Prostatitis, other genitourinary infections and prostate cancer risk: Influence of non-steroidal anti-inflammatory drugs? Results from the EPICAP study

Sexually and non-sexually transmitted infections and the risk of prostate cancer: Results from the EPICAP study

INTRODUCTION

Prostate cancer (PCa) is by far the most common type of cancer among men in western countries. However, relatively little is known about its etiology despite the high morbidity and mortality. It has been suggested that chronic inflammation may be involved in prostate carcinogenesis. We investigated the role of sexually and non-sexually transmitted infections in prostate cancer risk with a specific interest in the aggressive types.

METHODS

We used data from epidemiological study of prostate cancer (EPICAP), a population-based case-control study. A total of 819 incident cases and 879 controls were interviewed face-to-face using a standardized questionnaire gathering information on known or suspected risk factors of prostate cancer and personal history of specific sexually and non-sexually transmitted infections: gonorrhea, syphilis, trichomonas, herpes, mononucleosis, Epstein-Barr virus, varicella-zoster, and dengue. Odds ratios (OR) and their 95% confidence interval were estimated using multivariate unconditional logistic regression.

RESULTS

There was no significant association between gonorrhea (OR: 0.90, 95% CI: 0.61-1.33), trichomonas (OR: 0.74, 95% CI: 0.27-2.07), genital herpes (OR: 0.69, 95% CI: 0.38-1.27), and the risk of prostate cancer. No association emerged for overall sexually transmitted bacterial and viral infections (OR 1.05, 95% CI: 0.86-1.29) and overall non-sexually transmitted viral infections (OR 1.11, 95% CI: 0.90-1.35) and the risk of prostate cancer.

CONCLUSION

Our results showed that sexually or non-sexually transmitted infections, either bacterial or viral, were not associated to prostate cancer. Therefore, further investigation is needed to help advance our understanding of the role of chronic inflammation in the etiology of prostate cancer, with a particular focus on its most aggressive types.

The association between prostatitis and risk of prostate cancer: a National Health Insurance Database study

PURPOSE

Inflammation is thought to affect the development of prostate cancer (PCa). By retrospectively investigating the database of the National Health Insurance Service, this study attempted to perform a relevant analysis of patients with prostatitis and PCa.

METHODS

Participants were aged ≥ 50 years. Patients diagnosed with prostatitis between 2010 and 2013 and matched controls were followed up until 2019. We selected controls with matched propensity scores for age, diabetes, hypertension, and the Charlson comorbidity index. Multivariate Cox regression analysis was conducted to determine the hazard ratio (HR) and 95% confidence interval (CI) of the association between prostatitis and PCa. The HR for PCa according to the presence of prostatitis was classified as acute, chronic, or other prostatitis.

RESULTS

A total of 746,176 patients from each group were analyzed. The incidence of PCa was significantly higher in the group with prostatitis (1.8% vs 0.6%, p < 0.001). The HR for PCa was significantly higher in patients with prostatitis (HR 2.99; 95% CI 2.89-3.09, p < 0.001). The HR for PCa was significantly higher in acute prostatitis than in chronic prostatitis (3.82; 95% CI 3.58-4.08; p < 0.001; HR 2.77; 95% CI 2.67-2.87, p < 0.001). The incidence of all-cause death in patients diagnosed PCa was significantly lower in prostatitis group (HR 0.58, 95% CI 0.53-0.63, p < 0.001).

CONCLUSION

Prostatitis is associated with an increased incidence of PCa. Acute prostatitis is associated with higher risk of PCa than chronic prostatitis. Clinicians should inform patients with prostatitis that they may have an increased risk of diagnosing PCa, and follow-up is needed.

Oncogenic gene fusions in nonneoplastic precursors as evidence that bacterial infection can initiate prostate cancer

Prostate adenocarcinoma is the second most commonly diagnosed cancer in men worldwide, and the initiating factors are unknown. Oncogenic TMPRSS2:ERG (ERG+) gene fusions are facilitated by DNA breaks and occur in up to 50% of prostate cancers. Infection-driven inflammation is implicated in the formation of ERG+ fusions, and we hypothesized that these fusions initiate in early inflammation-associated prostate cancer precursor lesions, such as proliferative inflammatory atrophy (PIA), prior to cancer development. We investigated whether bacterial prostatitis is associated with ERG+ precancerous lesions in unique cases with active bacterial infections at the time of radical prostatectomy. We identified a high frequency of ERG+ non-neoplastic-appearing glands in these cases, including ERG+ PIA transitioning to early invasive cancer. These lesions were positive for ERG protein by immunohistochemistry and ERG messenger RNA by in situ hybridization. We additionally verified TMPRSS2:ERG genomic rearrangements in precursor lesions using tricolor fluorescence in situ hybridization. Identification of rearrangement patterns combined with whole-prostate mapping in three dimensions confirmed multiple (up to eight) distinct ERG+ precancerous lesions in infected cases. We further identified the pathogen-derived genotoxin colibactin as a potential source of DNA breaks in clinical cases as well as cultured prostate cells. Overall, we provide evidence that bacterial infections can initiate driver gene alterations in prostate cancer. In addition, our observations indicate that infection-induced ERG+ fusions are an early alteration in the carcinogenic process and that PIA may serve as a direct precursor to prostate cancer.

