Therapeutic effects of finasteride: inhibition of disease progression and serum prostate-specific antigen reduction in patients with prostatic intraepithelial neoplasia.

The objective of this study was to evaluate the impact of finasteride on the progression of prostate intraepithelial neoplasia and levels of prostate-specific antigen (PSA) in patients. A total of 120 patients with high-grade prostatic intraepithelial neoplasia were included in this study from January 2013 to January 2018. All patients underwent prostate biopsies. Among them, 60 patients were assigned to the observation group and received a daily dosage of 5 mg finasteride for 60 months, while the remaining 60 patients were assigned to the control group and did not receive finasteride. PSA levels were measured every six months, and imaging scans were conducted throughout the five-year study period. Additional biopsies were performed if PSA levels exceeded 10 ng/mL or imaging suggested the presence of prostate cancer. Statistical analysis was applied to the collected data. In total, 25 cases of prostate cancer were identified in this study. Of these cases, 7 patients belonged to the observation group, whereas the remaining 18 patients were from the control group. The observation group exhibited significantly lower levels of total serum PSA (p < 0.001) and Gleason scores (p < 0.001) compared to the control group. Our study, which involved 120 participants, demonstrated that finasteride effectively reduces serum PSA levels and mitigates the severity of prostate cancer. These findings suggest that finasteride holds potential as a treatment option for patients with -high-grade prostatic intraepithelial neoplasia.

Single-cell analyses unravel cell type-specific responses to a vitamin D analog in prostatic precancerous lesions.

Epidemiological data have linked vitamin D deficiency to the onset and severity of various cancers, including prostate cancer, and although in vitro studies have demonstrated anticancer activities for vitamin D, clinical trials provided conflicting results. To determine the impact of vitamin D signaling on prostatic precancerous lesions, we treated genetically engineered Pten(i)pe-/- mice harboring prostatic intraepithelial neoplasia (PIN) with Gemini-72, a vitamin D analog with reported anticancer activities. We show that this analog induces apoptosis in senescent PINs, normalizes extracellular matrix remodeling by stromal fibroblasts, and reduces the prostatic infiltration of immunosuppressive myeloid-derived suppressor cells. Moreover, single-cell RNA-sequencing analysis demonstrates that while a subset of luminal cells expressing Krt8, Krt4, and Tacstd2 (termed luminal-C cells) is lost by such a treatment, antiapoptotic pathways are induced in persistent luminal-C cells. Therefore, our findings delineate the distinct responses of PINs and the microenvironment to Gemini-72, and shed light on mechanisms that limit treatment's efficacy.

The impact of metformin use on the risk of prostate cancer after prostate biopsy in patients with high grade intraepithelial neoplasia

ABSTRACT Purpose We report our experience on metformin use in diabetic patients and its impact on prostate cancer (PCa) after a high-grade prostatic intraepithelial neoplasia (HGPIN) diagnosis. Materials and Methods We retrospectively analyzed 551 patients with a diagnosis of HGPIN without PCa in a first prostate biopsy. The cohort of the study consisted of 456 nondiabetic subjects, and 95 diabetic patients. Among the patients with diabetes 44 were treated with metformin, and 51 with other antidiabetic drugs. A transrectal ultrasound prostate biopsy scheme with 22 cores was carried out 4-6 months after the first diagnosis of HGPIN. Results Among 195 (35.4%) patients with cancer, there were statistically significant differences in terms of PCa detection (p<0.001), Gleason score distribution (p<0.001), and number of positive biopsy cores (p<0.002) between metformin users and non-users. Metformin use was associated with a decreased risk of PCa compared with neveruse (p<0.001). Moreover, increasing duration of metformin assumption (≥2 years) was associated with decreasing incidence of PCa and higher Gleason score ≥7 compared with assumption <2 years. Conclusions This preliminary experience suggests that metformin use may have some beneficial effects in patients with diabetes and HGPIN; metformin should not be overlooked in these patients because it is neither new nor expensive.

The impact of metformin use on the risk of prostate cancer after prostate biopsy in patients with high grade intraepithelial neoplasia.

