Studies of genetic factors in prostate cancer in a twin population

Current evidence on the relationships among five polymorphisms in the matrix metalloproteinases genes and prostate cancer risk

Matrix metalloproteinases (MMPs) had a variety of subtypes, which may be related to tumor invasion and angiogenesis, and the polymorphisms from MMPs have been also associated with the susceptibility to a variety of tumors, including prostate cancer (PCa). However, previous studies have not systematically analyzed the association between MMP and prostate cancer, so we conducted systematic data collection and analyzed to evaluate the relationship among polymorphisms in MMPs and PCa susceptibility. We searched PubMed, Web of Science, Embase and Google Scholar for all papers published up to Apr 3rd, 2023, and systematically analyzed the relationship among MMP1-1607 2G/1G, MMP2-1306 T/C, MMP2-735 T/C, MMP7-181 G/A, MMP9-1562 T/C and PCa susceptibility using multiple comparative models and subgroup analyses. We found that MMP2-1306 T/C polymorphism showed associations with PCa susceptibility, with the Ethnicity subgroup (Asian) being more pronounced. Similarly, MMP9-1562 T/C has also had associations with PCa susceptibility. Our current study found that the polymorphisms of, MMP2-1306 T/C, and MMP9-1562 T/C had strong associations with PCa risk.

Inflammation in Prostate Cancer: Exploring the Promising Role of Phenolic Compounds as an Innovative Therapeutic Approach

Prostate cancer (PCa) remains a significant global health concern, being a major cause of cancer morbidity and mortality worldwide. Furthermore, profound understanding of the disease is needed. Prostate inflammation caused by external or genetic factors is a central player in prostate carcinogenesis. However, the mechanisms underlying inflammation-driven PCa remain poorly understood. This review dissects the diagnosis methods for PCa and the pathophysiological mechanisms underlying the disease, clarifying the dynamic interplay between inflammation and leukocytes in promoting tumour development and spread. It provides updates on recent advances in elucidating and treating prostate carcinogenesis, and opens new insights for the use of bioactive compounds in PCa. Polyphenols, with their noteworthy antioxidant and anti-inflammatory properties, along with their synergistic potential when combined with conventional treatments, offer promising prospects for innovative therapeutic strategies. Evidence from the use of polyphenols and polyphenol-based nanoparticles in PCa revealed their positive effects in controlling tumour growth, proliferation, and metastasis. By consolidating the diverse features of PCa research, this review aims to contribute to increased understanding of the disease and stimulate further research into the role of polyphenols and polyphenol-based nanoparticles in its management.

Validation of prostate cancer risk variants rs10993994 and rs7098889 by CRISPR/Cas9 mediated genome editing

GWAS have identified numerous SNPs associated with prostate cancer risk. One such SNP is rs10993994. It is located in the β-microseminoprotein (MSMB) promoter region, mediates MSMB prostate secretion levels, and is linked to mRNA expression changes in both MSMB and the adjacent gene NCOA4. In addition, our previous work showed a second SNP, rs7098889, is in positive linkage disequilibrium with rs10993994 and associated with MSMB expression independent of rs10993994. Here, we generate a series of clones with single alleles removed by double guide RNA (gRNA) mediated CRISPR/Cas9 deletions, through which we demonstrate that each of these SNPs independently and greatly alters MSMB expression in an allele-specific manner. We further show that these SNPs have no substantial effect on the expression of NCOA4. These data demonstrate that a single SNP can have a large effect on gene expression and illustrate the importance of functional validation studies to deconvolute observed correlations. The method we have developed is generally applicable to test any SNP for which a relevant heterozygous cell line is available. AUTHOR SUMMARY: In pursuing the underlying biological mechanism of prostate cancer pathogenesis, scientists utilized the existence of common single nucleotide polymorphisms (SNPs) in the human genome as genetic markers to perform large scale genome wide association studies (GWAS) and have so far identified more than a hundred prostate cancer risk variants. Such variants provide an unbiased and systematic new venue to study the disease mechanism, and the next big challenge is to translate these genetic associations to the causal role of altered gene function in oncogenesis. The majority of these variants are waiting to be studied and lots of them may act in oncogenesis through gene expression regulation. To prove the concept, we took rs10993994 and its linked rs7098889 as an example and engineered single cell clones by allelic-specific CRISPR/Cas9 deletion to separate the effect of each allele. We observed that a single nucleotide difference would lead to surprisingly high level of MSMB gene expression change in a gene specific and cell-type specific manner. Our study strongly supports the notion that differential level of gene expression caused by risk variants and their associated genetic locus play a major role in oncogenesis and also highlights the importance of studying the function of MSMB encoded β-MSP in prostate cancer pathogenesis.

Abiraterone acetate and acute leukemia: a casual association?

We present the case of a 70-year-old patient affected by metastatic castration-resistant prostate cancer. He underwent radical prostatectomy in 2007 and subsequent adjuvant radiotherapy and hormonal therapy for 2 years. In 2011, he developed bilateral lung metastases, and therefore he received chemotherapy (eight cycles of docetaxel 75 mg/sqm every 3 weeks) with partial remission; rechallenge with the same drug was performed 7 months later due to recurrence of lung metastases. In August 2013, abiraterone acetate was started for progression of lung metastases. The patient received abiraterone for almost 5 years with stability of disease. During the 60th cycle of abiraterone, a diagnosis of acute myeloid leukemia was made.

Admixture Mapping Links RACGAP1 Regulation to Prostate Cancer in African Americans

BACKGROUND/AIM

Prostate cancer is the most common malignancy in US males. African American men have higher incidence and mortality rates than European Americans. Five single nucleotide polymorphisms are associated with PCa. We hypothesized haplotypes inferred from these SNPs are also associated with PCa.

PATIENTS AND METHODS

We genotyped SNPs in a case-control admixture mapping study. SNP haplotypes inferred for 157 PCa cases and 150 controls were used in the regression analysis.

RESULTS

We found an association between "GTCCC", "ATTCT", and "ACCCC" haplotypes and PCa after ancestry adjustment (OR=3.62, 95%CI=1.42-9.21, p=0.0070; OR=7.89, 95%CI=2.36-26.31, p=0.0008; OR=4.34, 95%CI=1.75-10.78, p=0.0016). The rs615382 variant disrupts the recombination signal binding protein with immunoglobulin kappa J binding site in Rac GTPase activating protein 1 (RACGAP1).

