Baseline prostate inflammation is associated with a reduced risk of prostate cancer in men undergoing repeat prostate biopsy: results from the REDUCE study

Patterns of B-cell lymphocyte expression changes in pre- and post-malignant prostate tissue are associated with prostate cancer progression

BACKROUND

Inflammation characterized by the presence of T and B cells is often observed in prostate cancer, but it is unclear how T- and B-cell levels change during carcinogenesis and whether such changes influence disease progression.

METHODS

The study used a retrospective sample of 73 prostate cancer cases (45 whites and 28 African Americans) that underwent surgery as their primary treatment and had a benign prostate biopsy at least 1 year before diagnosis. CD3+, CD4+, and CD20+ lymphocytes were quantified by immunohistochemistry in paired pre- and post-diagnostic benign prostate biopsy and tumor surgical specimens, respectively. Clusters of similar trends of expression across two different timepoints and three distinct prostate regions-benign biopsy glands (BBG), tumor-adjacent benign glands (TAG), and malignant tumor glandular (MTG) regions-were identified using Time-series Anytime Density Peaks Clustering (TADPole). A Cox proportional hazards model was used to estimate the hazard ratio (HR) of time to biochemical recurrence associated with region-specific lymphocyte counts and regional trends.

RESULTS

The risk of biochemical recurrence was significantly reduced in men with an elevated CD20+ count in TAG (HR = 0.81, p = 0.01) after adjusting for covariates. Four distinct patterns of expression change across the BBG-TAG-MTG regions were identified for each marker. For CD20+, men with low expression in BBG and higher expression in TAG compared to MTG had an adjusted HR of 3.06 (p = 0.03) compared to the reference group that had nominal differences in CD20+ expression across all three regions. The two CD3+ expression patterns that featured lower CD3+ expression in the BBG compared to the TAG and MTG regions had elevated HRs ranging from 3.03 to 4.82 but did not reach statistical significance.

CONCLUSIONS

Longitudinal and spatial expression patterns of both CD3+ and CD20+ suggest that increased expression in benign glands during prostate carcinogenesis is associated with an aggressive disease course.

Exploring the role of the inflammasomes on prostate cancer: Interplay with obesity

Obesity is a weight-related disorder characterized by excessive adipose tissue growth and dysfunction which leads to the onset of a systemic chronic low-grade inflammatory state. Likewise, inflammation is considered a classic cancer hallmark affecting several steps of carcinogenesis and tumor progression. In this regard, novel molecular complexes termed inflammasomes have been identified which are able to react to a wide spectrum of insults, impacting several metabolic-related disorders, but their contribution to cancer biology remains unclear. In this context, prostate cancer (PCa) has a markedly inflammatory component, and patients frequently are elderly individuals who exhibit weight-related disorders, being obesity the most prevalent condition. Therefore, inflammation, and specifically, inflammasome complexes, could be crucial players in the interplay between PCa and metabolic disorders. In this review, we will: 1) discuss the potential role of each inflammasome component (sensor, molecular adaptor, and targets) in PCa pathophysiology, placing special emphasis on IL-1β/NF-kB pathway and ROS and hypoxia influence; 2) explore the association between inflammasomes and obesity, and how these molecular complexes could act as the cornerstone between the obesity and PCa; and, 3) compile current clinical trials regarding inflammasome targeting, providing some insights about their potential use in the clinical practice.

Correlation Between Long-Term Acetylsalicylic Acid Use and Prostate Cancer Screening with PSA. Should We Reduce the PSA Cut-off for Patients in Chronic Therapy? A Multicenter Study

Purpose

To evaluate the prostate cancer (PCa) detection rate in men with chronic use of Aspirin and to compare it with the detection rate of non-users.

Patients and Methods

Prospectively maintained database regarding patients undergoing prostate biopsy over the last 10 years in five institutions. Patients were divided into two groups according to their exposure to Aspirin. We relied on multivariable linear and logistic regression models to test whether Aspirin administration was associated with lower PSA values at prostate biopsy, higher PCa diagnosis, and higher Gleason Grade Grouping (GGG) at biopsy.

Results

Were identified 1059 patients, of whom 803 (76%) did not take Aspirin vs 256 (24%) were taking it. In multivariable log-linear regression analysis, Aspirin administration was associated with lower PSA levels (OR 0.83, 95% CI 0.71–0.97, p = 0.01), after controlling for age, prostate volume, smoking history, associated inflammation at prostate biopsy, presence of PCa at biopsy, and GGG. In multivariable logistic regression analysis, Aspirin administration was not found to be a predictor of PCa at prostate biopsy (OR 1.40, 95% CI 0.82–2.40, p = 0.21) after controlling for age, PSA, smoking history, prostate volume, findings at digital rectal examination and the number of biopsy cores. In patients with PCa at prostate biopsy (n = 516), Aspirin administration was found to predict higher GGG (OR 2.24, 95% CI 1.01–4.87, p = 0.04).

Conclusion

Aspirin administration was found to be a predictor of more aggressive GGG. These findings suggest that a lower PSA threshold should be considered in patients taking Aspirin, as, despite low PSA levels, they might harbour aggressive PCa.

Inflammation and Prostate Cancer: A Multidisciplinary Approach to Identifying Opportunities for Treatment and Prevention

Prostate cancer is a major cause of disease for men globally. Inflammation, an established hallmark of cancer, is frequently observed in the prostate, though its contribution to prostate cancer risks and outcomes is not fully understood. Prostate cancer is biologically and clinically heterogeneous, and there is now evidence that inflammation and immunological characteristics vary by the genomic and mutational landscape of the tumor. Moreover, it is now recognized that risk factor profiles vary between tumor subgroups, as defined by histopathological and molecular features. Here, we provide a review centered around the relationship between inflammation and prostate cancer, with a consideration of molecular tumor features and a particular focus on the advanced and lethal stages of disease. We summarize findings from epidemiological studies of the etiology and role of inflammation in prostate cancer. We discuss the pathology of prostate inflammation, and consider approaches for assessing the tumor immune microenvironment in epidemiological studies. We review emerging clinical therapies targeting immune biology within the context of prostate cancer. Finally, we consider potentially modifiable risk factors and corresponding lifestyle interventions that may affect prostate inflammation, impacting outcomes. These emerging insights will provide some hints for the development of treatment and prevention strategies for advanced and lethal prostate cancer.

Racial differences in the systemic inflammatory response to prostate cancer

Systemic inflammation may increase risk for prostate cancer progression, but the role it plays in prostate cancer susceptibility is unknown. From a cohort of over 10,000 men who had either a prostate biopsy or transurethral resection that yielded a benign finding, we analyzed 517 incident prostate cancer cases identified during follow-up and 373 controls with one or more white blood cell tests during a follow-up period between one and 18 years. Multilevel, multivariable longitudinal models were fit to two measures of systemic inflammation, neutrophil-to-lymphocyte ratio (NLR) and monocyte-to-lymphocyte ratio (MLR), to determine NLR and MLR trajectories associated with increased risk for prostate cancer. For both measures, we found no significant differences in the trajectories by case/control status, however in modeling NLR trajectories there was a significant interaction between race (white or Black and case-control status. In race specific models, NLR and MLR values were consistently higher over time among white controls than white cases while case-control differences in NLR and MLR trajectories were not apparent among Black men. When cases were classified as aggressive as compared to non-aggressive, the case-control differences in NLR and MLR values over time among white men were most apparent for non-aggressive cases. For NLR among white men, significant case-control differences were observed for the entire duration of observation for men who had inflammation in their initial prostate specimen. It is possible that, among white men, monitoring of NLR and MLR trajectories after an initial negative biopsy may be useful in monitoring prostate cancer risk.

