What is CMF?

CMF is a combination chemotherapy treatment used to treat breast cancer. It may sometimes be used to treat other cancers. It is best to read this information with our general in-formation about chemotherapy and the type of cancer you have.

Your doctor will talk to you about this treatment and its possible side effects before you agree (consent) to have treatment.

The drugs used in CMF

CMF comes from the initials of the drugs used:

How CMF is given

You will be given 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, and a specialist pharmacist. This is who we mean when we mention doctor, nurse or pharmacist in this information.

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 your blood cells are at a safe level to have chemotherapy. 

You will see a doctor or nurse before you have chemotherapy. They will ask you how you have been feeling. If your blood results are okay, the pharmacist will prepare your chemotherapy. Your nurse will tell you when your treatment is likely to be ready. 

Your nurse usually gives you anti-sickness (anti-emetic) drugs before the chemotherapy. The chemotherapy drugs can be given: 

  • through a short thin tube the nurse puts into a vein in your arm or hand (cannula)
  • through a fine tube that goes under the skin of your chest and into a vein close by (central line)
  • through a fine tube that is put into a vein in your arm and goes up into a vein in your chest (PICC line)
  • as tablets which are swallowed.

Usually your nurse gives you cyclophosphamide as an injection or a drip (infusion). Cyclo-phosphamide can also be given as a course of tablets over two weeks.

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.

Your course of chemotherapy

You usually have a course of several cycles of treatment over a few months. Your nurse or doctor will talk to you about how the treatment will be given.

Each cycle of CMF takes 28 days (4 weeks). Once you have had the chemotherapy drugs there is usually a rest period of 2 or 3 weeks depending on the schedule. After the rest period, you will start your second cycle of CMF. This is exactly the same as the first cycle. Your doctor or nurse will tell you the number of cycles you are likely to have.

CMF can be given in different ways and sometimes it can be given over 21 days (3 weeks). Your doctor or nurse will explain how long each cycle takes.

Taking cyclophosphamide tablets

You should not have anything to eat an hour before, or an hour after, taking the capsules or tablets. They must be swallowed whole with a glass of water. They should not be chewed, opened or crushed. Take them at the same time every day.  

If you forget to take the capsules or tablets, you should take the missed dose as soon as possible within the same day. If a full day has gone by, let your doctor or nurse know. Do not take a double dose unless your doctor tells you to.

Other things to remember about your capsules:

  • Keep them in the original package and at room temperature, away from heat and direct sunlight.
  • Keep them safe and out of sight and reach of children.
  • If you are sick just after taking the capsules or tablets, contact the hospital. Do not take another dose.
  • If your treatment is stopped, return any unused capsules or tablets to the pharmacist.

About side effects

We explain the most common side effects of this treatment here. We also include some less common side effects. You may get some of the side effects we mention, but you are unlikely to get all of them.

You may also have some side effects that we have not listed here. Always tell your doctor, nurse or pharmacist about any side effects you have.

Your doctor can give you drugs to help control some side effects. It is important to take them exactly as your nurse or pharmacist explains. This means they will be more likely to work for you. Your nurse will give you advice about managing your side effects. After your treatment is over, most side effects start to improve.

Folinic acid tablets

Your doctor may give you folinic acid tablets to take 24 hours after having the methotrexate. This is given if you have severe side effects from methotrexate, such as:

  • a very sore mouth or eyes
  • severe diarrhoea.

Serious and life-threatening side effects

Some cancer treatments can cause severe side effects. Rarely, these may be life-threatening. Your cancer doctor or nurse can explain the risk of these side effects to you.

Contact the hospital

Your nurse will give you telephone numbers for the hospital. If you feel unwell or need advice, you can call them at any time of the day or night. Save these numbers in your phone or keep them somewhere safe.

More information

We cannot list every side effect for this treatment. There are some rare side effects that are not listed. You can visit the electronic Medicines Compendium (eMC) to download a Patient Information Leaflet (PIL) for these drugs. The leaflet lists all known side effects.

Side effects while treatment is being given

Some people may have side effects while they are being given the chemotherapy or shortly after they have it:

Allergic reaction

Some people have an allergic reaction while having this treatment. Before treatment, you will be given medicines to help prevent or reduce any reaction.

