Unravelling the genetics of prostate cancer

Differences in inherited risk among relatives of hereditary prostate cancer patients using genetic risk score

PURPOSE

Family history assigns equivalent risk to all relatives based upon the degree of relationship. Recent genetic studies have identified single nucleotide polymorphisms (SNPs) that can be used to calculate a genetic risk score (GRS) to determine prostate cancer (PCa) risk. We sought to determine whether GRS can stratify PCa risk among individuals in families considered to be at higher risk due their family history of PCa.

MATERIALS AND METHODS

Family members with hereditary PCa were recruited and genotyped for 17 SNPs associated with PCa. A GRS was calculated for all subjects. Analyses compared the distribution of GRS values among affected and unaffected family members of varying relationship degrees.

RESULTS

Data was available for 789 family members of probands including 552 affected and 237 unaffected relatives. Median GRSs were higher among first-degree relatives compared to second- and third-degree relatives. In addition, GRS values among affected first- and second-degree relatives were significantly higher than unaffected relatives (P = 0.042 and P = 0.016, respectively). Multivariate analysis including GRS and degree of relationship demonstrated that GRS was a significant and independent predictor of PCa (OR 1.52, 95%CI 1.15-2.01).

CONCLUSION

GRS is an easy-to-interpret, objective measure that can be used to assess differences in PCa risk among family members of affected men. GRS allows for further differentiation among family members, providing better risk assessment. While prospective validation studies are required, this information can help guide relatives in regards to the time of initiation and frequency of PCa screening.

A novel BRCA2 mutation in prostate cancer sensitive to combined radiotherapy and androgen deprivation therapy

Genetic factors contribute to more than 40% of prostate cancer risk, and mutations in BRCA1 and BRCA2 are well-established risk factors. By using target capture-based deep sequencing to identify potential pathogenic germline mutations, followed by Sanger sequencing to determine the loci of the mutations, we identified a novel pathogenic BRCA2 mutation caused by a cytosine-to-guanine base substitution at position 4211, resulting in protein truncation (p.Ser1404Ter), which was confirmed by immunohistochemistry. Analysis of peripheral blood also identified benign polymorphisms in BRCA2 (c.7397T>C, p.Val2466Ala) and SRD5A2 (c.87G>C, p.Lys29Asn). Analysis of tumor tissues revealed seven somatic mutations in prostate tumor tissue and nine somatic mutations in esophageal squamous carcinoma tissue (single nucleotide polymorphisms, insertions, and deletions). Five-year follow-up results indicate that ADT combined with radiotherapy successfully treated the prostate cancer. To our knowledge, we are the first to report the germline BRCA2 mutation c.4211C>G (p.Ser1404Ter) in prostate cancer. Combined ADT and radiotherapy may be effective in treating other patients with prostate cancer caused by this or similar mutations.

The molecular biology of prostate cancer: current understanding and clinical implications

BACKGROUND

With continuous progress over the past few decades in understanding diagnosis, treatment, and genetics, much has been learned about the prostate cancer-diagnosed genome.

METHODS

A comprehensive MEDLINE® and Google scholar literature search was conducted using keyword variations relating to the genetics of prostate cancer such as chromosomal alterations, androgen receptor, castration-resistant, inheritance, polymorphisms, oncogenes, metastasis, biomarkers, and immunotherapy.

RESULTS

Traditionally, androgen receptors (AR) have been the focus of research. Recently, identification of recurrent chromosomal alterations that lead to either multiplication of regions (gain-of-function) or deletion of regions (loss-of-function) has opened the door to greater genetic accessibility. These chromosomal aberrations lead to variation in copy number and gene expression. Some of these chromosomal alterations are inherited, while others undergo somatic mutations during disease progression. Inherited gene mutations that make one susceptible to prostate cancer have been identified with familial-linked studies. Somatic genes that progress tumorigenesis have also been identified. Research on the molecular biology of prostate cancer has characterized these genes into tumor suppressor genes or oncogenes. Additionally, genome-wide assay studies have identified many high-risk single-nucleotide polymorphisms recurrent throughout the prostate cancer-diagnosed genome. Castration-resistant prostate cancer is the most aggressive form of prostate cancer, and its research has elucidated many types of mutations associated with AR itself, including enhanced expression and amplification, point mutations, and alternative splicing. Understanding the molecular biology of prostate cancer has permitted more accurate identification using advanced biomarkers and therapy for aggressive forms using immunotherapy.

CONCLUSIONS

An age-related disease, prostate cancer commands profound attention. With increasing life expectancy and the continuous pursuit of it, prostate cancer is a powerful obstacle best defeated using targeted therapies specifically designed for the unique molecular profile of the malignancy.

The complexity of prostate cancer: genomic alterations and heterogeneity

Although prostate cancer is the most common malignancy to affect men in the Western world, the molecular mechanisms underlying its development and progression remain poorly understood. Like all cancers, prostate cancer is a genetic disease that is characterized by multiple genomic alterations, including point mutations, microsatellite variations, and chromosomal alterations such as translocations, insertions, duplications, and deletions. In prostate cancer, but not other carcinomas, these chromosome alterations result in a high frequency of gene fusion events. The development and application of novel high-resolution technologies has significantly accelerated the detection of genomic alterations, revealing the complex nature and heterogeneity of the disease. The clinical heterogeneity of prostate cancer can be partly explained by this underlying genetic heterogeneity, which has been observed between patients from different geographical and ethnic populations, different individuals within these populations, different tumour foci within the same patient, and different cells within the same tumour focus. The highly heterogeneous nature of prostate cancer provides a real challenge for clinical disease management and a detailed understanding of the genetic alterations in all cells, including small subpopulations, would be highly advantageous.

Cyclooxygenase 2 (rs2745557) Polymorphism and the Susceptibility to Benign Prostate Hyperplasia and Prostate Cancer in Egyptians

Cyclooxygenase-2 (COX-2), an inducible isoform of cyclooxygenase, has been reported to be correlated with tumorigenesis, tumor progression, and metastasis. We aimed to evaluate the association between COX-2 (rs2745557) polymorphism and prostate cancer (PCa), benign prostate hyperplasia (BPH) risk. We also assessed the influence of other risk factors such as obesity, smoking, diabetes in modulating the risk of PCa in Egyptian men. COX-2 (rs2745557) was genotyped in 112 PC patients, 111 BPH and 120 subjects as a control group. COX-2 and PSA levels were measured by ELISA. We found that GG genotype was associated with a 17-fold increased risk for PCa and 20-fold increased the risk for BPH more than AA genotype. Also, G allele carriers of COX-2 were associated with metastatic cancer (OR = 1.3, P < 0.05) and disease aggressiveness (OR = 3.5, P < 0.001). The coexistence of obesity, smoking, or diabetes with GG genotype may lead to increasing the risk of developing BPH (OR = 3.3, 4, and 2.7, respectively) and of developing PCa (OR = 2.9, 4.9, and 3.2, respectively). Our results showed evidence suggesting the involvement of the COX-2 (rs2745557) polymorphism and its protein in PCa or BPH initiation and progression. Also, the coexistence of COX-2 (rs2745557) and obesity, smoking, or diabetes may lead to the development of PCa or BPH.

