1. What is FEC?
2. When is FEC given?
3. How is FEC given?
4. How long does treatment take?
5. Side effects of FEC
6. Things to be aware of during treatment

1. What is FEC?

FEC is a combination of three chemotherapy drugs used to treat breast cancer. 

It takes its name from the initials of the drugs:

  • 5 fluorouracil (also known as 5FU) 
  • epirubicin 
  • cyclophosphamide

FEC destroys cancer cells by interfering with their ability to divide and grow. 

2. When is FEC given?

FEC may be given after surgery for primary breast cancer to reduce the risk of breast cancer coming back in future. 

It usually starts within a few weeks of your operation. If you’re going to have radiotherapy you’ll usually complete your course of FEC first.

FEC can be given before surgery to shrink a larger breast cancer. This may mean breast-conserving surgery is an option, rather than a mastectomy. Or it might be given before surgery to slow down the growth of a rapidly growing breast cancer and reduce the chance of it spreading to other parts of the body.

FEC may also be given to people with secondary breast cancer, when breast cancer has spread to other parts of the body. 

3. How is FEC given?

The drugs are usually given as a drip into a vein (intravenously). 

There are various ways that intravenous chemotherapy can be given depending on factors such as how easy it is for chemotherapy staff to find suitable veins, and your preferences. 

You can read more information on the different ways chemotherapy can be given on our chemotherapy page. 

Before you start chemotherapy 

Before starting your treatment most hospitals will arrange a chemotherapy information session. At this appointment a member of your treatment team will discuss how and when your chemotherapy will be given and how side effects can be managed. 

You will have bloods tests and your height and weight will also be measured. 

You may also have tests to check how well your heart is working such as: 

  • an ECG (electrocardiogram), a simple test that checks your heart rhythm
  • an echocardiogram (an ultrasound scan of the heart) 
  • a MUGA scan (an injection and scan)

4. How long does treatment take?

It normally takes about an hour for the drugs to be given, although you’re likely to be at the hospital for longer than this. 

The treatment is repeated every three weeks. The break between each treatment gives your body time to recover from any short-term side effects. It may vary depending on whether the number of blood cells has returned to normal. 

The treatment and period of time before the next one starts is known as a cycle.

You will usually have six cycles of treatments. 

The total length of your treatment is usually three to four months.

5. Side effects of FEC

Common side effects 

Like any treatment, FEC can cause side effects. Everyone reacts differently to drugs and some people have more side effects than others. These can usually be controlled and those described here will not affect everyone.

If you’re worried about any side effects, regardless of whether they are listed here, talk to your chemotherapy nurse or treatment team. 

Before starting chemotherapy you should be given a 24-hour contact number or told who to contact if you feel unwell at any time during your treatment, including at night or at the weekends.

Effects on the blood

FEC can temporarily affect the number of healthy blood cells in the body.

Not having enough white blood cells can increase the risk of getting an infection.

Contact your hospital immediately if:

  • you have a high temperature (over 37.5°C) or low temperature (under 36°C), or whatever your chemotherapy team has advised
  • you suddenly feel unwell, even with a normal temperature
  • you have any symptoms of an infection, for example a sore throat, a cough, a need to pass urine frequently or feeling cold and/or shivery

Having too few red blood cells is called anaemia. If you feel particularly tired, breathless or dizzy, let your treatment team know.

You may bruise more easily, have nosebleeds or your gums may bleed when you brush your teeth. Tell your treatment team if you have any of these symptoms.

You’ll have regular blood tests throughout your treatment to check your blood count. If the number of blood cells is too low, your next course of treatment may be delayed or the dose of the chemotherapy reduced.

Nausea and vomiting 

You may experience nausea (feeling sick) and vomiting (being sick), but this can usually be controlled. You’ll be given anti-sickness medication by mouth or intravenously before each cycle of chemotherapy is given, as well as some anti-sickness drugs to take home.

Diarrhoea or constipation

You may have diarrhoea or constipation. Your chemotherapy team can prescribe medicine to help and can give you information about diet. 

