Chemoradiotherapy for anal cancer

Chemoradiotherapy means having chemotherapy and radiotherapy treatment together.

Chemotherapy uses anti cancer (cytotoxic) drugs to destroy cancer cells. The drugs circulate throughout the body in the bloodstream.

Radiotherapy uses high energy waves similar to x-rays to kill cancer cells.

When do you have chemoradiotherapy for anal cancer?

Chemoradiotherapy is the most common treatment for anal cancer if your cancer hasn't spread to other parts of your body. 

You might have surgery after chemoradiotherapy if it hasn't been successful or your cancer comes back. 

What chemotherapy will I have?

Your exact treatment plan will depend on what your treatment team thinks is best for you.

The most common treatment is a combination of the chemotherapy drugs mitomycin C and fluorouracil (5FU). You have these drugs through a drip.

You might have a drug called capecitabine instead of fluorouracil (5FU). You take this as a tablet.

Having fluorouracil and mitomycin C

You have mitomycin and fluorouracil into your bloodstream. You start chemotherapy on the same day that you have your first radiotherapy treatment. 

You have:

  • mitomycin on day 1
  • 5FU as a continuous infusion from day 1 to day 4

You then have no chemotherapy treatment but continue to have radiotherapy for several weeks.

At the beginning of week 5 of radiotherapy you have:

  • 5FU as a continuous infusion from day 1 to day 4

You might need to stay in hospital while you have your chemotherapy treatments. Or you might be able to have the infusions of 5FU though a portable pump at home if you have a central line. A central line is a long plastic tube that goes into a large vein in your chest. The tube stays in place throughout the course of treatment. 

Taking capecitabine tablets

You must take tablets according to the instructions your doctor or pharmacist gives you.

Whether you have a full or empty stomach can affect how much of a drug gets into your bloodstream.

You should take the right dose, not more or less.

Never stop taking a cancer drug without talking to your specialist first.

Radiotherapy treatment

On the first day of chemotherapy you also have your first radiotherapy treatment.

You have treatment in the hospital radiotherapy department.

Before you begin treatment, the radiotherapy team work out how much radiation you need. They divide it into a number of smaller treatments. They call each treatment a fraction. At your planning appointment the radiographers might make pen marks or small tattoos on your skin in the treatment area.

Your treatment starts a few days or up to 3 weeks after the planning session. You have radiotherapy from an external machine as a daily treatment, five days a week for around 5 weeks.

Side effects

You might have side effects from chemoradiotherapy to the anus. These can be more severe than either radiotherapy or chemotherapy on their own.

Side effects can include: 

  • feeling tired 
  • opening your bowels more often (diarrhoea) 
  • sore skin around the anus and groin - which can make opening your bowels more painful

Tell your nurse or doctor if this happens. They can give you painkillers and tell you about how to look after your skin. 

Use only creams or dressings on your skin that your nurse or doctor recommends.

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

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.

Last reviewed: 
03 May 2019
  • Anal cancer: ESMO-ESSO-ESTRO Clinical Practice Guidelines for diagnosis, treatment and follow-up
    R. Glynne-Jones and others.
    Annals of Oncology 2014. Volume 25, Pages iii10-iii20

  • Principles and practice of oncology (10th edition)
    De Vita VT, Lawrence TS and Rosenberg SA
    Lipponcott, Wiliams, Wilkins, 2015

Related links