Treatment for anal cancer

This treatment combines a course of radiation therapy with some chemotherapy sessions. The chemotherapy makes the cancer cells more sensitive to the radiation therapy.

For anal cancer, a typical treatment plan might involve a session of radiation therapy every weekday for several weeks, as well as chemotherapy on some days during the first and fifth weeks. This approach allows for lower doses of radiation therapy.

Radiation therapy – Also known as radiotherapy, this treatment uses targeted radiation, such as x-ray beams, to kill or damage cancer cells.  Treatment is carefully planned to do as little harm as possible to the normal body tissue around the cancer. During a treatment session, you lie under a machine that delivers radiation to the treatment area. It usually takes 10–20 minutes to set up the machine, but the treatment itself takes only a few minutes and is painless. You will be able to go home afterwards.

Download our booklet ‘Understanding Radiation Therapy’

Chemotherapy – This is the treatment of cancer with anti-cancer (cytotoxic) drugs. It aims to kill cancer cells while doing the least possible damage  to healthy cells. For anal cancer, the drugs are usually given into a vein through an intravenous (IV) drip.

Download our booklet ‘Understanding Chemotherapy’

Side effects of chemoradiation

Both radiation therapy and chemotherapy can have side effects. These can occur during or soon after the treatment (early side effects), or many  months or years later (late side effects).

Early side effects – These usually settle down in the weeks after treatment. They may include:

• tiredness
• appetite loss, nausea and vomiting – nausea and vomiting are usually prevented with medicines
• bowel changes, such as diarrhoea and more frequent, urgent or painful bowel movements
• passing urine more often, experiencing pain when urinating, or leaking urine (incontinence)
• skin changes, with redness, itching, peeling or blistering around the anus, genital areas and groin – your team will recommend creams for this
• pain in the anal region – talk to your treatment team about a pain management plan
• increased risk of infection – if you have a temperature over 38°C, contact your doctor or go to a hospital emergency department
• loss of pubic hair.

Late side effects – These can occur several months, or even years, after treatment ends. They vary a lot from person to person, but may include:

• bowel changes, with scar tissue in the anal canal or rectum leading to ongoing frequent, urgent or painful bowel movements
• dryness, shortening or narrowing of the vagina (vaginal stenosis) – can be prevented or minimised by using vaginal dilators regularly
• impacts on sexuality, including painful intercourse, difficulty getting erections or loss of pleasure
• effects on the ability to have children (fertility).

Effects on sexuality and fertility

Chemoradiation for anal cancer can have a range of effects on sexuality and may also affect fertility. Ask your doctor about ways to manage these
changes, as early treatment and support can help.

Download our booklet ‘Sexuality, Intimacy and Cancer’

Download our booklet ‘Fertility and Cancer’

Surgery may be used to treat very early anal cancer or in a small number of other situations.

Surgery for very small tumours – An operation called local excision can remove very small tumours located near the entrance of the anus (anal  margin) if they are not too close to the muscles of the anus. The surgeon will give you a local or general anaesthetic and insert an instrument into the anus to remove the tumours. Once the wound heals, the anal canal will still work in the normal way.

Abdominoperineal resection – For most people with anal cancer, chemoradiation is the main treatment. It is usually very effective and allows you
to keep your anal canal. A major operation called an abdominoperineal resection may be an option if you cannot have chemoradiation because you have previously had radiation therapy to the pelvic region. This operation may also be used if anal cancer comes back after chemoradiation.

In an abdominoperineal resection, the anus, rectum and part of the colon (large bowel) are removed. The surgeon uses the remaining colon to create a permanent stoma, an opening in the abdomen that allows faeces to leave the body. A stoma bag is worn on the outside of the body to collect the faeces.

For more information about this surgical procedure and about stomas see ‘Treatment for bowel cancer‘.