Virus may cause prostate cancer: study
A virus known to cause cancer in animals has been found in some prostate tumours and might be a cause of prostate cancer, according to US researchers.
They found xenotropic murine leukemia virus-related virus or XMRV in more than a quarter of the human prostate tumours they looked at, especially aggressive tumours.
The findings, published in the Proceedings of the National Academy of Science, may offer ways to better identify dangerous prostate tumours and vaccines to treat or prevent prostate cancer.
"Our analysis of 233 cases of prostate cancers and 101 benign controls showed an association of XMRV infection with prostate cancer, especially with more aggressive tumours," write Dr Ila Singh of the University of Utah and colleagues.
Viruses have recently been found to cause some cancers, notably the human papillomavirus that causes cervical cancer and some cases of penile, anal and head and neck cancers.
A vaccine to prevent HPV infection, and hopefully reduce the incidence of cervical cancer, is in now in widespread use.
The market for a vaccine to prevent prostate cancer or for better drugs to treat it could be substantial. Prostate cancer is the second most common cancer in men worldwide after lung cancer.
According to the Australian Institute of health and Welfare, in 2006 more than 16,000 Australian men were diagnosed with prostate cancer with close to 3000 deaths recorded.
The researchers were scanning for genetic material from any viruses in prostate tumours.
"We found that XMRV was present in 27% of prostate cancers we examined and that it was associated with more aggressive tumours," says Singh.
"We still don't know that this virus causes cancer in people, but that is an important question we're going to investigate."
XMRV is a retrovirus, a type of virus that inserts its genes into the cells it infects. This will either kill the cell or turn it cancerous by affecting its genes.
Singh says she was looking to see if this might be going on with XMRV.
"Is the virus associated with cancers in tissues other than the prostate or in gynecologic malignancies? How is XMRV transmitted? These are all intriguing questions that deserve further exploration," the researchers write.