CONCLUSION

Disruption of notch 1 mediated-repression of RACGAP1 may contribute to PCa in African Americans.

Prostate cancer

Much progress has been made in research for prostate cancer in the past decade. There is now greater understanding for the genetic basis of familial prostate cancer with identification of rare but high-risk mutations (eg, BRCA2, HOXB13) and low-risk but common alleles (77 identified so far by genome-wide association studies) that could lead to targeted screening of patients at risk. This is especially important because screening for prostate cancer based on prostate-specific antigen remains controversial due to the high rate of overdiagnosis and unnecessary prostate biopsies, despite evidence that it reduces mortality. Classification of prostate cancer into distinct molecular subtypes, including mutually exclusive ETS-gene-fusion-positive and SPINK1-overexpressing, CHD1-loss cancers, could allow stratification of patients for different management strategies. Presently, men with localised disease can have very different prognoses and treatment options, ranging from observation alone through to radical surgery, with few good-quality randomised trials to inform on the best approach for an individual patient. The survival of patients with metastatic prostate cancer progressing on androgen-deprivation therapy (castration-resistant prostate cancer) has improved substantially. In addition to docetaxel, which has been used for more than a decade, in the past 4 years five new drugs have shown efficacy with improvements in overall survival leading to licensing for the treatment of metastatic castration-resistant prostate cancer. Because of this rapid change in the therapeutic landscape, no robust data exist to inform on the selection of patients for a specific treatment for castration-resistant prostate cancer or the best sequence of administration. Moreover, the high cost of the newer drugs limits their widespread use in several countries. Data from continuing clinical and translational research are urgently needed to improve, and, crucially, to personalise management.

Dysregulation of the homeobox transcription factor gene HOXB13: role in prostate cancer

Prostate cancer (PC) is the most common noncutaneous cancer in men, and epidemiological studies suggest that about 40% of PC risk is heritable. Linkage analyses in hereditary PC families have identified multiple putative loci. However, until recently, identification of specific risk alleles has proven elusive. Cooney et al used linkage mapping and segregation analysis to identify a putative risk locus on chromosome 17q21-22. In search of causative variant(s) in genes from the candidate region, a novel, potentially deleterious G84E substitution in homeobox transcription factor gene HOXB13 was observed in multiple hereditary PC families. In follow-up testing, the G84E allele was enriched in cases, especially those with an early diagnosis or positive family history of disease. This finding was replicated by others, confirming HOXB13 as a PC risk gene. The HOXB13 protein plays diverse biological roles in embryonic development and terminally differentiated tissue. In tumor cell lines, HOXB13 participates in a number of biological functions, including coactivation and localization of the androgen receptor and FOXA1. However, no consensus role has emerged and many questions remain. All HOXB13 variants with a proposed role in PC risk are predicted to damage the protein and lie in domains that are highly conserved across species. The G84E variant has the strongest epidemiological support and lies in a highly conserved MEIS protein-binding domain, which binds cofactors required for activation. On the basis of epidemiological and biological data, the G84E variant likely modulates the interaction between the HOXB13 protein and the androgen receptor, as well as affecting FOXA1-mediated transcriptional programming. However, further studies of the mutated protein are required to clarify the mechanisms by which this translates into PC risk.

Translating genetic risk factors for prostate cancer to the clinic: 2013 and beyond

Prostate cancer (PrCa) is the most commonly diagnosed cancer in the male UK population, with over 40,000 new cases per year. PrCa has a complex, polygenic predisposition, due to rare variants such as BRCA and common variants such as single nucleotide polymorphisms (SNPs). With the introduction of genome-wide association studies, 78 susceptibility loci (SNPs) associated with PrCa risk have been identified. Genetic profiling could risk-stratify a population, leading to the discovery of a higher proportion of clinically significant disease and a reduction in the morbidity related to age-based prostate-specific antigen screening. Based on the combined risk of the 78 SNPs identified so far, the top 1% of the risk distribution has a 4.7-times higher risk of developing PrCa compared with the average of the general population.

Admixture mapping of prostate cancer in African Americans participating in the North Carolina-Louisiana Prostate Cancer Project (PCaP)

BACKGROUND

Few genetic risk factors have been uncovered that contribute specifically to the racial disparity in prostate cancer (CaP) observed in African Americans (AA). With the advent of ancestry informative marker (AIM) single nucleotide polymorphism (SNP) panels and powerful genetic strategies such as mapping by admixture linkage disequilibrium (MALD) it is possible to discover genes that underlie ethnic variation in disease risk.

METHODS

One thousand one hundred thirty AA CaP cases enrolled in the North Carolina-Louisiana Prostate Cancer Project (PCaP) were genotyped using a 1,509 AIM SNP panel. MALD was performed using ADMIXMAP to test for linkage between CaP risk and ancestry estimates at each AIM SNP.

RESULTS

The largest increase of African ancestry was observed at marker rs12543473 (P = 0.0011), located on chromosome 8q24.21, and the greatest excess of European ancestry was observed at marker rs10768140 (P = 0.0004) at chromosome 11p13.

CONCLUSIONS

The study confirmed the 8q24 risk loci and identified a novel genomic region on 11p13 that is associated with CaP risk. These findings should be replicated in larger AA populations and combined with fine mapping data to further refine the novel 11p13 CaP risk loci.

Germline BRCA1 mutations increase prostate cancer risk

BACKGROUND

Prostate cancer (PrCa) is one of the most common cancers affecting men but its aetiology is poorly understood. Family history of PrCa, particularly at a young age, is a strong risk factor. There have been previous reports of increased PrCa risk in male BRCA1 mutation carriers in female breast cancer families, but there is a controversy as to whether this risk is substantiated. We sought to evaluate the role of germline BRCA1 mutations in PrCa predisposition by performing a candidate gene study in a large UK population sample set.

METHODS

We screened 913 cases aged 36–86 years for germline BRCA1 mutation, with the study enriched for cases with an early age of onset. We analysed the entire coding region of the BRCA1 gene using Sanger sequencing. Multiplex ligation-dependent probe amplification was also used to assess the frequency of large rearrangements in 460 cases.