The role of BRCA1 and BRCA2 mutations in prostate, pancreatic and stomach cancers

The association of germline mutations in the breast cancer susceptibility gene 1 (BRCA1) and the breast cancer susceptibility gene 2 (BRCA2) with the development of breast and ovarian cancers have been widely researched and recognised. It is known that these genes function at multiple sites in the body. Research has subsequently evolved into the connection of BRCA1/2 with cancers at other sites within the body. This review examines the association of BRCA1/2 germline gene mutations with prostate, pancreatic and stomach cancers. An extensive literature search revealed conflicting findings regarding the association of BRCA1/2 gene mutations with these cancers. Most studies suggest that there is an association between BRCA1/2 mutations and carcinoma of the prostate, pancreas and stomach, but some reports propose that such a correlation may be due to factors other than possessing a mutated BRCA1/2 gene, and other associations may be revealed as further epidemiological information becomes available. The review concludes that as more knowledge arises about the mechanisms of BRCA1/2 gene mutations, it should pave the way for future screening programmes to be applied effectively.

A genetic-based approach to personalized prostate cancer screening and treatment

PURPOSE OF REVIEW

Recent advances in sequencing technologies have allowed for the identification of genetic variants within germline DNA that can explain a significant portion of the genetic underpinnings of prostate cancer. Despite evidence suggesting that these genetic variants can be used for improved risk stratification, they have not yet been routinely incorporated into routine clinical practice. This review highlights their potential utility in prostate cancer screening.

RECENT FINDINGS

There are now almost 100 genetic variants, called single nucleotide polymorphisms (SNPs) that have been recently found to be associated with the risk of developing prostate cancer. In addition, some of these prostate cancer risk SNPs have also been found to influence prostate specific antigen (PSA) expression levels and potentially aggressive disease.

SUMMARY

Incorporation of panels of prostate cancer risk SNPs into clinical practice offers potential to provide improvements in patient selection for prostate cancer screening; PSA interpretation (e.g. by correcting for the presence of SNPs that influence PSA expression levels; decision for biopsy (using prostate cancer risk SNPs); and possibly the decision for treatment. A proposed clinical algorithm incorporating these prostate cancer risk SNPs is discussed.

Relationship between gene polymorphisms and prostate cancer risk

OBJECTIVE

To investigate the relationship between genetic factor and prostate cancer (Pca) risk and the possible cause in it.

METHODS

The polymorphisms of cytochrome P450 family 17 (CYPl7) rs743572, p27 V109G and androgen receptor (AR) gene CAG repeat length in peripheral blood from 70 cases and 70 controls were detected through the polymerase chain reaction-restriction fragment length polymorphism technique or short tandem repeat-polymerase chain reaction technique. Then, according to the results of case-control study, the recombinant plasmids containing the wild/mutant p27 gene were constructed and transfected Pca LNcap cells. After 24 and 72 h of transfection, the cell proliferative activity was determined by MTT method, cell cycle distribution and apoptosis was detected by flow cytometry, and the expression level of bcl-2, caspase-3 and p27 protein was determined by Western-blot.

RESULTS

In three target polymorphisms, only p27 V109G polymorphism was related to Pca risk (P = 0.030, OR = 0.202, 95% CI = 0.042-0.973). Pca risk of p27-109G allele was lower than -109V allele (P = 0.006, OR = 0.285, 95% CI = 0.110-0.737). Cells transfected with wild/mutant p27 gene both showed the higher cells apoptosis rate and the lower cell proliferative activity than mock cells (P < 0.05 or 0.01), the regulatory effect of mutant p27 on cell proliferation and apoptosis was stronger than the wild p27 (P < 0.05).

CONCLUSIONS

p27-109G allele that could cause higher p27 protein expression than -109V allele in LNcap cells, maybe is the protective factor of Pca.

Prostate cancer: The main risk and protective factors-Epigenetic modifications

With 13 million new cases worldwide every year, prostate cancer is as a very real public health concern. Prostate cancer is common in over-50s men and the sixth-leading cause of cancer-related death in men worldwide. Like all cancers, prostate cancer is multifactorial - there are non-modifiable risk factors like heredity, ethnicity and geographic location, but also modifiable risk factors such as diet. Diet-cancer linkages have risen to prominence in the last few years, with accruing epidemiological data pointing to between-population incidence differentials in numerous cancers. Indeed, there are correlations between fat-rich diet and risk of hormone-dependent cancers like prostate cancer and breast cancer. Diet is a risk factor for prostate cancer, but certain micronutrients in specific diets are considered protective factors against prostate cancer. Examples include tomato lycopene, green tea epigallocatechin gallate, and soy phytoestrogens. These micronutrients are thought to exert cancer-protective effects via anti-oxidant pathways and inhibition of cell proliferation. Here, we focus in on the effects of phytoestrogens, and chiefly genistein and daidzein, which are the best-researched to date. Soy phytoestrogens are nonsteroid molecules whose structural similarity lends them the ability to mimic the effects of 17ß-estradiol. On top of anti-oxidant effects, there is evidence that soy phytoestrogens can modulate the epigenetic modifications found in prostate cancer. We also studied the impact of phytoestrogens on epigenetic modifications in prostate cancer, with special focus on DNA methylation, miRNA-mediated regulation and histone modifications.

Assessing interactions of two loci (rs4242382 and rs10486567) in familial prostate cancer: statistical evaluation of epistasis

Understanding the impact of multiple genetic variants and their interactions on the disease penetrance of familial multiple prostate cancer is very relevant to the overall understanding of carcinogenesis. We assessed the joint effect of two loci on rs4242382 at 8q24 and rs10486567 at 7p15.2 to this end. We analyzed the data from a Finnish family-based genetic study, which was composed of 947 men including 228 cases in 75 families, to evaluate the respective effects of the two loci on the disease penetrance; in particular, the occurrence and number of prostate cancer cases within a family were utilized to evaluate the interactions between the two loci under the additive and multiplicative Poisson regression models. The risk alleles A at rs4242382 (OR = 1.14, 95% CI 1.08–1.19, P<0.0001) and a risk allele A at rs10486567 (OR = 1.06, 96%CI 1.01–1.11, P = 0.0208) were found to be associated with an increased risk of familial PrCa, especially with four or more cases within a family. A multiplicative model fitted the joint effect better than an additive model (likelihood ratio test X² = 13.89, P<0.0001). The influence of the risk allele A at rs10486567 was higher in the presence of the risk allele A at rs4242382 (OR = 1.09 (1.01–1.18) vs. 1.01 (0.95–1.07)). Similar findings were observed in non-aggressive PrCa, but not in aggressive PrCa. We demonstrated that two loci (rs4242382 and rs10486567) are highly associated with familial multiple PrCa, and the gene-gene interaction or statistical epistasis was consistent with the Fisher's multiplicative model. These loci's association and epistasis were observed for non-aggressive but not for aggressive tumors. The proposed statistical model can be further developed to accommodate multi-loci interactions to provide further insights into epistasis.

