Fluorouracil (5FU) and mitomycin C

Fluorouracil (5FU) and mitomycin C is the name of a chemotherapy combination. It is a treatment for anal, vulva and bladder cancer.

What is fluorouracil (5FU) and mitomycin C?

Fluorouracil (5FU) and mitomycin C is a chemotherapy combination that includes: 

  • mitomycin C
  • fluorouracil (5FU or FU)

It is a treatment for:

  • anal cancer
  • a type of bladder cancer called muscle invasive bladder cancer
  • vulval cancer that has spread to surrounding tissues and not suitable for surgery (locally advanced vulva cancer)

You usually have it alongside a course of radiotherapy. This combined treatment is called chemoradiotherapy.

How does fluorouracil (5FU) and mitomycin C work?

These chemotherapy drugs destroy quickly dividing cells, such as cancer cells.

How do you have fluorouracil (5FU) and mitomycin C?

You have mitomycin and fluorouracil into your bloodstream. You may be able to have the infusions of 5FU at home if you have a central line.

To have the 5FU at home, you need to have the infusions through a small pump. You can keep the pump in a small bag, or a bag on a belt (like a bum bag). You’ll need to go back to the hospital to have the pump changed or taken down. Or sometimes a chemotherapy nurse may be able to do this at your home.

Into your bloodstream

You might have treatment through a long plastic tube that goes into a large vein in your chest. The tube stays in place throughout the course of treatment. This can be a:

  • central line
  • PICC line
  • portacath

You might have treatment through a thin short tube (a cannula) that goes into a vein in your arm. You have a new cannula each time you have treatment.

How often do you have 5FU and mitomycin C?

You usually have fluorouracil and mitomycin as a course of several cycles of treatment Open a glossary item. Each cycle varies depending on what type of cancer you have. Your doctor or nurse will tell you more about this.


You have blood tests before and during your treatment. They check your levels of blood cells and other substances in the blood. They also check how well your liver and kidneys are working.

What are the side effects of 5FU and mitomycin C?

We haven't listed all the side effects. It's very unlikely that you will have all of these side effects, but you might have some of them at the same time.

How often and how severe the side effects are can vary from person to person. They also depend on what other treatments you're having. For example, your side effects could be worse if you're also having other drugs or radiotherapy.

When to contact your team

Your doctor, nurse or pharmacist will go through the possible side effects. They will monitor you closely during treatment and check how you are at your appointments. Contact your advice line as soon as possible if:

  • you have severe side effects
  • your side effects aren’t getting any better
  • your side effects are getting worse

Early treatment can help manage side effects better. 

Contact your doctor or nurse immediately if you have signs of infection, including a temperature above 37.5C or below 36C or if you develop a severe skin reaction. Signs of a severe skin reaction include peeling or blistering of the skin.

Common side effects

These side effects happen in more than 10 in 100 people (more than 10%). You might have one or more of them. They include:

Risk of infection 

Increased risk of getting an infection is due to a drop in white blood cells. Symptoms include a change in temperature, aching muscles, headaches, feeling cold and shivery and generally unwell. You might have other symptoms depending on where the infection is.

Infections can sometimes be life threatening. You should contact your advice line urgently if you think you have an infection. 


You might be breathless and look pale due to a drop in red blood cells. This is called anaemia.

Bruising and bleeding

This is due to a drop in the number of platelets in your blood. These blood cells help the blood to clot when we cut ourselves. You may have nosebleeds or bleeding gums after brushing your teeth. Or you may have lots of tiny red spots or bruises on your arms or legs (known as petechiae).

Difficulty breathing 

You might have a sudden feeling of tightness in your chest, difficulty catching your breath, wheezing and a cough. This is caused by spasms in the muscles of your airways. Contact your healthcare advice line or tell your doctor.

Feeling generally unwell

Speak to your doctor or nurse if you feel generally unwell after having this treatment.

Feeling weak

You might feel weak while having this treatment. 

Loss of appetite

You might lose your appetite for various reasons while having cancer treatment. Sickness, taste changes or tiredness can put you off food and drinks.

Feeling or being sick

Feeling or being sick is usually well controlled with anti sickness medicines. It might help to avoid fatty or fried foods, eat small meals and snacks and take regular sips of water. Relaxation techniques might also help.