The interplay of growth differentiation factor 15 (GDF15) expression and M2 macrophages during prostate carcinogenesis

M2 (tumor-supportive) macrophages may upregulate growth differentiation factor 15 (GDF15), which is highly expressed in prostate tumors, but the combined utility of these markers as prognostic biomarkers are unclear. We retrospectively studied 90 prostate cancer cases that underwent radical prostatectomy as their primary treatment and were followed for biochemical recurrence (BCR). These cases also had a benign prostate biopsy at least 1 year or more before their prostate cancer surgery. Using computer algorithms to analyze digitalized immunohistochemically stained slides, GDF15 expression and the presence of M2 macrophages based on the relative density of CD204- and CD68-positive macrophages were measured in prostate: (i) benign biopsy, (ii) cancer and (iii) tumor-adjacent benign (TAB) tissue. Both M2 macrophages (P = 0.0004) and GDF15 (P < 0.0001) showed significant inter-region expression differences. Based on a Cox proportional hazards model, GDF15 expression was not associated with BCR but, in men where GDF15 expression differences between cancer and TAB were highest, the risk of BCR was significantly reduced (hazard ratio = 0.26; 95% confidence interval = 0.09-0.94). In addition, cases with high levels of M2 macrophages in prostate cancer had almost a 5-fold increased risk of BCR (P = 0.01). Expression of GDF15 in prostate TAB was associated with M2 macrophage levels in both prostate cancer and TAB and appeared to moderate M2-macrophage-associated BCR risk. In summary, the relationship of GDF15 expression and CD204-positive M2 macrophage levels is different in a prostate tumor environment compared with an earlier benign biopsy and, collectively, these markers may predict aggressive disease.

Growth and differentiation factor 15 and NF-κB expression in benign prostatic biopsies and risk of subsequent prostate cancer detection

Growth and differentiation factor 15 (GDF‐15), also known as macrophage inhibitory cytokine 1 (MIC‐1), may act as both a tumor suppressor and promotor and, by regulating NF‐κB and macrophage signaling, promote early prostate carcinogenesis. To determine whether expression of these two inflammation‐related proteins affect prostate cancer susceptibility, dual immunostaining of benign prostate biopsies for GDF‐15 and NF‐κB was done in a study of 503 case‐control pairs matched on date, age, and race, nested within a historical cohort of 10,478 men. GDF‐15 and NF‐κB expression levels were positively correlated (r = 0.39; p < 0.0001), and both were significantly lower in African American (AA) compared with White men. In adjusted models that included both markers, the odds ratio (OR) for NF‐κB expression was statistically significant, OR =0.87; p = 0.03; 95% confidence interval (CI) =0.77–0.99, while GDF‐15 expression was associated with a nominally increased risk, OR =1.06; p = 0.27; 95% CI =0.96–1.17. When modeling expression levels by quartiles, the highest quartile of NF‐κB expression was associated with almost a fifty percent reduction in prostate cancer risk (OR =0.51; p = 0.03; 95% CI =0.29–0.92). In stratified models, NF‐κB had the strongest negative association with prostate cancer in non‐aggressive cases (p = 0.03), older men (p = 0.03), and in case‐control pairs with longer follow‐up (p = 0.02). Risk associated with GDF‐15 expression was best fit using nonlinear regression modeling where both first (p = 0.02) and second (p = 0.03) order GDF‐15 risk terms were associated with significantly increased risk. This modeling approach also revealed significantly increased risk associated with GDF‐15 expression for subsamples defined by AA race, aggressive disease, younger age, and in case‐control pairs with longer follow‐up. Therefore, although positively correlated in benign prostatic biopsies, NF‐κB and GDF‐15 expression appear to exert opposite effects on risk of prostate tumor development.

Why Do Epidemiologic Studies Find an Inverse Association Between Intraprostatic Inflammation and Prostate Cancer: A Possible Role for Colliding Bias?

Inflammation is an emerging risk factor for prostate cancer based largely on evidence from animal models and histopathologic observations. However, findings from patho-epidemiologic studies of intraprostatic inflammation and prostate cancer have been less supportive, with inverse associations observed in many studies of intraprostatic inflammation and prostate cancer diagnosis. Here, we propose collider stratification bias as a potential methodologic explanation for these inverse findings and provide strategies for conducting future etiologic studies of intraprostatic inflammation and prostate cancer.

Monocyte counts and prostate cancer outcomes in white and black men: results from the SEARCH database

PURPOSE

Circulating inflammatory markers may predict prostate cancer (PC) outcomes. For example, a recent study showed that higher peripheral blood monocyte counts were associated with aggressive PC in Asian men undergoing radical prostatectomy (RP). Herein, we investigated whether peripheral monocyte count can predict long-term PC outcomes after RP in black and white men.

METHODS

We retrospectively reviewed data on 2345 men undergoing RP from 2000 to 2017 at eight Veterans Affairs hospitals. Data on monocyte count within 6 and 12 months prior to surgery were collected. The study outcomes were biochemical recurrence (BCR), castration-resistant PC (CRPC), metastasis, all-cause mortality (ACM), and PC-specific morality (PCSM). Cox-proportional hazard models were used to assess the associations between pre-operative monocyte count and the above-mentioned outcomes accounting for confounders.

RESULTS

Of 2345 RP patients, 972 (41%) were black and 1373 (59%) were white men. In multivariable analyses, we found no associations between monocyte count and BCR among all men (HR: 1.36, 95%CI 0.90-2.07) or when analyses were stratified by race (HR: 1.30, 95%CI 0.69-2.46, in black men; HR:1.33, 95%CI 0.76-02.33, in white men). Likewise, no overall or race-specific associations were found between monocyte count and CRPC, metastases, ACM, and PCSM, all p ≥ 0.15. Results were similar for monocyte count measured at 12 months prior to RP.

CONCLUSION

In black and white PC patients undergoing RP, peripheral monocyte count was not associated with long-term PC outcomes. Contrary to what was found in Asian populations, monocyte count was not associated with PC outcomes in this study.

Chronic IL-1 exposure drives LNCaP cells to evolve androgen and AR independence

Chronic inflammation promotes prostate cancer (PCa) initiation and progression. We previously reported that acute intereluekin-1 (IL-1) exposure represses androgen receptor (AR) accumulation and activity, providing a possible mechanism for IL-1-mediated development of androgen- and AR-independent PCa. Given that acute inflammation is quickly resolved, and chronic inflammation is, instead, co-opted by cancer cells to promote tumorigenicity, we set out to determine if chronic IL-1 exposure leads to similar repression of AR and AR activity observed for acute IL-1 exposure and to determine if chronic IL-1 exposure selects for androgen- and AR-independent PCa cells. We generated isogenic sublines from LNCaP cells chronically exposed to IL-1α or IL-1β. Cells were treated with IL-1α, IL-1β, TNFα or HS-5 bone marrow stromal cells conditioned medium to assess cell viability in the presence of cytotoxic inflammatory cytokines. Cell viability was also assessed following serum starvation, AR siRNA silencing and enzalutamide treatment. Finally, RNA sequencing was performed for the IL-1 sublines. MTT, RT-qPCR and western blot analysis show that the sublines evolved resistance to inflammation-induced cytotoxicity and intracellular signaling and evolved reduced sensitivity to siRNA-mediated loss of AR, serum deprivation and enzalutamide. Differential gene expression reveals that canonical AR signaling is aberrant in the IL-1 sublines, where the cells show constitutive PSA repression and basally high KLK2 and NKX3.1 mRNA levels and bioinformatics analysis predicts that pro-survival and pro-tumorigenic pathways are activated in the sublines. Our data provide evidence that chronic IL-1 exposure promotes PCa cell androgen and AR independence and, thus, supports CRPCa development.

Prediction of clinically significant prostate cancer after negative prostate biopsy: The current value of microscopic findings

OBJECTIVE

To assess the current ability of atypical small acinar proliferation (ASAP), multifocal high-grade prostatic intraepithelial neoplasia (mHGPIN), HGPIN with atypia (PINATYP) and other non-malignant lesions to predict clinically significant prostate cancer (csPCa) in repeat prostate biopsies.