PURPOSE: We report our experience on metformin use in diabetic patients and its impact on prostate cancer (PCa) after a high-grade prostatic intraepithelial neoplasia (HGPIN) diagnosis. MATERIALS AND METHODS: We retrospectively analyzed 551 patients with a diagnosis of HGPIN without PCa in a first prostate biopsy. The cohort of the study consisted of 456 nondiabetic subjects, and 95 diabetic patients. Among the patients with diabetes 44 were treated with metformin, and 51 with other antidiabetic drugs. A transrectal ultrasound prostate biopsy scheme with 22 cores was carried out 4-6 months after the first diagnosis of HGPIN. RESULTS: Among 195 (35.4%) patients with cancer, there were statistically significant differences in terms of PCa detection (p<0.001), Gleason score distribution (p<0.001), and number of positive biopsy cores (pv0.002) between metformin users and non-users. Metformin use was associated with a decreased risk of PCa compared with neveruse (p<0.001). Moreover, increasing duration of metformin assumption (≥2 years) was associated with decreasing incidence of PCa and higher Gleason score ≥7 compared with assumption <2 years. CONCLUSIONS: This preliminary experience suggests that metformin use may have some beneficial effects in patients with diabetes and HGPIN; metformin should not be overlooked in these patients because it is neither new nor expensive.

Effect of green tea catechins in patients with high-grade prostatic intraepithelial neoplasia: Results of a short-term double-blind placebo controlled phase II clinical trial.

BACKGROUND AND STUDY OBJECTIVE: Several studies suggest a protective role of green tea catechins against prostate cancer (PCa). In order to evaluate the efficacy of green tea catechins for chemoprevention of PCa in patients with high-grade prostate intraepithelial neoplasia (HG-PIN) we performed a phase II clinical trial. METHODS: Sixty volunteers with HG-PIN were enrolled to carry out a double-blind randomized placebo-controlled phase II clinical trial. Treated group took daily 600 mg of green tea catechins (Categ Plus®) for 1 year. Patients were screened at 6 and 12 months through prostatic biopsy and measurements of prostate-specific antigen (PSA). RESULTS: Despite the statistically significant reduction of PSA observed in subjects who received green tea catechins for 6 and 12 months, we did not find any statistical difference in PCa incidence between the experimental groups neither after 6 nor after 12 months. However, throughout the one-year follow- up we observed very limited adverse effects induced by green tea catechins and a not significant improvement in lower urinary tract symptoms and quality of life. CONCLUSIONS: Although the small number of patients enrolled in our study and the relatively short duration of intervention, our findings seems to deny the efficacy of green tea catechins. However, results of our clinical study, mainly for its low statistical strength, suggest that the effectiveness of green tea catechins should be evaluated in both a larger cohort of men and longer trial.

Co-clinical Analysis of a Genetically Engineered Mouse Model and Human Prostate Cancer Reveals Significance of NKX3.1 Expression for Response to 5α-reductase Inhibition.

BACKGROUND: Although men on active surveillance for prostate cancer (PCa) may benefit from intervention with 5α-reductase inhibitors (5-ARIs), it has not been resolved whether 5-ARIs are effective for delaying disease progression and, if so, whether specific patients are more likely to benefit. OBJECTIVE: To identify molecular features predictive of patient response to 5-ARIs. DESIGN, SETTING, AND PARTICIPANTS: Nkx3.1 mutant mice, a model of early-stage PCa, were treated with the 5-ARI finasteride, and histopathological and molecular analyses were performed. Cross-species computational analyses were used to compare expression profiles for treated mice with those of patients who had received 5-ARIs before prostatectomy. INTERVENTION: Finasteride administered to Nkx3.1 mutant mice. 5-ARI-treated patient specimens obtained retrospectively. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Endpoints in mice included histopathology, immunohistochemistry, and molecular profiling. GraphPad Prism software, R-studio, and Matlab were used for statistical and data analyses. RESULTS AND LIMITATIONS: Finasteride treatment of Nkx3.1 mutant mice resulted in a significant reduction in prostatic intraepithelial neoplasia (PIN), as evident from histopathological and expression profiling analyses. Cross-species computational analysis comparing finasteride-treated mice with two independent 5-ARI-treated patient cohorts showed that reduced NKX3.1 expression is predictive of response to 5-ARI. A limitation of the study is that these retrospective human cohorts have relatively few patients with limited clinical outcome data. Future prospective clinical trials are needed to validate whether stratifying patients on the basis of NKX3.1 expression improves the benefit of 5-ARIs during active surveillance. CONCLUSIONS: This co-clinical study implicates NKX3.1 status as a predictor of response to 5-ARIs, and suggests that molecular features, including NKX3.1 expression, may help to identify PCa patients most likely to benefit from 5-ARIs during active surveillance. PATIENT SUMMARY: The aim of precision cancer prevention is to tailor interventions on the basis of individualized patient characteristics. We propose that patients with low NKX3.1 expression are optimal candidates for intervention with 5α-reductase inhibitors as an adjunct to active surveillance.

