OBJECTIVE: To report the first year's screening results for all men at enrollment in the study.
DESIGN, SETTING AND PARTICIPANTS: We recruited men aged 40-69 yr with germline BRCA1/2 mutations and a control group of men who have tested negative for a pathogenic BRCA1 or BRCA2 mutation known to be present in their families. All men underwent prostate-specific antigen (PSA) testing at enrollment, and those men with PSA >3 ng/ml were offered prostate biopsy.
OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: PSA levels, PCa incidence, and tumour characteristics were evaluated. The Fisher exact test was used to compare the number of PCa cases among groups and the differences among disease types.
RESULTS AND LIMITATIONS: We recruited 2481 men (791 BRCA1 carriers, 531 BRCA1 controls; 731 BRCA2 carriers, 428 BRCA2 controls). A total of 199 men (8%) presented with PSA >3.0 ng/ml, 162 biopsies were performed, and 59 PCas were diagnosed (18 BRCA1 carriers, 10 BRCA1 controls; 24 BRCA2 carriers, 7 BRCA2 controls); 66% of the tumours were classified as intermediate- or high-risk disease. The positive predictive value (PPV) for biopsy using a PSA threshold of 3.0 ng/ml in BRCA2 mutation carriers was 48%-double the PPV reported in population screening studies. A significant difference in detecting intermediate- or high-risk disease was observed in BRCA2 carriers. Ninety-five percent of the men were white, thus the results cannot be generalised to all ethnic groups.
CONCLUSIONS: The IMPACT screening network will be useful for targeted PCa screening studies in men with germline genetic risk variants as they are discovered. These preliminary results support the use of targeted PSA screening based on BRCA genotype and show that this screening yields a high proportion of aggressive disease.
PATIENT SUMMARY: In this report, we demonstrate that germline genetic markers can be used to identify men at higher risk of prostate cancer. Targeting screening at these men resulted in the identification of tumours that were more likely to require treatment.
MATERIALS AND METHODS: MicroRNA software predicted that miR21 targets VCL while miR29a targets CX3CL1. Twenty benign prostatic hyperplasia (BPH) and 16 high grade CaP formalinfixed paraffin embedded (FFPE) specimens were analysed. From the bone scan results, high grade CaP samples were further classified into CaP with no BM and CaP with BM. Transient transfection with respective microRNA inhibitors was done in both RWPE1 (normal) and PC3 cell lines. QPCR was performed in all FFPE samples and transfected cell lines to measure VCL and CX3CL1 levels.
RESULTS: QPCR confirmed that VCL messenger RNA (mRNA) was significantly down regulated while CX3CL1 was upregulated in all FFPE specimens. Transient transfection with microRNA inhibitors in PC3 cells followed by qPCR of the targeted genes showed that VCL mRNA was significantly up regulated while CX3CL1 mRNA was significantly downregulated compared to the RWPE1 case.
CONCLUSIONS: The downregulation of VCL in FFPE specimens is most likely regulated by miR21 based on the in vitro evidence but the exact mechanism of how miR21 can regulate VCL is unclear. Upregulated in CaP, CX3CL1 was found not regulated by miR29a. More microRNA screening is required to understand the regulation of this chemokine in CaP with bone metastasis. Understanding miRNAmRNA interactions may provide additional knowledge for individualized study of cancers.
METHODS: PSAV was calculated using logistic regression to determine if PSA or PSAV predicted the result of prostate biopsy (PB) in men with elevated PSA values. Cox regression was used to determine whether PSA or PSAV predicted PSA elevation in men with low PSAs. Interaction terms were included in the models to determine whether BRCA status influenced the predictiveness of PSA or PSAV.
RESULTS: 1634 participants had ⩾3 PSA readings of whom 174 underwent PB and 45 PrCas diagnosed. In men with PSA >3.0 ng ml-l, PSAV was not significantly associated with presence of cancer or high-grade disease. PSAV did not add to PSA for predicting time to an elevated PSA. When comparing BRCA1/2 carriers to non-carriers, we found a significant interaction between BRCA status and last PSA before biopsy (P=0.031) and BRCA2 status and PSAV (P=0.024). However, PSAV was not predictive of biopsy outcome in BRCA2 carriers.
CONCLUSIONS: PSA is more strongly predictive of PrCa in BRCA carriers than non-carriers. We did not find evidence that PSAV aids decision-making for BRCA carriers over absolute PSA value alone.
MATERIALS AND METHODS: From a PSA screening initiative, 161 men were shown to have elevated PSA levels in their blood and underwent prostatic tissue biopsy. DNA was extracted from the blood, and exon 1 of the AR gene amplified by PCR and sequenced. The number of CAG repeat sequences were counted and compared to the immunohistochemical expression of ERG and AR in the matched tumour biopsies.