METHODS

This retrospective study analyzed 377 repeat prostate biopsies, carried out between 2.014 and 2.017, and excluding those with previous PCa or 5-alpha reductase inhibitors treatment. ASAP, mHGPIN, PINATYP, prostatic atrophy, prostatic hyperplastic atrophy, proliferative inflammatory atrophy (PIA), chronic prostatitis, acute prostatitis, or granulomatous prostatitis, were prospectively reported after 12-core transrectal ultrasound (TRUS) systematic negative previous biopsies. 3T-multiparametric magnetic resonance imaging (mpMRI) was performed previous repeat biopsies. At least 2-core TRUS targeted biopsies of Prostate Imaging-Reporting and Data Systemv2 lesions ≥3, and/or 12-core TRUS systematic biopsy were performed in repeat prostate biopsies. The main outcome measurements were csPCa detection, which was defined when the International Society of Uro-Pathology group grade >1 and avoided biopsies. After logistic regression analysis the most efficient model was selected, nomogram was designed with internal validation, and clinical utility was analyzed.

RESULTS

Normal benign tissue alone was present in less than 2% of previous negative biopsies. mHGPIN (39.7%), ASAP (4.3%) and PINATYP (3.7%) failed to predict csPCa risk in repeat biopsies. The finding of PIA (38.2%) associated with a decreased the risk of csPCa with an Odd ratio of 0.54 (95% confidence interval: 0.31-0.95), P= 0.031. The area under the curve, to predict csPCa, of mpMRI was 0.736, increasing up to 0.860 (95% confidence internal:0.82-0.90) when PSA density, age, digital rectal examination, and differential PSA between biopsies and PIA finding were integrated in a predictive model. At 6% threshold, more than 20% of repeat prostate biopsies were saved without missing csPCa.

CONCLUSION

Currently, mHGPIN in negative prostate biopsy seems not able to predict the risk of future csPCa. The low incidence of ASAP and PINATYP, in our series, did not allow us to draw conclusions. PIA finding associated with a reduced risk of csPCa, and it could be integrated in a useful based-mpMRI predictive nomogram.

Asian Race and Risk of Prostate Cancer: Results from the REDUCE Study

BACKGROUND

Global prostate cancer incidence rates are lower in Asian men than Caucasian men. Whether this is the result of less screening in Asian men remains to be determined. We examined whether Asian race was associated with prostate cancer diagnosis in the Reduction by Dutasteride of Cancer Events (REDUCE) study.

METHODS

REDUCE was a 4-year, multicenter, randomized trial of dutasteride versus placebo for prostate cancer prevention among men who underwent prostate-specific antigen (PSA)-independent biopsies at 2 and 4 years. Eligible men were ages 50 to 75 years, had PSA between 2.5 and 10 ng/mL, and a negative prestudy prostate biopsy. We tested the association between Asian and Caucasian race and prostate cancer diagnosis using logistic regression.

RESULTS

Of 8,122 men in REDUCE, 5,755 (71%) were Caucasian and 105 (1.8%) were Asian. Asians had lower body mass index (24.8 vs. 26.9 kg/m², P < 0.001), had smaller prostate volume (35.0 vs. 43.5 cc, P < 0.001), and were less likely to have abnormal digital rectal exams (P = 0.048), but were similar in baseline age, PSA, family history of prostate cancer, and smoking status compared with Caucasian men (all P ≥ 0.164). Asian men were equally likely to receive any on-study biopsy compared with Caucasian men (P = 0.634). After adjusting for potential confounders, Asian men were less likely to be diagnosed with prostate cancer during the 4-year study (OR = 0.49; 95% confidence interval, 0.28-0.88; P = 0.016), compared with Caucasian men.

CONCLUSIONS

In REDUCE, where all men underwent biopsies largely independent of PSA, Asian race was associated with lower prostate cancer diagnosis.

IMPACT

These findings suggest that lower prostate cancer risk in Asian men may be due to biological, genetic, and/or lifestyle factors.

Application of Anti-Inflammatory Agents in Prostate Cancer

Chronic inflammation is a major cause of human cancers. The environmental factors, such as microbiome, dietary components, and obesity, provoke chronic inflammation in the prostate, which promotes cancer development and progression. Crosstalk between immune cells and cancer cells enhances the secretion of intercellular signaling molecules, such as cytokines and chemokines, thereby orchestrating the generation of inflammatory microenvironment. Tumor-associated macrophages (TAMs) and myeloid-derived suppressor cells (MDSCs) play pivotal roles in inflammation-associated cancer by inhibiting effective anti-tumor immunity. Anti-inflammatory agents, such as aspirin, metformin, and statins, have potential application in chemoprevention of prostate cancer. Furthermore, pro-inflammatory immunity-targeted therapies may provide novel strategies to treat patients with cancer. Thus, anti-inflammatory agents are expected to suppress the “vicious cycle” created by immune and cancer cells and inhibit cancer progression. This review has explored the immune cells that facilitate prostate cancer development and progression, with particular focus on the application of anti-inflammatory agents for both chemoprevention and therapeutic approach in prostate cancer.

Bioptic intraprostatic chronic inflammation predicts adverse pathology at radical prostatectomy in patients with low-grade prostate cancer

PURPOSE

To determine the potential role of bioptic inflammation (Irani score) in predicting adverse pathology (AP) at radical prostatectomy (RP) in patients with low-grade (ISUP Gleason Group [ISUP GG] 1 and 2) prostate cancer (CaP).

METHODS

After institutional review board-approval, we identified patients who underwent prostate biopsy, had bioptic Irani score assessment, were diagnosed with low-grade CaP (ISUP GG 1-2, prostate-specific antigen [PSA] <20 ng/ml), and underwent RP. The impact of standard clinicopathological variables and bioptic Irani Score (G = grade and A = aggressiveness) on AP at RP, defined as stage ≥T3 and/or ISUP GG ≥3, was assessed by univariate and multivariate logistic regression analysis.

RESULTS

A total of 282 patients were eligible for this study. AP at RP occurred in 37 of 214 (17.3%) patients with ISUP GG 1, and 26 of 68 (38.2%) with ISUP GG 2. At univariate analysis, serum PSA, PSA density, bioptic ISUP GG, number of positive cores, total percentage of core involvement and Irani G score emerged as significant risk factors of AP. At multivariate analysis, however, only PSA density, bioptic ISUP GG, total percentage of core, and Irani G score kept statistical significance. The area under the curve for the resulting model was 0.75.

CONCLUSIONS

This is the first study demonstrating that low-grade inflammation is associated with a significantly increased risk of AP at RP. These findings would support the concept of prostatic inflammation being inversely correlated with presence and aggressiveness of CaP. Further studies are needed to externally validate the role of this readily available parameter in the decision-making process of patients with low-grade CaP.

Is there a correlation between the aggressiveness of chronic asymptomatic prostatitis National Institutes of Health category IV and the Gleason score in patients with prostate cancer?

INTRODUCTION

We evaluated the correlation between the International Society of Urological Pathology (ISUP) grades and the aggressiveness grades of prostate inflammation in newly diagnosed prostate cancer patients with chronic asymptomatic prostatitis National Institiutes of Health (NIH) category IV (CAPNIHIV).

METHODS

The study comprised 357 consecutive patients with prostate cancer in whom a cancer diagnosis had been made via a prostate needle biopsy. Histological sections of the prostate biopsy specimens of the patients were reviewed and scored. Prostatic inflammation was scored using the aggressiveness grade of inflammation. The associations between the ISUP grades and the aggressiveness grades of inflammation were analyzed using logistic regression. The limitations of the study were its retrospective design and the limited number of cases.

RESULTS

In 110 (31%) patients, CAPNIHIV was detected: 56 (51%) patients had a grade 0 aggressiveness score, 34 (31%) patients had a grade 1 aggressiveness score, and 20 (18%) patients had a grade 2 aggressiveness score. The patients who had prostatic inflammation had 1.65 times (95% confidence interval [CI] 1.05-2.61) greater likelihood of a high ISUP grade (grade ≥3) compared with the patients who did not have prostatic inflammation. The association between the ISUP grade and the aggressiveness grade of inflammation was more pronounced for a grade 2 aggressiveness score (n= 20; odds ratio 2.97; 95% CI 1.14-7.71).