Cyclooxygenase 2 genotypes influence prostate cancer susceptibility in Japanese Men

This study aims to evaluate the relationship between the cyclooxygenase 2 (COX2) G1195A (rs689465) polymorphism and the risk of prostate cancer in a Japanese population and the associations between COX2 polymorphisms and clinicopathological characteristics, including Gleason grade and prostate-specific antigen (PSA) grade. We recruited 134 patients with prostate cancer and 86 healthy controls matched for age and smoking status. The COX2 G1195A polymorphism status was determined by polymerase chain reaction and restriction fragment length polymorphism analysis. Genotype distributions (p = 0.028) and allelic frequencies (p = 0.014) differed significantly between prostate cancer and control groups in terms of the COX2 G1195A polymorphism (Pearson's χ (2) test). Logistic regression analysis of case and control outcomes showed an odds ratio between the GG and AA genotypes of 3.15 (95% confidence interval = 1.27-8.08, p = 0.014), indicating an increased risk of prostate cancer associated with the AA genotype. Subset analysis revealed no significant associations between this polymorphism and clinicopathological characteristics of prostate cancer. This study demonstrated a relationship between the COX2 G1195A variant and prostate cancer risk. This polymorphism may merit further investigation as a potential genomic marker for the early detection of prostate cancer. Our results support the hypothesis that rs689465 influences susceptibility to prostate cancer; however, prostate cancer progression was not associated with rs689465 in a Japanese population.

Aspirin use is associated with lower prostate cancer risk in male carriers of BRCA mutations

Previous studies have shown that male BRCA mutation carriers stand at increased risk of developing prostate cancer and have concerns about developing cancer. Genetic counseling practitioners often discuss strategies for reducing the risk of cancer for patients at high risk due to their genetic background. Addressing modifiable health habits is one such strategy. Unfortunately, modifiable risk factors for prostate cancer have only been documented in the general population and have not yet been studied in the BRCA carrier subpopulation. Therefore, this study aimed to identify modifiable risk factors for prostate cancer in BRCA carriers. We examined prostate cancer risk factors in 74 men who were part of families with a BRCA mutation. This study examined nine dichotomous variables including: exercise, history of vasectomy, smoking history, alcohol use, finasteride use, statin use, aspirin use, coffee use, and vitamin use. The survey was sent to all cases of prostate cancer in the Hereditary Cancer Center Database at Creighton University with a known BRCA status. This study confirmed the protective benefits of daily aspirin use, which have been observed in previous studies of the general population, and suggests its benefit in BRCA carriers. Protective benefits from regular vigorous exercise and daily coffee use trended towards significance, but neither factor withstood the Bonferroni Correction for multiple comparisons.

Germline BRCA mutations are associated with higher risk of nodal involvement, distant metastasis, and poor survival outcomes in prostate cancer

PURPOSE

To analyze the baseline clinicopathologic characteristics of prostate tumors with germline BRCA1 and BRCA2 (BRCA1/2) mutations and the prognostic value of those mutations on prostate cancer (PCa) outcomes.

PATIENTS AND METHODS

This study analyzed the tumor features and outcomes of 2,019 patients with PCa (18 BRCA1 carriers, 61 BRCA2 carriers, and 1,940 noncarriers). The Kaplan-Meier method and Cox regression analysis were used to evaluate the associations between BRCA1/2 status and other PCa prognostic factors with overall survival (OS), cause-specific OS (CSS), CSS in localized PCa (CSS_M0), metastasis-free survival (MFS), and CSS from metastasis (CSS_M1).

RESULTS

PCa with germline BRCA1/2 mutations were more frequently associated with Gleason ≥ 8 (P = .00003), T3/T4 stage (P = .003), nodal involvement (P = .00005), and metastases at diagnosis (P = .005) than PCa in noncarriers. CSS was significantly longer in noncarriers than in carriers (15.7 v 8.6 years, multivariable analyses [MVA] P = .015; hazard ratio [HR] = 1.8). For localized PCa, 5-year CSS and MFS were significantly higher in noncarriers (96% v 82%; MVA P = .01; HR = 2.6%; and 93% v 77%; MVA P = .009; HR = 2.7, respectively). Subgroup analyses confirmed the poor outcomes in BRCA2 patients, whereas the role of BRCA1 was not well defined due to the limited size and follow-up in this subgroup.

CONCLUSION

Our results confirm that BRCA1/2 mutations confer a more aggressive PCa phenotype with a higher probability of nodal involvement and distant metastasis. BRCA mutations are associated with poor survival outcomes and this should be considered for tailoring clinical management of these patients.

Genetic sequence variants are associated with severity of lower urinary tract symptoms and prostate cancer susceptibility

PURPOSE

While a clear heritable component underlies lower urinary tract symptoms and benign prostatic hyperplasia, few studies have identified specific genetic factors. In contrast, recent genome-wide association studies identified single nucleotide polymorphisms that increase prostate cancer risk. Some of these single nucleotide polymorphisms may also predispose to surgical intervention for benign prostatic hyperplasia. We determined whether these single nucleotide polymorphisms are also associated with lower urinary tract symptom severity and benign prostatic hyperplasia medication use.

MATERIALS AND METHODS

The genotypes of 38 single nucleotide polymorphisms previously associated with prostate cancer risk were determined for 1,168 healthy white male volunteers. American Urological Association symptom index score and medication for benign prostatic hyperplasia were documented prospectively. Statistical analyses were done to compare the frequency of the single nucleotide polymorphisms with American Urological Association symptom index and benign prostatic hyperplasia medication use.

RESULTS

Several single nucleotide polymorphisms, including rs2736098 on chromosome 5p15, showed a significant relationship with benign prostatic hyperplasia medication. After adjusting for the other genetic variants, patient age and medication use, rs1571801 on chromosome 9q33.2 (OR 1.31, 95% CI 1.0-1.74) and rs5945572 on chromosome Xp11 (OR 1.28, 95% CI 1.04-1.59) were significantly associated with increased urinary symptoms. In contrast, rs445114 on chromosome 8q24 was marginally associated with decreased urinary symptoms (OR 0.83, 95% CI 0.66-1.01).

CONCLUSIONS

Of 38 single nucleotide polymorphisms that predispose to prostate cancer we identified 3 that are also associated with a well characterized lower urinary tract symptom phenotype. These single nucleotide polymorphisms may aid in the improved characterization of men with lower urinary tract symptoms/benign prostatic hyperplasia.