Diagnostic Performance of PI-RADS v2, Proposed Adjusted PI-RADS v2 and Biparametric Magnetic Resonance Imaging for Prostate Cancer Detection: A Preliminary Study

Purpose: To evaluate the diagnostic performance of PI-RADS v2, proposed adjustments to PI-RADS v2 (PA PI-RADS v2) and biparametric magnetic resonance imaging (MRI) for prostate cancer detection. Methods: A retrospective cohort of 224 patients with suspected prostate cancer was included from January 2016 to November 2018. All the patients underwent a multi-parametric MR scan before biopsy. Two radiologists independently evaluated the MR examinations using PI-RADS v2, PA PI-RADS v2, and a biparametric MRI protocol, respectively. Receiver operating characteristic (ROC) curves for the three different protocols were drawn. Results: In total, 90 out of 224 cases (40.18%) were pathologically diagnosed as prostate cancer. The area under the ROC curves (AUC) for diagnosing prostate cancers by biparametric MRI, PI-RADS v2, and PA PI-RADS v2 were 0.938, 0.935, and 0.934, respectively. For cancers in the peripheral zone (PZ), the diagnostic sensitivity was 97.1% for PI-RADS v2/PA PI-RADS v2 and 96.2% for biparametric MRI. Moreover, the specificity was 84.0% for biparametric MRI and 58.0% for PI-RADS v2/PA PI-RADS v2. For cancers in the transition zone (TZ), the diagnostic sensitivity was 93.4% for PA PI-RADS v2 and 88.2% for biparametric MRI/PI-RADS v2. Furthermore, the specificity was 95.4% for biparametric MRI/PI-RADS v2 and 78.0% for PA PI-RADS v2. Conclusions: The overall diagnostic performance of the three protocols showed minimal differences. For lesions assessed as being category 3 using the biparametric MRI protocol, PI-RADS v2, or PA PI-RADS v2, it was thought prostate cancer detection could be improved. Attention should be paid to false positive results when PI-RADS v2 or PA PI-RADS v2 are used.

Inflammation driven tumor-like signaling in prostatic epithelial cells by sexually transmitted Trichomonas vaginalis

OBJECTIVES

To identify the sequence of inflammation-driven signaling cascades and other molecular events that might cause tumor-like transformation of prostatic cells.

METHODS

Cytokine array analysis, Reactome and STRING analysis, immunoblotting, and immunocytochemistry were used to investigate the molecular mechanisms governing inflammation-driven adverse changes in human prostatic cells caused by the sexually transmitted infection, Trichomonas vaginalis, resulting in prostatitis, benign prostatic hyperplasia and prostate cancer.

RESULTS

Array analysis showed upregulation of 23 cytokines within 24 h of infection of human prostatic epithelial RWPE-1 cells with the parasite, in vitro. Reactome and STRING analysis of array data identified interleukin-6, interleukin-8, nuclear factor kappa B, signal transducer and activator of transcription 3 and cyclooxygenase 2 as chief instigators of prostatic anomaly, which were found to be significantly upregulated by immunofluorescence and western blotting analyses. STRING further connected these instigators with macrophage migration inhibitory factor, PIM-1 and prostate-specific antigen; which was confirmed by their marked stimulation in infected prostatic cells by immunoblotting and immunocytochemistry. Upregulated proliferation markers, such as Ki67, proliferating cell nuclear antigen and B-cell lymphoma 2, suggested tumor-like signaling in infected RWPE-1 cells, which was further supported by downregulation of E-cadherin, upregulation of vimentin and activation of focal adhesion kinase. Prostate tumor DU145 cells were more sensitive to parasite invasion, and showed rapid upregulation with nuclear translocation of sensitive parameters, such as nuclear factor kappa B, signal transducer and activator of transcription 3, and macrophage migration inhibitory factor. The migration of DU145 cells augmented when incubated in spent media from parasite-infected RWPE-1 cells.

CONCLUSION

The initiation of inflammation driven tumor-like cell signaling in parasite-infected human prostatic epithelial cells is apparent, with the prostate tumor (DU145) cells being more sensitive to T. vaginalis than normal (RWPE-1) prostatic cells.

