Anal cancer

Anal cancer is a rare type of cancer that affects the anus (the end of the bowel).

About 1,300 people are diagnosed with cancer of the anus each year in the UK.

The symptoms of anal cancer are often similar to more common and less serious conditions affecting the anus, such as piles (haemorrhoids) and small tears or sores called anal fissures.

Symptoms of anal cancer can include:

• bleeding from the bottom (rectal bleeding)
• itching and pain around the anus
• small lumps around the anus
• a discharge of mucus from the anus
• loss of bowel control (bowel incontinence)

Some people with anal cancer do not have any symptoms.

See a GP if you develop any of these symptoms. While they're unlikely to be caused by anal cancer, it's best to get them checked out.

Diagnosing anal cancer

A GP will usually ask about your symptoms and carry out some examinations.

They may feel your tummy and carry out a rectal examination. This involves your doctor inserting a gloved finger into your bottom so they can feel any abnormalities.

They'll refer you to hospital if they think further tests are necessary. You should receive an appointment within 2 weeks if there's a chance you might have cancer.

If you're referred to hospital, a number of different tests may be carried out to check for anal cancer and rule out other conditions.

Some of the tests you may have include a:

• sigmoidoscopy – where a thin, flexible tube with a small camera and light is inserted into your bottom to check for any abnormalities
• proctoscopy – where the inside of your rectum is examined using a hollow tube-like instrument (proctoscope) with a light on the end
• biopsy – where a small tissue sample is removed from your anus during a sigmoidoscopy or proctoscopy so it can be examined in a laboratory under a microscope 

If these tests suggest you have anal cancer, you may have some scans to check whether the cancer has spread.

Once these are complete, your doctors will be able to "stage" the cancer. This means giving it a score to describe how large it is and how far it's spread.

You can read more about the stages of anal cancer on the Cancer Research UK website.

If you're diagnosed with anal cancer, you'll be cared for by a team of different specialists who work together to provide the best treatment and care.

The main treatments used for anal cancer are:

• chemoradiation – a combination of chemotherapy and radiotherapy
• surgery – to remove a tumour or a larger section of bowel

If the cancer has spread and cannot be cured, chemotherapy alone may be considered to help relieve symptoms. This is known as palliative care.

Chemoradiation

Chemoradiation is a treatment that combines chemotherapy (cancer-killing medication) and radiotherapy (where radiation is used to kill cancer cells).

It's currently the most effective treatment for anal cancer. You do not usually need to stay in hospital when you're having chemoradiation.

In many cases, part of the chemotherapy is delivered through a small tube called a peripherally inserted central catheter (PICC) in your arm, which can stay in place until your treatment has finished.

The tube means you do not need to stay in hospital during each of the cycles of chemotherapy. But you'll be attached to a small plastic pump, which you take home with you.

A few hospitals now offer tablet chemotherapy for anal cancer, which avoids the need for the pump and PICC.

Find out more about how chemotherapy is carried out

Radiotherapy is usually given in short sessions over several weeks.

Find out more about how radiotherapy is carried out

Both chemotherapy and radiotherapy often cause significant side effects, including:

• tiredness
• sore skin around the anus
• sore skin around the penis and scrotum in men, or vulva in women
• hair loss – limited hair loss from the head, but total loss from the pubic area
• feeling sick
• diarrhoea

These side effects are usually temporary, but there's also a risk of longer term problems, such as infertility.

If you're concerned about the potential side effects of treatment, discuss this with your care team before treatment begins.

Other possible long-term side effects can include:

• bowel control problems
• long-term (chronic) diarrhoea
• erectile dysfunction
• vaginal pain when having sex
• dry and itchy skin around the groin and anus
• bleeding from the anus, rectum, vagina or bladder

Tell your doctor if you develop any of these symptoms so they can be investigated and treated.

Surgery

Surgery is a less common treatment option for anal cancer. It's usually only considered if the tumour is small and can be easily removed, or if chemoradiation has not worked.

If the tumour is very small, it may be cut out during a procedure called a local excision.

This is a relatively simple procedure carried out under general anaesthetic, and usually only requires a stay in hospital of a few days.

If chemoradiation has not been successful or the cancer has returned after treatment, a more complex operation called an abdominoperineal resection may be recommended.

As with a local excision, this operation is carried out under general anaesthetic.

An abdominoperineal resection involves removing your anus, rectum, part of the colon, some surrounding muscle tissue, and sometimes some of the surrounding lymph nodes (small glands that form part of the immune system) to reduce the risk of the cancer returning.

You'll usually need to stay in hospital for a bit longer after this type of surgery.

During the operation, a permanent colostomy will also be formed to allow you to pass poo.

This is where a section of the large intestine is diverted through an opening made in your tummy called a stoma. The stoma is attached to a pouch that will collect your poo after the operation.

Before and after the operation, you'll see a specialist nurse who can offer support and advice to help you adapt to life with a colostomy.

Adjusting to life with a colostomy can be challenging, but most people get used to it over time.

Find out more about living with a colostomy

Follow-up

After your course of treatment ends, you'll need to have regular follow-up appointments to monitor your recovery and check for any signs of the cancer returning.

To start with, these appointments will be every few weeks or months, but they'll gradually become less frequent over time.

The exact cause of anal cancer is unknown, although a number of factors can increase your risk of developing the condition.

These include:

• infection with human papillomavirus (HPV) – a common and usually harmless group of viruses spread through sexual contact, which can affect the moist membranes lining your body
• having anal sex or lots of sexual partners – possibly because this increases your risk of developing HPV
• having a history of cervical, vaginal or vulval cancer
• smoking
• having a weakened immune system – for example, if you have HIV

Your risk of developing anal cancer increases as you get older, with half of all cases diagnosed in people aged 65 or over.

The condition is also more common in women than men.

Outlook

The outlook for anal cancer depends on how advanced the condition is when it's diagnosed. The earlier it's diagnosed, the better the outlook.

Compared with many other types of cancer, the outlook for anal cancer is generally better because treatment is often very effective.

Read more about anal cancer survival statistics on the Cancer Research UK website.

Further information about anal cancer

• Cancer Research UK: anal cancer
• Macmillan: anal cancer