The role of BRCA1 and BRCA2 in prostate cancer

One of the strongest risk factors for prostate cancer is a family history of the disease. Germline mutations in the breast cancer predisposition gene 2 (BRCA2) are the genetic events known to date that confer the highest risk of prostate cancer (8.6-fold in men ≤65 years). Although the role of BRCA2 and BRCA1 in prostate tumorigenesis remains unrevealed, deleterious mutations in both genes have been associated with more aggressive disease and poor clinical outcomes. The increasing incidence of prostate cancer worldwide supports the need for new methods to predict outcome and identify patients with potentially lethal forms of the disease. As we present here, BRCA germline mutations, mainly in the BRCA2 gene, are one of those predictive factors. We will also discuss the implications of these mutations in the management of prostate cancer and hypothesize on the potential for the development of strategies for sporadic cases with similar characteristics.

Genetic variants associated with predisposition to prostate cancer and potential clinical implications

Prostate cancer is the commonest cancer in the developed world. There is an inherited component to this disease as shown in familial and twin studies. However, the discovery of these variants has been difficult. The emergence of genome-wide association studies has led to the identification of over 46 susceptibility loci. Their clinical utility to predict risk, response to treatment, or treatment toxicity, remains undefined. Large consortia are needed to achieve adequate statistical power to answer these genetic-clinical and genetic-epidemiological questions. International collaborations are currently underway to link genetic with clinical/epidemiological data to develop risk prediction models, which could direct screening and treatment programs.

Polymorphisms in COX-2 gene influence prostate cancer susceptibility in a northern Indian cohort

BACKGROUND AND AIMS

Cyclooxygenase-2 (COX-2) converts arachidonic acid to prostaglandins, which are important mediators of cell proliferation and inflammation. Evidence indicates that COX-2 plays a role in carcinogenesis and that it is overexpressed in prostate tumors. We examined whether sequence variants in the COX-2 gene were associated with prostate cancer (PCa) risk.

METHODS

In a hospital-based case/control study, 195 subjects with PCa and 250 healthy controls were investigated for the association of COX-2 -765 G>C (rs20417) and +8473 T>C (rs5275) promoter polymorphism with PCa susceptibility using the polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) method.

RESULT

Variant allele 'C' carriers of COX-2 -765 G>C polymorphism were associated with a 1.7-fold increased risk for PCa (p = 0.016; OR = 1.74). The variant genotype CC of COX-2 +8473 T>C polymorphism was found to be significantly associated with the overall higher risk of PCa (p = 0.045; OR = 1.82). Combined genotype (TC + CC) also demonstrated a 1.5-fold significant risk with PCa (p = 0.040; OR = 1.52). The diplotype C-C was observed to be associated with a significant increase in PCa risk (Bonferroni corrected p value, Pc = 0.004; OR = 4.26). Stratification of cases based on clinical pathological grade of tumors revealed no association with PCa risk.

CONCLUSIONS

Our findings suggest COX-2 -765G>C and +8473 T>C polymorphism and diplotype C-C to be a risk factor for PCa. However, further validation in large population-based studies is needed to confirm the finding.

BRCA2 is a moderate penetrance gene contributing to young-onset prostate cancer: implications for genetic testing in prostate cancer patients

BACKGROUND

A family history of prostate cancer (PrCa) is a strong risk factor for the disease, indicating that inherited factors are important in this disease. We previously estimated that about 2% of PrCa cases diagnosed ≤ 55 years harbour a BRCA2 mutation and PrCa among BRCA2 carriers has been shown to be more aggressive, with poorer survival.

METHODS

To further evaluate the role of BRCA2 in PrCa predisposition, we screened 1864 men with PrCa aged between 36 and 88 years. We analysed the BRCA2 gene using a novel high-throughput multiplex fluorescence heteroduplex detection system developed for the ABI3130xl genetic analyzer.

RESULTS

We identified 19 protein-truncating mutations, 3 in-frame deletions and 69 missense variants of uncertain significance (UV) in our sample set. All the carriers of truncating mutations developed PrCa at ≤ 65 years, with a prevalence of BRCA2 mutation of 1.20% for cases in this age group.

CONCLUSION

Based on the estimated frequency of BRCA2 mutations in the United Kingdom we estimate that germline mutations in the BRCA2 gene confer an ∼ 8.6-fold increased risk of PrCa by age 65, corresponding to an absolute risk of ∼ 15% by age 65. These results suggest that routine testing of early onset PrCa cases for germline BRCA2 mutations will further help to refine the prevalence and risk associated with BRCA2 mutations and may be useful for guiding management options.

Cytogenomic aberrations associated with prostate cancer

Genetic changes associated with prostate cancer have finally begun to elucidate some of the mechanisms involved in the etiology of this complex and common disease. We highlight consistent and relatively frequent abnormalities seen by various methodologies. Specifically, the results of conventional and molecular cytogenetic studies, genome-wide association studies with single nucleotide polymorphisms, recurrent gene fusions, and epigenetic analyses are discussed.

Identification of a novel prostate cancer susceptibility variant in the KLK3 gene transcript

Genome-wide association studies (GWAS) have identified more than 30 prostate cancer (PrCa) susceptibility loci. One of these (rs2735839) is located close to a plausible candidate susceptibility gene, KLK3, which encodes prostate-specific antigen (PSA). PSA is widely used as a biomarker for PrCa detection and disease monitoring. To refine the association between PrCa and variants in this region, we used genotyping data from a two-stage GWAS using samples from the UK and Australia, and the Cancer Genetic Markers of Susceptibility (CGEMS) study. Genotypes were imputed for 197 and 312 single nucleotide polymorphisms (SNPs) from HapMap2 and the 1000 Genome Project, respectively. The most significant association with PrCa was with a previously unidentified SNP, rs17632542 (combined P = 3.9 × 10⁻²²). This association was confirmed by direct genotyping in three stages of the UK/Australian GWAS, involving 10,405 cases and 10,681 controls (combined P = 1.9 × 10⁻³⁴). rs17632542 is also shown to be associated with PSA levels and it is a non-synonymous coding SNP (Ile179Thr) in KLK3. Using molecular dynamic simulation, we showed evidence that this variant has the potential to introduce alterations in the protein or affect RNA splicing. We propose that rs17632542 may directly influence PrCa risk.

Prostate cancer in BRCA2 germline mutation carriers is associated with poorer prognosis

Background:

The germline BRCA2 mutation is associated with increased prostate cancer (PrCa) risk. We have assessed survival in young PrCa cases with a germline mutation in BRCA2 and investigated loss of heterozygosity at BRCA2 in their tumours.

Methods:

Two cohorts were compared: one was a group with young-onset PrCa, tested for germline BRCA2 mutations (6 of 263 cases had a germline BRAC2 mutation), and the second was a validation set consisting of a clinical set from Manchester of known BRCA2 mutuation carriers (15 cases) with PrCa. Survival data were compared with a control series of patients in a single clinic as determined by Kaplan–Meier estimates. Loss of heterozygosity was tested for in the DNA of tumour tissue of the young-onset group by typing four microsatellite markers that flanked the BRCA2 gene, followed by sequencing.