Signs of a reaction can include:

  • feeling hot or flushed
  • shivering
  • itching
  • a skin rash
  • feeling dizzy
  • a headache
  • feeling breathless or wheezy
  • swelling of your face or mouth
  • pain in your back, tummy or chest.

Your nurse will check you for signs of a reaction during your treatment. If you feel unwell or have any of these signs, tell them straight away. If you do have a reaction, it can be treated quickly.

Sometimes a reaction happens a few hours after treatment. If you develop any signs or feel unwell after you get home, contact the hospital straight away.

Pain along the vein

You may get pain at the place where the injection is given or along the vein. If you feel pain, tell your nurse or doctor straight away so that they can check the site. They may give the drug more slowly or flush it through with more fluid to reduce pain.

The drug leaks outside the vein

If the drug leaks outside the vein, it can damage the surrounding tissue. This is called extravasation. Extravasation is not common but if it happens it is important to treat it quickly. Tell your nurse straight away if you have any stinging, pain, redness or swelling around the vein.

If you get any of these symptoms after you get home, contact the doctor or nurse straight away on the contact telephone number they gave you.

Common side effects of CMF

Risk of infection

This treatment can reduce the number of white blood cells in your blood. These cells fight infection. If the number of white blood cells is low, you are more likely to get an infection. A low white blood cell count is sometimes called neutropenia.

An infection can be very serious when the number of white blood cells is low. It is important to get any infection treated as soon as possible. Contact the hospital straight away on the 24-hour contact number you have been given if:

  • your temperature goes over 37.5°C (99.5°F)
  • you suddenly feel unwell, even with a normal temperature
  • you have symptoms of an infection
  • your temperature goes below 36°C (96.8°F).

Symptoms of an infection include:

  • feeling shivery and shaking
  • a sore throat
  • a cough
  • breathlessness
  • diarrhoea
  • needing to pass urine (pee) a lot, or discomfort when you pass urine.

It is important to follow any specific advice your cancer treatment team gives you.

The number of white blood cells will usually return to normal before your next treatment. You will have a blood test before having more treatment. If your white blood cell count is low, your doctor may delay your treatment for a short time, until your cell count increases.

Bruising and bleeding

This treatment can reduce the number of platelets in your blood. Platelets are cells that help the blood to clot.

If the number of platelets is low, you may bruise or bleed easily. You may have:

  • nosebleeds
  • bleeding gums
  • heavy periods
  • blood in your urine (pee) or stools (poo)
  • tiny red or purple spots on the skin that may look like a rash.

Tell your doctor if you have any unexplained bruising or bleeding. You may need a drip to give you extra platelets. This is called a platelet transfusion.

Anaemia (low number of red blood cells)

This treatment can reduce the number of red blood cells in your blood. Red blood cells carry oxygen around the body. If the number of red blood cells is low, this is called anaemia. You may have symptoms such as:

  • pale skin
  • lack of energy
  • feeling breathless
  • feeling dizzy and light-headed.

Tell your doctor or nurse if you have these symptoms.

If you are very anaemic, you may need a drip to give you extra red blood cells. This is called a blood transfusion.

Bladder irritation

Cyclophosphamide may irritate your bladder and cause discomfort when you pass urine (pee). Drink plenty of fluids, at least 2 litres (3 ½ pints) during the first 24 hours after chemotherapy. It is also important to empty your bladder regularly and to try to pass urine as soon as you feel you need to. Contact the hospital straight away if you find it difficult to pass urine. Or contact the hospital if you feel any discomfort or stinging when you pass urine. If you notice any blood in your urine tell your doctor straight away.

Feeling sick

Your doctor will give you anti-sickness drugs to help prevent or control sickness during your treatment. Take the drugs exactly as your nurse or pharmacist tells you. It is easier to prevent sickness than to treat it after it has started.

If you feel sick, take small sips of fluids often and eat small amounts regularly. It is important to drink enough fluids. If you continue to feel sick, or are sick (vomit) more than once in 24 hours, contact the hospital as soon as possible. They will give you advice. Your doctor or nurse may change the anti-sickness drug to one that works better for you.

