Acne bacteria could reduce prostate cancer risk
MedWire News: Australian researchers have found a possible link between Propionibacterium acnes (P. acnes) and prostate cancer, indicating that higher antibody titers of the bacterium are associated with a lower risk for the disease.
Previous research has suggested that although the bacterium normally lives on the skin, P. acnes is also prevalent in the prostate, and has been associated with both acute and chronic prostatic inflammation.
If the finding from the current research is confirmed, it may open novel avenues for the prevention of prostate cancer, say author Gianluca Severi, from The University of Melbourne in Victoria, and colleagues.
The team investigated a potential link between P. acnes and prostate cancer risk using data from the Risk Factors for Prostate Cancer Study conducted in Melbourne and Perth, Australia, between 1994 and 1998.
The study cohort comprised 809 men aged up to 70 years with moderate- (Gleason score 5-7) or high-grade (Gleason score 8-10) prostate cancer, and 584 age- and city-matched controls without the disease.
The men answered questions concerning their medical history, smoking status, diet, sexual activity, and family history of prostate cancer, as well as their acne status in adolescence. The men also gave blood samples, which the researchers used to assess plasma P. acnes antibody levels.
The median levels of P. acnes antibodies detected in the plasma of the whole cohort was 1:1024 titers, with high levels (1:2048 or more) observed more frequently in cases than in controls.
After adjusting the analysis for age, year of selection for study, and health center, P. acnes titers were 85% higher for men who reported a history of acne in adolescence compared with those who did not report a history.
Further analysis revealed that men with P. acnes titers above the median were 27% less likely to develop prostate cancer, and were 41% less likely to develop advanced stage disease compared with men with P. acnes titers below the median.
The results did not conclusively indicate whether the association differed by tumor stage, the researchers note.
They believe a likely explanation for their finding is that, "higher antibody titers are an indirect marker of increased cell-mediated immunity caused by P. acnes infection, and this increased immunity protects from prostate cancer."
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By Sarah Guy