Results:

Median survival of all PrCa cases with a germline BRCA2 mutation was shorter at 4.8 years than was survival in controls at 8.5 years (P=0.002). Loss of heterozygosity was found in the majority of tumours of BRCA2 mutation carriers. Multivariate analysis confirmed that the poorer survival of PrCa in BRCA2 mutation carriers is associated with the germline BRCA2 mutation per se.

Conclusion:

BRCA2 germline mutation is an independent prognostic factor for survival in PrCa. Such patients should not be managed with active surveillance as they have more aggressive disease.

Cancer biomarker discovery: the entropic hallmark

Background

It is a commonly accepted belief that cancer cells modify their transcriptional state during the progression of the disease. We propose that the progression of cancer cells towards malignant phenotypes can be efficiently tracked using high-throughput technologies that follow the gradual changes observed in the gene expression profiles by employing Shannon's mathematical theory of communication. Methods based on Information Theory can then quantify the divergence of cancer cells' transcriptional profiles from those of normally appearing cells of the originating tissues. The relevance of the proposed methods can be evaluated using microarray datasets available in the public domain but the method is in principle applicable to other high-throughput methods.

Methodology/Principal Findings

Using melanoma and prostate cancer datasets we illustrate how it is possible to employ Shannon Entropy and the Jensen-Shannon divergence to trace the transcriptional changes progression of the disease. We establish how the variations of these two measures correlate with established biomarkers of cancer progression. The Information Theory measures allow us to identify novel biomarkers for both progressive and relatively more sudden transcriptional changes leading to malignant phenotypes. At the same time, the methodology was able to validate a large number of genes and processes that seem to be implicated in the progression of melanoma and prostate cancer.

Conclusions/Significance

We thus present a quantitative guiding rule, a new unifying hallmark of cancer: the cancer cell's transcriptome changes lead to measurable observed transitions of Normalized Shannon Entropy values (as measured by high-througput technologies). At the same time, tumor cells increment their divergence from the normal tissue profile increasing their disorder via creation of states that we might not directly measure. This unifying hallmark allows, via the the Jensen-Shannon divergence, to identify the arrow of time of the processes from the gene expression profiles, and helps to map the phenotypical and molecular hallmarks of specific cancer subtypes. The deep mathematical basis of the approach allows us to suggest that this principle is, hopefully, of general applicability for other diseases.

Mutation analysis of the MSMB gene in familial prostate cancer

Background:

MSMB, a gene coding for β-microseminoprotein, has been identified as a candidate susceptibility gene for prostate cancer (PrCa) in two genome-wide association studies (GWAS). SNP rs10993994 is 2 bp upstream of the transcription initiation site of MSMB and was identified as an associated PrCa risk variant. The MSMB protein is underexpressed in PrCa and it was previously proposed to be an independent marker for the recurrence of cancer after radical prostatectomy.

Methods:

In this study, the coding region of this gene and 1500 bp upstream of the 5′UTR has been sequenced in germline DNA in 192 PrCa patients with family history. To evaluate the possible effects of these variants we used in silico analysis.

Results:

No deleterious mutations were identified, however, nine new sequence variants were found, most of these in the promoter and 5′UTR region. In silico analysis suggests that four of these SNPs are likely to have some effect on gene expression either by affecting ubiquitous or prostate-specific transcription factor (TF)-binding sites or modifying splicing efficiency.

Interpretation

We conclude that MSMB is unlikely to be a familial PrCa gene and propose that the high-risk alleles of the SNPs in the 5′UTR effect PrCa risk by modifying MSMB gene expression in response to hormones in a tissue-specific manner.

A recurrent truncating germline mutation in the BRIP1/FANCJ gene and susceptibility to prostate cancer

Although prostate cancer (PrCa) is one of the most common cancers in men in Western countries, little is known about the inherited factors that influence PrCa risk. On the basis of the fact that BRIP1/FANCJ interacts with BRCA1 and functions as a regulator of DNA double-strand break repair pathways, and that germline mutations within the BRIP1/FANCJ gene predispose to breast cancer, we chose this gene as a candidate for mutation screening in familial and young-onset PrCa cases. We identified a truncating mutation, R798X, in the BRIP1/FANCJ gene in 4 out of 2714 UK PrCa cases enriched for familial (2 out of 641; 0.3%) and young-onset cases (2 out of 2073; 0.1%). On screening 2045 controls from the UK population, we found one R798X sequence alteration (0.05%; odds ratio 2.4 (95% CI 0.25-23.4)). In addition, using our data from a genome-wide association study, we analysed 25 SNPs in the genomic region of the BRIP1/FANCJ gene. Two SNPs showed evidence of association with familial and young-onset PrCa (rs6504074; P(trend)=0.04 and rs8076727; P(trend)=0.01). These results suggest that truncating mutations in BRIP1/FANCJ might confer an increased risk of PrCa and common SNPs might also contribute to the alteration of risk, but larger case-control series will be required to confirm or refute this association.

Multiple novel prostate cancer predisposition loci confirmed by an international study: the PRACTICAL Consortium

A recent genome-wide association study found that genetic variants on chromosomes 3, 6, 7, 10, 11, 19 and X were associated with prostate cancer risk. We evaluated the most significant single-nucleotide polymorphisms (SNP) in these loci using a worldwide consortium of 13 groups (PRACTICAL). Blood DNA from 7,370 prostate cancer cases and 5,742 male controls was analyzed by genotyping assays. Odds ratios (OR) associated with each genotype were estimated using unconditional logistic regression. Six of the seven SNPs showed clear evidence of association with prostate cancer (P = 0.0007-P = 10(-17)). For each of these six SNPs, the estimated per-allele OR was similar to those previously reported and ranged from 1.12 to 1.29. One SNP on 3p12 (rs2660753) showed a weaker association than previously reported [per-allele OR, 1.08 (95% confidence interval, 1.00-1.16; P = 0.06) versus 1.18 (95% confidence interval, 1.06-1.31)]. The combined risks associated with each pair of SNPs were consistent with a multiplicative risk model. Under this model, and in combination with previously reported SNPs on 8q and 17q, these loci explain 16% of the familial risk of the disease, and men in the top 10% of the risk distribution have a 2.1-fold increased risk relative to general population rates. This study provides strong confirmation of these susceptibility loci in multiple populations and shows that they make an important contribution to prostate cancer risk prediction.

Identification of new genetic risk factors for prostate cancer

There is evidence that a substantial part of genetic predisposition to prostate cancer (PCa) may be due to lower penetrance genes which are found by genome-wide association studies. We have recently conducted such a study and seven new regions of the genome linked to PCa risk have been identified. Three of these loci contain candidate susceptibility genes: MSMB, LMTK2 and KLK2/3. The MSMB and KLK2/3 genes may be useful for PCa screening, and the LMTK2 gene might provide a potential therapeutic target. Together with results from other groups, there are now 23 germline genetic variants which have been reported. These results have the potential to be developed into a genetic test. However, we consider that marketing of tests to the public is premature, as PCa risk can not be evaluated fully at this stage and the appropriate screening protocols need to be developed. Follow-up validation studies, as well as studies to explore the psychological implications of genetic profile testing, will be vital prior to roll out into healthcare.

