Two common viruses associated with cancers may be interacting to exacerbate prostate tumours, a study suggests.
The human papilloma virus (HPV) and Epstein Barr virus (EBV) have both been found in more than half of sampled malignant prostate cancers and a high number of benign cancers in Australian men, University of NSW researchers have found.
HPV alone was found in about 70 per cent of the 100 prostate cancer samples surveyed while both HPV and EBV were located in 55 per cent.
Lead researcher Noel Whitaker said experimental research suggested the two viruses could collaborate to promote the survival and proliferation of cancer cells.
This had been observed in cervical cancer cells and could differ in glandular prostate cells, the authors said.
But Professor Whitaker, from the university's School of Biotechnology and Biomolecular Sciences, said the findings could still have important implications for understanding and preventing prostate cancer.
A high-risk strain of the human papilloma virus, HPV 18, was found in the prostate samples, he said.
The strain is associated with other human cancers and is a target of the Gardasil cervical cancer vaccine.
The vaccine, which is already available free to teenage girls, will be rolled out to boys through a school-based program next year.
"If HPV 18 is also associated with prostate cancers, as our research suggests, vaccinating boys may yet prove to have an unexpected direct benefit for them as well," Prof Whitaker said.
HPV had been found in prostate cancers but this was the first time an Australian study had found both HPV and EBV in the same tissue, he said.
EBV, which has been linked to head and neck cancers, is spread by close skin contact.
Prof Whitaker warned that the presence of the viruses was not conclusive evidence of a role in prostate cancer.
The researchers found it was possible the viruses were harmless because their presence in normal, benign and malignant prostate tissues was ubiquitous.
"But given their well-established track record with other cancers, it would seem quite unlikely that they are harmless," Prof Whitaker said.
Prostate Cancer Foundation of Australia CEO Anthony Lowe said the research was interesting but did not show that the viruses actually caused prostate cancer.
"A lot more work will be needed to establish a causal link," Dr Lowe said.
The study, co-led by Professor James Lawson, was published in the journal The Prostate.
Rodger.