RESULTS

We identified 4 deleterious mutations and 45 unclassified variants (UV). The frequency of deleterious BRCA1 mutation in this study is 0.45%; three of the mutation carriers were affected at age 65 years and one developed PrCa at 69 years. Using previously estimated population carrier frequencies, deleterious BRCA1 mutations confer a relative risk of PrCa of ~3.75-fold, (95% confidence interval 1.02–9.6) translating to a 8.6% cumulative risk by age 65.

CONCLUSION

This study shows evidence for an increased risk of PrCa in men who harbour germline mutations in BRCA1. This could have a significant impact on possible screening strategies and targeted treatments.

Genetic ancestry, self-reported race and ethnicity in African Americans and European Americans in the PCaP cohort

Background

Family history and African-American race are important risk factors for both prostate cancer (CaP) incidence and aggressiveness. When studying complex diseases such as CaP that have a heritable component, chances of finding true disease susceptibility alleles can be increased by accounting for genetic ancestry within the population investigated. Race, ethnicity and ancestry were studied in a geographically diverse cohort of men with newly diagnosed CaP.

Methods

Individual ancestry (IA) was estimated in the population-based North Carolina and Louisiana Prostate Cancer Project (PCaP), a cohort of 2,106 incident CaP cases (2063 with complete ethnicity information) comprising roughly equal numbers of research subjects reporting as Black/African American (AA) or European American/Caucasian/Caucasian American/White (EA) from North Carolina or Louisiana. Mean genome wide individual ancestry estimates of percent African, European and Asian were obtained and tested for differences by state and ethnicity (Cajun and/or Creole and Hispanic/Latino) using multivariate analysis of variance models. Principal components (PC) were compared to assess differences in genetic composition by self-reported race and ethnicity between and within states.

Results

Mean individual ancestries differed by state for self-reporting AA (p = 0.03) and EA (p = 0.001). This geographic difference attenuated for AAs who answered “no” to all ethnicity membership questions (non-ethnic research subjects; p = 0.78) but not EA research subjects, p = 0.002. Mean ancestry estimates of self-identified AA Louisiana research subjects for each ethnic group; Cajun only, Creole only and both Cajun and Creole differed significantly from self-identified non-ethnic AA Louisiana research subjects. These ethnicity differences were not seen in those who self-identified as EA.

Conclusions

Mean IA differed by race between states, elucidating a potential contributing factor to these differences in AA research participants: self-reported ethnicity. Accurately accounting for genetic admixture in this cohort is essential for future analyses of the genetic and environmental contributions to CaP.

Concordance of tumor differentiation among brothers with prostate cancer

BACKGROUND

Genetic factors seem to be of greater importance in prostate cancer than in other forms of cancer. Studies have suggested familial concordance in survival, but the extent to which that is due to tumor characteristics is not known.

OBJECTIVE

We hypothesized that a brother of an index case with prostate cancer is at particularly increased risk of prostate cancer with the same tumor differentiation as the index case.

DESIGN, SETTING AND PARTICIPANTS

We identified 21,930 brothers of index cases with prostate cancer in the Prostate Cancer Data Base Sweden and followed them up for incidence of prostate cancer.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The relative risk of Gleason score-specific prostate cancer in the cohort of brothers was estimated by using the standardized incidence ratio (SIR) stratified by Gleason score of the index case. We estimated 95% confidence intervals (CIs) assuming a Poisson distribution.

RESULTS AND LIMITATIONS

Among brothers of index cases with Gleason score 8-10 cancer, the SIR was 2.53 (95% CI, 1.97-3.21) for a Gleason score 2-6 cancer and 4.00 (95% CI, 2.63-5.82) for a Gleason score 8-10 cancer. SIR for Gleason score 2-6 cancer among brothers decreased with time since the date of the index cases' diagnoses, whereas the risk of Gleason 8-10 cancer increased over time for brothers of index cases with Gleason 8-10 cancer (p for trend = 0.009).

CONCLUSIONS

Brothers of men with high-grade prostate cancer are at particularly increased risk of high-grade prostate cancer. Likewise, there is a concordance of less malignant prostate cancers within families. These findings may have direct clinical relevance for counseling men with a family history of prostate cancer.

AMACR polymorphisms, dietary intake of red meat and dairy and prostate cancer risk

BACKGROUND

Alpha-methylacyl CoA racemase (AMACR) is an enzyme involved in fatty acids metabolism. One of AMACRs primary substrates, phytanic acid, is principally obtained from dietary red meat/dairy, which are associated with prostate cancer (PCa) risk. AMACR is also a tumor tissue biomarker over-expressed in PCa. In this study, we explored the potential relationship between AMACR polymorphisms, red meat/dairy intake, and PCa risk.

METHODS

Caucasian participants from two population-based PCa case-control studies were included. AMACR single nucleotide polymorphisms (SNPs) were selected to capture variation across the gene and regulatory regions. Red meat and dairy intake was determined from food frequency questionnaires. The odds ratio (OR) of PCa (overall and by disease aggressiveness) was estimated by logistic and polytomous regression. Potential interactions between genotypes and dietary exposures were evaluated.

RESULTS

Data from 1,309 cases and 1,267 controls were analyzed. Carriers of the variant T allele (rs2287939) had an OR of 0.81 (95% CI 0.68-0.97) for less aggressive PCa, but no alteration in risk for more aggressive PCa. Red meat consumption was positively associated with PCa risk, and the association was stronger for more aggressive disease (lowest vs. highest tertile OR=1.55, 95% CI 1.10-2.20). No effect modification of AMACR polymorphisms by either dietary red meat or dairy intake on PCa risk was observed.

CONCLUSIONS

PCa risk varied by level of red meat intake and by one AMACR SNP, but there was no evidence for gene-environment interaction. These findings suggest that the effects of AMACR polymorphisms and red meat and dairy on PCa risk are independent.

The evolving role of familial history for prostate cancer

BACKGROUND

family history of prostate cancer is a risk factor for prostate cancer occurrence. Differently from other neoplasms no major predisposing gene has been identified.

