Anal cancer research

All treatments must be fully researched before they can be adopted as standard treatment for everyone. This is so that

• We can be sure they work
• We can be sure they work better than the treatments that are available at the moment
• They are known to be safe

First of all, treatments are developed and tested in laboratories. For ethical and safety reasons, experimental treatments must be tested in the laboratory before they can be tried in patients. If a treatment described here is said to be at the laboratory stage of research, it is not ready for patients and is not available either within or outside the NHS.

Tests in patients are called clinical trials. The trials and research section has information about what trials are. If you are interested in taking part in a clinical trial, visit our searchable database of clinical trials in the UK and choose 'bowel' and then 'anal' from the drop down menu of cancer types.

If there is a trial you are interested in, print off that page and take it to your own specialist. If the trial is suitable for you, your doctor will need to make the referral to the research team. The database also has information about closed trials and trial results.

All the new approaches covered here are part of ongoing research. Until studies are completed and new effective treatments are found, these potential new treatments cannot be used as standard therapy for cancer of the anus.

Because anal cancer is rare, there are fewer clinical trials than for more common types of cancer. It is hard to organise and run trials for rare cancers. And it can take a long time to recruit the number of patients needed. Getting enough patients is critical to the success of a trial. If the trial is too small, the results won't be powerful enough to prove that one type of treatment is any better than any other.

We know that if you have the human papilloma virus (HPV), you are at greater risk of getting anal cancer. Vaccines have been developed to prevent HPV. The research so far has mainly looked at using the vaccine to prevent cervical cancer. However a recent study looked at giving the HPV vaccine to men who have sex with men, as they have an increased risk of developing anal cancer. This study showed that the vaccine reduced the rates of pre cancerous cell changes in the anus (AIN). If left untreated AIN may develop into anal cancer.

Routine screening for anal cancer is not available at the moment. However, doctors have been looking at whether there is a way that we can screen for anal cancer. One option would be to take cells from the area and examine them under the microscope to look for early changes in the cells. This is called anal cytology.

Doctors in London have carried out an early study to see if they could find early changes in anal cells (AIN) which then may go on to develop into cancer. Just under 100 homosexual or bisexual men had samples of cells taken from the anus. The results of this early investigation showed that it is a reliable way of detecting changes in the cells, and recommended that further research should be carried out.

The researchers chose this group of men because they are at increased risk of developing cancer of the anus. There is information about the risks and causes of anal cancer in the section about cancer of the anus.

Research is going on all the time to try to improve the current treatment for cancer and reduce the amount of side effects people have.

Chemotherapy for anal cancer is usually fluorouracil (5FU) and mitomycin C which you have with radiotherapy. A trial called ACT 2 looked at using the chemotherapy drug cisplatin, instead of mitomycin C, with 5FU. It was also trying to find out whether having further chemotherapy at the end of treatment lowers the chance of the cancer coming back. Early results have suggested that cisplatin is just as good as mitomycin C in treating anal cancer. But there is no benefit in giving further chemotherapy after chemoradiation.

A phase 2 trial called EXTRA looked at using capecitabine instead of 5FU. It means that you don't need to stay in hospital as capecitabine is a tablet rather than a drip. The trial found that it was safe to give and had no more side effects than 5FU. The researchers recommend that a phase 3 trial is now done.

Doctors are looking at finding better ways of giving radiotherapy which reduces the side effects. One of these is intensity modulated radiotherapy (IMRT). This is radiotherapy where both the radiotherapy beam and the dose within the beam are shaped to match the tumour shape and thickness. IMRT gives less radiotherapy to normal tissues compared to standard radiotherapy and research is starting to show that IMRT causes less severe side effects. Early results are encouraging. Long term follow up will confirm if it works as well as standard radiotherapy.

Doctors are now also looking at a new type of IMRT called volumetric modulated arc radiotherapy (VMAT). This is where the radiotherapy machine rotates around the patient during treatment. The machine continuously reshapes and changes the intensity of the radiotherapy beam as it moves around the body. Studies are looking at this new technique for a number of different cancers.

In some countries, there have been trials of sentinel lymph node biopsy for people with anal cancer. This means removing the lymph node, or nodes closest to the anus. These are then checked for cancerous cells. The results help doctors to decide what treatment to offer next. For people whose sentinel lymph nodes are clear, they could reduce the area of the body that is given radiotherapy, keeping side effects to a minimum. But this is still an experimental procedure, and there have not yet been any trials of it in the UK.

To find trials for anal cancer visit our clinical trials database. Select 'bowel', then 'anal' from the drop down menu of cancer types.