Prostate cancer is the most common cancer in men and second most common cancer-related death in the United States (Siegel 2023). Chronic inflammation is highly prevalent in areas of the adult prostate and this inflammation has been hypothesized to contribute to prostate cancer development and/or progression, but the etiology of that inflammation has not been defined (Sfanos 2012, Marzo 2007, Sfanos 2013, Hrbacek 2013, Sfanos 2018). Since no specific biomarkers of prostate inflammation exist, establishing an epidemiological link between prostatic inflammation and prostate cancer development has been difficult.
Several groups have studied the prostate microbiome. The urinary microbiome is suggested to be different in men with prostate cancer (Shrestha 2018). Prostatic tissue from radical prostatectomy specimens has been shown to be non-sterile, and the microbial differences between benign and malignant tissue has been mixed (Feng 2019, Cavarretta 2017). However, a direct association to cancer has not been established.
This gap in knowledge may be related to limitations in the designs of the published studies. These limitations include the use of voided urine and/or transrectal prostate biopsy specimens or of radical prostatectomy specimens obtained from patients having undergone a transrectal prostate biopsy. Transperineal prostate biopsy has gained traction with urologists as it offers advantages compared to the transrectal method. The transperineal method offers equivalent cancer detection rates, but carries a lower risk of post-procedural sepsis compared to the transrectal approach (Shen 2012, Xiang 2019, Pepe 2013, Grummet 2014). This lack of contamination helps avoid the drawback of potential cross contamination in the studies mentioned above.
Here, we aim to characterize the prostate microbiome using a novel transperineal biopsy method. We hypothesize that certain prostatic microbiota are enriched within neoplastic prostatic tissue and/or in urinary specimens and that these microbiota may help predict the presence and virulence of prostate cancer. We also sought to determine if microbiota findings correlate with clinical findings at the time of presentation of patients for prostatic biopsy, including PSA levels, digital rectal examination (DRE), and multiparametric MRI findings. Less...