CONCLUSIONS

In prostate cancer patients with CAPNIHIV, there was a positive correlation between the inflammation aggressiveness grade and the ISUP grade. The aggressiveness of intraprostatic inflammation may be an important morphological factor affecting the Gleason score.

Inflammatory serum markers and risk and severity of prostate cancer: The PROCA-life study

Whether chronic inflammation mirrored by high levels of systemic inflammatory markers such as high sensitive-CRP (hs-CRP) and white blood cell count (WBC) are associated with prostate cancer development remains unclear. In the Prostate Cancer Study throughout Life (PROCA-life), a prospective population-based cohort study, 7,356 men were included. Prediagnostic WBC and hs-CRP were assessed from blood collected at study entry; 2,210 participants also had a second CRP measure during follow-up. During a mean 11.8 years follow-up, 509 men developed prostate cancer (mean age at diagnosis 71.7 years). Multivariable Cox proportional hazard regression models were used to study whether individual biomarkers (WBC, hs-CRP), a combined score based on analyte tertiles (score range 2-6), or change in CRP were associated with risk and severity of prostate cancer. We observed a positive dose-response relationship between hs-CRP and prostate cancer risk with a Hazard Ratio (HR) per mg/l of 1.3, 95% CI 1.00-1.07. Men with an increase in hs-CRP between two measurements (Δhs-CRP) of ≥1.00 mg/l had a 36% increased risk of prostate cancer (HR 1.36, 95% CI 1.02-1.82), compared to men with no change or decrease in hs-CRP. Men with a systemic inflammatory score of 5 or 6 had a 68% higher risk of being diagnosed with metastatic disease (HR 1.68, 95% CI, 1.04-2.73) compared to men with lower scores. Our study supports that hs-CRP including repeated measurements alone or in combination with WBC may be a useful inflammation-related biomarker for prostate cancer risk and prognosis.

A Prospective Study of Intraprostatic Inflammation, Focal Atrophy, and Progression to Lethal Prostate Cancer

BACKGROUND

Inflammation and focal atrophy are common features adjacent to prostate tumors. Limited evidence exists on whether these features have prognostic significance.

METHODS

In the Health Professionals Follow-Up Study and Physicians' Health Study, we studied 1,035 men diagnosed with prostate cancer. A genitourinary pathologist centrally reviewed tumor and normal areas of hematoxylin and eosin slides from prostate cancer specimens for the presence of acute and chronic inflammation, and four subtypes of focal atrophy. Cox proportional hazards models adjusted for potential confounders were used to estimate HRs and 95% confidence intervals (CI) for the association of these features with lethal prostate cancer, defined as development of metastatic disease or death during follow-up.

RESULTS

During a median of 12 years of follow-up, 153 men developed lethal prostate cancer. A total of 84% of men had histologic evidence of chronic inflammation and 30% had acute inflammation. Both chronic and acute inflammation were inversely associated with lethal prostate cancer in age- and lifestyle-adjusted models. Chronic inflammation remained inversely associated with lethal prostate cancer after additionally adjusting for prognostic clinical features (HR = 0.45; 95% CI, 0.30-0.69 for mild and HR = 0.51; 95% CI, 0.33-0.80 for moderate to severe). None of the atrophic lesions were associated with lethal prostate cancer.

CONCLUSIONS

Our data suggest that the presence of inflammation, particularly chronic inflammation, in prostate cancer tissue is associated with better prognosis among patients with prostate cancer.

IMPACT

This is the largest prospective cohort study to examine the association between inflammation, focal atrophy, and lethal prostate cancer.

In Search for risk predictors at the microscopic scenario of a negative biopsy. A systematic review

INTRODUCTION

In cases of persistent suspicion of prostate cancer (PC), repeat prostate biopsies (PB) are frequently performed in spite of their low yield. In the context of a negative PB, there is a microscopic scenario (MS), which we define as the group of recognizable non-neoplastic lesions. While some of these lesions seem to have a protective effect, the existence of others increases the risk of PC detection in posterior PB. The objective of this systematic review is to identify the lesions that may belong to the MS of a negative PB and analyse the current evidence of their association with the risk of detecting PC in subsequent PBs.

EVIDENCE ACQUISITION

Two independent reviewers conducted a literature search on Medline, Embase and Central Cochrane with the following search terms: small acinar proliferation, ASAP, prostatic intraepithelial neoplasia, HGPIN, adjacent small atypical glands, pinatyp, atrophy, proliferative inflammatory atrophy, pia, prostatic inflammation, prostatitis and prostate cancer. 1,015 references were first identified, and 57 original articles were included in the study, following the PRISMA declaration and the PICO selection principles.

EVIDENCE SYNTHESIS

Atypical small acinar proliferation is associated with PC detection in repeat PB with rates ranging between 32 and 48%. High-grade prostatic intraepithelial neoplasia (HGPIN) is related to PC in 13 to 42% of cases. Studies show that HGPIN, when multifocal, is a significant independent risk factor for PC. Prostatic atrophy, inflammatory proliferative atrophy and prostatic inflammation seem to act as protective factors on the detection of PC in repeat PB. On the other hand, the risk of PC detection reduces significantly in male patients with multifocal HGPIN and coexistent PIA.

CONCLUSIONS

The MS of a negative PB may include atypical small acinar proliferation, HGPIN, prostatic atrophy, inflammatory proliferative atrophy and prostatic inflammation lesions, since they all seem to be associated with the risk of PC detection in repeat PB. This review has led us to create the hypothesis that the MS of a negative PB might be a valuable and useful tool when considering repeat PB.

Current Knowledge of the Potential Links between Inflammation and Prostate Cancer

Inflammation is inherent in prostatic diseases and it is now accepted that it may facilitate cellular proliferation in both benign and malignant conditions. The strong relationship between prostatic inflammation and pathogenesis of benign prostatic hyperplasia (BPH) is supported by epidemiologic, histopathologic and molecular evidence. Contrariwise, the role of inflammation in prostate carcinogenesis is still controversial, although current data indicate that the inflammatory microenvironment can regulate prostate cancer (PCa) growth and progression. Knowledge of the complex molecular landscape associated with chronic inflammation in the context of PCa may lead to the introduction and optimization of novel targeted therapies. In this perspective, evaluation of the inflammatory component in prostate specimens could be included in routine pathology reports.

Chemoprevention in Prostate Cancer: Current Perspective and Future Directions

Chemoprevention of prostate cancer aims to reduce the mortality as well as the public burden of overdetection, which increases anxiety, cost, and morbidity related to the disease. The role of 5-α-reductase inhibitors has been well investigated and shown to decrease the risk of prostate cancer. No current evidence exists to encourage the use of nutrients or vitamins as chemopreventive agents. The modulation of inflammation is one of the most promising targets for chemoprevention of prostate cancer.

Association of Anthropometric Measures with Prostate Cancer among African American Men in the NCI-Maryland Prostate Cancer Case-Control Study

Background: Obesity is a cancer risk factor. Although it does not increase the risk of localized prostate cancer, it raises the risk of the aggressive disease in men of European ancestry. Few studies investigated obesity as a prostate cancer risk factor in men of African ancestry. Findings from those studies were heterogeneous, but some reported an association of excess body fatness with aggressive disease.Methods: We examined the relationship of body mass index (BMI), waist circumference, and waist-hip ratio with prostate cancer in African American (AA) and European American (EA) men in the NCI-Maryland Prostate Cancer Case-Control Study consisting of 798 men with incident prostate cancer (402 AA and 496 EA) and 1,008 population-based controls (474 AA and 534 EA). BMI was self-reported. Waist circumference and waist-hip ratio were calculated from measurements at enrollment.Results: A high BMI either at enrollment or years prior to it was associated with a decreased risk of prostate cancer in AA men. In contrast, an elevated BMI tended to increase the disease risk in EA men. Waist circumference was inversely associated with prostate cancer in both AA and EA men, whereas a high waist-hip ratio did not associate with prostate cancer in AA men but tended to be associated with advanced/aggressive disease in EA men.Conclusions: Our findings reveal an obesity paradox among AA men in this study population, where a high BMI and waist circumference associated with a decreased disease risk.Impact: Our observations expand the knowledge of how obesity may affect prostate cancer risks in AAs. Cancer Epidemiol Biomarkers Prev; 27(8); 936-44. ©2018 AACR.