Chemoprevention of prostate cancer in men with high-grade prostatic intraepithelial neoplasia (HGPIN): a systematic review and adjusted indirect treatment comparison.

BACKGROUND: High-grade prostatic intraepithelial neoplasia (HGPIN) is the precursor or premalignant form of prostate cancer. At least 30% patients with a confirmed HGPIN will develop prostate cancer within 1 year after repeated biopsy. HGPIN patients are the appropriate at-risk population for chemoprevention strategies investigation against prostate cancer. However the commonly used chemoprevention agents that targeted on hormonal imbalance or lifestyle-related factors showed varied results in HGPIN patients. METHODS: Literature searches were conducted in PubMed, EMBASE and Cochrane library according to Cochrane guidelines before January 31st, 2017. Direct meta-analysis were performed to summarize the efficacy of candidate chemopreventative agents Dutasteride, Flutamide, Toremifene, Selenium, Green tea components, Lycopene and natural food products combination. Adjusted indirect meta-analyses were employed to compare the relative efficacy of these candidate chemoprevention agents head-to-head. RESULTS: The overall incidence of prostate cancer in HGPIN was slightly decreased by chemoprevention agents (25.7% vs 31.5%, RR = 0.92, 95% CI: 0.83-1.03, P = 0.183), with minor heterogeneity (I2 = 22.3%, 𝟀2 = 15.08, P = 0.237), but without statistical significance. Subgroup analysis showed that green tea catechins significantly decreased prostate cancer in HGPIN patients (7.60% vs 23.1%, RR = 0.39, 95% CI: 0.16-10.97, P P = 0.044), with moderate heterogeneity (I2 = 47.9%, 𝟀2 = 1.92, P = 0.166). The adjusted indirect meta-analysis favored green tea catechins over other chemoprevention agents, and significantly when compared to natural food products combination (RR = 0.355, 95% CI: 0.134-0.934). CONCLUSION: The overall efficacy of chemoprevention agents in HGPIN patients is limited. But Green tea catechins showed the superiority to decrease prostate cancer in HGPIN patients.

Dutasteride for the prevention of prostate cancer in men with high-grade prostatic intraepithelial neoplasia: results of a phase III randomized open-label 3-year trial.

PURPOSE: High-grade prostatic intraepithelial neoplasia (HGPIN) is a potential precursor of prostate cancer (PCa), and patients with HGPIN are at high risk for PCa development. Objective of our study was to evaluate the efficacy of dutasteride 0.5 mg in PCa prevention among men with isolated HGPIN on biopsy. METHODS: This prospective, randomized, phase III, open-label 3-year trial assessed dutasteride versus active surveillance in patients with HGPIN. Patients were randomized to dutasteride 0.5 mg daily or active surveillance. Per-protocol prostate biopsies were performed at 6, 12, 24, and 36 months until cancer detection or study end. The primary end point was cancer-free survival (CFS). An intention-to-treat analysis was done for patients who underwent at least one per-protocol biopsy. An efficacy analysis was done for patients who completed the study. CFS was evaluated using Kaplan-Meier and log-rank analysis. RESULTS: In total, 220 men were randomized (dutasteride, n = 107; surveillance, n = 113). PCa was detected in 47.6: 49.1 % in the surveillance group and 45.9 % in the treatment group (p = 0.66). The detected PCa differentiation by Gleason score (GS) was GS 6 in 76.9 %, GS 7 in 19.8 %, and GS ≥ 8 in 3.3 %, with no difference between groups. The 3-year PCa-free survival was 43.6 % in the surveillance and 49.6 % in the dutasteride group (log rank p = 0.57). Limitations include a relatively high non-adherence rate, open-label design, and baseline sextant biopsy scheme. CONCLUSIONS: Dutasteride 0.5 mg for 3 years did not lower the PCa detection rate but did not worsen detected PCa characteristics in men with HGPIN.