MATERIAL AND METHODS

this review article presents the controversial results of studies about the prognostic and predictive role of family history in prostate cancer, reports the discovered predisposing genes, and biologic and pathologic findings.

RESULTS

mortality from PC remains a significant health care problem, but no trial investigated if it changed in presence of positive family history. The largest family study yet published concluded that men with family history are diagnosed and die at earlier ages than men without it. However, it failed to stress the prognostic value of family history. Genome-wide association studies of prostate cancer have identified a number of genetic variants at different loci in different populations. Prostate neoplasms of patients with positive family history exhibit a different pattern of expression of genes related with estrogen and androgen metabolism within the tumor. High-penetrance and low-penetrance genes in diagnosis and prognosis of prostate cancer, difficulties to define a classification and to quantify relative risks of single genes, documented gene-environment interactions are discussed.

CONCLUSION

family history stands for both shared genetic and environmental factors and their interaction. The availability of prostate-specific antigen test could explain partly the high familial risk, among brothers or shortly after the diagnosis of prostate cancer. Polymorphisms in genes associated with prostate cancer probably represent the most part of familial prostate cancer burden. An increasing knowledge of disregulated cellular pathways of lethal prostate cancer could define which of all genetic alterations have a role in defining new preventive and therapeutic strategies.

Global prostate cancer incidence and the migration, settlement, and admixture history of the Northern Europeans

The most salient feature of prostate cancer is its striking ethnic disparity. High incidences of the disease are documented in two ethnic groups: descendents of the Northern Europeans and African Americans. Other groups, including native Africans, are much less susceptible to the disease. Given that many risk factors may contribute to carcinogenesis, an etiological cause for the ethnic disparity remains to be defined. By analyzing the global prostate cancer incidence data, we found that distribution of prostate cancer incidence coincides with the migration and settlement history of Northern Europeans. The incidences in other ethnic groups correlate to the settlement history and extent of admixture of the Europeans. This study suggests that prostate cancer has been spread by the transmission of a genetic susceptibility that resides in the Northern European genome.

Vitamin D and prostate cancer risk: a review of the epidemiological literature

Prostate cancer is the most commonly diagnosed cancer in the United States. Prostate cells contain vitamin D receptors as well as enzymes necessary for vitamin D metabolism. Vitamin D metabolites have an antiproliferative and a pro-differentiating effect on prostate cancer cell lines in vitro and in vivo. As a result, there has been an emerging interest in the potential role of vitamin D in the etiology of prostate cancer. This review summarizes all available epidemiological literature on the association between dietary vitamin D, circulating levels of vitamin D and sunlight exposure in relation to prostate cancer risk. To place these studies in context, we also provide some background information on vitamin D, such as its dietary sources, metabolism, optimal levels, hypovitaminosis and relationship with the prostate.

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.

Genetic variability in inflammation pathways and prostate cancer risk

Genetic susceptibility to prostate cancer has been consistently observed by a large number of studies. Recently, several pieces of evidence obtained from epidemiological and pathological studies support that chronic inflammation in prostate tissues may play a role in prostate cancer development. Multiple genes that play critical roles in inflammatory pathways have been associated with prostate cancer risk. In this article we review the key genetic findings of the associated genes. This includes 2 genes identified through family studies, ribonuclease L (RNASEL) and macrophage scavenger receptor 1 (MSR1), as well as a number of genes suggested by case-control studies, such as macrophage inhibitory cytokine-1 (MIC-1), interleukins (IL-8, IL-10), vascular endothelial growth factor (VEGF), intercellular adhesion molecule (ICAM), and Toll-like receptors (TLR-4, TLR-1-6-10 gene cluster). Overall, recent studies seem to suggest multiple genes work together to increase prostate risk, and this is consistent with the reality that inflammation is a very complex process. Thus, future studies are expected to place an emphasis on the study of gene-gene interactions. Advances in high throughput genotyping, data mining, and algorithm development are needed in order to produce interpretable results.

Prostate cancer: epidemiology and risk factors

After years of rapid increase, the incidence of prostate cancer has begun to decline in certain areas in the USA. Although these temporal trends are consistent with the impact of screening, it still remains to be shown that early detection programmes and screening will result in a reduced mortality rate from this disease. A positive family history of prostate cancer has been established as an important risk factor, and recent research supports and points to the existence of a subgroup of prostate cancer families with a hereditary form of the disease. Diet is another well-known risk factor. Recently, it has become evident that nutritional factors might both prevent the progression of prostate cancer or induce it.

Epidemiology of Prostate Cancer

Prostate cancer is one of the most important cancers in men. With a worldwide incidence of 25.3 per 100,000 it is the second most common cancer in men, with large differences between countries. Important clues on risk factors remain to be found. Age, genetic factors and environmental influences have been studied. Incidence has been increasing over the last few decades, largely due to early detection procedures. The mortality rate of 8.1 per 100,000 mainly affects men at older ages; increases in this rate over time and differences between countries are markedly smaller than for incidence. For the future, prostate cancer will remain an important and--through evolutions in incidence and demography--growing health problem.

Suggestive genetic linkage to chromosome 11p11.2-q12.2 in hereditary prostate cancer families with primary kidney cancer

BACKGROUND

The Seattle-based PROGRESS study was started in 1995 to ascertain hereditary prostate cancer (HPC) families for studies of genetic susceptibility. Subsequent studies by several research groups, including our own, suggest that HPC is a genetically heterogeneous disease. To be successful in mapping loci for such a complex disease, one must consider ways of grouping families into subsets that likely share the same genetic origin. Towards that end, we analyzed a genome-wide scan of HPC families with primary kidney cancer.

METHODS

An 8.1 cM genome-wide scan including 441 microsatellite markers was analyzed by both parametric and non-parametric linkage approaches in fifteen HPC families with the co-occurrence of kidney cancer.

RESULTS

There was no evidence for significant linkage in the initial findings. However, two regions of suggestive linkage were observed at 11q12 and 4q21, with HLOD scores of 2.59 and 2.10, respectively. The primary result on chromosome 11 was strengthened after excluding two families with members who had rare transitional cell carcinoma (TCC). Specifically, we observed a non-parametric Kong and Cox P-value of 0.004 for marker D11S1290 at 11p11.2. The 8 cM region between 11p11.2 and 11q12.2 was refined by the addition of 16 new markers. The subset of HPC families with a median age of diagnosis >65 years demonstrated the strongest evidence for linkage, with an HLOD = 2.50. The P-values associated with non-parametric analysis ranged from 0.004 to 0.05 across five contiguous markers.