Hematologic Markers and Prostate Cancer Risk: A Prospective Analysis in UK Biobank

BACKGROUND

Risk factors for prostate cancer are not well understood. Red blood cell, platelet, and white blood cell indices may be markers of a range of exposures that might be related to prostate cancer risk. Therefore, we examined the associations of hematologic parameters with prostate cancer risk.

METHODS

Complete blood count data from 209,686 male UK Biobank participants who were free from cancer at study baseline were analyzed. Participants were followed up via data linkage. After a mean follow-up of 6.8 years, 5,723 men were diagnosed with prostate cancer and 323 men died from prostate cancer. Multivariable-adjusted Cox regression was used to estimate adjusted HRs and 95% confidence intervals (CI) for prostate cancer incidence and mortality by hematologic parameters, and corrected for regression dilution bias.

RESULTS

Higher red blood cell (HR per 1 SD increase = 1.09, 95% CI, 1.05-1.13) and platelet counts (HR = 1.07, 1.04-1.11) were associated with an increased risk of prostate cancer. Higher mean corpuscular volume (HR = 0.90, 0.87-0.93), mean corpuscular hemoglobin (HR = 0.90, 0.87-0.93), mean corpuscular hemoglobin concentration (HR = 0.87, 0.77-0.97), and mean sphered cell volume (HR = 0.91, 0.87-0.94) were associated with a lower prostate cancer risk. Higher white blood cell (HR = 1.14, 1.05-1.24) and neutrophil count (HR = 1.27, 1.09-1.48) were associated with prostate cancer mortality.

CONCLUSIONS

These associations of blood indices of prostate cancer risk and mortality may implicate shared common causes, including testosterone, nutrition, and inflammation/infection among several others in prostate cancer development and/or progression.

IMPACT

These associations provide insights into prostate cancer development and progression.

Calcitriol inhibits lipopolysaccharide-induced proliferation, migration and invasion of prostate cancer cells through suppressing STAT3 signal activation

Increasing evidence suggests that infection promotes the initiation and progression of prostate cancer. This study investigated the effects of lipopolysaccharide (LPS), a major component of Gram-negative bacilli, on proliferation, migration and invasion of prostate cancer cells and the protective effects of 1α,25(OH)2D3 (calcitriol). PC-3 and DU145 cells were stimulated with LPS (2.0 μg/mL) in the presence or absence of 1α,25(OH)2D3 (100 nM). Our results shown that 1α,25(OH)2D3 reduced the proportion of S phase cells in LPS-stimulated PC-3 and DU145 cells, and down-regulated the nuclear protein levels of Cyclin D1 and PCNA in LPS-stimulated PC-3 cells. In addition, 1α,25(OH)2D3 inhibited migration and invasion, as determined by wound healing and transwell assay, in LPS-stimulated PC-3 and DU145 cells. Of interest, we observed that 1α,25(OH)2D3 inhibits NF-κB activation and subsequent synthesis and secretion of IL-6 and IL-8 by promoting VDR and NF-κB p65 interaction. Surprisingly, 1α,25(OH)2D3 blocks nuclear translocation of pSTAT3 by promoting physical interaction between VDR and pSTAT3 (Tyr705) in LPS-stimulated PC-3 and DU145 cells. These results suggest that 1α,25(OH)2D3 inhibits LPS-induced proliferation, migration and invasion in prostate cancer cells by directly and indirectly blocking STAT3 signal transduction.

A Systematic Review and Meta-analysis of Associations between Clinical Prostatitis and Prostate Cancer: New Estimates Accounting for Detection Bias

BACKGROUND

Previous meta-analyses have estimated summary positive associations between clinical prostatitis and prostate cancer. However, none have accounted for detection bias, the possibility for increased prostate cancer screening and detection in men with clinical prostatitis, in their pooled estimates.

METHODS

We searched for studies that investigated the relation between clinical prostatitis and prostate cancer through November 2018. Random effects meta-analysis was used to calculate summary odds ratios (OR) among all studies and in strata defined by methods used to reduce detection bias.Results: Although an increased odds of prostate cancer was seen among men with a history of clinical prostatitis in all 38 eligible studies combined [OR, 2.05; 95% confidence interval (CI), 1.64-2.57], this estimate attenuated to null among studies that performed the most rigorous analyses to limit detection bias (OR, 1.16; 95% CI, 0.77-1.74).

CONCLUSIONS

Our findings indicate that previously reported positive associations between clinical prostatitis and prostate cancer are likely due to detection bias.

IMPACT

Studies using rigorous detection bias methods are warranted to replicate these findings, as well as to examine the possible relation between prostate inflammation and prostate cancer directly, rather than indirectly through the diagnosis of "prostatitis," which includes a large proportion of men without evidence of prostate inflammation.