Molecular markers in prostate cancer. Part I: predicting lethality

Assessing the lethality of 'early,' potentially organ-confined prostate cancer (PCa) is one of the central controversies in modern-day urological clinical practice. Such cases are often considered for radical 'curative' treatment, although active surveillance may be equally appropriate for many men. Moreover, the balance between judicious intervention and overtreatment can be difficult to judge. The patient's age, comorbidities, family history and philosophy of self-health care can be weighed against clinical features such as the palpability of disease, the number and percentage of biopsy cores involved with the disease, histological grade, presenting prostate-specific antigen (PSA) and possible previous PSA kinetics. For many years, scientists and physicians have sought additional molecular factors that may be predictive for disease stage, progression and lethality. Usually, claims for a 'new' unique marker fall short of true clinical value. More often than not, such molecular markers are useful only in multivariate models. This review summarizes relevant molecular markers and models reported up to and including 2008.

Concordant colon tumors in monozygotic twins previously treated for prostate cancer

This report describes the quasi-simultaneous occurrence of colon cancers in monozygotic twin brothers (age 63 years) who had undergone androgen deprivation therapy for prostate cancers 4 years earlier. Concordance among male twins for both of these cancers has never been reported. Although the family history suggested possible genetic predispositions to both cancers, the twins have no evidence of the genetic alterations associated with hereditary colorectal tumors. We explore the possibility that colorectal tumorigenesis in these twins was fuelled by a combination of genetic and iatrogenic factors, in particular the androgen deprivation therapy used to treat their prostate cancers.

Prostate cancer

In developed countries, prostate cancer is the second most frequently diagnosed cancer, and the third most common cause of death from cancer in men. Apart from age and ethnic origin, a positive family history is probably the strongest known risk factor. Clinically, prostate cancer is diagnosed as local or advanced, and treatments range from surveillance to radical local treatment or androgen-deprivation treatment. Androgen deprivation reduces symptoms in about 70-80% of patients with advanced prostate cancer, but most tumours relapse within 2 years to an incurable androgen-independent state. The recorded incidence of prostate cancer has substantially increased in the past two decades, probably because of the introduction of screening with prostate-specific antigen, the use of improved biopsy techniques for diagnosis, and increased public awareness. Trends in mortality from the disease are less clearcut. Mortality changes are not of the same magnitude as the changes in incidence, and in some countries mortality has been stable or even decreased. The disparity between reported incidence and mortality rates leads to the probable conclusion that only a small proportion of diagnosed low-risk prostate cancers will progress to life-threatening disease during the lifetime of the patient.

Evaluation of a variant in the transcription factor 7-like 2 (TCF7L2) gene and prostate cancer risk in a population-based study

BACKGROUND

Transcription factor 7-like 2 (TCF7L2) is a high mobility group-box containing protein that is a critical member of the Wnt/beta-catenin canonical signaling pathway. In addition to its recently recognized role in diabetes, aberrant TCF7L2 expression has been implicated in cancer through regulation of cell proliferation and apoptosis by c-MYC and cyclin D. It has been hypothesized that germline variants within the TCF7L2 gene previously associated with diabetes may affect cancer risk through the Wnt/beta-catenin signaling pathway. Specifically, the same risk allele of single nucleotide polymorphism (SNP) rs12255372 that is associated with diabetes (T allele) has recently been associated with an increased risk of breast cancer.

METHODS

Here, we investigated associations between rs12255372 and prostate cancer risk among 1,457 cases and 1,351 controls from a population-based study.

RESULTS

The variant TT genotype was not associated with overall prostate cancer risk. However, there was evidence that men homozygous for the variant T allele had an elevated relative risk of more aggressive prostate cancer, as defined by high Gleason score (OR = 1.7, 95% CI = 1.0-2.8) or regional/distant stage (OR = 1.7, 95% CI = 1.1-2.6) disease.

CONCLUSIONS

Our findings suggest that this variant in the TCF7L2 gene may be associated with risk of developing more clinically significant disease. These results need to be confirmed, but provide initial evidence that the TCF7L2 gene may alter risk of developing more aggressive prostate cancer.

Multiple newly identified loci associated with prostate cancer susceptibility

Prostate cancer is the most common cancer affecting males in developed countries. It shows consistent evidence of familial aggregation, but the causes of this aggregation are mostly unknown. To identify common alleles associated with prostate cancer risk, we conducted a genome-wide association study (GWAS) using blood DNA samples from 1,854 individuals with clinically detected prostate cancer diagnosed at </=60 years or with a family history of disease, and 1,894 population-screened controls with a low prostate-specific antigen (PSA) concentration (<0.5 ng/ml). We analyzed these samples for 541,129 SNPs using the Illumina Infinium platform. Initial putative associations were confirmed using a further 3,268 cases and 3,366 controls. We identified seven loci associated with prostate cancer on chromosomes 3, 6, 7, 10, 11, 19 and X (P = 2.7 x 10(-8) to P = 8.7 x 10(-29)). We confirmed previous reports of common loci associated with prostate cancer at 8q24 and 17q. Moreover, we found that three of the newly identified loci contain candidate susceptibility genes: MSMB, LMTK2 and KLK3.

Chemoprevention of prostate cancer: agents and study designs

PURPOSE

With the completion of the Prostate Cancer Prevention Trial and the ongoing performance of several additional large-scale prostate cancer prevention trials interest in this intervention has increased. We review promising agents for prostate cancer prevention, clinical trial designs and how these agents may be used clinically.

MATERIALS AND METHODS

We reviewed current and completed randomized chemoprevention trials for prostate cancer as well as the most promising agents for which evidence suggests that a decreased prostate cancer risk may result from their use.

RESULTS

Evidence suggests that lycopene, decreased dietary fat, antioxidants such as alpha-tocopherol and selenium, nonsteroidal anti-inflammatory drugs and selective estrogen receptor modulators such as toremifene and 5alpha-reductase inhibitors may prove useful for decreasing the risk of prostate cancer in a man. Ongoing studies are examining these agents in the 3 general scenarios of 1) general population studies (finasteride, alpha-tocopherol and selenium), 2) increased prostate specific antigen with negative biopsy (dutasteride) and 3) prostatic intraepithelial neoplasia (toremifene and selenium).

CONCLUSIONS

There are many agents that may decrease the risk of prostate cancer. It requires careful study of the agents in specific populations to determine whether risk is reduced, the magnitude of the risk reduction and the spectrum of side effects associated with the agent. Physicians caring for men entering the range of age of prostate cancer risk must be aware of these preventive opportunities.