CONCLUSIONS

Analysis of HPC families with members diagnosed with primary renal cell carcinoma demonstrates suggestive linkage to chromosome 11p11.2-q12.2.

Prostate cancer metastasis: role of the host microenvironment in promoting epithelial to mesenchymal transition and increased bone and adrenal gland metastasis

BACKGROUND

The ARCaP cell line was established from the ascites fluid of a patient with metastatic prostate cancer. This study characterized the host microenvironmental role in cancer progression, epithelial to mesenchymal transition (EMT), and bone and adrenal metastasis in parental ARCaP and its derived cell subclones.

METHODS

Cytogenetic profiles, growth, migration, invasion, cellular interaction, drug sensitivities, and gene expression of ARCaP cell subclones were compared. In vivo gene expression, behavior, and metastasis of ARCaP subclones were analyzed by serial intracardiac injections into SCID mice.

RESULTS

ARCaP(E) cells, with cobblestone morphology, underwent EMT through cellular interaction with host bone and adrenal gland. Lineage-derived ARCaP(M) cells, with spindle-shape fibroblastic morphology, exhibited decreased cell adhesion and increased metastasis to bone and adrenal gland. Cytogenetic analyses of parental and ARCaP subclones confirmed their clonality.

CONCLUSIONS

ARCaP uniquely models the molecular basis of prostate cancer bone and adrenal metastases and epithelial to mesenchymal transition.

Phorate exposure and incidence of cancer in the agricultural health study

BACKGROUND

We recently reported a link between use of the organophosphate pesticide phorate and risk of prostate cancer among applicators with a family history of prostate cancer in the Agricultural Health Study (AHS).

OBJECTIVE

This finding, together with findings of associations between other organophosphate pesticides and cancer more broadly, prompted us to examine phorate exposure and overall cancer incidence in the AHS. Adding 3 years of follow-up and using more detailed exposure information allowed us to see whether the prostate cancer finding held.

METHODS

The AHS is a prospective study of licensed restricted-use pesticide applicators from North Carolina and Iowa. To our knowledge, this is the largest examination of workers occupationally exposed to phorate. Pesticide exposure and other information was collected using two self-administered questionnaires completed from 1993 to 1997. Poisson regression was used to calculate rate ratios (RR) and 95% confidence intervals (CI), adjusting for potential confounders.

RESULTS

Phorate use was not related to the incidence of all cancers combined or to any individual cancer, although we had insufficient numbers to study non-Hodgkin lymphoma or leukemia, which have been linked to organophosphates in other studies. Although prostate cancer risk was not significantly related to phorate use overall or among those without a family history, the risk tended to increase among applicators with a family history of prostate cancer. The interaction RR was 1.53 (95% CI, 0.99-2.37).

CONCLUSION

The observed statistical interaction suggests a gene-environment interaction between family history and phorate exposure in the incidence of prostate cancer, but other explanations are also possible.

Meta-analysis of association of rare mutations and common sequence variants in the MSR1 gene and prostate cancer risk

BACKGROUND

MSR1 has been reported to be associated with increased risk of prostate cancer (PCa).

METHODS

We performed a meta-analysis of all eight published studies to evaluate the pooled effect of three rare mutations (R293X, S41T, and D174Y) and five common sequence variants (PRO3, INDEL1, IVS5-59, P275A, and INDEL7), stratified by race and sporadic/hereditary cancer.

RESULTS

Several variants were significantly or marginally significantly associated with sporadic, not hereditary PCa risk, including R293X in white men (random effect OR = 1.34, P = 0.09) and D174Y in black men (random effect OR = 2.41, P = 0.04). The associations were not significant when the initial study was excluded. However, the frequency of the D174Y mutation was consistently higher among cases in all three studies that examined black men.

CONCLUSIONS

Overall, this meta-analysis suggests the MSR1 gene does not independently confer a major risk to PCa but may confer a moderate risk to PCa, especially in black men.

The risk of cancer in twins: a report from the childhood cancer survivor study

BACKGROUND

Twin concordance studies help evaluate the contribution of genetic factors in childhood cancers, but previous reports have primarily focused on leukemia because of the rarity of other malignancies. In the current report, a large cohort of childhood cancer survivors was used to: (1) describe twin concordance patterns for a range of cancers, (2) calculate the standardized incidence rates of cancers in twins, and (3) describe clinical features and outcomes of concordant twins.

PROCEDURE

Cancer family history was obtained on the 211 twins participating in the Childhood Cancer Survivor Study (CCSS) (14,352 participants surviving > or =5 years after a malignancy diagnosed at <21 years during January 1, 1970-December 31, 1986) to calculate probandwise twin concordance rates and standardized incidence ratios (SIRs) using Surveillance, Epidemiology, and End-Results data.

RESULTS

Seven monozygotic twin pairs were concordant for cancer (six for leukemia, one for non-Hodgkin lymphoma), yielding probandwise concordance rates of 9.5%, 20.7%, and 20.0% for all cancer, leukemia, and non-Hodgkin lymphoma (NHL), respectively. No concordance was observed among dizygotic twins or for dissimilar cancers. The SIR in monozygotic twins was 23.3 (95% CI = 11.1-48.9) for all cancer, 112.4 (95% CI = 50.5-250.1) for leukemia, and 40.5 (5.7-287.5) for NHL. Concordant twins were similar in age at diagnosis and vital status.

CONCLUSIONS

Twin concordance for cancer is largely restricted to monozygotic twins and hematological malignancies, consistent with in utero malignancy transmission demonstrated by others. Our data support clinical monitoring of the twins of cases with hematological malignancies, and does not contribute evidence for genetic factors in other cancers.