A randomized double-blind placebo controlled phase I-II study on clinical and molecular effects of dietary supplements in men with precancerous prostatic lesions. Chemoprevention or "chemopromotion"?

BACKGROUND: Antioxidants effectiveness in prostate cancer (PCa) chemoprevention has been severely questioned, especially after the recent results of the Selenium and Vitamin E Cancer Prevention Trial. We present the results of a double-blind randomized controlled trial (dbRCT) on the pharmacokinetic, clinical, and molecular activity of dietary supplements containing lycopene, selenium, and green tea catechins (GTCs) in men with multifocal high grade prostatic intraepithelial neoplasia (mHGPIN) and/or atypical small acinar proliferation (ASAP). METHODS: From 2009 to 2014, we conducted a dbRCT including 60 patients with primary mHGPIN and/or ASAP receiving daily lycopene 35 mg, selenium 55 µg, and GTCs 600 mg, or placebo for 6 months. Pharmacokinetic analysis were performed with UV-Visible spectrophotometric assay under standard (SC) and accelerated (AC) conditions. Upon plasma lycopene concentrations falling within the expected range (1.2-90 mcg/l) and no side-effects of grade >1, study proceeded to phase II (n = 50). After unblinding of results, eight men (4 per arm, 2 without and 2 with PCa, respectively) were randomly selected and totRNA extracted from "non-pathological" tissues. MicroRNA profiling was performed with the Agilent platform. Raw data processing used R-statistical language and linear models for microarray analysis. RESULTS: Samples were stable except for lycopene, showing significant degradation (SC = 56%, AC = 59%) and consequently stabilized under vacuum in a dark packaging. Mean plasmatic lycopene concentration was 1,45 ± 0,4 µM. At 6 months, 53 men underwent re-biopsy and 13 (24.5%) were diagnosed with PCa (supplementation n = 10, placebo n = 3 [P = 0.053]). At a mean 37 months follow-up, 3 additional PCa were found in the placebo group. No significant variations in PSA, IPSS, and PR25 questionnaires were observed. Stronger modulation of miRNAs was present on re-biopsy in the supplementation group compared to the placebo, including: (i) overexpression of miRNAs present in PCa versus non-cancer tissue; (ii) underexpression of miRNAs suppressing PCa proliferation; (iii) detection of 35 miRNAs in PCa patients versus disease-free men, including androgen-regulated miR-125b-5p and PTEN-targeting miR-92a-3p (both upregulated). CONCLUSION: Administration of high doses of lycopene, GTCs, and selenium in men harboring HGPIN and/or ASAP was associated with a higher incidence of PCa at re-biopsy and expression of microRNAs implicated in PCa progression at molecular analysis. The use of these supplements should be avoided.

Plumbagin Inhibits Prostate Carcinogenesis in Intact and Castrated PTEN Knockout Mice via Targeting PKCε, Stat3, and Epithelial-to-Mesenchymal Transition Markers.