Contact your chemotherapy team if you have four or more episodes of diarrhoea within a 24–hour period.

Hair loss (alopecia)

Most people having FEC will lose all their hair, including eyebrows, eyelashes and body hair. 

Find out more about hair loss

Fatigue (extreme tiredness) 

Fatigue is a very common side effect of FEC and may last for weeks or months after your treatment has finished.

Find out more about fatigue, including tips for managing it. 

Pain in the injection site 

Tell the nurse giving the chemotherapy immediately if you have pain, stinging or a burning sensation around the cannula (small plastic tube) while the drug is being given. If epirubicin leaks out of the vein it’s being given in (called extravasation), it can damage the surrounding tissue.  

After treatment, you may experience pain where the needle was inserted, or along the vein. After a few weeks you may notice tenderness, darkening and hardening around where the needle was inserted. This should fade over time.

Change in the colour of urine

You may notice your urine is red or pink when you go to the toilet. This is because epirubicin is red and it’s being passed through your kidneys and bladder. This can last for one to two days after treatment.

Bladder irritation

Tell your treatment team if you notice any irritation or a burning or stinging feeling when passing urine.

Chemotherapy drugs and cyclophosphamide in particular can irritate the lining of the bladder. It’s important to drink plenty of fluids around the time you have your treatment, and to empty your bladder regularly and as soon as you feel the need to. 

Sore mouth and dental problems

You’ll be given mouthwash to try to reduce soreness in the mouth and gums and to stop mouth ulcers developing. Good mouth hygiene is very important during treatment.

See your dentist for a check-up before chemotherapy begins. If you need any dental work speak to your treatment team about the best time to do this.

Taste changes and loss of appetite

While you’re having FEC your taste can change. Some food may taste different, for example more salty, bitter or metallic. You may no longer enjoy some foods you used to enjoy. Your taste should return to normal once your treatment has finished, although for some people taste changes can last longer. 

You may lose your appetite while having FEC. Talk to your specialist or breast care nurse about this. They will give you information to help deal with loss of appetite and may refer you to a dietitian if needed.

Find out more about diet during treatment

Effects on your concentration (cognitive impairment)

Some people find treatment affects their ability to concentrate and makes them more forgetful. This is sometimes referred to as ‘chemo brain’ or ‘chemo fog’, but is more commonly known as cognitive impairment. It usually improves over time after treatment has finished. 

Menopausal symptoms 

Common menopausal symptoms can include: 

  • hot flushes
  • night sweats
  • mood changes
  • joint aches and pains
  • vaginal dryness 

You can talk to your breast care nurse or treatment team about ways of coping with any of these symptoms.

Effects on fertility 

FEC chemotherapy can affect your ability to become pregnant. 

It’s important to discuss any fertility concerns with your treatment team before you begin your treatment.

Find out more about fertility and breast cancer treatment

Hand-foot syndrome (Palmar-plantar syndrome) 

You may develop soreness or redness on the palms of your hands and soles of your feet. This is called Palmar-plantar or hand-foot syndrome

Your doctor may prescribe creams to try to help with this. 

Less common side effects 

Heart changes

Epirubicin and 5FU can cause changes to the way the heart works. This is usually temporary but for a small number of people it may be permanent. 

You may have tests to check how well your heart is working before, during and after your treatment.

Heart problems as a result of epirubicin are not common. However, because of the potential risk, before you start chemotherapy your specialist may arrange a heart (cardiac) function test. This could be:

  • an ECG (electrocardiogram), a simple test that checks your heart rhythm
  • an echocardiogram (an ultrasound scan of the heart) 
  • a MUGA scan (an injection and scan)

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.

Sore eyes and runny nose

FEC can cause a runny nose. It can also cause soreness and a gritty feeling in your eyes, or your eyes may water. Eye drops may be prescribed to relieve the soreness. 


FEC can cause headaches. These are usually mild and can be relieved with simple pain relief such as paracetamol. If your headache is severe, speak to a member of your treatment team.