Association of susceptibility alleles in ELAC2/HPC2, RNASEL/HPC1, and MSR1 with prostate cancer severity in European American and African American men

Reported associations of ELAC2/HPC2, RNASEL/HPC1, and MSR1 with prostate cancer have been inconsistent and understudied in African Americans. We evaluated the role of 16 sequence variants in these genes with prostate cancer using 888 European American and 131 African American cases, and 473 European American and 163 African American, controls. We observed significant differences in ELAC2, RNASEL, and MSR1 allele frequencies by race. However, we did not observe significant associations between prostate cancer and any variants examined for both races combined. Associations were observed when stratified by race, family history, or disease severity. European American men homozygous for MSR1 IVS7delTTA had an elevated risk for localized stage [odds ratio, (OR), 3.5; 95% confidence interval (95% CI), 1.4-6.9], low-grade (OR, 3.2; 95% CI, 1.4-7.3) disease overall, and with low-grade (OR, 2.9; 95% CI, 1.2-7.2) or late-stage disease (OR, 5.2; 95% CI, 1.1-25.7) in family history-negative African Americans. MSR1 Arg293X was associated with family history-negative high-grade disease (OR, 4.0; 95% CI, 1.1-14.1) in European Americans. RNASEL Arg462Gln was associated with low-grade (OR, 1.5; 95% CI, 1.04-2.2) and early-stage (OR, 1.5; 95% CI, 1.02-2.1) disease in family history-negative European Americans. In family history-positive individuals, Arg462Gln was inversely associated with low-grade (OR, 0.43; 95% CI, 0.21-0.88) and low-stage (OR, 0.46; 95% CI, 0.22-0.95) disease. In African Americans, Arg462Gln was associated with positive family history high-stage disease (OR, 14.8; 95% CI, 1.6-135.7). Meta-analyses revealed significant associations of prostate cancer with MSR1 IVS7delTTA, -14,742 A>G, and Arg293X in European Americans; Asp174Tyr in African Americans; RNASEL Arg462Gln in European American's overall and in family history-negative disease; and Glu265X in family history-positive European Americans. Therefore, MSR1 and RNASEL may play a role in prostate cancer progression and severity.

Association of CYP17, GSTP1, and PON1 polymorphisms with the risk of prostate cancer

BACKGROUND

Dietary factors, life-style as well as environmental conditions may contribute to the risk of prostate tumor together with genetic susceptibility, that may be an important factor in determining who is more likely to develop prostate malignancy. We have undertaken a case-control study in order to elucidate the association between polymorphisms in some metabolizing genes with the risk of prostate cancer (PCa).

METHODS

Polymorphisms of three xenobiotic genes (CYP17, GSTP1, PON1) were characterized in 384 patients with untreated PCa and 360 age-matched control patients with benign prostatic hyperplasia (BPH). All polymorphisms were investigated by PCR/RFLP methods using DNA from lymphocytes.

RESULTS

We found that men with the CYP17/A1A1-A1A2 genotypes, GSTP1/IleVal genotype, PON192/QR and PON55/LM-MM genotypes had a significantly higher risk of PCa compared with the others genotypes.

CONCLUSIONS

The three polymorphisms appear to be common genetic traits that are associated with an increased risk for PCa: the analysis of them all in each single case may be a predictable factor, particularly among groups exposed to PCa-related carcinogens.

Finding prostate cancer susceptibility genes

Prostate cancer is a heterogeneous disease with multiple loci contributing to susceptibility. Traditionally, genome-wide scans using high-risk families have utilized stratification by number of affected individuals, family history of other cancers, or family age at diagnosis to improve genetic homogeneity. In addition to locus heterogeneity, for later onset diseases such as prostate cancer, a major limitation to mapping efforts is that key parental DNA samples are rarely available. The lack of available samples from upper generations reduces inheritance information, and as a result, the standard 10-cM genome scan does not provide full power to detect linkage. To increase the ability to find disease-associated loci, much denser genome-wide scans must be undertaken in multiple ethnic groups. In addition, new ways of defining homogenous subsets of families need to be developed.

Prostate carcinogenesis and inflammation: emerging insights

Prostate cancer remains a significant health concern for men throughout the world. Recently, there has developed an expanding multidisciplinary body of literature suggesting a link between chronic inflammation and prostate cancer. In support of this hypothesis, population studies have found an increased relative risk of prostate cancer in men with a prior history of certain sexually transmitted infections or prostatitis. Furthermore, genetic epidemiological data have implicated germline variants of several genes associated with the immunological aspects of inflammation in modulating prostate cancer risk. The molecular pathogenesis of prostate cancer has been characterized by somatic alterations of genes involved in defenses against inflammatory damage and in tissue recovery. A novel putative prostate cancer precursor lesion, proliferative inflammatory atrophy, which shares some molecular traits with prostate intraepithelial neoplasia and prostate cancer, has been characterized. Here, we review the evidence associating chronic inflammation and prostate cancer and consider a number of animal models of prostate inflammation that should allow the elucidation of the mechanisms by which prostatic inflammation could lead to the initiation and progression of prostate cancer. These emerging insights into chronic inflammation in the etiology of prostate carcinogenesis hold the promise of spawning new diagnostic and therapeutic modalities for men with prostate cancer.

Cancer de la prostate. Épidémiologie. Facteurs de risques. Anatomopathologie

Prostate cancer (prostate adenocarcinoma) has become an important concern in terms of public health these past fifteen years; recent French epidemiological data revealed 10,104 deaths due to this disease in 2000. The two main factors involved are the serum prostatic specific antigen (PSA), routinely used since late 1980's and which allows early diagnosis (before symptom onset), and the lengthened duration of life. Such cancer is rare before the age of 50, but its frequency increases with age, making it the most frequent type of cancer in French men. Although the aetiology of this disease is unknown, the ethnic origin, and a familial history of prostate or breast cancer are known risk factors. Predisposing genes to such hereditary types remain to be identified. Other genetic factors (polymorphisms), combined with environmental factors such as nutrition, have been incriminated, which is likely to explain the geographical variations of this affection. At the molecular level, the mechanisms involved in the tumoral initiation and progression remain unclear. Various genetic alterations have been identified among the genome of cancerous cells, at various stages of the affection: intraepithelial neoplasia, localized, locally advanced, metastatic or hormone refractory stage -, hormonal escape). However, the precise sequence and nature of the complex molecular events remain to be determined prior to their routine utilisation in the determination of subjects at risk, or as prognostic factors, and even as therapeutic targets. The anatomopathology is a key for the diagnosis. Intraepithelial neoplasia is the pre-cancerous lesion observed in most adenocarcinomas; these are localized in the peripheral part of the prostate gland in 70% of the cases. Gleason's classification is the current gold standard for the determination of tumoral aggressiveness and categorisation of the adenocarcinomas which are basically heterogeneous (coexistence of tumors cells with different degrees of differenciation in the same tumor). This anatomopathological classification allows distinguishing the tumours in terms of potential progressiveness and prognosis, and hence, to orientate the therapeutic strategy in case of localised or locally advanced prostate cancer.