Prostate cancer continues to remain the most common cancer and the second leading cause of cancer-related deaths in American males. The Pten deletions and/or mutations are frequently observed in both primary prostate cancers and metastatic prostate tissue samples. Pten deletion in prostate epithelium in mice results in prostatic intraepithelial neoplasia (PIN), followed by progression to invasive adenocarcinoma. The Pten conditional knockout mice [(Pten-loxp/loxp:PB-Cre4(+)) (Pten-KO)] provide a unique preclinical model to evaluate agents for efficacy for both the prevention and treatment of prostate cancer. We present here for the first time that dietary plumbagin, a medicinal plant-derived naphthoquinone (200 or 500 ppm) inhibits tumor development in intact as well as castrated Pten-KO mice. Plumbagin has shown no signs of toxicity at either of these doses. Plumbagin treatment resulted in a decrease expression of PKCε, AKT, Stat3, and COX2 compared with the control mice. Plumbagin treatment also inhibited the expression of vimentin and slug, the markers of epithelial-to-mesenchymal transition (EMT) in prostate tumors. In summary, the results indicate that dietary plumbagin inhibits growth of both primary and castration-resistant prostate cancer (CRPC) in Pten-KO mice, possibly via inhibition of PKCε, Stat3, AKT, and EMT markers (vimentin and slug), which are linked to the induction and progression of prostate cancer.

Low prostate concentration of lycopene is associated with development of prostate cancer in patients with high-grade prostatic intraepithelial neoplasia.

Prostate cancer (PC) is a frequent male malignancy and represents the second most diagnosed cancer in men. Since pre-cancerous lesions, i.e., the high-grade prostatic intraepithelial neoplasia (HGPIN), can be detected years before progression to PC, early diagnosis and chemoprevention are targeted strategies to reduce PC rates. Animal studies have shown that lycopene, a carotenoid contained in tomatoes, is a promising candidate for the chemoprevention of PC. However, its efficacy in humans remains controversial. The present study aimed to investigate the relevance of plasma and prostate concentration of lycopene after a lycopene-enriched diet in patients diagnosed with HGPIN. Thirty-two patients diagnosed with HGPIN were administered a lycopene-enriched diet (20-25 mg/day of lycopene; through 30 g/day of triple concentrated tomato paste) for 6 months. A 6-month follow-up prostate biopsy assessed progression to PC. Patients were classified into three groups according to the histopathological features of the 6-month follow-up biopsy results: prostatitis; HGPIN and PC. PSA and plasma lycopene levels were measured before and after the dietary lycopene supplementation. Prostatic lycopene concentration was only assessed after the supplementation diet. Only prostatic lycopene concentration showed significant differences between the three groups (p = 0.03). Prostatic lycopene concentration below a 1 ng/mg threshold was associated with PC at 6-month follow-up biopsy (p = 0.003). We observed no overall benefits from a 6-month lycopene supplementation, as the rate of HGPIN progression to PC in our population (9/32, 28%) was similar to rates reported in the literature. Baseline PSA levels also showed no significant changes after a lycopene-enriched diet. Our findings point to prostatic lycopene concentration as a promising biomarker of PC. Further prospective longitudinal studies are needed to assess the prognostic role of prostatic lycopene in PC.

Sixth joint meeting of J-CaP and CaPSURE--a multinational perspective on prostate cancer management and patient outcomes.

This report summarizes the presentations and discussions that took place at the Sixth Joint Meeting of J-CaP and CaPSURE held in San Francisco, USA, in August 2012. The J-CaP and CaPSURE Joint Initiative was established in 2007 with the objective of analyzing, reviewing, comparing and contrasting data for prostate cancer patients from Japan and the USA within the two important large-scale, longitudinal, observational databases-J-CaP and CaPSURE. Since this initial collaboration between teams in the USA and Japan, the initiative has now expanded to include representatives of other Asian countries, several of whom have either established or are planning their own national prostate cancer databases. Several key topics were considered at this Sixth Joint Meeting including the current status of the J-CaP and CaPSURE databases and opportunities for collaboration with the more recently developed Asian prostate cancer databases. The latest comparative data from J-CaP and CaPSURE regarding outcomes following androgen deprivation therapy and combined androgen blockade were also reviewed. The possibility of a global chemoprevention trial to investigate the influence of soy isoflavones on prostate cancer incidence was considered. In addition, the ongoing debate regarding the role of screening and the use of active surveillance as a treatment option in the USA was discussed. The collaborators agreed that sharing of data and treatment practices on a global scale would undoubtedly benefit the clinical management of prostate cancer patients worldwide.