RESULTS: Of men with elevated PSA, 89 were diagnosed with prostate cancer, and 72 with benign prostatic hyperplasia (BPH). There was no significant difference in the length of the CAG repeat in men with prostate cancer and BPH. The CAG repeat length was not associated with; age, PSA or tumour grade, though a longer CAG repeat was associated with tumour stage. ERG and AR were expressed in 36% and 86% of the cancers, respectively. There was no significant association between CAG repeat length and ERG or AR expression. However, there was a significant inverse relationship between ERG and AR expression. In addition, a significantly great proportion of Indian men had ERG positive tumours, compared to men of Malay or Chinese descent.
CONCLUSIONS: CAG repeat length is not associated with prostate cancer or expression of ERG or AR. However, ERG appears to be more common in the prostate cancers of Malaysian Indian men than in the prostate cancers of other Malaysian ethnicities and its expression in this study was inversely related to AR expression.
MATERIALS AND METHODS: A total of 175 subjects comprising 84 patients and 91 healthy individuals were recruited. Multiplex PCR was optimized to co-amplify DYS388, DYS435, DYS437, and DYS439 loci. All samples were genotyped for alleles of four DYS loci using a Genetic Analysis System.
RESULTS: Of all DYS loci, allele 10 (A) of DYS388 had a significantly lower incidence of disease in compare with other alleles of this locus, while a higher incidence of disease was found among males who had either allele 12 (C) of DYS388 or allele 14 (E) of DYS439. Moreover, a total of 47 different haplotypes comprising different alleles of four DYS loci were found among the whole study samples, of which haplotypes AABC and CAAA showed a lower and higher frequency among cases than controls, respectively.
CONCLUSIONS: It is likely that Malaysian males who belong to Y-lineages with either allele 12 of DYS388, allele 14 of DYS439, or haplotype CAAA are more susceptible to develop prostate cancer, while those belonging to lineages with allele 10 of DYS388 or haplotype AABC are more resistant to the disease.
OBJECTIVE: To report the utility of PSA screening, PrCa incidence, positive predictive value of PSA, biopsy, and tumour characteristics after 3 yr of screening, by BRCA status.
DESIGN, SETTING, AND PARTICIPANTS: Men aged 40-69 yr with a germline pathogenic BRCA1/2 mutation and male controls testing negative for a familial BRCA1/2 mutation were recruited. Participants underwent PSA screening for 3 yr, and if PSA > 3.0 ng/ml, men were offered prostate biopsy.
OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: PSA levels, PrCa incidence, and tumour characteristics were evaluated. Statistical analyses included Poisson regression offset by person-year follow-up, chi-square tests for proportion t tests for means, and Kruskal-Wallis for medians.
RESULTS AND LIMITATIONS: A total of 3027 patients (2932 unique individuals) were recruited (919 BRCA1 carriers, 709 BRCA1 noncarriers, 902 BRCA2 carriers, and 497 BRCA2 noncarriers). After 3 yr of screening, 527 men had PSA > 3.0 ng/ml, 357 biopsies were performed, and 112 PrCa cases were diagnosed (31 BRCA1 carriers, 19 BRCA1 noncarriers, 47 BRCA2 carriers, and 15 BRCA2 noncarriers). Higher compliance with biopsy was observed in BRCA2 carriers compared with noncarriers (73% vs 60%). Cancer incidence rate per 1000 person years was higher in BRCA2 carriers than in noncarriers (19.4 vs 12.0; p = 0.03); BRCA2 carriers were diagnosed at a younger age (61 vs 64 yr; p = 0.04) and were more likely to have clinically significant disease than BRCA2 noncarriers (77% vs 40%; p = 0.01). No differences in age or tumour characteristics were detected between BRCA1 carriers and BRCA1 noncarriers. The 4 kallikrein marker model discriminated better (area under the curve [AUC] = 0.73) for clinically significant cancer at biopsy than PSA alone (AUC = 0.65).
CONCLUSIONS: After 3 yr of screening, compared with noncarriers, BRCA2 mutation carriers were associated with a higher incidence of PrCa, younger age of diagnosis, and clinically significant tumours. Therefore, systematic PSA screening is indicated for men with a BRCA2 mutation. Further follow-up is required to assess the role of screening in BRCA1 mutation carriers.
PATIENT SUMMARY: We demonstrate that after 3 yr of prostate-specific antigen (PSA) testing, we detect more serious prostate cancers in men with BRCA2 mutations than in those without these mutations. We recommend that male BRCA2 carriers are offered systematic PSA screening.
