A new genetic test could be an accurate and inexpensive way to find and treat those at highest risk of anal cancer.

The early research by Queen Mary University of London (QMUL) found that the test could lead to a reduction in painful procedures and minimise the over-treatment of people at low risk.

Anal cancer is mostly caused by human papillomavirus (HPV) - the same virus that causes cervical cancer. Diagnosis presents many challenges. Full biopsies are painful, and taking a small sample of cells ('cytology') is problematic because lesions can be hidden and clinicians give varying interpretations of results.

High-resolution anoscopy, where the anal canal is examined with a high resolution magnifying instrument, is often used as the primary screening tool for high-risk populations but is uncomfortable for the patient, expensive, complex and generates subjective results.

Once developed, the test would involve taking a small sample of cells from the anal canal via a swab and then sending the sample off to a laboratory for epigenetic analysis.

While a test could be developed within five years, the researchers caution that the results first need to be confirmed in a much larger study across the UK, and repeated using swab samples rather than the biopsies which were used in the current study.