Genetic services for men: the preferences of men with a family history of prostate cancer

PURPOSE

Men have a lower uptake of genetic services than women; however, the specific needs and preferences of men at risk of genetic conditions other than hereditary breast ovarian cancer are not known. We ascertain the information preferences of men with a family history of prostate cancer.

METHODS

Unaffected men and their partners were administered a written questionnaire.

RESULTS

Responses were received from 280 men (response rate: 59.2%) and 174 partners (response rate: 74%). Most men (59.6%) reported having insufficient information about their risk and wanted further information about personal risk (93.2%) and risk management (93.6%). Strikingly, 56.3% preferred to receive information related only to positive outcomes. Urologists were the preferred source of information, but there was considerable interest in a multidisciplinary service approach significantly associated with the number of affected relatives (odds ratio = 1.94, P < .002). Partners' level of concern was not associated with interest in multidisciplinary services, satisfaction with information, or support received.

CONCLUSIONS

Delivering services to men at risk will require a multifaceted approach by primary care providers and specialists. Challenges include meeting men's expectations in the face of uncertain medical knowledge, engaging those at high risk in multidisciplinary services, and delivering tailored information to those at lower risk.

UV, latitude, and spatial trends in prostate cancer mortality: all sunlight is not the same (United States)

OBJECTIVE

We showed previously that Caucasian mortality rates from prostate cancer for 1970-1979 are significantly inversely correlated with ultraviolet (UV) radiation. We now present the analysis of prostate cancer mortality data over a 45-year period (1950-1994) in order to examine the persistence of this pattern. Furthermore, because vitamin D synthesis does not occur during winter months at latitudes higher than 40 degrees N, we examined this relationship above and below 40 degrees N latitude.

METHODS

We used trend surface and linear regression analyses to characterize the relationship between prostate cancer mortality and UV radiation for U.S. counties at northern and southern latitudes.

RESULTS

For U.S. Caucasians, prostate cancer mortality rates at the county and SEA levels followed a significant north-south spatial trend that is the inverse of UV radiation. We found significant inverse correlations between UV radiation and prostate cancer mortality at all time points over this 45-year period. These correlations were significantly more pronounced at locations north of 40 degrees N latitude.

CONCLUSIONS

Our analyses confirm and extend our findings that the geographic distribution of prostate cancer mortality is the inverse of that of UV radiation. This effect is strongest in counties north of 40 degrees N latitude, where vitamin D synthesis is limited to non-winter months. These findings add additional support for the hypothesis that vitamin D insufficiency increases risk for prostate cancer.

Germ-line genetic variation in the key androgen-regulating genes androgen receptor, cytochrome P450, and steroid-5-alpha-reductase type 2 is important for prostate cancer development

Prostate cancer risk may be influenced by single genetic variants in the hormone-regulating genes androgen receptor (AR), cytochrome P450 (CYP17), and steroid-5-alpha-reductase type 2 (SRD5A2). In this study, we comprehensively investigated polymorphisms in these three loci and their joint effect in a large population-based study. We selected 23 haplotype-tagging single-nucleotide polymorphisms (htSNP) that could uniquely describe >95% of the haplotypes (6 in AR, 6 in CYP17, and 11 in SRD5A2). These htSNPs were then genotyped in the Cancer Prostate in Sweden population (2,826 case subjects and 1,705 controls). We observed significant association for several SNPs in the AR gene (P = 0.004-0.02) and CYP17 (P = 0.009-0.05) and one SNP in SRD5A2 (P = 0.02). Carriers of the most common AR haplotype had a significant excess risk to develop prostate cancer [odds ratio (OR), 1.25; 95% confidence interval (95% CI), 1.1-1.5; P = 0.002], yielding an estimated population attributable risk of 16% (95% CI, 0.06-0.25). Combining risk alleles from these genes yielded a 12% risk increase for each additional high-risk allele carried (95% CI, 1.1-1.2; P for trend = 9.2 x 10(-5)), with an overall OR of 1.87 (95% CI, 1.0-3.4) for carriers of all five included risk alleles, an OR of 2.13 (P for trend = 8 x 10(-4)) for advanced disease, and an OR of 4.35 (P for trend = 7 x 10(-5)) for disease onset before age 65 years. Genetic variation in key genes in the androgen pathway is important for development of prostate cancer and may account for a considerable proportion of all prostate cancers. Carriers of five high-risk alleles in the AR, CYP17, and SRD5A2 genes are at approximately 2-fold excess risk to develop prostate cancer.

Systematic replication study of reported genetic associations in prostate cancer: Strong support for genetic variation in the androgen pathway

BACKGROUND

Association studies have become a common and popular method to identify genetic variants predisposing to complex diseases. Despite considerable efforts and initial promising findings, the field of prostate cancer genetics is characterized by inconclusive reports and no prostate cancer gene has yet been established.

METHODS

We performed a literature review and identified 79 different polymorphisms reported to influence prostate cancer risk. Of these, 46 were selected and tested for association in a large Swedish population-based case-control prostate cancer population.

RESULTS

We observed significant (P < 0.05) confirmation for six polymorphisms located in five different genes. Three of them coded for key enzymes in the androgen biosynthesis and response pathway; the CAG repeat in the androgen receptor (AR) gene (P = 0.03), one SNP in the CYP17 gene (P = 0.04), two SNPs in the SRD5A2 gene (P = 0.02 and 0.02, respectively), a deletion of the GSTT1 gene (P = 0.006), and one SNP in the MSR1 gene, IVS5-59C > A, (P = 0.009).

CONCLUSIONS

Notwithstanding the difficulties to replicate findings in genetic association studies, our results strongly support the importance of androgen pathway genes in prostate cancer etiology.

An observational study of cancers among female partners of UK-resident prostate cancer patients

Epidemiological studies suggest that environment plays an important role in the aetiology of cancer. Thus, if a cancer (e.g. prostate cancer (CaP)) arises in males, one could hypothesize that risk in co-habiting partners might be elevated. We conducted an observational-questionnaire study in NorthWest England evaluating the medical histories of CaP males and their female partners. Details regarding previous partners (>10y) were also sought. Self-filled questionnaires were obtained from 548 males, 81 of whom provided information on previous female partners (PFPs) and 448 current female partners (CFPs). Observed rates over a 30-y period (1971-2001) of common cancers (breast, colorectal or lung) in female partners and colorectal cancer in males were compared to the cumulative expected probability (estimated using crude incidence rates for England provided by the Office of National Statistics, UK) using a Chi-Square Goodness-of-Fit test. Colorectal cancers in males were similar to national estimates. Rates for breast, colorectal or lung cancer among CFPs and the total female cohort (CFPs plus PFPs) were also similar to estimates. However, observed rates for breast or lung cancers among PFPs were significantly (P< or =0.001) elevated. Our results suggest no evidence of elevated risk among female partners of CaP males.