Loss of appetite

This treatment can affect your appetite. Do not worry if you do not eat much for a day or two. But if your appetite does not come back after a few days, tell your nurse or dietitian. They will give you advice. They may give you food or drink supplements.

Sore mouth and throat

This treatment may cause a sore mouth and throat. You may also get mouth ulcers. This can make you more likely to get a mouth or throat infection. Use a soft toothbrush to clean your teeth or dentures in the morning, at night and after meals.

If your mouth or throat is sore:

  • tell your nurse or doctor – they can give you a mouthwash or medicines to help
  • try to drink plenty of fluids
  • avoid alcohol, tobacco, and foods that irritate your mouth and throat.

Sucking ice chips may sometimes help relieve mouth or throat pain. But if you are having radiotherapy to the head or neck, do not suck on ice. It can cause damage.

Diarrhoea

This treatment may cause severe diarrhoea. Diarrhoea means passing more stools (poo) than is usual for you, or having watery or loose stools. If you have a stoma, it will be more active than usual.

Your hospital team may give you anti-diarrhoea drugs to take at home.

If you have diarrhoea or a mild increase in stoma activity:

  • follow any advice from your cancer team about taking anti-diarrhoea drugs
  • drink at least 2 litres (3½ pints) of fluids each day
  • avoid alcohol, caffeine, milk products, high-fat foods and high-fibre foods.

Contact the hospital straight away if:

  • you have diarrhoea at night
  • you have diarrhoea more than 4 times in a day
  • you have a moderate or severe increase in stoma activity
  • the anti-diarrhoea drugs do not work within 24 hours.

You may need to go to hospital to have fluids through a drip.

Eye problems

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.

Hair loss

Your hair will get thinner. Or you may lose all the hair from your head. You may also lose your eyelashes and eyebrows, as well as other body hair. Hair loss usually starts after your first or second treatment.

Your nurse can talk to you about ways to cope with [hair loss]. There are ways to cover up hair loss if you want to. Your scalp may be sensitive. It is important to cover your head to protect your skin when you are out in the sun.

Hair loss is almost always temporary. Your hair will usually grow back after treatment ends.

Feeling tired

Feeling tired is a common side effect of this treatment. It is often worse towards the end of treatment and for some weeks after it has finished. Try to pace yourself and plan your day so you have time to rest. Gentle exercise, like short walks, can give you more energy.

If you feel sleepy, do not drive or use machinery.

Headaches

This treatment may cause headaches. If you have headaches, tell your doctor. They may give you painkillers to help.

Less common side effects of CMF

Skin changes

CMF 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. CMF can cause a rash, which may be itchy.

During treatment and for several months afterwards, you will 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 sun cream 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 give you creams or medicines to help. Any changes to your skin are usually temporary and improve when treatment finishes.

Nail changes

This treatment can affect your nails. They may grow more slowly or break more easily. You might notice ridges or white or dark lines across your nails. Sometimes nails can become loose or fall out. When treatment finishes, any changes usually disappear as the nails grow out.

There are things you can do to look after your nails:

  • Moisturise your nails and cuticles regularly.
  • Keep your nails clipped short.
  • Wear gloves to protect your nails when you are doing things in the house or garden.
  • Keep your hands and nails clean to help avoid infection, but avoid bathing in very hot water.
  • Do not use false nails, gels or other acrylics during this treatment, as they may increase the risk of infection.
  • It is fine to wear nail varnish, but try to use a water-based polish. Avoid using harsh chemicals, such as acetone, when taking off the polish.
  • If your toenails are affected, wear well-fitted shoes to cushion them.

Tell your doctor or nurse if you notice changes to your nails. They can give you advice or arrange for you to see a podiatrist for foot care advice if needed.

Changes to your taste

You may get a bitter or metal taste in your mouth. Sucking sugar-free sweets may help with this. Some foods may taste different or have no taste. Try different foods to find out what tastes best to you. Taste changes usually get better after treatment finishes. Your nurse can give you more advice.

Changes in the way the heart works

5FU can affect how the heart works. You may have tests to see how well your heart is working. These may be done before, during and after treatment.