Green tea polyphenols and cancer chemoprevention of genitourinary cancer.

Green tea, which has higher concentrations of polyphenols than other teas, has been correlated with reduced risk of various malignancies with most data supporting a potential protective role in prostate neoplasia. Preclinical studies over the last 25 years implicate constituent green tea catechins, epigallocatechin-3-gallate (EGCG) being the predominant form, as the main mechanistic ingredient in the observed biologic effects, which vary from proapoptotic effects to inhibition of androgen receptor and signal transduction pathways. There have been few prospective clinical trials of green tea polyphenols (GTP), especially with well-characterized formulations and doses. Although there have been hints of beneficial clinical activity in prostate neoplasia, other studies have raised concerns about the limited bioavailability and very low target-tissue concentrations of GTPs. At present there is no proven role for GTP supplementation in the prevention of genitourinary (GU) malignancies, but novel GTP formulations and further clinical testing may still support a future for GTP supplementation in GU cancer prevention.

Prostate cancer diagnosis among men with isolated high-grade intraepithelial neoplasia enrolled onto a 3-year prospective phase III clinical trial of oral toremifene.

PURPOSE: Prostate cancer (PCa) prevention remains an appealing strategy for the reduction of overtreatment and secondary adverse effects. We evaluated the efficacy of toremifene citrate 20 mg in PCa prevention among men with isolated high-grade prostatic intraepithelial neoplasia (HGPIN) on biopsy. PATIENTS AND METHODS: One thousand five hundred ninety men with HGPIN, or HGPIN and atypia, and no PCa on prostate biopsy were randomly assigned 1:1 to receive toremifene citrate 20 mg or placebo in a 3-year phase III, double-blind, multicenter trial. Men underwent annual biopsy until cancer detection or study end. Efficacy analysis was performed in 1,467 men who underwent at least one on-study biopsy. Baseline risk factors were evaluated to determine influence on cancer detection. RESULTS: Cancer was detected in 34.7% and 32.3% of men in the placebo and treatment groups, respectively, with no observed difference (P = .39, log-rank test) in PCa-free survival. The 3-year Kaplan-Meier PCa-free survival estimate was 54.9% (99% CI, 43.3% to 66.5%) in the placebo group and 59.5% (99% CI, 48.1% to 70.9%) in the treatment group. Exploration of baseline risk factors demonstrated no subset in which a risk reduction was observed. In the placebo group, 17.9%, 12.9%, and 13.6% of men at risk at the beginning of years 1, 2, and 3, respectively, were diagnosed with PCa. CONCLUSION: Although toremifene 20 mg did not lower the PCa detection rate, men with isolated HGPIN have a high likelihood of eventual PCa diagnosis, demonstrating they are ideal candidates for inclusion in chemoprevention trials and require surveillance by periodic prostate biopsy.

Dietary resveratrol prevents development of high-grade prostatic intraepithelial neoplastic lesions: involvement of SIRT1/S6K axis.

SIRT1 (mammalian ortholog of the yeast silent information regulator 2) is a NAD-dependent histone deacetylase belonging to the multigene family of sirtuins. Anecdotal and epidemiologic observations provide evidence for beneficial effects of the calorie restriction mimetic resveratrol (RES), a SIRT1 activator in preventing cardiovascular diseases and cancer. Although SIRT1 possesses both tumorigenic and antitumorigenic potential, the molecular mechanisms underlying SIRT1-mediated tumor progression or inhibition are poorly understood. In this study, we investigated the role of SIRT1 in multiple human prostate cancer cell lines and prostate-specific PTEN knockout mouse model using resveratrol. Androgen-independent prostate cancer cell lines (C42B, PC3, and DU145) express higher levels of SIRT1 than androgen-responsive (LNCaP) and nontumorigenic prostate cells (RWPE-1). Resveratrol enhanced this expression without any significant effect on SIRT1 enzymatic activity. Inhibition of SIRT1 expression using shRNA enhanced cell proliferation and inhibited autophagy by repressing phosphorylation of S6K and 4E-BP1. These biologic correlates were reversed in the presence of resveratrol. Analysis of prostates from dietary intervention with resveratrol showed a significant reduction in prostate weight and reduction in the incidence of high-grade prostatic intraepithelial neoplastic (HGPIN) lesions by approximately 54% with no significant change in body weight. Consistent with the in vitro findings, resveratrol intervention in the PTEN knockout mouse model was associated with reduction in the prostatic levels of mTOR complex 1 (mTORC1) activity and increased expression of SIRT1. These data suggest that SIRT1/S6K-mediated inhibition of autophagy drives prostate tumorigenesis. Therefore, modulation of SIRT1/S6K signaling represents an effective strategy for prostate cancer prevention.