It is important to take anti sickness medicines as prescribed even if you don’t feel sick. It is easier to prevent sickness rather than treat it once it has started.

A sore mouth

Mouth sores and ulcers can be painful. It helps to keep your mouth and teeth clean, drink plenty of fluids and avoid acidic foods such as lemons. Chewing gum can help to keep your mouth moist. Tell your doctor or nurse if you have ulcers.

Inflammation of the digestive system

This treatment may cause inflammation of the digestive system Open a glossary item. This can cause pain and soreness.

It might include one or all of the following:

  • the throat
  • the tummy (stomach)
  • the back passage (rectum)

You can have painkillers to reduce the soreness. Take them half an hour before meals to make eating easier. Your nurse, doctor or dietician will explain the best foods to have if you have any of these symptoms.


Contact your advice line if you have diarrhoea. For example, in one day you have 2 or more loose bowel movements than usual. If you have a stoma, you might have more output than normal. Your doctor may give you anti diarrhoea medicine to take home with you after treatment.

Try to eat small meals and snacks regularly. It’s best to try to have a healthy balanced diet if you can. You don’t necessarily need to stop eating foods that contain fibre. But if your diet is normally very high in fibre, it might help to cut back on high fibre foods such as beans, nuts, seeds, dried fruit, bran and raw vegetables. 

Drink plenty to try and replace the fluid lost. Aim for 8 to 10 glasses per day.

Heart problems

You might have heart rhythm changes picked up on a heart trace (ECG). Less commonly it can cause chest pain. Other heart problems include a heart attack or problems with your heart muscle not working properly to pump blood around the body, but these are rare.  

Tell your doctor or nurse straight away if you have any chest pain.

Soreness, redness and peeling of palms and soles (hand foot syndrome)

The skin on your hands and feet may become sore, red, or may peel. You may also have tingling, numbness, pain and dryness. This is called hand-foot syndrome or palmar plantar syndrome.

Moisturise your skin regularly. Your healthcare team will tell you what moisturiser to use.

Hair loss

You could lose all your hair. This includes your eyelashes, eyebrows, underarms, legs and sometimes pubic hair. Your hair will usually grow back once treatment has finished but it is likely to be softer. It may grow back a different colour or be curlier than before. 

Raised uric acid levels in the blood

High levels of uric acid in your blood can lead to a build up of crystals in body tissues and cause inflamed joints. You’ll have regular blood tests to check your levels. Drinking plenty of fluids helps to flush out the excess uric acid. You might also have medicines to control the uric acid levels.

Occasional side effects

These side effects happen in between 1 and 10 out of every 100 people (between 1 and 10%). You might have one or more of them. They include:

  • changes in the way your kidneys work -you have regular blood tests to check this
  • eye problems such as red, gritty, itchy, and watery eyes (conjunctivitis), rarely you might have rapid eye movement side to side, inflammation of the eyelids, blocked tear ducts, sensitivity to light, blurred or double vision, or eyelid turning outwards
  • redness, swelling or leaking at your drip site. Tell your nurse or doctor straight away if you notice this
  • skin problems such as a rash or skin that becomes dry and itchy (contact dermatitis), you might have increased sensitivity to sunlight, hives, or darkening of the skin, but this is rare.

Rare side effects

This side effects happens in fewer than 1 in 100 people (fewer than 1%). You might have one or more of them. They include:

  • confusion or unsteadiness
  • an allergic reaction that can cause a rash, shortness of breath, redness or swelling of the face and dizziness
  • feeling happy and excited
  • shaking and trembling
  • stiffness and slow movement (symptoms of Parkinson's disease)
  • headaches
  • dizziness
  • low blood pressure that can make you feel faint and dizzy
  • nail problems including thickening, pain, changes in colour of the nail and nail bed
  • changes to how your liver works - you have regular blood tests to check this
  • dark or discoloured veins around the injection site
  • difficulty getting to sleep and sleeping
  • a blood disorder called haemolytic anaemia where the red blood cells are destroyed faster than they can be made

Coping with side effects

We have more information about side effects and tips on how to cope with them.

What else do I need to know?