Both acute and chronic inflammation are associated with less perineural invasion in men with prostate cancer on repeat biopsy

OBJECTIVES

To evaluate the association between acute and chronic inflammation with the presence of perineural invasion (PNI) in prostate biopsies positive for prostate cancer (PCa).

MATERIAL AND METHODS

We conducted a retrospective analysis of 1 399 prostate biopsies positive for PCa in the Reduction by Dutasteride of PCa Events (REDUCE) study. PCa, acute and chronic prostate inflammation and PNI were assessed by central pathology review. The association between acute and chronic inflammation with PNI was evaluated using chi-squared and Kruskal-Wallis tests, and logistic regression adjusting for clinicopathological and biochemical variables.

RESULTS

The presence of PNI was identified in 133 biopsies (9.5%). In all, 267 biopsies (19.1%) had acute inflammation, 1 038 (74.2%) had chronic inflammation, and 255 (18.2%) had both. The presence of both acute and chronic inflammation had a mutual association (P < 0.001). Chronic inflammation was associated with a lower Gleason score (P = 0.009) and lower tumour volume (P < 0.001), while acute inflammation was associated with lower Gleason score (P = 0.04), lower tumour volume (P = 0.004) and higher prostate-specific antigen levels (P = 0.05). In both univariable and multivariable analyses, chronic prostate inflammation was significantly associated with less PNI (univariable odds ratio [OR] 0.54, 95% confidence interval [CI] 0.37-0.79, P = 0.001; multivariable OR 0.65, 95% CI 0.43-0.99, P = 0.045). Acute prostate inflammation was associated with less PNI only in univariable analysis (univariable OR 0.51, 95% CI 0.29-0.89, P = 0.018; multivariable OR 0.63, 95% CI 0.35-1.13, P = 0.12).

CONCLUSION

Acute and chronic prostate inflammation were both associated with a lower prevalence of PNI in prostate biopsies positive for PCa. If confirmed, this suggests that inflammation and immunomodulation can serve as areas of potential therapeutic design to mitigate PNI in patients with PCa.

Geographic Differences in Baseline Prostate Inflammation and Relationship with Subsequent Prostate Cancer Risk: Results from the Multinational REDUCE Trial

Background: Prostate cancer incidence rates vary 25-fold worldwide. Differences in PSA screening are largely, but not entirely, responsible. We examined geographic differences in prevalence of histologic prostate inflammation and subsequent prostate cancer risk.Methods: Seven thousand nonHispanic white men were enrolled in the REduction by DUtasteride of prostate Cancer Events (REDUCE) trial from Europe (n = 4,644), North America (n = 1,746), South America (n = 466), and Australia/New Zealand (n = 144). Histologic inflammation in baseline negative prostate biopsies was classified as chronic (lymphocytes/macrophages) or acute (neutrophils). Multivariable logistic regression was used to examine associations between region and prostate inflammation, and between region and prostate cancer risk at 2-year biopsy.Results: Prevalence of prostate inflammation varied across region, with broadly similar patterns for acute and chronic inflammation. Relative to Europe, prevalence of acute inflammation was higher in North America [odds ratio (OR), 1.77; 95% confidence interval (CI), 1.51-2.08] and Australia/New Zealand (OR, 2.07; 95% CI, 1.40-3.06). Men from these regions had lower prostate cancer risk than Europeans at biopsy. Among North Americans, prevalence of acute inflammation was higher in Canada versus the United States (OR, 1.40; 95% CI, 1.07-1.83), but prostate cancer risk did not differ between these regions. Among Europeans, prevalence of acute inflammation was lower in Northern and Eastern (OR, 0.79; 95% CI, 0.65-0.97 and OR 0.62; 95% CI, 0.45-0.87, respectively), relative to Western Europe, and these men had higher prostate cancer risk at biopsy.Conclusions: Prevalence of histologic prostate inflammation varied by region. Geographic differences in prostate inflammation tracked inversely with geographic differences in prostate cancer risk.Impact: Characterization of premalignant prostate biology and the relationship with subsequent prostate cancer risk could inform prostate cancer prevention efforts. Cancer Epidemiol Biomarkers Prev; 27(7); 783-9. ©2018 AACR.

Neutrophil, lymphocyte and platelet counts, and risk of prostate cancer outcomes in white and black men: results from the SEARCH database

PURPOSE

Systemic inflammation, as measured by C-reactive protein, has been linked with poor prostate cancer (PC) outcomes, predominantly in white men. Whether other immune measures like white blood cell counts are correlated with PC progression and whether results vary by race is unknown. We examined whether complete blood count (CBC) parameters were associated with PC outcomes and whether these associations varied by race.

METHODS

Analyses include 1,826 radical prostatectomy patients from six VA hospitals followed through medical record review for biochemical recurrence (BCR). Secondary outcomes included castration-resistant PC (CRPC), metastasis, all-cause mortality (ACM), and PC-specific mortality (PCSM). Cox-proportional hazards were used to assess the associations between pre-operative neutrophils, lymphocytes, platelets, neutrophil-lymphocyte ratio (NLR), and platelet-lymphocyte ratio (PLR) with each outcome. We used a Bonferroni-corrected p-value of 0.05/5 = 0.01 as the threshold for statistical significance.

RESULTS

Of 1,826 men, 794 (43%) were black and 1,032 (57%) white. Neutrophil count (p < 0.001), NLR (p < 0.001), and PLR (p < 0.001) were significantly lower, while lymphocyte count (p < 0.001) was significantly higher in black versus white men. After adjusting for clinicopathological features, no CBC measures were significantly associated with BCR. There were no interactions between CBC and race in predicting BCR. Similarly, no CBC values were significantly associated with CRPC, metastases, or PCSM either among all men or when stratified by race. However, higher neutrophil count was associated with higher ACM risk in white men (p = 0.004).

CONCLUSION

Pre-operative CBC measures were not associated with PC outcomes in black or white men undergoing radical prostatectomy, except for neutrophils-positive association with risk of ACM in white men. Whether circulating immune cell markers provide insight to the pathophysiology of PC progression or adverse treatment outcomes requires further study.

The role of prostatic inflammation in the development and progression of benign and malignant diseases

PURPOSE OF REVIEW

To evaluate the role of prostatic inflammation in the development and progression of benign and malignant prostatic diseases.

RECENT FINDINGS

Preclinical studies demonstrate that the activation of a chronic inflammatory prostatic response plays an important role in the pathogenesis and progression of benign prostatic hyperplasia (BPH) and prostate cancer (PCa). Approximately 40-70% of patients with BPH-related lower urinary tract symptoms harbour chronic inflammation at pathologic evaluation. These individuals should be considered at increased risk of symptom progression and acute urinary retention. Although currently available drugs approved for the treatment of BPH do not have an anti-inflammatory activity, the development of novel molecules that target the inflammatory pathway represents a promising area in the pharmacological treatment of BPH. Preclinical evidences support a potential role of chronic prostatic inflammation in the malignant transformation of prostatic cells. However, clinical investigations on the association between prostatic inflammation and the risk of PCa report conflicting results.

SUMMARY

Men with BPH-related lower urinary tract symptoms and chronic prostatic inflammation should be considered at increased risk of symptom progression and acute urinary retention during follow-up. Although preclinical studies provide a biological rationale for the relationship between inflammation and the risk of PCa, clinical investigations report conflicting results and the direct relationship between inflammation and malignant transformation in the human prostate is still debated.

