A study looking at screening for anal cancer (ANALOGY)

Cancer type:

Anal cancer





This study looked at the possibility of screening for anal cancer in high risk groups.

More about this trial

The anus is the part of the bowel that opens to the outside of the body. Cancer of the anus (anal cancer) can be caused by an infection called human papilloma virus (HPV). This is the same virus that can cause cervical cancer.
Anal cancer is rare in the general population, but some groups of people are at increased risk. This includes:
  • men who are HIV positive and have sex with men (MSM)
  • people who are HIV negative and have anal sex
  • women who are HIV negative and have had genital warts or abnormal cells 
  • people whose immune system has been affected by having an organ transplant such as a kidney transplant
These people are at higher risk of getting anal HPV, which increases their risk of anal cancer.
In this study, researchers looked at the possibility of screening for anal cancer in these high risk groups. They wanted to:
  • see if people found this type of screening acceptable
  • find out how well it worked

Summary of results

The study team found that screening is possible and acceptable with the high risk group of men who have sex with other men.
This study was open for people to join between March 2013 and March 2015. These results were published in 2016.
About this study
Everyone had:
  • an examination of their anal canal where the doctor inserts a finger into the anus (digital examination)
  • a swab taken from the anal canal
  • an examination of the anal canal using a tube inserted into the anus (an anoscopy)
These examinations were repeated 6 months later.
The swab was sent to a laboratory to see if there were any abnormal cells in the sample.
During the anoscopy small pieces of tissue (biopsy Open a glossary item) was taken from areas that didn’t appear to be normal. These samples were sent to a laboratory for a closer examination of the cells. 
Everyone was tested for the human papilloma virus (HPV).
Everyone filled in questionnaires:
  • when they agreed to join the study 
  • 6 months later
The questions asked were about:
  • level of pain felt during and after the tests
  • how distressing it was waiting for the results 
  • how distressing it was receiving the results
  • willingness to attend for anal cancer screening
  • knowledge of HPV and anal cancer 
Of the 284 men who took part:
  • 203 were HIV positive 
  • 81 were HIV negative
Tests showed that 281 men had HPV. Of these 239 men had a high risk HPV:
  • 176 men were HIV positive
  • 63 men were HIV negative
Of the 279 swab samples looked at in the laboratory, 120 samples had abnormal cells:
  • 92 samples came from men with HIV
  • 8 samples came from men who were HIV negative
In the laboratory the tissue samples taken during the anoscopy were looked at for signs of cancer or early changes in the cells that could lead to cancer. 
These early changes are called anal interepithelial neoplasia (AIN). There are different grades of AIN. From AIN1 to AIN3. The grade relates to the thickness of the surface skin layer that is affected by abnormal cells. AIN3 means that the abnormal cells are in the full thickness of the skin of the anus and needs treatment.
Almost half of the 120 samples had AIN.
17 of these samples were AIN3 (high grade):
  • 14 came from men with HIV
  • 3 came from men who were HIV negative
3 of the 203 men who were HIV positive had cancer cells in their tissue samples. 
On a scale of 0 (no pain) to 10 (worst pain/discomfort) the average level of pain reported during the test was 3.7 and after was 3.8. The pain lasted an average of 3 days after. 
The scale of distress was from 0 (no distress) to 10 (extreme distress). Waiting for the results the mean score was 2.5. Four men reported a score of 8 or more. 
When asked about their distress level on receiving their results, the mean score was 2.3. Five men who were HIV positive reported a score of 8 or higher. 
On their first visit the men were asked about their knowledge regarding HPV and anal cancer. Of the 281 men:
  • 214 men (76.2%) had heard of anal cancer
  • 177 men (63%) had heard of HPV
  • 140 men (49.8%) knew of the link between HPV and anal cancer
On their return visit 167 men filled in the questionnaire about their willingness to have anal screening.
  • 117 men (70.1%) were willing to have screening every year
  • 42 men (25.1) were willing to have screening every 2 to 3 years
  • 6 men (3.6%) were willing to have screening every 4 to 5 years
  • 1 man (0.6%) was willing to have screening every 6 to 10 years
  • 1 man (0.6%) didn’t want screening at all

The study team said that these results demonstrate that anal screening is possible and acceptable among men who have anal sex with other men. 
The frequency of high grade AIN in HIV positive men and HIV negative men was similar to the frequency reported in other studies. 
The 3 cancers found provides evidence of the ability to detect early cancer that don’t cause symptoms as well as the changes that could lead to cancer developing.
The study team are continuing to analyse the information from the other groups of people in the study. When these results are available we will update this summary.
Where this information comes from
We have based this summary on information from the research team. The information they sent us has been reviewed by independent specialists (peer reviewed Open a glossary item) and published in a medical journal. The figures we quote above were provided by the trial team who did the research. We have not analysed the data ourselves.

Recruitment start:

Recruitment end:

How to join a clinical trial

Please note: In order to join a trial you will need to discuss it with your doctor, unless otherwise specified.

Please note - unless we state otherwise in the summary, you need to talk to your doctor about joining a trial.

Chief Investigator

Professor Henry Kitchener

Supported by

Central Manchester University Hospitals NHS Foundation Trust
NHS Cancer Screening Programmes
NIHR Clinical Research Network: Cancer
University of Manchester

If you have questions about the trial please contact our cancer information nurses

Freephone 0808 800 4040

Last review date

CRUK internal database number:


Please note - unless we state otherwise in the summary, you need to talk to your doctor about joining a trial.

Last reviewed:

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