DPD Deficiency

Between 2 and 8 out of 100 people (2 to 8%) have low levels of an enzyme called dihydropyrimidine dehydrogenase (DPD) in their bodies. A lack of DPD can mean you’re more likely to have severe side effects from capecitabine or fluorouracil. It might take you a bit longer to recover from the chemotherapy. These side effects can rarely be life threatening.

Before starting treatment with capecitabine or fluorouracil you have a blood test to check levels of DPD. So you may start treatment with a lower amount (dose) of the drug or have a different treatment. Your doctor or nurse will talk to you about this.

Other medicines, foods and drink

Cancer drugs can interact with some other medicines and herbal products. Tell your doctor or pharmacist about any medicines you are taking. This includes vitamins, herbal supplements and over the counter remedies.

Pregnancy and contraception

This treatment may harm a baby developing in the womb. It is important not to become pregnant or get someone pregnant while you're having treatment and for at least 6 months afterwards.

Talk to your doctor or nurse about effective contraception before starting treatment. Let them know straight away if you or your partner become pregnant while having treatment. 

Loss of fertility

You may not be able to become pregnant or get someone pregnant after treatment with these drugs. Talk to your doctor before starting treatment if you think you may want to have a baby in the future.

Men might be able to store sperm before starting treatment. And women might be able to store eggs or ovarian tissue. But these services are not available in every hospital, so you would need to ask your doctor about this.    


Don’t breastfeed during this treatment. This is because the drugs may come through in your breast milk.

Treatment for other conditions 

If you are having tests or treatment for anything else, always mention your cancer treatment. For example, if you are visiting your dentist.


Don’t have immunisations with live vaccines while you’re having treatment and for up to 12 months afterwards. The length of time depends on the treatment you are having. Ask your doctor or pharmacist how long you should avoid live vaccinations.

In the UK, live vaccines include rubella, mumps, measles, BCG, yellow fever and one of the shingles vaccines called Zostavax.

You can have:

  • other vaccines, but they might not give you as much protection as usual
  • the flu vaccine (as an injection)
  • the coronavirus (COVID-19) vaccine - talk to your doctor or pharmacist about the best time to have it in relation to your cancer treatment

Members of your household who are aged 5 years or over are also able to have the COVID-19 vaccine. This is to help lower your risk of getting COVID-19 while having cancer treatment and until your immune system Open a glossary item recovers from treatment.

Contact with others who have had immunisations - You can be in contact with other people who have had live vaccines as injections. Avoid close contact with people who have recently had live vaccines taken by mouth (oral vaccines) such as the oral typhoid vaccine. Sometimes people who have had the live shingles vaccine can get a shingles type rash. If this happens they should keep the area covered.

If your immune system is severely weakened, you should avoid contact with children who have had the flu vaccine as a nasal spray as this is a live vaccine. This is for 2 weeks following their vaccination.

Babies have the live rotavirus vaccine. The virus is in the baby’s poo for about 2 weeks and could make you ill if your immunity is low. Get someone else to change their nappies during this time if you can. If this isn't possible, wash your hands well after changing their nappy.

More information about this treatment

For further information about this treatment and possible side effects go to the electronic Medicines Compendium (eMC) website. You can find the patient information leaflet on this website.

You can report any side effect you have to the Medicines Health and Regulatory Authority (MHRA) as part of their Yellow Card Scheme.

  • Electronic Medicines Compendium 
    Accessed September 2021

  • Immunisation against infectious disease: Chapter 6: General contraindications to vaccination
    Public Health England
    First published: March 2013 and regularly updated on the Gov.UK website

  • Chemoradiation with 5-fluorouracil and mitomycin C in the treatment of vulvar squamous cell carcinoma
    N Mulayim and others 
    Gynaecology Oncology, 2004. Volume 93, Issue 3, pages 659-666

  • Consent forms for SACT (Systemic Anti-Cancer Therapy)​
    Cancer Research UK, Accessed September 2021

  • A comparison between 5-fluorouracil/mitomycin and capecitabine/mitomycin in combination with radiation for anal cancer

    Renata D’Alpino Peixoto,

    Journal of gastrointestinal oncology,  2016. Volume 7, Issue 4, Pages  665–672

Last reviewed: 
29 Jul 2021
Next review due: 
29 Jul 2024

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