IMPORTANCE Soy consumption has been suggested to reduce risk or recurrence of prostate cancer, but this has not been tested in a randomized trial with prostate cancer as the end point. OBJECTIVE To determine whether daily consumption of a soy protein isolate supplement for 2 years reduces the rate of biochemical recurrence of prostate cancer after radical prostatectomy or delays such recurrence. DESIGN, SETTING, AND PARTICIPANTS Randomized, double-blind trial conducted from July 1997 to May 2010 at 7 US centers comparing daily consumption of a soy protein supplement vs placebo in 177 men at high risk of recurrence after radical prostatectomy for prostate cancer. Supplement intervention was started within 4 months after surgery and continued for up to 2 years, with prostate-specific antigen (PSA) measurements made at 2-month intervals in the first year and every 3 months thereafter. INTERVENTION Participants were randomized to receive a daily serving of a beverage powder containing 20 g of protein in the form of either soy protein isolate (n=87)or, as placebo, calcium caseinate (n=90). MAIN OUTCOMES AND MEASURES Biochemical recurrence rate of prostate cancer (defined as development of a PSA level of ≥0.07 ng/mL) over the first 2 years following randomization and time to recurrence. RESULTS The trial was stopped early for lack of treatment effects at a planned interim analysis with 81 evaluable participants in the intervention group and 78 in the placebo group. Overall, 28.3% of participants developed biochemical recurrence within 2 years of entering the trial (close to the a priori predicted recurrence rate of 30%). Among these, 22 (27.2%) occurred in the intervention group and 23 (29.5%) in the placebo group. The resulting hazard ratio for active treatment was 0.96 (95% CI, 0.53–1.72; log-rank P = .89). Adherence was greater than 90% and there were no apparent adverse events related to supplementation. CONCLUSION AND RELEVANCE Daily consumption of a beverage powder supplement containing soy protein isolate for 2 years following radical prostatectomy did not reduce biochemical recurrence of prostate cancer in men at high risk of PSA failure.

Background A diverse body of evidence suggests that lycopene might inhibit prostate cancer development. We conducted a 6-month repeat biopsy randomized trial among men with HGPIN. Here we report results for serum lycopene, PSA and IGF proteins, histopathological review, and tissue markers for proliferation (MCM-2) and cell cycle inhibition (p27). Methods Participants consumed placebo or tomato extract capsules containing 30 mg/day lycopene. Pre- and post-treatment biopsies were immunostained and digitally scored. Serum lycopene was determined by LC-MS-MS. In secondary analyses, pathologists blindly reviewed each biopsy to score histological features. Results 58 men completed the trial. Serum lycopene increased 0.55 μmol/L with treatment and declined 0.29 μmol/L with placebo. We observed no meaningful differences in PSA, IGF-1 or IGFBP3 concentrations between groups, nor any differences in expression of MCM-2 or p27 in epithelial nuclei. Prevalences of cancer, HGPIN, atrophy or inflammation post-treatment were similar; however, more extensive atrophy and less extensive HGPIN was more common in the lycopene group. Conclusions Despite large differences in serum lycopene following intervention, no treatment effects were apparent on either the serum or benign tissue endpoints. Larger studies are warranted to determine whether changes observed in extent of HGPIN and focal atrophy can be replicated.

BackgroundOur objective was to develop and validate a multi-feature nuclear score based on image analysis of direct DNA staining, and to test its association with field effects and subsequent detection of prostate cancer (PCa) in benign biopsies.MethodsTissue sections from 39 prostatectomies were Feulgen-stained and digitally scanned (400×), providing maps of DNA content per pixel. PCa and benign epithelial nuclei were randomly selected for measurement of 52 basic morphometric features. Logistic regression models discriminating benign from PCa nuclei, and benign from malignant nuclear populations, were built and cross-validated by AUC analysis. Nuclear populations were randomly collected <1 mm or >5 mm from cancer foci, and from cancer-free prostates, HGPIN, and PCa Gleason grade 3–5. Nuclei also were collected from negative biopsy subjects who had a subsequent diagnosis of PCa and age-matched cancer-free controls (20 pairs).ResultsA multi-feature nuclear score discriminated cancer from benign cell populations with AUCs of 0.91 and 0.79, respectively, in training and validation sets of patients. In prostatectomy samples, both nuclear- and population-level models revealed cancer-like features in benign nuclei adjacent to PCa, compared to nuclei that were more distant or from PCa-free glands. In negative biopsies, a validated model with 5 variance features yielded significantly higher scores in cases than controls (P = 0.026).ConclusionsA multifeature nuclear morphometric score, obtained by automated digital analysis, was validated for discrimination of benign from cancer nuclei. This score demonstrated field effects in benign epithelial nuclei at varying distance from PCa lesions, and was associated with subsequent PCa detection in negative biopsies.ImpactThis nuclear score shows promise as a risk predictor among men with negative biopsies and as an intermediate biomarker in Phase II chemoprevention trials. The results also suggest that subvisual disturbances in nuclear structure precede the development of pre-neoplastic lesions.

