Genetic test for anal cancer could identify those at high risk

Image result for Genetic test for anal cancer could identify those at high risk

Media Release
A new genetic test could be an
accurate and inexpensive way to find and treat those at highest risk of anal
cancer – a disease with growing incidence in women, men who have sex with men
(MSM) and people with HIV.
The early research by Queen
Mary University of London (QMUL), which was funded by Cancer Research UK, finds
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. In
2014, the UK had around 1,300 new cases of anal cancer and 360 deaths. In
addition to rising levels in women and MSM, anal cancer is more common in
HIV-positive MSM with around 100 cases per 100,000, compared to 25 in
HIV-negative MSM, and only 1.5 in men in general.
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.
Lead researcher Professor
Attila Lorincz from QMUL said: “The widespread over-treatment of anal
precancerous lesions is necessary today because we don’t know which ones will
progress to cancer. But this creates a large burden on anoscopy clinics in the
UK and the procedures can be detrimental to people’s quality of life. Many
people are undergoing these procedures unnecessarily, so what we really need is
precision medicine to identify those who do need treatment.”
The research, published in the
journal Oncotarget, involved studying anal biopsy specimens from 148 patients
in London, including 116 men (mostly MSM). The specimens were analysed to look
for genetic markers that may be associated with the presence of anal cancer.
The team specifically looked
at the patients’ ‘epigenetics’1 and found that all of the anal cancers showed
the presence of specific epigenetic markers on the patients’ EPB41L3 gene (a
tumour suppressor gene) and also on certain regions of their viral HPV genome.
The results suggest that
epigenetic testing may be an accurate and thorough method to indicate whether a
patient’s lesions are destined to progress to anal cancer. This could reduce
the costs, pain and anxiety from other methods of diagnosis, and minimise
over-treatment of low risk people.
Professor Lorincz added:
“We believe this new set of biomarkers goes a long way to indicating which
men and women are at risk of developing anal cancer. Now that we can identify
those at risk, and conversely, those not at risk, we hope to see a big
improvement, by making sure that anoscopies and laser or chemical surgery are
only given to those who need it.”
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.
Dr Rachel Orritt, Cancer
Research UK’s health information officer, said: “This study builds on what
we already know about the link between changes to cell DNA and cervical cancer,
and shows that similar changes to the DNA in anal cells could suggest anal
“If other studies confirm
and build upon these findings, this promising research could be used to develop
a less invasive method to help doctors identify people who are at a higher risk
of anal cancer and avoid unnecessary procedures for those who are at a lower
Article: Methylation of HPV
and a tumor suppressor gene reveals anal cancer and precursor lesions, Attila T
Lorincz, Mayura Nathan, Caroline Reuter, Rhian Warman, Mohamed A Thaha, Michael
Sheaff, Natasa Vasiljevic, Amar Ahmad, Jack Cuzick, Peter Sasieni, Oncotarget,
doi: 10.18632/oncotarget.17984, published 18 May 2017.
Kayode Ojo
Kayode Emmanuel Ojo is the Co-Founder and Managing Director at SHEFFA Limited. He is presently studying Computer Science at the National Open University, Victoria Island, Lagos.