anti-emetic) drugs to prevent or greatly reduce nausea and vomiting. If the sickness isn't controlled, or if it continues, tell your doctor; they can prescribe other anti-sickness drugs that may be more effective.
Some anti-sickness drugs can cause constipation. Let your doctor or nurse know if this is a problem.
Your mouth may become sore or dry, or you may notice small ulcers during this treatment. Drinking plenty of fluids, and cleaning your teeth regularly and gently with a soft toothbrush, can help reduce the risk of this happening. Some people may find sucking on ice soothing. Tell your nurse or doctor if you have any of these problems, as they can prescribe mouthwashes and medicine to prevent or clear mouth infections.
You may notice that food tastes different. Normal taste usually comes back after treatment finishes. A dietitian or specialist nurse at your hospital can give you advice about ways of coping with this side effect.
CMF can cause diarrhoea. This can usually be easily controlled with medicine, but tell your doctor if it's severe or continues. It's important to drink plenty of fluids if you have diarrhoea.
CMF may cause an inflammation of the lining of the eyelids (conjunctiva) that makes your eyes feel sore, red and itchy. Let your doctor know so they can prescribe soothing eye drops if necessary.
Cyclophosphamide may irritate your bladder. It’s important to drink as much fluid as you can (at least two litres) during the 24 hours following chemotherapy to help to prevent this. Let your doctor know if you have any discomfort when you pass urine, or if you notice any blood in it.
Less common side effects
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This is rare with this treatment, but your hair may become thinner. If you lose any hair it will grow back once the treatment has finished. Your nurse can give you advice about coping with hair loss.
CMF can cause a rash or dry skin, which may be itchy. Your doctor can prescribe medicine to help with this
Rarely, your skin may darken. If it does, it usually goes back to normal a few months after the treatment has finished. During treatment and for several months afterwards, you'll be more sensitive to the sun, and your skin may burn more easily than normal. You can still go out in the sun but should wear a suncream with a high sun protection factor (SPF), and cover up with clothing and a hat.
The colour of your nails may change. They may become darker and white lines may appear on them. These usually grow out over several months once the treatment has finished.
Treatment with CMF may cause changes in the way your liver works, although it will return to normal when the treatment finishes. You're very unlikely to notice any problems, but your doctor will take regular blood samples to check your liver is working properly.
Changes in the way your heart works
5FU may affect the way your heart works. Some people can experience chest pain and tightening across the centre of the chest while taking it, but this is very rare. Chest pain can be caused by many different things other than chemotherapy. If you develop any of these symptoms, contact your doctor immediately.
It’s important to let your doctor know straight away if you feel unwell or have any severe side effects, even if they’re not mentioned above.
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Risk of developing a blood clot
Cancer can increase the risk of developing a blood clot (thrombosis), and chemotherapy may increase this risk further.
A blood clot may cause symptoms such as pain, redness and swelling in a leg, or breathlessness and chest pain. Blood clots can be very serious, so it’s important to tell your doctor straight away if you notice any of these symptoms. Most clots can be treated with drugs that thin the blood. The doctor or nurse can give you more information.
Some medicines, including those you can buy in a shop or chemist, can be harmful to take when you're having chemotherapy. Tell your doctor about any medicines you're taking, including over-the-counter drugs, complementary therapies and herbal drugs.
Some painkillers, such as ibuprofen, can make the side effects of CMF worse. Before taking any painkillers, check with your chemotherapy nurse, pharmacist or doctor.
Folinic acid tablets
If you have bad side effects from the methotrexate, such as a very sore mouth and gritty eyes, your doctor may give you folinic acid tablets to take 24 hours after having the methotrexate.
CMF may interact with alcohol. It is advisable not to drink alcohol while you're having treatment.
Your ability to become pregnant or father a child may be affected by having this treatment. It's important to discuss fertility with your doctor before starting treatment.
It's not advisable to become pregnant or father a child while having CMF, as it may harm the developing baby. It’s important to use effective contraception while having this chemotherapy and for at least a few months afterwards. You can discuss this with your doctor.
It’s not known whether chemotherapy drugs can be present in semen or vaginal fluids. To protect your partner, it’s safest to either avoid sex or use a barrier form of contraception for about 48 hours after chemotherapy.
Loss of periods in women
Because of the effect of chemotherapy on the ovaries, women may find that their periods become irregular and may eventually stop. In some women this may be temporary, but for others it will be permanent. This will result in menopausal symptoms, such as hot flushes, sweats and vaginal dryness.
There's a potential risk that chemotherapy drugs may be present in breast milk. Women are advised not to breastfeed during chemotherapy and for a few months afterwards.
If you’re admitted to hospital for a reason not related to the cancer, it’s important to tell the doctors and nurses looking after you that you're having chemotherapy treatment. You should tell them the name of your cancer specialist so that they can ask for advice.
It’s a good idea to know who you should contact if you have any problems or troublesome side effects when you’re at home. Your chemotherapy nurse or doctor will give you details of who to contact for advice. This should include ‘out-of hours’ contact details if you need to call someone at evenings, overnight or at the weekend.
Things to remember about cyclophosphamide tablets
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Swallow your tablets whole with a glass of water.
It’s important to take your tablets at the right times as directed by your doctor.
Always tell any doctors treating you for non-cancerous conditions that you're taking a course of chemotherapy tablets that should not be stopped or restarted without advice from your cancer specialist.
Keep the tablets in their original packaging, and store them at room temperature away from heat and direct sunlight.
Keep the tablets in a safe place and out of the reach of children.
If your doctor decides to stop the treatment, return any remaining tablets to the pharmacist. Don't flush them down the toilet or throw them away.
If you're sick just after taking the tablets tell your doctor as you may need to take another dose. Don't take another tablet without telling your doctor first.
If you forget to take a tablet, don't take a double dose. Let your doctor know and keep to your regular dose schedule.
This section is based upon our CMF chemotherapy fact sheet, which has been compiled using information from a number of reliable sources including:
Sweetman, et al. Martindale: The Complete Drug Reference. 37th edition. 2011. Pharmaceutical Press.
British National Formulary. 62nd edition. 2011. British Medical Association and Royal Pharmaceutical Society of Great Britain.
electronic Medicines Compendium (eMC). (accessed October 2011).
Perry MC. The Chemotherapy Source Book. 4th edition. 2007. Lippincott Williams and Wilkins.