BACKGROUND Alpha-methylacyl-CoA racemase (AMACR) is an enzyme involved in fatty acid metabolism that is markedly over-expressed in virtually all prostate cancers (PCa), relative to benign tissue. One of AMACR’s primary substrates, phytanic acid, is derived predominately from red meat and dairy product consumption. Epidemiological evidence suggests links between dairy/red meat intake, as well as phytanic acid levels, and elevated PCa risk. This study investigates the relationships among dietary intake, serum and tissue concentrations of phytanic acid, and AMACR expression (mRNA and protein) in the histologically benign human prostate. METHODS Men undergoing radical prostatectomy for the treatment of localized disease provided a food frequency questionnaire (n = 68), fasting blood (n = 35), benign fresh frozen prostate tissue (n = 26), and formalin-fixed paraffin-embedded (FFPE) sections (n = 67). Serum and tissue phytanic acid concentrations were obtained by gas chromatography–mass spectrometry. We extracted RNA from epithelial cells using laser capture microdissection and quantified mRNA expression of AMACR and other genes involved in the peroxisomal phytanic acid metabolism pathway via qRT-PCR. Immunohistochemistry for AMACR was performed on FFPE sections and subsequently quantified via digital image analysis. Associations between diet, serum, and tissue phytanic acid levels, as well as AMACR and other gene expression levels were assessed by partial Spearman correlation coefficients. RESULTS High-fat dairy intake was the strongest predictor of circulating phytanic acid concentrations (r = 0.35, P = 0.04). Tissue phytanic acid concentrations were not associated with any dietary sources and were only weakly correlated with serum levels (r = 0.29, P = 0.15). AMACR gene expression was not associated with serum phytanic acid (r = 0.13, P = 0.47), prostatic phytanic acid concentrations (r = 0.03, P = 0.88), or AMACR protein expression (r = −0.16, P = 0.20). CONCLUSIONS Our data underscore the complexity of the relationship between AMACR and its substrates and do not support the unifying hypothesis that excess levels of dietary phytanic acid are responsible for both the overexpression of AMACR in prostate cancer and the potential association between PCa risk and intake of dairy foods and red meat.

Previous research indicates that lycopene and associated compounds in tomato foods could have cancer chemopreventive properties in the prostate. Pre-clinical and clinical studies provide support for mechanisms involving androgen or IGF-1 regulation, oxidative stress response, inflammation and DNA repair. We undertook a 6-month repeat biopsy trial in men with HGPIN, randomly assigned to consume placebo or LycoMato® capsules, a tomato oleoresin containing 30 mg/day of lycopene. Benign epithelium from fixed prostate biopsy sections (pre- and post-treatment) was laser capture microdissected and RNA was extracted. We reverse transcribed RNA and pre-amplified for 92 target and 4 housekeeping (HK) genes. Pre-amped RNA was loaded unto custom Taqman® Low Density Arrays for qPCR quantitation. For each gene, Ct values were standardized to the mean HK gene values and fold-change (RV, relative value) in expression between baseline and follow-up was determined. Evaluable data was obtained from 16 lycopene subjects and 22 placebo controls. Serum lycopene increased by 83.3% on average in the active group and declined by 35.0% in the placebo group, although changes varied considerably across subjects. Individual gene comparisons by assigned group revealed statistically significant relative downregulation of DDB1, SOD3, and CXCL12 in the lycopene group. Expression changes in GCLC a rate-limiting enzyme in glutathione synthesis and an NRF2 oxidative stress response gene - were positively correlated with serum lycopene changes (Spearman R = 0.42, P = 0.009). Ongoing gene set analysis, by sum of Wilcoxon signed-rank and permutation tests, thus far suggest non-significant trends for treatment effects in the androgen, DNA repair and oxidative stress response gene groups. Initial results from unsupervised hierarchical clustering and principal components analysis for 34 genes with the highest variance showed evidence for classification by treatment group. Among all subjects, baseline serum lycopene was inversely correlated with baseline expression of AMACR, XRCC1, ERCC3, and OGG1 (R −0.32 to −0.38, P &lt; .05). Follow-up studies on protein expression of key targets using immunohistochemistry are underway. The results from this small but unique trial demonstrate the feasibility of this approach and so far indicate that long-term lycopene status may be associated with down-regulation of DNA repair genes in benign prostate and that a 6-month intervention could cause changes in expression of genes and gene sets selected a priori. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr LB-217. doi:1538-7445.AM2012-LB-217