CMF is a chemotherapy treatment used to treat breast cancer.
This information should ideally be read with our general information about chemotherapy and your type of cancer.
CMF comes from the initials of the drugs used:
You have CMF in the chemotherapy day unit. A chemotherapy nurse will give it to you. During treatment, you usually see a cancer doctor, a chemotherapy nurse or a specialist nurse. This is who we mean when we mention doctor or nurse in this information.
A few days before or on the day of treatment, a nurse or person trained to take blood (phlebotomist) will take a blood sample from you. This is to check that it is okay for you to have chemotherapy.
On the day of your treatment, you will see a doctor or nurse. They will check your blood results and ask about how you have been. If your blood results are alright, the pharmacist will prepare your chemotherapy. This can take some time. Your nurse will tell you when your treatment is likely to be ready.
Your nurse gives you anti-sickness drugs as an injection into a vein or as tablets. They give you the drugs and chemotherapy through one of the following (depending if you have a line in or not):
a short thin tube (cannula) that the nurse puts into a vein in your arm or hand
a fine tube that goes under the skin of your chest and into a vein close by (central line)
a fine tube that is put into a vein in your arm and goes up into a vein in your chest (PICC line).
Usually your nurse gives you cyclophosphamide as a drip (infusion).
Cyclophosphamide can also be given as a course of tablets over two weeks – see Schedule A listed below under the heading ‘Your course of CMF’. Methotrexate (a yellow fluid) is given as an injection along with a drip (infusion) to flush it through. 5FU is given as an injection in the same way. This can take up to an hour.
When the chemotherapy is being given
Some people might have the following side effect while they are having the chemotherapy:
Pain along the vein
If this happens, tell your nurse straight away. They will check your drip site and slow the drip to ease the pain.
Taking your chemotherapy tablets
If you are having cyclophosphamide as tablets, always take them exactly as explained. This is important to make sure they work as well as possible for you. Swallow the tablets whole, preferably on an empty stomach, with a full glass of water.
If you are sick just after taking the tablets, contact the hospital. You may need to take another dose. If you forget to take a tablet, do not take a double dose. Keep to your regular schedule and let your doctor or nurse know.
Other things to remember about your tablets:
Keep them in the original package
Store them at room temperature away from heat and direct sunlight
Keep them safe and out of the reach of children
Return any remaining tablets to the pharmacist if your treatment is stopped.
Your course of CMF
CMF chemotherapy can be given in different ways as described below. Your doctor or nurse will explain which one you will have.
On the first day of your treatment, you'll be given injections of methotrexate and 5FU as described above. You'll also start taking cyclophosphamide tablets. You will take the tablets for two weeks. One week after the start of the treatment (day eight), you'll be given methotrexate and 5FU again. When you finish your cyclophosphamide tablets, you'll have a rest period with no chemotherapy for two weeks. This completes a cycle of your chemotherapy. The cycle lasts four weeks in total.
You'll start the next cycle of your treatment after the rest period.
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 three weeks. This completes a cycle of your treatment. After the rest period, you’ll start the next cycle of your treatment and the same drugs will be given to you again.
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 two weeks. After the rest period, you will start 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.
Before you go home, the nurse or pharmacist will give you anti-sickness drugs to take. Take all your tablets exactly as explained.
Possible side effects of CMF
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We explain the most common side effects of CMF here. But we don’t include all the rare ones that are unlikely to affect you.
You may get some of the side effects we mention, but you are very unlikely to get all of them. Always tell your doctor or nurse about the side effects you have. Your doctor can prescribe drugs to help control some of these.
It is very important to take the drugs exactly as your nurse or pharmacist has explained. This means they will be more likely to work better for you.
Your nurse will give you advice about managing your side effects. After your treatment is over, the side effects will start to improve.
Contact the hospital
Your nurse will give you telephone numbers for the hospital. You can call them if you feel unwell or need advice any time of day or night. Save these numbers in your phone or keep them somewhere safe.
Risk of infection
Chemotherapy can reduce the number of white blood cells in your blood. This will make you more likely to get an infection. When the number of white blood cells is low, it’s called neutropenia.
Contact the hospital straight away on the contact number you’ve been given if:
your temperature goes over 37.5°C (99.5°F) or over 38°C (100.4°F), depending on the advice given by your chemotherapy team
you suddenly feel unwell, even with a normal temperature
you have symptoms of an infection – this can include feeling shaky, a sore throat, a cough, diarrhoea or needing to pass urine a lot.
The number of white blood cells usually increases steadily and returns to normal before your next treatment. You will have a blood test before having more chemotherapy. If your white blood cells are still low, your doctor may delay your treatment for a short time.
Bruising and bleeding
CMF can reduce the number of platelets in your blood. Platelets are cells that help the blood to clot. Tell your doctor if you have any bruising or bleeding you can’t explain. This includes nosebleeds, bleeding gums, blood spots or rashes on the skin.
Anaemia (low number of red blood cells)
CMF can reduce the number of red blood cells in your blood. These cells carry oxygen around the body. If the number of red blood cells is low, you may be tired and breathless. Tell your doctor or nurse if you feel like this. If you are very anaemic, you may need a drip to give you extra red blood cells (blood transfusion).
This may happen in the first few days after chemotherapy. Your doctor will prescribe anti-sickness (anti-emetic) drugs to help prevent or control sickness. Take the drugs exactly as your nurse or pharmacist explains to you. It’s easier to prevent sickness than to treat it after it has started.
If you still feel sick or are vomiting, contact the hospital as soon as possible. They can give you advice and change the anti-sickness drug to one that works better for you.
