Scientists don’t yet know if the microbes are causative, but if proven it could save thousands of lives
Researchers performed genetic analyses on the urine and prostate tissue of more than 600 men. Photograph: Andrew Brookes/Getty Images/Image Source
https://www.theguardian.com-Ian Sample Science editor
Scientists have discovered bacteria linked to aggressive prostate cancer in work hailed as a potential revolution for the prevention and treatment of the most deadly form of the disease.
Researchers led by the University of East Anglia performed sophisticated genetic analyses on the urine and prostate tissue of more than 600 men with and without prostate cancer and found five species of bacteria linked to rapid progression of the disease.
The study does not prove that the bacteria drive or exacerbate prostate cancer, but if work now under way confirms their role, researchers can develop tests to identify men most at risk and potentially find antibiotics to prevent the cancer from claiming thousands of lives each year.
“This is an exciting discovery that has the potential to truly revolutionise treatment for men,” said Dr Hayley Luxton of Prostate Cancer UK, which co-funded the research.
Writing in the journal European Urology Oncology, the scientists describe how their genetic investigations found five species of bacteria – three new to science – that were associated with advanced prostate cancer. Men who had one or more of the species in their urine, prostate or tumour tissue were 2.6 times more likely to see their early stage cancer progress to advanced disease than men who did not.
Lead scientist Colin Cooper, a professor of cancer genetics at the University of East Anglia, said it was possible the bacteria are not involved in the disease. For example, men with more aggressive prostate cancer may have immune system deficiencies that allow certain bacteria to thrive. But the researchers strongly suspect the microbes are involved, just as Helicobacter pylori infections raise the risk of stomach cancer.
“If you knew for sure that a species of bacteria was causing prostate cancer, you could work out an antibiotic to remove it and that would prevent progression, one would hope,” Cooper said. But this is not as straightforward as it sounds, he cautioned. “There are many complications. Antibiotics don’t get into the prostate very well and you would need to choose an antibiotic that only kills certain bacteria,” he said.
While prostate cancer is the most common form of the disease found in men, in many cases patients die with the disease rather than because of it. The more aggressive forms of prostate cancer claim about 12,000 lives in the UK each year.
Prof Rosalind Eeles, a cancer geneticist on the study at the Institute of Cancer Research in London, said it was a “very interesting result” to find “novel micro-organisms” in prostate cancer cases. “It is not yet known if they are causative but if this could be proven then we have a potential route for prevention,” she said. “The way that we may be able to prove this is to look to see if these organisms are never found in prostate samples which have no cancer.”
Genetic information on the microbes has already allowed the scientists to piece together how they may behave in the body, including what toxins and other substances they might release. This has led them to develop half a dozen hypotheses around how the bugs could cause prostate cancer.
“We currently have no way of reliably identifying aggressive prostate cancers, and this research could help make sure men get the right treatment for them,” Luxton added.
“If the team can demonstrate that these newly identified bacteria can not only predict, but actually cause aggressive prostate cancer, for the first time we may actually be able to prevent prostate cancer occurring. This would be a huge breakthrough that could save thousands of lives each year.”