Scientists have produced compelling evidence that a virus known to cause cancer in animals is linked to prostate cancer in humans.
The researchers from the University of Utah and Columbia University medical schools found the virus in 27% of the 200 cancerous prostates they looked at.
They say it was associated with more aggressive tumours and found in only 6% of non-cancerous prostates.
The finding raises the prospect of one day producing a vaccine.
Previous research has linked XMRV (Xenotropic murine leukaemia virus) to prostate cancer but not in such an aggressive way.
The research does not necessarily mean that the XMRV virus causes malignant tumours such as prostate cancer in humans, but it is an approach worth investigating.
Cancer is caused when there is an assault on the tissues in some shape or form that leads to injury. This might be through exposure to toxic chemicals or even a virus. As we know more about the science and biology of disease, we learn that cancer is increasingly not one homogenous disease and even different tumour types have many different subsets, leading to new targets.