Associations of Transitional Zone Volume with Intraprostatic Chronic Inflammation and Prostate Cancer Risk in Patients Undergoing a First Random Biopsy Set

Objectives

To investigate associations of the transitional zone volume (TZV) with intraprostatic chronic inflammatory infiltrate (CII) and prostate cancer (PCa) risk in patients undergoing a first random biopsy set.

Materials and Methods

The study included a homogenous population of 596 patients. The volume of the prostate and TZV were separately measured. Independent associations were investigated by multivariate logistic regression analysis.

Results

The median TZV was 18 ml, CII was detected in 157 cases (26.3%), and PCa was present in 292 patients (49%). TZV was the only independent clinical factor associated with CII risk (OR = 1.014). After correcting for CII (OR = 0.276; p < 0.0001), independent factors associated with PCa risk included age (OR = 1.066), prostate specific antigen (OR = 1.177), TZV (OR = 0.919), and an abnormal digital rectal exam (OR = 2.024).

Conclusion

In a patient population undergoing a first random prostate biopsy set because of suspected cancer, independent associations were detected among TZV, CII, and PCa. The association between TZV and CII was direct, but the relation between TZV and PCa was inverse. The measurement of the volume of the transitional zone was a useful parameter for evaluating chronic intraprostatic inflammation and PCa risk.

Inflammation on Prostate Needle Biopsy is Associated with Lower Prostate Cancer Risk: A Meta-Analysis

PURPOSE

We performed a comprehensive literature review and meta-analysis to evaluate the association of inflammation on prostate needle biopsies and prostate cancer risk.

MATERIALS AND METHODS

We searched Embase®, PubMed® and Web of Science™ from January 1, 1990 to October 1, 2016 for abstracts containing the key words prostate cancer, inflammation and biopsy. Study inclusion criteria were original research, adult human subjects, cohort or case-control study design, histological inflammation on prostate needle biopsy and prostate cancer on histology. Two independent teams reviewed abstracts and extracted data from the selected manuscripts. Combined ORs and 95% CIs of any, acute and chronic inflammation were calculated using the random effects method.

RESULTS

Of the 1,030 retrieved abstracts 46 underwent full text review and 25 were included in the final analysis, comprising a total of 20,585 subjects and 6,641 patients with prostate cancer. There was significant heterogeneity among studies (I² = 84.4%, p <0.001). The presence of any inflammation was significantly associated with a lower prostate cancer risk in 25 studies (OR 0.455, 95% CI 0.337-0.573). There was no evidence of publication bias (p >0.05). When subanalyzed by inflammation type, acute inflammation in 4 studies and chronic inflammation in 15 were each associated with a lower prostate cancer risk (OR 0.681, 95% CI 0.450-0.913 and OR 0.499, 95% CI 0.334-0.665, respectively).

CONCLUSIONS

In a meta-analysis of 25 studies inflammation on prostate needle biopsy was associated with a lower prostate cancer risk. Clinically the presence of inflammation on prostate needle biopsy may lower the risk of a subsequent prostate cancer diagnosis.

Do antibiotics decrease prostate-specific antigen levels and reduce the need for prostate biopsy in type IV prostatitis? A systematic literature review

INTRODUCTION

Inflammation of the prostate can be a cause of elevated prostate-specific antigen (PSA) in men referred for suspected prostate cancer. This systematic review assesses the evidence for antibiotic therapy in patients with type IV (asymptomatic) prostatitis with regard to reduction of PSA levels and discrimination between prostate cancer and inflammation.

METHODS

MEDLINE, EMBASE, and the Cochrane registry were searched for papers reporting on cohorts of men with elevated PSA and type IV prostatitis that were treated with antibiotics.

RESULTS

The search yielded 160 papers, of which 11 met the inclusion criteria: two randomized trials and nine cohort studies. In total, the studies reported on 1011 patients with type IV prostatitis, of whom 926 were treated with antibiotics. PSA normalization was seen after antibiotic treatment in 33.2% of patients (95% confidence interval [CI] 24.9-42.8). Meta-analysis of the randomized trials did not demonstrate a higher likelihood of PSA normalization in the antibiotics arm as compared to the control arm (odds ratio [OR] 1.27; 95% CI 0.58-2.76; p=0.553). Four studies performed prostate biopsies in all patients. Although three of these studies demonstrated lower prevalence of prostate cancer in patients in whom PSA had normalized, meta-analysis failed to show a statistically significant difference (OR 0.39; 95% CI 0.06-2.49; p=0.319).

CONCLUSIONS

The available evidence does not support antibiotic therapy for differentiation between benign and malignant cause of elevated PSA in men with type IV prostatitis.

Natriuretic Peptides: The Case of Prostate Cancer

Cardiac natriuretic peptides have long been known to act as main players in the homeostatic control of blood pressure, salt and water balance. However, in the last few decades, new properties have been ascribed to these hormones. A systematic review of English articles using MEDLINE Search terms included prostate cancer, inflammation, cardiac hormones, atrial natriuretic peptide, and brain natriuretic peptide. Most recent publications were selected. Natriuretic peptides are strongly connected to the immune system, whose two branches, innate and adaptive, are finely tuned and organized to kill invaders and repair injured tissues. These peptides control the immune response and act as anti-inflammatory and immune-modulatory agents. In addition, in cancers, natriuretic peptides have anti-proliferative effects by molecular mechanisms based on the inhibition/regulation of several pathways promoting cell proliferation and survival. Nowadays, it is accepted that chronic inflammation is a crucial player in prostate cancer development and progression. In this review, we summarize the current knowledge on the link between prostate cancer and inflammation and the potential use of natriuretic peptides as anti-inflammatory and anticancer agents.

Prostate-specific antigen increase during dutasteride to indicate the need for prostate biopsy: influence of prostatic inflammation

INTRODUCTION

The aim of this study was to analyze the significance of an increase in total prostate-specific antigen (PSA) serum levels despite dutasteride treatment as a predictor of prostate cancer (PC) at biopsy. We focused our attention on the rate of the first PSA increase and on the influence of prostatic inflammation.

METHODS

From 2011 to 2016, 365 men with a previous negative prostate biopsy and persistent elevated PSA levels received dutasteride treatment. The population was followed for a range of 12-48 months.

RESULTS

One hundred twelve cases with a confirmed PSA increase >0.5 ng/ml over the nadir value during the follow-up were included in Group A and underwent a new prostate biopsy. In Group A, the PSA increase was associated with PC at the re-biopsy in 66% of cases. The percentage of PSA reduction after 6 months of treatment was not a significant indicator of the risk for PC. The distribution of inflammatory infiltrates significantly (p<00.01) varied from positive to negative prostate biopsies. The relative risk for PC at biopsy significantly increased according to PSA level during dutasteride.

CONCLUSIONS

Treatment with dutasteride can help to analyze PSA kinetic. A persistent prostatic inflammation is a factor able to reduce the performance of PSA kinetic during dutasteride treatment.

A Prospective Study of Chronic Inflammation in Benign Prostate Tissue and Risk of Prostate Cancer: Linked PCPT and SELECT Cohorts

Background: We leveraged two trials to test the hypothesis of an inflammation-prostate cancer link prospectively in men without indication for biopsy.Methods: Prostate Cancer Prevention Trial (PCPT) participants who had an end-of-study biopsy performed per protocol that was negative for cancer and who subsequently enrolled in the Selenium and Vitamin E Cancer Prevention Trial (SELECT) were eligible. We selected all 100 cases and sampled 200 frequency-matched controls and used PCPT end-of-study biopsies as "baseline." Five men with PSA > 4 ng/mL at end-of-study biopsy were excluded. Tissue was located for 92 cases and 193 controls. We visually assessed inflammation in benign tissue. We estimated ORs and 95% confidence intervals (CI) using logistic regression adjusting for age and race.Results: Mean time between biopsy and diagnosis was 5.9 years. In men previously in the PCPT placebo arm, 78.1% of cases (N = 41) and 68.2% of controls (N = 85) had at least one baseline biopsy core (∼5 evaluated per man) with inflammation. The odds of prostate cancer (N = 41 cases) appeared to increase with increasing mean percentage of tissue area with inflammation, a trend that was statistically significant for Gleason sum <4+3 disease (N = 31 cases; vs. 0%, >0-<1.8% OR = 1.70, 1.8-<5.0% OR = 2.39, ≥5% OR = 3.31, P_trend = 0.047). In men previously in the finasteride arm, prevalence of inflammation did not differ between cases (76.5%; N = 51) and controls (75.0%; N = 108).Conclusions: Benign tissue inflammation was positively associated with prostate cancer.Impact: This first prospective study of men without biopsy indication supports the hypothesis that inflammation influences prostate cancer development. Cancer Epidemiol Biomarkers Prev; 26(10); 1549-57. ©2017 AACR.