Unravelling the genetics of prostate cancer

This review describes what is currently known about the genetics of prostate cancer. Traditionally, the genetics of a suspected inherited cancer predisposition have generally been thought of in terms of a single, high-risk gene with a dominant mode of inheritance. Such a gene might be observed in families, as has been documented in familial breast cancer (BRCA1/2), familial colorectal cancer (HNPCC), retinoblastoma (RB1), and Wilms tumor (WT1). This review investigates the evidence for the existence, first of familial prostate cancer, and second, for the presence of such a high-risk gene in those families by epidemiological and experimental approaches. Another current area of interest in prostate cancer is the investigation of the contribution of common lower penetrance genes to the disease. This alternative approach has become popular, as it raises the issue of frequently seen genetic variations such as single nucleotide polymorphisms (SNPs) having relevance to the risk of developing the disease. Finally, this article will explore the way forward, with emphasis on worldwide collaboration from teams attempting to find the genes responsible for the disease and investment in new technologies that will aid in their discovery.

Facteurs de risque génétiques pour le cancer de la prostate

Prostate cancer is the most frequent malignant tumor among men over 50 years old. Its incidence varies according to countries and ethnic group. Known risk factors are race and positive family history of the disease. Familial aggregation (at least 2 cases in the family) is observed in about 20% of cases and an hereditary form of prostate cancer in 5%. This proportion increases with younger age at diagnosis. Six putative loci are already identified but undoubtedly, others will be found in forthcoming studies. The genetic heterogeneity observed in hereditary prostate cancer reflects variety of origins of the studied families. In some families, aggregation of prostate cancer and other cancers suggests the involvement of common predisposing genes. In other familial and in sporadic cases, the genetic component should be polygenic: prostate cancer wouldn't result to segregation of a major gene mutations transmitted according to a monogenic inheritance, but rather to sharing of alleles at many loci, each contributing to a small increase in cancer risk. Indeed, several genetic polymorphism were associated with an increased risk of developing prostate cancer and could explain the variations of prostate cancer incidence observed between populations.

Human prostate cancer risk factors

Prostate cancer has the highest prevalence of any nonskin cancer in the human body, with similar likelihood of neoplastic foci found within the prostates of men around the world regardless of diet, occupation, lifestyle, or other factors. Essentially all men with circulating androgens will develop microscopic prostate cancer if they live long enough. This review is a contemporary and comprehensive, literature-based analysis of the putative risk factors for human prostate cancer, and the results were presented at a multidisciplinary consensus conference held in Crystal City, Virginia, in the fall of 2002. The objectives were to evaluate known environmental factors and mechanisms of prostatic carcinogenesis and to identify existing data gaps and future research needs. The review is divided into four sections, including 1) epidemiology (endogenous factors [family history, hormones, race, aging and oxidative stress] and exogenous factors [diet, environmental agents, occupation and other factors, including lifestyle factors]); 2) animal and cell culture models for prediction of human risk (rodent models, transgenic models, mouse reconstitution models, severe combined immunodeficiency syndrome mouse models, canine models, xenograft models, and cell culture models); 3) biomarkers in prostate cancer, most of which have been tested only as predictive factors for patient outcome after treatment rather than as risk factors; and 4) genotoxic and nongenotoxic mechanisms of carcinogenesis. The authors conclude that most of the data regarding risk relies, of necessity, on epidemiologic studies, but animal and cell culture models offer promise in confirming some important findings. The current understanding of biomarkers of disease and risk factors is limited. An understanding of the risk factors for prostate cancer has practical importance for public health research and policy, genetic and nutritional education and chemoprevention, and prevention strategies.

Genetic susceptibility to prostate cancer: a review

A genetic component in prostate cancer has been recognized since decades. Through numerous epidemiological and molecular biological studies, much evidence has accumulated in favor of a significant but heterogeneous hereditary component in prostate cancer (PCa) susceptibility. Since the mapping of a high-penetrant PCa susceptibility locus at 1q24-25, much attention has been paid to the identification of PCa susceptibility genes. So far, seven loci have been mapped, and at three of these loci, genes have been cloned and mutations identified. Yet their role in hereditary and sporadic disease is still under debate and probably very modest. Although research on hereditary prostate cancer has improved our knowledge of the genetic etiology of the disease, still a lot of questions remain unanswered. Here, we aim to review the genetic epidemiological and molecular biological research in the field of hereditary prostate cancer and the problems that are encountered with this research.

Genomic scan of 254 hereditary prostate cancer families

Hereditary prostate cancer (HPC) is a genetically heterogeneous disease, complicating efforts to map and clone susceptibility loci. We have used stratification of a large dataset of 254 HPC families in an effort to improve power to detect HPC loci and to understand what types of family features may improve locus identification. The strongest result is that of a dominant locus at 6p22.3 (heterogeneity LOD (HLOD) = 2.51), the evidence for which is increased by consideration of the age of PC onset (HLOD = 3.43 in 214 families with median age-of-onset 56-72 years) and co-occurrence of primary brain cancer (HLOD = 2.34 in 21 families) in the families. Additional regions for which we observe modest evidence for linkage include chromosome 7q and 17p. Only weak evidence of several previously implicated HPC regions is detected. These analyses support the existence of multiple HPC loci, whose presence may be best identified by analyses of large, including pooled, datasets which consider locus heterogeneity.

Family history of prostate cancer and relapse after definitive external beam radiation therapy

PURPOSE

The influence of family history on outcome after definitive therapy for prostate cancer has been disputed. One series reported increased relapse rates in men with a positive family history of prostate cancer treated with radical prostatectomy or radiation therapy, whereas others have reported no difference in outcome. We examined our series of patients treated with definitive external beam radiation therapy to determine if a positive family history for prostate cancer is associated with better or worse outcome.

