London, Researchers in the UK have identified five types of bacteria in urine which may be linked to aggressive prostate cancer. The findings, published in the journal European Urology Oncology, could help pave the way for treatments that could target these particular bacteria and slow or prevent the development of aggressive disease.
"We already know of some strong associations between infections and cancer," said project lead Colin Cooper, a professor at the University of East Anglia (UEA) in the UK.
"For example, the presence of Helicobacter pylori bacteria in the digestive tract can lead to stomach ulcers and is associated with stomach cancer, and some types of the HPV virus can cause cervical cancer," Cooper said.
The team worked with colleagues at the Norfolk and Norwich University Hospital, the Quadram Institute, and other collaborators to analyse urine or tissue samples from more than 600 patients with or without prostate cancer.
They developed methods of finding the bacteria associated with aggressive prostate cancer.
"To detect the bacteria, we used many different approaches including whole genome sequencing of the tissue samples, a method which is being used increasingly as we transition into an era of genomic medicine," said Rachel Hurst, first author of the study, from UEA's Norwich Medical School.
"We found several types of bacteria associated with aggressive prostate cancer, some of which are new types of bacteria never found before," Hurst said.
The set of bacteria found by the team include Anaerococcus, Peptoniphilus, Porphyromonas, Fenollaria and Fusobacterium. All of these are anaerobic, which means they like to grow without oxygen present.
"When any of these specific anaerobic bacteria were detected in the patient's samples, it was linked to the presence of higher grades of prostate cancer and more rapid progression to aggressive disease," Hurst said.
"We also identified potential biological mechanisms of how these bacteria may be linked to cancer," the researcher added.
Among the things that scientists don't yet know is how people pick up these bacteria, whether they are causing the cancer, or whether a poor immune response permits the growth of the bacteria.
"We hope that our findings and future work could lead to new treatment options, that could slow or prevent aggressive prostate cancer from developing. Our work could also lay the foundations for new tests that use bacteria to predict the most effective treatment for each man's cancer," she added.
The team also noted that many bacteria are beneficial to human life and it is not a simple matter to remove the harmful bacteria without removing the protection provided by the good bacteria.
"If we can target aggressive cancers while sparing others from unnecessary treatment it will dramatically improve the way we manage this disease," said professor Daniel Brewer from UEA's Norwich Medical School.
"There seems to be a clear link between these bacteria and the way the cancer is behaving. We need to understand this relationship in more detail but it is a major step towards developing a cheap and quick test that could guide treatment decisions," he added.