Statin Use, Serum Lipids, and Prostate Inflammation in Men with a Negative Prostate Biopsy: Results from the REDUCE Trial

Statin use is associated with lower advanced prostate cancer risk. In addition to cholesterol lowering, statins have systemic anti-inflammatory properties. However, their effect on histologic prostate inflammation is not well understood, particularly among men at increased prostate cancer risk but with a negative prostate biopsy. We examined associations between serum lipid levels, statin use, and histologic prostate inflammation using data from 6,655 men with a negative baseline prostate biopsy in the REduction by DUtasteride of prostate Cancer Events (REDUCE) trial. Statin use and lipid levels [total cholesterol, low-density lipoprotein (LDL), high-density lipoprotein (HDL), triglycerides] were assessed at baseline. Inflammation was assessed by central review. Logistic regression was used to examine the effects of lipids and statin use on presence and extent of chronic and acute prostate inflammation [none, moderate (<20%), severe (≥20% biopsy cores)]. Chronic and acute inflammation affected 77% and 15% of men, respectively. Men with high HDL (≥60 vs. <40 mg/dL) had reduced presence of acute inflammation [OR, 0.79; 95% confidence interval (CI), 0.63-0.99] and were less likely to have severe acute inflammation (OR, 0.66; 95% CI, 0.45-0.97), but there were no other associations between lipids and inflammation. Statin users had reduced presence of chronic inflammation (OR, 0.81; 95% CI, 0.69-0.95) and were less likely to have severe chronic (OR, 0.80; 95% CI, 0.68-0.95) and severe acute inflammation (OR, 0.73; 95% CI, 0.53-1.00), relative to non-users. Given the possible role for inflammation in prostate cancer, the inverse association between statins and prostate inflammation suggests a mechanism linking statins with lower advanced prostate cancer risk. Cancer Prev Res; 10(6); 319-26. ©2017 AACR.

Intraprostatic chronic inflammation is associated with a reduced risk of prostate cancer in patients elected to a first random biopsy set

OBJECTIVES

To investigate the associations of clinical factors and intraprostatic chronic inflammatory infiltrate (CII) with the risk of prostate cancer (PCa) in a large contemporary cohort of patients elected to a first random biopsy set.

MATERIALS AND METHODS

The study evaluated 596 patients who were elected to a first random biopsy set because of suspected PCa in the period between September 2010 and September 2015. The multivariate logistic regression model investigated the possible associations of clinical factors and intraprostatic CII with PCa.

RESULTS

Prostate cancer was detected in 292 of 596 patients (49%). Intraprostatic CII was detected in 26.3% of cases. Age (odds ratio, OR = 1.060; p<.0001), prostate-specific antigen (PSA; OR = 1.174; p<.0001), prostate volume (PV; OR = 0.951; p<.0001) and abnormal digital rectal examination (DRE; OR = 2.170; p = 0.001) were independent predictors of PCa risk; moreover, intraprostatic CII was an important independent factor lowering the risk of PCa (OR = 0.258; p<.0001) in the multivariate clinical model.

CONCLUSIONS

In a large contemporary cohort of patients elected to a first random biopsy set, the detection of intraprostatic CII was not negligible (26.3%) and associated with a reduced risk of PCa. In the prostate microenvironment, intraprostatic CII might lower the risk of PCa by activating the response of the immune system at the early stages of cancer induction and progression. Specific serum biomarkers and imaging modalities associated with intraprostatic CII are required. Advanced basic science research is warranted to investigate and develop the controversial topic of intraprostatic chronic inflammation in relation to PCa.

Prostate cancer incidence in men with self-reported prostatitis after 15 years of follow-up

Controversy exists regarding a possible association between prostatitis and prostate cancer. To further evaluate the incidence of prostate cancer following prostatitis, a study of prostate cancer incidence in a cohort of Finnish men was performed. The original survey evaluating self-reported prostatitis was conducted in 1996-1997. A database review was conducted focusing on prostate cancer diagnoses in the cohort. In 2012, there were 13 (5.2%) and 27 (1.8%) prostate cancer cases among men with (n=251) and without (n=1,521) prostatitis symptoms, respectively. There were no significant differences in age, primary therapy distribution, prostate-specific antigen levels, Gleason score, clinical T-class at the time of prostate cancer diagnosis, or time lag between the original survey and prostate cancer diagnosis. The standardized incidence ratio (SIR) of prostate cancer was 1.16 [95% confidence interval (CI), 0.62-1.99] and 0.44 (95% CI, 0.29-0.64) among men with and without prostatitis symptoms, respectively. After 15 years of follow-up subsequent to self-reported prostatitis, no evident increase in incidence of prostate cancer was detected among Finnish men with prostatitis symptoms. The higher percentage of prostate cancer among men with prostatitis symptoms appears to be due to coincidentally low SIR of prostate cancer among men without prostatitis symptoms, and may additionally be due to increased diagnostic examinations. Further research is required to confirm this speculation.

The role of prostate inflammation and fibrosis in lower urinary tract symptoms

Lower urinary tract symptoms (LUTS) in aging men are extremely common. They have historically been attributed to benign prostatic hyperplasia (BPH), enlargement of the prostate, and bladder outlet obstruction. However, recent studies have revealed acute and chronic inflammation to be highly associated with LUTS, correlated with prostatic enlargement, and implicated as a cause of prostatic fibrosis that contributes to bladder outlet obstruction. This review examines the evidence implicating inflammation and fibrosis in BPH/LUTS. It identifies potential mechanisms by which inflammation may drive nociceptive signaling as well as hyperplastic growth and fibrosis and identifies targets for pharmacological intervention. This is a promising area for research and development of novel therapies to prevent or more effectively treat LUTS in aging men.

Racial differences in prostate inflammation: results from the REDUCE study

Prostate cancer (PC) risk differs between races, and we previously showed prostate inflammation in benign prostate tissue was linked with a lower future PC risk. However, whether prostate tissue inflammation varies by race is unknown. We analyzed baseline acute and chronic prostate inflammation by race in REDUCE, a 4-year, multicenter, placebo-controlled study where all men had a negative prostate biopsy prior to enrollment. We included 7,982 men with standardized central pathology review to determine the presence or absence of chronic or acute inflammation in baseline prostate biopsy tissue. Logistic regression was used to compare prostate inflammation by race, adjusting for confounders. Of 7,982 men, 7,271 were white (91.1%), 180 (2.3%) black, 131 (1.6%) Asian, 319 (4.0%) Hispanic and 81 (1%) unknown. A total of 78% had chronic and 15% had acute inflammation. On multivariable analysis relative to white men, black men were less likely (OR = 0.65, 95%CI: 0.41-1.03, p = 0.07) and Asian men more likely to have acute inflammation (OR = 1.74, 95%CI: 1.14-2.65, p = 0.001). Hispanic men had similar levels of acute inflammation as white men. Chronic inflammation did not significantly differ across races. We identified racial differences in acute inflammation, particularly in Asian men, in benign prostate tissue that inversely mirrored population-level data on PC race disparity. As we showed in REDUCE that acute inflammation is linked with lower future PC risk, if validated in future studies, these data suggest racial differences in prostatic acute inflammation may contribute in part to race differences in PC risk, especially among Asian men.