METHODS AND MATERIALS

Family history information was available for 538 patients treated with radiation therapy for prostate cancer between 1983 and 2001. Prostate cancer in one or more first-degree relatives (father, brother, or son) was considered a positive family history. The endpoint of interest was time to prostate-specific antigen failure or initiation of hormonal therapy after radiation therapy.

RESULTS

Ninety-seven of 538 patients (18%) had a positive family history. There were no significant differences between the positive and negative family history groups. Family history had no effect on relapse-free survival rates in the entire cohort (p = 0.94) or in any subgroup. African American patients with a positive family history had significantly worse 5-year relapse-free survival rates, although there were few patients in this subgroup. Neither family history nor race was a statistically significant predictor of relapse in multivariate analysis; however, combined African American race and positive family history was associated with worse relapse-free survival rates.

CONCLUSIONS

In this large study of patients receiving definitive radiation therapy for localized prostate cancer, no relationship was found between positive first-degree family history of prostate cancer and relapse. The influence of family history on clinical outcome may be more understandable once the gene or genes responsible for hereditary prostate cancer are identified.

Population Screening for Prostate Cancer and Emerging Concepts for Young Men

Prostate cancer is the most common malignancy in American men, accounting for > 29% of all diagnosed cancers and approximately 13% of all cancer deaths. Nearly 1 of every 6 men will be diagnosed with the disease at some time in their lives. In 2003 alone, an estimated 221000 men in the United States will be diagnosed with prostate cancer and > 28000 will die of the disease. An elevated level of prostate-specific antigen (PSA) is correlated with the presence of prostate cancer, and since 1989 we have been living in the "PSA era," in which the PSA screening test is widely used in clinical practice. This article summarizes what has been learned about the use of PSA screening, including the intricacies of free PSA, PSA doubling time, and various factors that may affect PSA and confound screening in young men. Although population-based screening for prostate cancer has yet to be definitively proven to affect disease-specific mortality, PSA testing is detecting cancers in younger men and at earlier stages of disease progression and, partly as a result, 5-year cancer-specific survival is increasing. Even though this lead-time effect may not translate into long-term improvement, these changes are very promising and are a necessary prerequisite to effective screening. For patients at high risk with a family history of the disease and for black men, a strategy consisting of an annual PSA blood test and digital rectal examination for men >or=40 years of age appears to be prudent. Use of age- and race-specific reference ranges for PSA based on sensitivity, or maximal cancer detection, is the most appropriate approach in this high-risk group. Specifically among black men 40-49 years of age, those with a PSA value > 2.0 ng/mL should consider further evaluation. Many men at low/average risk aged 40-49 years also request testing and it is reasonable to offer testing and risk assessment to these young men. The exact screening threshold for total PSA in these men is unknown, but 95% of these men will have a PSA < 2.5 ng/mL. Prostate-specific antigen velocity, percentage of free PSA, and perhaps complexed PSA may be used to help determine risk, but further study of young men is needed. In the future, a risk-stratified approach using molecular biomarkers and/or proteomics in young men is anticipated.

Oligogenic segregation analysis of hereditary prostate cancer pedigrees: evidence for multiple loci affecting age at onset

Previous studies have suggested strong evidence for a hereditary component to prostate cancer (PC) susceptibility. Here, we analyze 3,796 individuals in 263 PC families recruited as part of the ongoing Prostate Cancer Genetic Research Study (PROGRESS). We use Markov chain Monte Carlo (MCMC) oligogenic segregation analysis to estimate the number of quantitative trait loci (QTLs) and their contribution to the variance in age at onset of hereditary PC (HPC). We estimate 2 covariate effects: diagnosis of PC before and after prostate-specific antigen (PSA) test availability, and presence/absence of at least 1 blood relative with primary neuroepithelial brain cancer (BC). We find evidence that 2 to 3 QTLs contribute to the variance in age at onset of HPC. The 2 QTLs with the largest contribution to the total variance are both effectively dominant loci. We find that the covariate for diagnosis before and after PSA test availability is important. Our findings for the number of QTLs contributing to HPC and the variance contribution of these QTLs will be instructive in mapping and identifying these genes.

Linkage analysis of prostate cancer susceptibility: confirmation of linkage at 8p22-23

Frequent loss of heterogeneity in prostate cancer cells and linkage studies of families affected by hereditary prostate cancer (HPC) have implied that the short arm of chromosome 8, specifically 8p22-23, may harbor a prostate-cancer-susceptibility gene. In a recent study, seven potentially important mutations in the macrophage scavenger receptor 1 gene (MSR1), located at 8p22, were observed in families affected with HPC, and an indication of co-segregation between these mutations and prostate cancer was reported. In an attempt to confirm linkage at 8p22-23, we performed linkage analyses in 57 families affected with HPC (ascertained throughout Sweden) by using 13 markers on the short arm of chromosome 8. In the complete set of families, evidence for prostate cancer linkage was observed at 8p22-23, with a peak hold of 1.08 (P=0.03), observed at D8S1731, approximately 1 cM centromeric to the MSR1 gene. At marker D8S1135, the closest marker to MSR1, a hlod of 1.07 (P=0.03) was observed. Evidence of linkage was seen in families with early-onset HPC and in families with a small number of affected individuals. The peak multipoint non-parametric linkage score was 2.01 (P=0.03) at D8S552 in the 14 pedigrees with mean age at onset <65 years, and 2.25 (P=0.01) at D8S1731 in the 36 pedigrees with fewer than five affected family members. Thus, we have confirmed evidence for prostate cancer linkage at 8p22-23. Follow-up studies to evaluate the possible association between prostate cancer and genes in this region, especially the MSR1 gene, are warranted.

Prostate cancer epidemiology

Because more and more men are being diagnosed with prostate cancer worldwide, knowledge about and prevention of this disease is important. Epidemiological studies have provided some insight about the cause of prostate cancer in terms of diet and genetic factors. However, compared with other common cancers such as breast and lung cancer, the causes remain poorly understood. Several important issues could help in our understanding of this disease-the variation in incidence of prostate cancer between ethnic populations and the factors leading to familial clustering of the diseases.