METHODS: DNA samples from 92 patients and 156 healthy controls collected from two medical centers in Riyadh, Saudi Arabia were analyzed for four regions located at X-chromosome using the Investigator® Argus X-12 QS Kit.
RESULTS: The results demonstrated that microvariant alleles of (DXS7132, DXS10146, HPRTB, DXS10134, and DXS10135) are overrepresented in the BPH group (p < 0.00001). Allele 28 of DXS10135 and allele 15 of DXS7423 could have a protective effect, OR 0.229 (95%CI, 0.066-0.79); and OR 0.439 (95%CI, 0.208-0.925). On the other hand, patients carrying allele 23 of DXS10079 and allele 26 of DXS10148 presented an increased risk to PrCa OR 4.714 (95%CI, 3.604-6.166).
CONCLUSION: The results are in concordance with the involvement of the X chromosome in PrCa and BPH development. STR allele studies may add further information from the definition of a genetic profile of PrCa resistance or susceptibility. As TBL1, AR, LDOC1, and RPL10 genes are located at regions Xp22.31, Xq11.2-12, Xq26.2, and Xq28, respectively, these genes could play an essential role in PrCa or BPH.
METHODS: To this end, we undertook a pilot genome-wide CNV analysis approach in 36 subjects (18 patients with high-grade PCa and 18 controls that were matched by age and ethnicity) in search of more accurate biomarkers that could potentially explain susceptibility toward high-grade PCa. We conducted this study using the array comparative genomic hybridization technique. Array results were validated in 92 independent samples (46 high-grade PCa, 23 benign prostatic hyperplasia, and 23 healthy controls) using polymerase chain reaction-based copy number counting method.
RESULTS: A total of 314 CNV regions were found to be unique to PCa subjects in this cohort (P<0.05). A log2 ratio-based copy number analysis revealed 5 putative rare or novel CNV loci or both associated with susceptibility to PCa. The CNV gain regions were 1q21.3, 15q15, 7p12.1, and a novel CNV in PCa 12q23.1, harboring ARNT, THBS1, SLC5A8, and DDC genes that are crucial in the p53 and cancer pathways. A CNV loss and deletion event was observed at 8p11.21, which contains the SFRP1 gene from the Wnt signaling pathway. Cross-comparison analysis with genes associated to PCa revealed significant CNVs involved in biological processes that elicit cancer pathogenesis via cytokine production and endothelial cell proliferation.
CONCLUSION: In conclusion, we postulated that the CNVs identified in this study could provide an insight into the development of advanced PCa.
METHODS: We performed a genome-wide survival analysis of cause-specific death in 24,023 prostate cancer patients (3,513 disease-specific deaths) from the PRACTICAL and BPC3 consortia. Top findings were assessed for replication in a Norwegian cohort (CONOR).
RESULTS: We observed no significant association between genetic variants and prostate cancer survival.
CONCLUSIONS: Common genetic variants with large impact on prostate cancer survival were not observed in this study.
IMPACT: Future studies should be designed for identification of rare variants with large effect sizes or common variants with small effect sizes.
SIGNIFICANCE: We demonstrate that combining large-scale GWA meta-analysis findings across cancer types can identify completely new risk loci common to breast, ovarian, and prostate cancers. We show that the identification of such cross-cancer risk loci has the potential to shed new light on the shared biology underlying these hormone-related cancers. Cancer Discov; 6(9); 1052-67. ©2016 AACR.This article is highlighted in the In This Issue feature, p. 932.
METHODS: Immunoblotting, immunofluorescence, quantitative real-time PCR and flow cytometry assays investigated the expression of E-cadherin and CXCR3 isoforms. Intrasplenic inoculation of human prostate cancer (PCa) cells with spontaneous metastasis to the liver analyzed E-cadherin and CXCR3-B expression during cancer progression in vivo.
RESULTS: We found reciprocal regulation of E-cadherin and CXCR3 isoforms. E-cadherin surface expression promoted CXCR3-B presentation on the cell membrane, and to a lesser extent increased its mRNA and total protein levels. In turn, forced expression of CXCR3-A reduced E-cadherin expression level, whereas CXCR3-B increased E-cadherin in PCa. Meanwhile, a positive correlation of E-cadherin and CXCR3-B expression was found both in experimental PCa liver micro-metastases and patients' tissue.
CONCLUSIONS: CXCR3-B and E-cadherin positively correlated in vitro and in vivo in PCa cells and liver metastases, whereas CXCR3-A negatively regulated E-cadherin expression. These results suggest that CXCR3 isoforms may play important roles in cancer progression and dissemination via diametrically regulating tumor's phenotype.