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Fluorouracil (5FU) and mitomycin C


What fluorouracil and mitomycin is

Having chemotherapy alongside a course of radiotherapy is the standard treatment for anal cancer. This combined treatment is called chemoradiation.

The chemotherapy drugs used are

Fluorouracil is also called FU or 5FU. The links above take you to information about the side effects of these individual chemotherapy drugs.


How you have this treatment

You have mitomycin and fluorouracil into your bloodstream (intravenously). You can have them through a thin, short tube (a cannula) put into a vein in your arm each time you have treatment. Or you may have them through a central line, a portacath or a PICC line. These are long, plastic tubes that give the drugs directly into a large vein in your chest. You have the tube put in just before your course of treatment starts and it stays in place as long as you need it.

On the first day of your treatment, you have an injection of mitomycin. You will also start an infusion of fluorouracil that lasts for 4 days. You may stay in hospital while having your chemotherapy.

You start radiotherapy to the anal area on the same day as you begin chemotherapy. You then continue having radiotherapy every weekday (Monday to Friday) for approximately 5 weeks. You have between 25 and 28 sessions (fractions). You can usually go home once your 4 days of chemotherapy are finished if you feel well enough. And you carry on having radiotherapy as an outpatient.

At the beginning of the fifth week of your radiotherapy treatment you have another 4 day drip (infusion) of fluorouracil.

The side effects of a combination of drugs or treatments are usually a mixture of the effects of each drug. You may get some or all of the side effects. The combination of drugs and radiotherapy treatment may increase the risk of getting some side effects. Or it may make some side effects more severe.

The side effects associated with this chemotherapy combination are listed below. The underlined links take you to information about each side effect. For more information on general side effects see our cancer drugs side effects section.


Common side effects

More than 10 in every 100 people have one or more of the side effects listed below.

A temporary drop in the number of blood cells made by the bone marrow, causing

  • An increased risk of getting an infection from a drop in white blood cells – it is harder to fight infections and you can become very ill. You may have headaches, aching muscles, a cough, sore throat, pain passing urine, or feel cold and shivery
  • Tiredness and breathlessness due to a drop in red blood cells (anaemia) – you may need a blood transfusion
  • Bruising more easily due to a drop in platelets – you may have nosebleeds, bleeding gums after brushing your teeth, or lots of tiny red spots or bruises on your arms or legs (known as petechia)

Some of these side effects can be life threatening, particularly infections. You should contact your cancer centre if you have any of these effects. Your doctor will check your blood counts regularly to see how well your bone marrow is working.

Other common side effects include

  • Fatigue (tiredness) during and after treatment – most people find their energy levels are back to normal within 6 months to a year
  • Loss of appetite
  • Feeling or being sick – this is usually mild and can be well controlled with anti sickness medicines
  • A sore mouth
  • Diarrhoea – tell your doctor or nurse if this becomes severe, if you cannot drink to replace the lost fluid, or if it carries on for more than 3 days. You may be given medicines to stop this
  • Women may stop having periods (amenorrhoea) – this may be temporary
  • Loss of fertility – it is not known exactly what effect these drugs may have on your fertility. It is important to talk with your doctor before starting treatment if you want to have a child in the future

Occasional side effects

Between 1 and 10 in every 100 people have one or more of these.

  • Hair thinning
  • Brittle, ridged or dark nails
  • Sensitivity of the skin to sunlight – don’t sit out in the sun and do cover up or use sun block on exposed skin
  • Skin rashes, which could be itchy
  • Watery eyes from increased production of tears
  • Gritty eyes and blurred vision
  • Coughing or breathlessness
  • Kidney changes that are mild and unlikely to cause symptoms may occur – they will almost certainly go back to normal when treatment is finished, but you will have regular blood tests to check how well your kidneys are working
  • Brown marking on the skin following the line of the vein where fluorouracil has been injected
  • Some people develop soreness, redness and peeling on the palms of the hands and soles of the feet (palmar - plantar syndrome), which may cause tingling, numbness, pain and dryness
  • Inflammation around the drip site – if you notice any signs of redness, swelling or leaking at your drip site, tell your chemotherapy nurse straight away

Rare side effects

Fewer than 1 in 100 people have these.

  • Total hair loss but the hair will grow back once the treatment ends
  • Damage to heart muscle, which is usually temporary but for a small number of people may be permanent – your doctor or nurse will check your heart before and after your treatment
  • Confusion or unsteadiness

Radiotherapy side effects

Radiotherapy also has side effects and you can find information about side effects of radiotherapy for anal cancer and possible long term radiotherapy side effects in the anal cancer section. Having radiotherapy as well as chemotherapy can make side effects more severe.


Important points to remember

Not everyone will get these side effects. You may have 1 or 2 or several. A side effect may get worse through your course of treatment. Or you may have more side effects as the course goes on. This depends on

  • How many times you've had a drug before
  • Your general health
  • How much of the drug you have (the dose)
  • Other drugs you are having

Talk to your doctor, pharmacist or nurse about all your side effects so they can help you manage them. They can give you advice or reassure you. Your nurse will give you a contact number to ring if you have any questions or problems. If in doubt, call them.

Tell your doctor about any other medicines you are taking, including vitamins, herbal supplements and over the counter remedies – some drugs can react together.

These drugs may have a harmful effect on a baby developing in the womb. It is not advisable to become pregnant or father a child if you are having this treatment. Talk about contraception with your doctor or specialist nurse before starting the treatment.

Breastfeeding is not advisable during this treatment because the drug may come through in the breast milk.


Immunisations and chemotherapy

You should not have immunisations with live vaccines while you are having chemotherapy or for at least 6 months afterwards. In the UK, these include rubella, mumps, measles (usually given together as MMR), BCG, yellow fever and Zostavax (shingles vaccine).

You can have other vaccines, but they may not give you as much protection as usual until your immune system has fully recovered from your chemotherapy. It is safe to have the flu vaccine.

It is safe for you to be in contact with other people who've had live vaccines as injections. There can be problems with vaccines you take by mouth (oral vaccines), but not many people in the UK have these now. So there is usually no problem in being with any baby or child who has recently had any vaccination in the UK. You might need to make sure that you aren't in contact with anyone who has had oral polio, cholera or typhoid vaccination recently, particularly if you live abroad.


More information about this treatment

This information does not list all the very rare side effects of this treatment that are very unlikely to affect you. For further information look at the Electronic Medicines Compendium website at

If you have a side effect not mentioned here that you think may be due to this treatment you can report it to the Medicines Health and Regulatory Authority (MHRA) at

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Updated: 15 March 2013