Skin changes

FEC can make your skin dry, more sensitive or prone to reactions. 

If you develop a rash tell your treatment team as soon as possible.

Your skin may be more sensitive to the sun, so use a high factor suncream.

Nail changes

Chemotherapy may cause changes to the appearance of your nails. This can be a change in the nail colour or texture, such as ridges forming. Nails can become more brittle and cracked. Occasionally the nail may lift off the nail bed and fall out. 

Tell your treatment team if you have any signs of infection such as redness, heat, swelling or pain in or under your fingernails and toenails. 

Rare side effects 

Allergic reaction

Symptoms of an allergic reaction include:

  • flushing
  • skin rash
  • itching
  • back pain
  • shortness of breath
  • faintness
  • fever or chills

If you have an allergic reaction to FEC, it will probably happen within the first few minutes of your treatment and is most likely the first or second time you have the drug. Reactions can vary from mild to severe, but severe reactions are uncommon. You’ll be monitored closely so that any reaction can be dealt with immediately. 

If you have a severe reaction, treatment will be stopped immediately. If you have a reaction, medication can be given before future treatments to reduce the risk of further reactions. 

Liver or kidney changes

FEC can cause changes to the way the kidneys or liver work. Changes are usually minimal and go back to normal when treatment is finished. You’ll have regular blood tests to monitor your liver and kidneys throughout your chemotherapy.

6. Things to be aware of during treatment

Blood clots

People with breast cancer have a higher risk of blood clots. Their risk is higher because of the cancer itself and some treatments for breast cancer. If the cancer has spread to other parts of the body, this also increases the risk.

Having FEC chemotherapy increases the risk of blood clots such as deep vein thrombosis (DVT). People with a DVT are at risk of developing a pulmonary embolism. This is when part of the blood clot breaks away and travels to the lung. 

Blood clots can be harmful but are treatable so it’s important to report symptoms as soon as possible.

If you have any of the following symptoms contact your local A&E department, GP or treatment team straight away:

  • pain, redness or discolouration, heat and swelling of the calf, leg or thigh
  • swelling, redness or tenderness where a central line is inserted to give chemotherapy, for example in the arm, chest area or up into the neck
  • shortness of breath
  • tightness in the chest
  • unexplained cough (may cough up blood)

Find out more about blood clots.

Sex, contraception and pregnancy

You’re advised not to become pregnant while having treatment because FEC can harm a developing baby. If you haven’t been through the menopause, talk to your team about the most suitable method of birth control for you. It’s still possible to become pregnant even if your periods become irregular or stop completely.

You can still have sex during treatment. It’s thought that chemotherapy drugs can’t pass into vaginal fluids or semen, but this can’t be completely ruled out as chemotherapy drugs can pass into the blood and some other body fluids. Most hospital specialists will advise using barrier methods of contraception, such as condoms, for a few days after chemotherapy is given. 

Find out more about how breast cancer and its treatment can affect sex and intimacy and read our tips on how to manage these changes.

Travel and vaccinations

If you’re planning a holiday or need to travel overseas, check with your treatment team first. 

You shouldn’t have any live vaccines while you’re having chemotherapy. Live vaccines include measles, rubella (German measles), polio, BCG (tuberculosis), shingles and yellow fever. 

Live vaccines contain a small amount of live virus or bacteria. If you have a weakened immune system, which you may do during chemotherapy, they could be harmful.

It’s safe to have these vaccinations six months after your treatment finishes. Talk to your GP or treatment team before having any vaccinations.

If someone you live with needs to have a live vaccine speak to your treatment team or GP. They can advise what precautions you may need to take depending on the vaccination.

Flu vaccination

Anyone at risk of a weakened immune system, and therefore more prone to infection, should have the flu vaccine. This includes people due to have or already having chemotherapy. The flu vaccine is not a live vaccine so doesn’t contain any active viruses. If you’re already having chemotherapy, talk to your chemotherapy team or breast care nurse about the best time to have your flu jab.

Last reviewed: January 2019
Next planned review begins 2021

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