Genetic variation in the COX-2 gene and the association with prostate cancer risk

COX-2 is a key enzyme in the conversion of arachidonic acid to prostaglandins. The prostaglandins produced by COX-2 are involved in inflammation and pain response in different tissues in the body. Accumulating evidence from epidemiologic studies, chemical carcinogen-induced rodent models and clinical trials indicate that COX-2 plays a role in human carcinogenesis and is overexpressed in prostate cancer tissue. We examined whether sequence variants in the COX-2 gene are associated with prostate cancer risk. We analyzed a large population-based case-control study, cancer prostate in Sweden (CAPS) consisting of 1,378 cases and 782 controls. We evaluated 16 single nucleotide polymorphisms (SNPs) spanning the entire COX-2 gene in 94 subjects of the control group. Five SNPs had a minor allele frequency of more than 5% in our study population and these were genotyped in all case patients and control subjects and gene-specific haplotypes were constructed. A statistically significant difference in allele frequency between cases and controls was observed for 2 of the SNPs (+3100 T/G and +8365 C/T), with an odds ratio of 0.78 (95% CI=0.64-0.96) and 0.65 (95% CI=0.45-0.94) respectively. In the haplotype analysis, 1 haplotype carrying the variant allele from both +3100 T/G and +8365 C/T, with a population frequency of 3%, was also significantly associated with decreased risk of prostate cancer (p=0.036, global simulated p-value=0.046). This study supports the hypothesis that inflammation is involved in prostate carcinogenesis and that sequence variation within the COX-2 gene influence the risk of prostate cancer.

Characterization of the TSU-PR1 cell line by chromosome painting and flow cytometry

TSU-PR1 was originally reported as a prostatic carcinoma cell line derived from a lymph node metastasis. Recently, however, this cell line was reported to be derived from T24 bladder carcinoma cells, and thus further definition of its origin is needed. Conventional cytogenetic study of TSU-PR1 showed aneuploidy, ranging from 65 to 86 chromosome with a modal number of 80, and with 10 marker chromosomes, thus conventional cytogenetics cannot be used to determine which chromosomes or regions of chromosomes are critical in cancer development and progression of this cell line. The present study was conducted to characterize genetic changes of the cell line using comparative genomic hybridization (CGH), fluorescence in situ hybridization (FISH), and flow cytometry. CGH results showed that green-to-red fluorescence ratios were within the range of 0.85-1.15, except for a few chromosomes, which reflected near tetraploidy in TSU-PR1. Flow cytometric analysis of TSU-PR1 revealed a DNA index of 3.46n, which is close to the 3.48n calculated from a modal number of 80. The copy numbers of chromosomes 4, 6, 7, 17, and 20 determined by the DNA index and the CGH analyses were 2.85 +/- 0.09, 3.22 +/- 0.77, 3.01 +/- 0.26, 4.05 +/- 0.44, and 4.99 +/- 0.48, respectively. These numbers are also in accordance with the chromosome copy numbers determined with FISH: 2.98 +/- 0.23, 2.91 +/- 0.44, 2.74 +/- 0.44, 3.93 +/- 0.38, and 5.05 +/- 0.78 for chromosomes 4, 6, 7, 17, and 20, respectively (P > 0.05).

Genomics of prostate cancer: Is there anything to „translate”?

This review provides an up-dated collection of data concerning the genetic and epigenetic changes during development, growth and progression of prostate cancer. Hereditary and susceptibility factors have a long list, similarly to the expression of single genes connected to various cell functions. It was a hope that covering a large set of genes, array technologies would clarify very rapidly the role of genetics in malignant diseases, offering targets for molecular diagnostics and therapy. The power of high-throughput techniques for the detection and global analysis of gene expression is unquestionable, interesting, astonishing as well as puzzling data have already been obtained. However, the standardization of the procedures is still missing and the reproducibility is rather low in many instances. Moreover, the different array methods can select different gene expression profiles, which makes the decision rather difficult. Another important question is, coming again from the array technologies, how far the genotype (the gene profiles or fingerprints) can reflect the actual phenotype in a highly complex and readily changing disease as cancer. Proteomics will provide a closer look to this seemingly unanswerable problem. We are at the beginning of the exploration of the behavior of cancer cells in order to apply a more effective therapy based on a more reliable set of diagnostic and prognostic informations.

Familial association of prostate cancer with other cancers in the Swedish Family-Cancer Database

BACKGROUND

Familial associations between cancer sites may implicate true familial clustering which is relevant for the identification of new cancer syndromes and for clinical counseling.

METHODS

We used the nation-wide Swedish Family-Cancer Database, containing 10,553 sons and 107,518 fathers with prostate cancer among a total of 170,000 cancer patients in the 0- to 70-year-old offspring generation and over 800,000 cancer patients in the parental generation. We calculated familial standardized incidence ratios (SIRs) and confidence intervals (CIs) for prostate cancers and other cancers in family members.

RESULTS

SIRs for prostate cancer were increased in sons when mothers were diagnosed with breast and ovarian cancers, and when siblings were diagnosed with Hodgkins disease (1.78, N = 18, 95% CI 1.05-2.82) and leukemia (1.39, 43, 1.01-1.88). Liver cancer and melanoma were also in excess in the high-risk families.

CONCLUSIONS

The present analysis, the largest yet carried out, found many novel associations implying familial links between prostate cancer and other sites.

A combined genomewide linkage scan of 1,233 families for prostate cancer-susceptibility genes conducted by the international consortium for prostate cancer genetics

Evidence of the existence of major prostate cancer (PC)-susceptibility genes has been provided by multiple segregation analyses. Although genomewide screens have been performed in over a dozen independent studies, few chromosomal regions have been consistently identified as regions of interest. One of the major difficulties is genetic heterogeneity, possibly due to multiple, incompletely penetrant PC-susceptibility genes. In this study, we explored two approaches to overcome this difficulty, in an analysis of a large number of families with PC in the International Consortium for Prostate Cancer Genetics (ICPCG). One approach was to combine linkage data from a total of 1,233 families to increase the statistical power for detecting linkage. Using parametric (dominant and recessive) and nonparametric analyses, we identified five regions with "suggestive" linkage (LOD score >1.86): 5q12, 8p21, 15q11, 17q21, and 22q12. The second approach was to focus on subsets of families that are more likely to segregate highly penetrant mutations, including families with large numbers of affected individuals or early age at diagnosis. Stronger evidence of linkage in several regions was identified, including a "significant" linkage at 22q12, with a LOD score of 3.57, and five suggestive linkages (1q25, 8q13, 13q14, 16p13, and 17q21) in 269 families with at least five affected members. In addition, four additional suggestive linkages (3p24, 5q35, 11q22, and Xq12) were found in 606 families with mean age at diagnosis of < or = 65 years. Although it is difficult to determine the true statistical significance of these findings, a conservative interpretation of these results would be that if major PC-susceptibility genes do exist, they are most likely located in the regions generating suggestive or significant linkage signals in this large study.