Loss of appetite
You may lose your appetite during your treatment. Try to eat small meals regularly. Don’t worry if you don’t eat much for a day or two. If your appetite doesn’t improve after a few days, let your nurse or dietitian know. They can give you advice on getting more calories and protein in your diet. They may give you food supplements or meal replacement drinks to try. Your doctor can prescribe some of these and you can buy them from chemists.
Your mouth may become sore and you may get ulcers. This can make you more likely to get an infection in your mouth. Gently clean your teeth and/or dentures morning and night and after meals. Use a soft-bristled or children’s toothbrush. Your nurse might ask you to rinse your mouth regularly or use mouthwashes. It’s important to follow any advice you are given and to drink plenty of fluids.
Your doctor can prescribe drugs to control diarrhoea. Let them know if it is severe or if it doesn’t get better. Make sure you drink at least two litres (three and a half pints) of fluids every day if you have diarrhoea.
Your hair may thin but you’re unlikely to lose all the hair from your head. This usually starts after your first or second cycle of chemotherapy. It is almost always temporary and your hair will grow back after chemotherapy ends. Your nurse can give you advice about coping with hair loss.
Your eyes may feel dry and sore and may become more sensitive to light. Your doctor can prescribe eye drops to help with this. If your eyes get red and inflamed (conjunctivitis), tell your doctor. This is because you may need antibiotic eye drops.
Cyclophosphamide may irritate your bladder and cause discomfort when you pass urine. Drink plenty of fluids – at least two litres (three and a half pints) during the 24 hours following chemotherapy. It is also important to empty your bladder regularly and to try to pass urine as soon as you feel the need to go.
Contact the hospital straight away if you feel any discomfort or stinging when you pass urine or if you notice any blood in it.
Feeling very tired is a common side effect. It’s often worse towards the end of treatment and for some weeks after it’s finished. Try to pace yourself and get as much rest as you need. It helps to balance this with some gentle exercise, such as short walks. If you feel sleepy, don’t drive or operate machinery.
If this happens, let your doctor or nurse know. They can give you painkillers.
Less common side effects of CMF
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Chemotherapy may affect your skin. Your doctor or nurse can tell you what to expect. If your skin feels dry, try using an unperfumed moisturising cream every day. During treatment and for several months afterwards, you'll be more sensitive to the sun and your skin may burn more easily than usual. You can still go out in the sun, but use a suncream with a sun protection factor (SPF) of at least 30, and cover up with clothing and a hat.
Always tell your doctor or nurse about any skin changes. They can give you advice and may prescribe creams or medicines to help. Any changes to your skin are usually temporary and improve when treatment finishes.
Your nails may become brittle and break easily. They may get darker or discoloured, and/or you may get lines or ridges on them. These changes grow out after treatment finishes. Wearing gloves when washing dishes or using detergents will help protect your nails during treatment.
Changes in the way the heart works
This treatment can affect the way the heart works. You may have tests to see how well your heart is working before, during and sometimes after treatment.
If you have pain or tightness in your chest or feel breathless or notice changes to your heartbeat at any time during or after treatment, tell a doctor straight away. These symptoms can be caused by other conditions but it’s important to get them checked by a doctor.
Changes in the way the kidneys and liver work
Treatment can affect how your kidneys and liver work. This is usually mild and goes back to normal after treatment. You will have blood tests before chemotherapy to check how well your kidneys and liver are working.
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.
Other information about CMF
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Blood clot risk
Cancer increases the chance of a blood clot (thrombosis) and chemotherapy can add to this. A clot can cause symptoms such as pain, redness and swelling in a leg, breathlessness and chest pain. Contact your doctor straight away if you have any of these symptoms. A blood clot is serious but your doctor can treat it with drugs that thin the blood. Your doctor or nurse can give you more information.
Some medicines can interact with chemotherapy or be harmful when you are having chemotherapy. This includes medicines you can buy in a shop or chemist. Tell your doctor about any medicines you are taking, including over-the-counter drugs, complementary therapies and herbal drugs.
Some painkillers, such as ibuprofen, can make the side effects of methotrexate worse. Before taking any painkillers, check with your chemotherapy nurse, pharmacist or doctor.
Folinic acid tablets
If you have severe 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 affect your fertility (being able to get pregnant or father a child). If you are worried about this, you can talk to your doctor or nurse before treatment starts.
Your doctor will advise you not to become pregnant or to father a child during treatment. This is because the drugs may harm a developing baby. It’s important to use effective contraception during and for a few months after chemotherapy. You can talk to your doctor or nurse about this.
If you have sex within the first couple of days of having chemotherapy, you need to use a condom. This is to protect your partner in case there is any chemotherapy in semen or vaginal fluid.
Changes to your periods
Chemotherapy can sometimes stop the ovaries working. You may not get a period every month and they may eventually stop. In some women, this is temporary, but for others it is permanent and they start the menopause.
Women are advised not to breastfeed during treatment and for a few months after. This is in case there is chemotherapy in their breast milk.
Medical and dental treatment
If you need to go into hospital for any reason other than cancer, always tell the doctors and nurses that you are having chemotherapy. Explain you are taking chemotherapy tablets that no one should stop or restart without advice from your cancer doctor. Give them contact details for your cancer doctor.
Talk to your cancer doctor or nurse if you think you need dental treatment. Always tell your dentist you are having chemotherapy.
This section has been compiled using a number of reliable sources including:
electronic Medicines Compendium (eMC). medicines.org.uk (accessed July 2013)
Perry MC. The Chemotherapy Source Book. 5th edition. Lippincott Williams and Wilkins. 2012
With thanks to Netty Cracknell, Lead Pharmacist Electronic Prescribing, who reviewed this edition.
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