It is still possible for the heart to be affected even if these test results are normal. Very rarely, this can cause heart failure or a heart attack. The risk of this happening is very low (less than 1 in 100 or 1%). But it is important that you know about it.

Call your doctor straight away on the 24-hour number the hospital has given you if you have any of these symptoms at any time during treatment:

  • pain or tightness in your chest
  • breathlessness
  • changes to your heartbeat.

If you cannot get through to your doctor, call the NHS urgent advice number which is 111.

Effects on the lungs

This treatment can cause changes to the lungs. Tell your doctor if you develop:

  • a cough
  • wheezing
  • breathlessness.

You should also tell them if any existing breathing problems get worse. You may have tests to check your lungs.

Effects on the liver and kidneys

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 is 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.

Second cancer

Cyclophosphamide can increase the risk of developing a second cancer, years later. If a second cancer develops it is usually leukaemia.

But the benefits of treatment outweigh this risk. Your doctor can talk to you about this.

Other information

Blood clot risk

Cancer and some cancer treatments can increase the risk of a blood clot. Symptoms of a blood clot include:

  • throbbing pain, redness or swelling in a leg or arm
  • suddenly feeling breathless or coughing
  • sharp chest pain, which may be worse when you cough or take a deep breath.

If you have any of these symptoms, contact the hospital straight away on the 24-hour contact number you have been given. If you cannot get through to your doctor, call the NHS urgent advice number on 111.

A blood clot is serious, but it can be treated with drugs that thin the blood (anticoagulants). Your doctor or nurse can give you more information.

You can help reduce the risk of developing a blood clot by:
  • staying active during treatment
  • drinking plenty of fluids, especially water.

You may be given anticoagulants to help prevent a clot.

Other medicines and foods

Some medicines can affect how this treatment works or be harmful when you are having it. Always tell your cancer doctor about any drugs you are taking or planning to take, such as:

  • medicines you have been prescribed
  • medicines you buy in a shop or chemist
  • vitamins, herbal drugs and complementary therapies.

Tell other doctors, pharmacists or dentists who prescribe or give you medicines that you are having this cancer treatment.

You can visit the electronic Medicines Compendium (eMC) for more detailed information about your treatment.

During treatment with cyclophosphamide you should avoid grapefruit and grapefruit juice as it can react with the drug.

Vaccinations

Vaccinations can reduce your risk of getting certain infections. Your doctor or nurse may talk to you about having vaccinations.

Doctors usually recommend that people with cancer have a flu vaccination and a coronavirus vaccination. These are both inactivated vaccinations that can help reduce the risk of infection. People with weak immune systems can have these, as they are not live vaccinations.

If your immune system is weak, you need to avoid live vaccinations. This is because they can make you unwell. Live vaccines, such as shingles, contain a very weak version of the illness they are vaccinating you against. Your cancer doctor or GP can tell you more about live and inactivated vaccinations.

Contraception

Your doctor will advise you not to get pregnant or make someone pregnant while having this treatment. The drugs may harm the developing baby. It is important to use effective contraception during your treatment and for 12 months after treatment finishes. Your doctor, nurse or pharmacist can tell you more about this.

Breastfeeding

You are advised not to breastfeed while having this treatment, or for some time after treatment finishes. This is because the drugs could be passed to the baby through breast milk.

Your doctor or nurse can give you more information.

Fertility

Some cancer drugs can affect whether you can get pregnant or make someone pregnant

If you are a woman, your periods may become irregular or stop. This may be temporary, but for some women it is permanent. Your menopause may start sooner than it would have done.

There may be ways to preserve fertility for men and women. If you are worried about fertility, it is important to talk with your doctor before you start treatment.

Sex

If you have sex in the first few days after chemotherapy, you need to use a condom. This is to protect your partner in case there is any chemotherapy in semen or vaginal fluids.

Medical and dental treatment

If you need medical treatment for any reason other than cancer, always tell the doctors and nurses you are having cancer treatment. Give them the contact details for your cancer doctor so they can ask for advice.

If you think you need dental treatment, talk to your cancer doctor or nurse. Always tell your dentist you are having cancer treatment.