Metastasis suppressors in human benign prostate, intraepithelial neoplasia, and invasive cancer: their prospects as therapeutic agents.

Despite advances in diagnosis and treatment of prostate cancer, development of metastases remains a major clinical challenge. Research efforts are dedicated to overcome this problem by understanding the molecular basis of the transition from benign cells to prostatic intraepithelial neoplasia (PIN), localized carcinoma, and metastatic cancer. Identification of proteins that inhibit dissemination of cancer cells will provide new perspectives to define novel therapeutics. Development of antimetastatic drugs that trigger or mimic the effect of metastasis suppressors represents new therapeutic approaches to improve patient survival. This review focuses on different biochemical and cellular functions of metastasis suppressors known to play a role in prostate carcinogenesis and progression. Ten putative metastasis suppressors implicated in prostate cancer are discussed. CD44s is decreased in both PIN and cancer; Drg-1, E-cadherin, KAI-1, RKIP, and SSeCKS show similar expression between benign epithelia and PIN, but are downregulated in invasive cancer; whereas, maspin, MKK4, Nm23 and PTEN are upregulated in PIN and downregulated in cancer. Moreover, the potential role of microRNA in prostate cancer progression, the understanding of the cellular distribution and localization of metastasis suppressors, their mechanism of action, their effect on prostate invasion and metastasis, and their potential use as therapeutics are addressed.

Chemoprevention of prostate cancer: an updated view.

OBJECTIVES: To place chemoprevention of prostate cancer in current clinical context. METHODS: Review of recently published updates of large, randomized, controlled trials of primary chemoprevention of prostate cancer. RESULTS: With extended post-intervention follow-up, SELECT demonstrated a 17% increased risk of prostate cancer relative to placebo in the vitamin E alone arm. Two other trials in men with high-grade PIN demonstrated no effect of selenium alone or in combination with soy and lycopene. Trials of 5α-reductase inhibitors show an approximate 25% relative risk reduction in men at average risk and in those with an "elevated" PSA and prior negative biopsy, but adoption of these agents in clinical practice has been limited by concerns over an apparently increased risk of high-grade disease. CONCLUSIONS: Primary prevention of prostate cancer remains an attractive goal because of its prevalence and treatment-related morbidity. Neither selenium nor vitamin E prevents prostate cancer. The benefit/risk ratio for 5α-reductase inhibitors can be improved by limiting their use to men at high risk.

Diet and prostate cancer - a holistic approach to management.

There is now increasing evidence from epidemiologic surveys and from laboratory, intervention, and case-control studies that diet and lifestyle plays a crucial role in prostate cancer biology and tumorigenesis. This applies to both the development and progression of prostate cancer, although in many cases the specific initiating factors in the diet are poorly understood. Conversely, many nutrients and herbs also show significant promise in helping to treat prostate cancer by slowing progression and reducing recurrence, ultimately reducing the risk of morbidity and mortality from the disease. Furthermore for all grades of prostate cancer, nutritional interventions complement conventional treatment to improve response and quality of life. Slowing or even reversing the progression of, high-grade prostate intraepithelial neoplasia [HGPIN]). with chemo-preventative agents could be the best primary defense against prostate cancer, preventing it from occurring in the first place. The information given in this review about prostate cancer chemoprevention summarizes the key evidence for the role of different dietary components and their effect on prostate cancer prevention and progression. Most nutritional chemoprevention agents also have the added benefit of being beneficial for the cardiovascular system, bone health and for the prevention of other cancers.