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.

Chemoradiotherapy is the most common treatment for anal cancer if your cancer hasn't spread to other parts of your body. The chemotherapy drugs mostly used with radiotherapy are mitomycin C and fluorouracil (5FU).

This page is about treatment for cancer that hasn’t spread to another part of the body. We have information about chemotherapy for advanced anal cancer.

When you have it

Chemoradiotherapy is the most common treatment for anal cancer if your cancer hasn't spread to other parts of your body. So, you might have it if your cancer is:

  • stage 1 to 3 in the anal canal
  • stage 2 to 3 in the anal margin

Chemotherapy after surgery

Some people might have low dose chemoradiotherapy after surgery for stage 1 cancer of the anal margin. This is usually when there is a risk that some cancer cells might have been left behind.

Types of chemotherapy

You usually have a combination of chemotherapy drugs with radiotherapy. The most common types of chemotherapy are:

  • mitomycin C and fluorouracil (5FU)
  • mitomycin C and capecitabine

Check the name of the chemotherapy treatment with your doctor or nurse, then find out about it on our A to Z list of cancer drugs.

How you have chemotherapy

You have mitomycin and fluorouracil into your bloodstream. Capecitabine is a tablet.

Into your bloodstream

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

Or you might have treatment through a long line: a central line, a PICC line or a portacath. These are long plastic tubes that give the drug into a large vein in your chest. The tube stays in place throughout the course of treatment. This means your doctor or nurse won't have to put in a cannula every time you have treatment.

Taking your tablets

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

Speak to your pharmacist if you have problems swallowing the tablets.

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

You should take the right dose, no more or less.

Talk to your healthcare team before you stop taking a cancer drug or if you miss a dose.

Treatment cycles

You take some cancer medicines in treatment cycles. This means you take the drug for a set period, followed by a break. For example, you might take a drug every day for a week and then not take it for 2 weeks. This 3 week period in total is one cycle of treatment.

Take your cancer drugs exactly as your doctor, specialist nurse or pharmacist has told you to. The break from treatment is important too. For many cancer drugs, it allows your body to recover.

Where you have chemotherapy

You usually have treatment into your bloodstream at the cancer day clinic. You might sit in a chair for a few hours so it’s a good idea to take things in to do. For example, newspapers, books or electronic devices can all help to pass the time. You can usually bring a friend or family member with you.

You have some types of chemotherapy over several days. You might be able to have some drugs through a small portable pump that you take home.

For some types of chemotherapy you have to stay in a hospital ward. This could be overnight or for a couple of days.

Some hospitals may give certain chemotherapy treatments to you at home. Your doctor or nurse can tell you more about this.

Watch the video below about what happens when you have chemotherapy. It is almost 3 minutes long.

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.

Before you start chemotherapy

You need to have blood tests to make sure it’s safe to start treatment. You usually have these a few days before or on the day you start treatment. You have blood tests before each round or cycle of treatment.

Your blood cells need to recover from your last treatment before you have more chemotherapy. Sometimes your blood counts are not high enough to have chemotherapy. If this happens, your doctor usually delays your next treatment. They will tell you when to repeat the blood test. 

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.

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.

The most common side effects are: 

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

Other side effects can include:

  • feeling sick
  • loss of appetite
  • losing weight
  • a lower resistance to infections
  • bleeding and bruising easily
  • constipation
  • hair loss

Contact your doctor or nurse immediately if you have signs of infection. These include a temperature above 37.5C or below 36C, or generally feeling unwell. Infections can make you very unwell very quickly.

Side effects depend on:

  • which drugs you have
  • how much of each drug you have
  • how you react

Tell your treatment team about any side effects that you have.

Dietary or herbal supplements and chemotherapy

Let your doctors know if you:

  • take any supplements
  • have been prescribed anything by alternative or complementary therapy practitioners

It’s unclear how some nutritional or herbal supplements might interact with chemotherapy. Some could be harmful.

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