Anal cancer: symptoms, causes, tests and treatment

The NHS lists the symptoms as bleeding from your bottom, itching and pain around your anus, small lumps around and inside your bottom, a discharge of mucus from your bottom, problems controlling when you poo (bowel incontinence), and needing to poo often with looser, runnier poos. Anal cancer may have no symptoms at all, or they might be hard to spot.

Cancer Research UK says bleeding is the most common symptom, with anal pain and the feeling of a lump in or around the anus also common. Less common symptoms include a sore (ulcer) that does not heal, severe itching around the anus, passing mucus, difficulty controlling your bowels, needing to poo urgently, thin poos, feeling you have not emptied your bowel, and swollen lymph nodes in the groin.

Cancer Research UK adds that passing wind or poo from the vagina can be a symptom of a fistula connecting the anus or rectum to the vagina.

• Bleeding from the bottom, or blood on the paper or in the toilet water.

• Pain, itching or soreness in or around the anus.

• A lump or the feeling of a lump.

• A sore that does not heal.

• Mucus discharge, bowel changes or difficulty controlling your bowels.

• Swollen lumps in the groin.

The NHS says to see a GP if you have symptoms of anal cancer or you notice a change around your anus that is not normal for you. It stresses that these symptoms are very common and can be caused by many different conditions, so having them does not mean you have anal cancer, but that if they are caused by cancer, finding it early means treatment is more likely to be successful.

Cancer Research UK says that blood in your poo with other symptoms such as tiredness or unexpected weight loss, or bleeding for more than 3 weeks with no other symptoms, should be seen by a GP. If your poo is very red or you have very loose poo with blood, it says to see your GP urgently or call NHS 111, and if the bleeding will not stop or there is a lot of blood, call 999 or go to A&E.

The NHS says the GP may ask questions about your health and symptoms, feel your tummy and insert a gloved finger into your bottom to feel for lumps or anything wrong. You may get an urgent referral for more tests, which does not definitely mean you have cancer.

Cancer Research UK describes anal cancer as abnormal cells in the anus dividing in an uncontrolled way. It can start in different parts of the anus and different types of cell. The NHS says anal cancer is rare.

The anus is the opening at the end of the digestive tract through which poo leaves the body. Cancer Research UK notes that anal cancer is separate from cancers in the anal margin (the perianal skin), which have different statistics.

The NHS says most anal cancers are caused by an infection called human papillomavirus (HPV). You can get HPV from any skin-to-skin contact of the genital area, vaginal, anal or oral sex, and sharing sex toys. Anal cancer is rare and most people affected by HPV will not develop cancer.

You may be more likely to get anal cancer, according to the NHS, if you have anal sex, are over the age of 75, smoke, have had cervical, vaginal or vulval cancer, or have a weakened immune system, such as from HIV or an organ transplant.

The NHS says you cannot always prevent anal cancer. HPV vaccination is one of the best ways to protect against it, and all children aged 12 to 13 are offered the HPV vaccine. It is also recommended for other groups at higher risk of HPV, including men aged 45 and under who have sex with men, trans men and trans women aged 45 and under at the same risk, sex workers and people with HIV. Using a condom, keeping sex toys clean and not sharing them, and trying to quit smoking can lower your chances.

Cancer Research UK says the tests your GP might do include an examination of your tummy, anus and rectum, a test for tiny traces of blood in a poo sample (FIT) and blood tests. Not everyone has the FIT; your GP may refer you to a specialist without it if you have a lump or an abnormal looking ulcer.

The NHS says that if a GP refers you to a specialist, the tests may include putting a thin tube with a camera and light into your bottom to check for changes, taking a small sample (biopsy) to be looked at under a microscope, and blood tests. Cancer Research UK says you are usually referred to a lower gastrointestinal clinic, where the specialist usually does an anal examination with a thin tube (anoscopy) and takes a biopsy, often in outpatients under a local anaesthetic.

If the biopsy shows cancer cells, you usually have other tests such as an MRI scan of the pelvis, a CT scan of the chest, tummy and pelvis, a PET-CT scan and sometimes an ultrasound of the groin to check the lymph nodes. The NHS says these tests, with the ones you have already had, help specialists find out the size of the cancer and how far it has spread (the stage). It says you should get results within a few weeks.

The NHS says anal cancer is often treatable when found early. Treatment depends on the size of the cancer, where it is, whether it has spread and your general health. The main treatment is a combination of radiotherapy and chemotherapy, called chemoradiation, which is usually given if the cancer has not spread. The NHS says this means most people with anal cancer do not need to have surgery.

Surgery is sometimes used, for example if the cancer is small and has not spread, if chemoradiation does not get rid of all the cancer or it comes back, or if you cannot have radiotherapy because you have had radiotherapy to the pelvic area before. The NHS says surgery usually involves removing just the part of the anus that is affected. If the cancer has spread or come back, you may need surgery to remove all of the anus, the rectum and part of the bowel, which means a colostomy and support from a specialist stoma nurse.

The specialist care team will explain the treatments, benefits and side effects, work with you to create a treatment plan, help you manage side effects including changes to your diet, and support your recovery. The NHS says you will have regular check-ups during and after treatment and do not need to wait for your next check-up if a symptom worries you.

Cancer Research UK says survival depends on different factors, that no one can tell you exactly how long you will live, and that because anal cancer is less common, survival is harder to estimate and some statistics are based on a small number of people.

For people diagnosed in England between 2015 and 2019, it gives five-year survival of almost 90 out of 100 for stage 1, more than 75 out of 100 for stage 2, around 60 out of 100 for stage 3 and around 20 out of 100 for stage 4. For all stages, 85 out of 100 survive for 1 year or more, more than 60 out of 100 for 5 years or more and more than 50 out of 100 for 10 years or more.

Cancer Research UK says all the symptoms of anal cancer can be caused by other conditions such as piles (haemorrhoids) or an infection, and the NHS says anal cancer symptoms are often similar to piles and anal fissures. Because they overlap, a clinician has to examine you to tell them apart.

Most people start with their GP surgery. The NHS says a GP who thinks symptoms could be cancer may refer you urgently for tests or to a hospital specialist. Treatment is planned by a group of specialists, and the NHS says your team will include a clinical nurse specialist who is your main point of contact.

Private assessment is possible, and treatment is usually given by a specialist cancer team. Whichever route you use, ask who will coordinate your care and how and when you will receive results. Macmillan Cancer Support has a free helpline that the NHS lists as a source of support.