A link has been found between a virus common for causing leukaemia in animals and human prostate cancer, meaning the disease could possibly have a viral origin.
If this is the case, improved screening and a vaccine could be developed to protect against the disease.
Current risk factors associated with prostate cancer are family history, old age and bad diet. Now however, scientists have discovered that men with XMRV xenotropic murine leukaemia virus-related virus also have an increased risk of getting the disease.
Approximately 35,000 men were diagnosed with prostate cancer in Britain last year, making it the most common cancer to affect British men.
Past research has shown that although the virus can cause cancer in mice, it has never been found to affect humans. While it is unclear how the virus is contracted, there has been a suggestion that it could be sexually transmitted.
The study, which was published in the journal PNAS ( Proceedings of the National Academy of Sciences ), took 200 samples of cancerous prostate tissue and 100 samples of non infected tissue.
The results showed that the virus was present in 27 per cent of the prostate cancer samples and was linked to the more aggressive tumours. The virus was also present in 6 per cent of the benign samples.
Professor Greg Towers, an immunologist at University College London said, “If this is found to be a cause, I’d expect a big change in policy,” As viruses can often be easy to spot testing could determine men at high risk who would then be screened for cancer.
To develop a vaccine on the other hand would take a long time, “If this virus contributes to the development of some prostate cancers, then we could speculate about the possibility of vaccination, similar to the approach used to prevent cervical cancer,” said Chris Parker, a prostate cancer specialist at the Royal Marsden NHS Trust.
Human papillomavirus (HPV), which is sexually transmitted, occurs in the majority of cervical cancer cases, however it is possible for women to carry it but never develop cancer.
There is now a vaccine for the HPV virus, and a programme is in place where all British girls between 16 and 18 will be offered it by the end of the year. Scientists are keen to determine whether the XMRV virus is also sexually transmitted. To begin with , cervical and semen samples will be analysed for evidence of the virus.
Helen Rippon, the head of research management at The Prostate Cancer Charity said, The findings of this study are intriguing but pose several questions about the role infection has to play in prostate cancer.
“The researchers have yet to discover whether the virus is a cause, an effect or simply an innocent bystander in the development of the disease.”