Chronic Inflammation in Prostate Biopsy Cores is an Independent Factor that Lowers the Risk of Prostate Cancer Detection and is Inversely Associated with the Number of Positive Cores in Patients Elected to a First Biopsy

OBJECTIVES

To investigate associations of chronic inflammatory infiltrate (CII) with prostate cancer (PCa) risk and the number of positive cores in patients elected to a first set of biopsies.

MATERIALS AND METHODS

Excluding criteria were as follows: active surveillance, prostate specific antigen (PSA) ≥ 30 ng/l, re-biopsies, incidental PCa, less than 14 cores, metastases, or 5-alpha reductase inhibitors. The cohort study was classified as negative (control group) and positive cores between 1 and 2 or > 2.

RESULTS

The cohort included 421 cases who did not meet the exclusion criteria. PCa was detected in 192 cases (45.6%) of which the number of positive cores was between 1 and 2 in 77 (40.1%) cases. The median PSA was 6.05 ng/ml (range 0.3-29 ng/ml). Linear regression models showed that CII was an independent predictor inversely associated with the risk of PCa. Multinomial logistic regression models showed that CII was an independent factor that was inversely associated with PCa risk in cases with positive cores between 1 and 2 (OR = 0.338; p = 0.004) or more than 2 (OR = 0.076; p < 0.0001) when compared to the control group.

CONCLUSION

In a cohort of men undergoing the first biopsy set after prostate assessment, the presence of CII in the biopsy core was an independent factor inversely associated with PCa risk as well as with the number of positive biopsy cores (tumor extension). Clinically, the detection of CII in negative biopsy cores might reduce the risk of PCa in repeat biopsies as well as the probability of detecting multiple positive cores.

Vitamin D and Immune Response: Implications for Prostate Cancer in African Americans

Prostate cancer (PCa) is the most common cancer among men in the U.S. African American (AA) men have a higher incidence and mortality rate compared to European American (EA) men, but the cause of PCa disparities is still unclear. Epidemiologic studies have shown that vitamin D deficiency is associated with advanced stage and higher tumor grade and mortality, while its association with overall PCa risk is inconsistent. Vitamin D deficiency is also more common in AAs than EAs, and the difference in serum vitamin D levels may help explain the PCa disparities. However, the role of vitamin D in aggressive PCa in AAs is not well explored. Studies demonstrated that the active form of vitamin D, 1,25-dihydroxyvitamin D, has anti-inflammatory effects by mediating immune-related gene expression in prostate tissue. Inflammation also plays an important role in PCa pathogenesis and progression, and expression of immune-related genes in PCa tissues differs significantly between AAs and EAs. Unfortunately, the evidence linking vitamin D and immune response in relation to PCa is still scarce. This relationship should be further explored at a genomic level in AA populations that are at high risk for vitamin D deficiency and fatal PCa.

Prevention of prostate cancer: outcomes of clinical trials and future opportunities

Prostate cancer is an excellent target for prevention, to reduce both mortality and the burden of overdetection of potential inconsequential disease whose diagnosis increases cost, morbidity, and anxiety. The Prostate Cancer Prevention Trial has demonstrated that finasteride significantly reduces the risk of prostate cancer but only low-grade disease; overall survival is unaffected. In the Selenium and Vitamin E Cancer Prevention Trial (SELECT) clinical trial, selenium had no effect on prostate cancer risk, but alpha tocopherol significantly increased the risk by 17%. The most promising future approaches to prostate cancer prevention will likely focus on nutrition, especially weight control, and through modulation of inflammation.

Racial differences in the relationship between clinical prostatitis, presence of inflammation in benign prostate and subsequent risk of prostate cancer

BACKGROUND

Epidemiologic studies, primarily done in white men, suggest that a history of clinically-diagnosed prostatitis increases prostate cancer risk, but that histological prostate inflammation decreases risk. The relationship between a clinical history of prostatitis and histologic inflammation in terms of how these two manifestations of prostatic inflammation jointly contribute to prostate cancer risk and whether racial differences exist in this relationship is uncertain.

METHODS

Using a nested design within a cohort of men with benign prostate tissue specimens, we analyzed the data on both clinically-diagnosed prostatitis (NIH categories I-III) and histological inflammation in 574 prostate cancer case-control pairs (345 white, 229 African American).

RESULTS

Clinical prostatitis was not associated with increased prostate cancer risk in the full sample, but showed a suggestive inverse association with prostate cancer in African Americans (odds ratio (OR)=0.47; 95% confidence interval (CI)=0.27-0.81). In whites, clinical prostatitis increased risk by 40%, but was only associated with a significant increased prostate cancer risk in the absence of evidence of histological inflammation (OR=3.56; 95% CI=1.15-10.99). Moreover, PSA velocity (P=0.008) and frequency of PSA testing (P=0.003) were significant modifiers of risk. Clinical prostatitis increased risk of prostate cancer almost three-fold (OR=2.97; 95% CI=1.40-6.30) in white men with low PSA velocity and about twofold in white men with more frequent PSA testing (OR=1.91; 95% CI=1.09-3.35).

CONCLUSIONS

In our cohort of men with benign prostate specimens, race, and histological inflammation were important cofactors in the relationship between clinical prostatitis and prostate cancer. Clinical prostatitis was associated with a slightly decreased risk for prostate cancer in African American men. In white men, the relationship between clinical prostatitis and prostate cancer risk was modified by histological prostatic inflammation, PSA velocity, and frequency of PSA testing-suggesting a complex interplay between these indications of prostatic inflammation and prostate cancer detection.

Prostate chronic inflammation type IV and prostate cancer risk in patients undergoing first biopsy set: Results of a large cohort study

OBJECTIVE

In prostate specimens, chronic inflammatory infiltrate (CII) type IV has been detected, but its association with prostate cancer (PCa) is controversial. The aim of the present study is to investigate on associations of CII with PCa detection in patients undergoing prostate first biopsy set.

METHODS

Ultrasound transrectal-guided biopsies by the transperineal approach were retrospectively evaluated in 441 consecutive patients. The study excluded patients who were in active surveillance, prostate specific antigen (PSA) ≥30 ng/mL, re-biopsies, incidental PCa after transurethral resection of the prostate (TURP), less than 14 cores or metastatic. Analysis of population and subpopulations (with or without PCa) was performed by statistical methods which included Mann-Whitney (U test), Kruskal-Wallis test, Chi-squared statistic, logistic regression. Multivariate logistic regression models predicting mean probability of PCa detection were established.

RESULTS

PCa detection rate was 46.03%. Age, PSA, prostate volume (PV), prostate intraepithelial neoplasia (PIN) and CII were the significant independent predictors of PCa detection. PV (OR = 0.934) and CII (OR = 0.192) were both negative independent predictors. CII was a significant negative independent predictor in multivariate logistic regression models predicting the mean probability of PCa detection by age, PSA and PV. The inverse association of CII with PCa does not necessary mean protection because of PSA confounding.

CONCLUSION

In a population of patients undergoing prostate first biopsy set, CII was a strong negative independent predictor of PCa detection. CII type IV should be considered as an adjunctive parameter in re-biopsy or active surveillance protocols.

Immune Infiltration and Prostate Cancer

It is becoming increasingly clear that inflammation influences prostate cancer (PCa) development and that immune cells are among the primary drivers of this effect. This information has launched numerous clinical trials testing immunotherapy drugs in PCa patients. The results of these studies are promising but have yet to generate a complete response. Importantly, the precise immune profile that determines clinical outcome remains unresolved. Individual immune cell types are divided into various functional subsets whose effects on tumor development may differ depending on their particular phenotype and functional status, which is often shaped by the tumor microenvironment. Thus, this review aims to examine the current knowledge regarding the role of inflammation and specific immune cell types in mediating PCa progression to assist in directing and optimizing immunotherapy targets, regimens, and responses and to uncover areas in which further research is needed. Finally, a summary of ongoing immunotherapy clinical trials in PCa is provided.