Chemotherapy uses drugs to treat cancer and it is a common treatment for anal cancer. It is often given with radiotherapy (called chemoradiation).

What is chemotherapy?

Chemotherapy uses anti-cancer (cytotoxic) drugs to destroy cancer cells. These drugs disrupt the growth of cancer cells, but they also affect normal cells. The chemotherapy drugs are usually given by injection into a vein (intravenously) or as tablets.

How chemotherapy is given

For people with anal cancer, chemotherapy is usually given in combination with radiotherapy (chemoradiation). Chemotherapy can also be used on its own if the cancer has spread to other parts of the body. It may help control the cancer and improve symptoms.

The most commonly used chemotherapy drugs for anal cancer are:

Other drugs that may be used are:

Common side effects of chemotherapy

Chemotherapy can sometimes cause side effects. But if the cancer is causing symptoms, it can also make you feel better by relieving them. Most people have some side effects from chemotherapy. Your doctor or nurse will tell you more about what to expect.

Tell them about any side effects you have, as they can usually be well controlled with medicines.

We describe the common side effects here. Although they can be hard to deal with, they usually slowly disappear when your treatment finishes.

Risk of infection

Chemotherapy can reduce the number of white blood cells in your blood. These cells fight infection. If the number of white blood cells is low, you are more likely to get an infection. A low white blood cell count is called neutropenia.

If you have an infection, it is important to treat it as soon as possible. Contact the hospital straight away on the 24-hour contact number you have if:

  • your temperature goes over 37.5°C (99.5F) or over 38°C (100.4F), depending on the advice given by your chemotherapy team
  • you suddenly feel unwell, even with a normal temperature
  • you have symptoms of an infection.

Symptoms of an infection include:

  • feeling shivery
  • a sore throat
  • a cough
  • diarrhoea
  • needing to pass urine often.

The number of white blood cells will usually return to normal before your next treatment. You will have a blood test before having more chemotherapy. If your white blood cell count is low, your doctor may delay your treatment for a short time.

We have information about avoiding infections.

Bruising and bleeding

Chemotherapy can reduce the number of platelets in your blood. Platelets are cells that help the blood to clot. If you develop any unexplained bruising or bleeding, such as nosebleeds, bleeding gums, blood spots or rashes on the skin, contact your doctor or the hospital straight away.

Anaemia (low number of red blood cells)

If chemotherapy reduces the number of red blood cells in your blood, you may become very tired and feel you have no energy. You may also become breathless and feel dizzy and light-headed. These symptoms happen because the red blood cells contain haemoglobin, which carries oxygen around the body.

If your haemoglobin is low you may be offered a blood transfusion. You’ll feel more energetic and any breathlessness will be eased.

Tiredness (fatigue)

You're likely to become tired and have to take things slowly. Try to pace yourself and save your energy for things that you want to do or that need doing. Balance rest with some physical activity – even going for short walks will help increase your energy levels.

Feeling sick or being sick

Some chemotherapy drugs can make you feel sick (nauseated) or possibly be sick (vomit). Your cancer specialist will prescribe anti-sickness (anti-emetic) drugs to prevent this. Let your doctor or nurse know if your anti-sickness drugs are not helping, as there are several different types you can try.


Some chemotherapy drugs used to treat anal cancer can cause diarrhoea. This often starts several days after the treatment. If you’re taking chemotherapy tablets or capsules at home, it’s important to let your doctor or nurse know if you have diarrhoea. Your treatment may need to be stopped until the diarrhoea is better. It’s important to drink plenty of fluids if you have diarrhoea. You may also be able to help control it by eating a low-fibre diet.

Sore mouth

Chemotherapy can cause mouth problems such as a sore mouth, mouth ulcers or infection. Drinking plenty of fluids, and cleaning your teeth regularly and gently with a soft toothbrush can help to reduce the risk of this happening. Your chemotherapy nurse will explain how to look after your mouth to reduce the risk of problems. They can give you mouthwashes, medicines and gels to help.

Sore hands and feet

This is sometimes known as palmar-plantar or hand-foot syndrome. It can be caused by capecitabine or 5FU, but gets better when treatment ends. Your doctor or nurse may prescribe creams to improve the symptoms. Using non-perfumed moisturising creams can help to relieve symptoms. It can help to keep your hands and feet cool and to avoid tight-fitting socks, shoes and gloves.


Some chemotherapy drugs can affect whether you can get pregnant or father a child. If you are worried about this, it is important to talk with your doctor before you start chemotherapy treatment. We have more information on fertility for men and fertility for women.


Your doctor will advise you not to get pregnant or father a child while having this treatment and for some time afterwards. The drugs may harm the developing baby. It is important to use effective contraception.


If you have sex within the first couple of days of having chemotherapy, you need to use a condom. This is to protect your partner in case there is any chemotherapy in semen or vaginal fluid. We have more information on coping with changes to your sex life.

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