Urinary bacteria and prostate cancer: towards a new prognostic tool?
Bacteria present in the prostate and in the urine, some of which were previously unknown, are associated with a higher risk of aggressive prostate cancer, reveals a recent study1. They could therefore serve as prognostic markers of the disease for the development of urine tests, which are simpler and less invasive than biopsies.
About this article
The second most common cancer in men worldwide, prostate cancer is also the fifth deadliest cancer with more than 375,000 deaths in 20202. Its course, often slow, however varies significantly from one patient to another. The degree of aggressiveness of the tumor (or "grade") therefore plays a major role in the treatment decision.
5th Prostate cancer is the fifth deadliest cancer...
375 000 ... with more than 375,000 deaths in 2020.
Treatment can also be deferred in favor of monitoring if the cancer seems to be progressing little. To determine this grade and monitor its progession, doctors must resort to biopsies, which are invasive examinations. New ways of detecting aggressive forms of prostate cancer, ideally through urine tests, are therefore eagerly awaited.
Urine and prostate microbiota under the microscope
It is already known that bacteria play a role in several types of cancer. Recent studies also showed that prostate cancer was associated with a particular urinary microbial profile. Finally, a recent publication suggests that the gut microbiota could be used as a marker of progression of this cancer.
English researchers therefore analyzed more than 600 samples of urine, of secretions and of prostate tissue from men stratified according to their risk of disease progression.
The objective was twofold:
- to study the urinary and prostatic microbiota of the subjects
- and to see if the bacteria that compose them were linked to tumor aggressiveness in the affected patients.
The urinary microbiota
Previously unknown bacteria: new weapons against prostate cancer?
The researchers were not only able to show a link between the presence of bacteria in urine and a higher risk of prostate cancer, but also identified four previously unknown bacteria for the first time. Additionally, five specific bacterial genera, three of which include these newcomers, were associated with a 2.6-fold increased risk of rapid disease progression. They could therefore serve as potential prognostic markers for the progression of prostate cancer.
But the authors remain cautious :
Further research must determine whether these bacteria play a role in the progression of the disease, or even its onset. If so, there is another hope: eradication of these (sidenote: Pathogen A pathogen is a microorganism that causes, or may cause, disease. Pirofski LA, Casadevall A. Q and A: What is a pathogen? A question that begs the point. BMC Biol. 2012 Jan 31;10:6. ) with antibiotics to prevent prostate cancer.
1. Hurst R, Meader E, Gihawi A et al. : Microbiomes of Urine and the Prostate are Linked to Human Prostate Cancer Risk Groups, European Urology Oncology, April 2022, in press
2. Wang L, Lu B, He M, et al. Prostate Cancer Incidence and Mortality: Global Status and Temporal Trends in 89 Countries From 2000 to 2019. Front Public Health. 2022 Feb 16;10:811044