Germline BRCA1 185delAG mutations in Jewish women with breast cancer

Disparities in Breast Cancer Outcomes and How to Resolve Them

There has been a 40% decline in breast cancer age-adjusted death rate since 1990. Black American women have not experienced as great a decline; indeed, the Black-White disparity in mortality in the United States is greater today than it has ever been. Certain states (areas of residence), however, do not see such dramatic differences in outcome by race. This latter finding suggests much more can be done to reduce disparities and prevent deaths. Interventions to get high-quality care (screening, diagnostics, and treatment) involve understanding the needs and concerns of the patient and addressing those needs and concerns. Patient navigators are 1 way to improve outcomes.

Prevalence of Germline BRCA1/2 Variants in Ashkenazi and Non-Ashkenazi Prostate Cancer Populations: A Systematic Review and Meta-Analysis

BACKGROUND AND AIMS

International guidelines recommend testing BRCA2 in men with prostate cancer, due to the presence of a strong association with this gene. Some ethnicities present disparities in genetic distribution for the relation with specific founder variants. Ashkenazi Jewish people are, importantly, at high risk of breast cancer for their inherited cluster with germline BRCA1/2 variants. However, in Ashkenazi men with prostate cancer, the prevalence of BRCA1 and/or BRCA2 is not well defined. We assessed the frequency of these variants in Ashkenazi vs. non-Ashkenazi men with prostate cancer. Materials and Methods: In accord with the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) statement, we revised all germline BRCA variants reported in MEDLINE from 1996 to 2021 in Ashkenazi and non-Ashkenazi men with prostate cancer. Results: Thirty-five original studies were selected for the analysis. Among populations from Israel and North America, Ashkenazi Jewish men presented higher prevalence of BRCA1 variants [0.9% (0.4-1.5) vs. 0.5% (0.2-1.1), p = 0.09] and a lower prevalence of BRCA2 variants [1.5% (1.1-2.0) vs. 3.5% (1.7-5.9), p = 0.08] in comparison to the non-Ashkenazi population. Conclusions: Since germline BRCA1 variants are more prevalent and BRCA2 variants are less prevalent in PCa patients of Ashkenazi Jewish ethnicity in comparison to non-Ashkenazi patients, prostate cancer genetic screening in Ashkenazi men should not be restricted to the BRCA2 gene.

Orthodox Jewish Thought Leaders' Insights Regarding BRCA Mutations: A Descriptive Study

PURPOSE

To examine the factors that influence Orthodox Jewish (OJ) thought leaders' perceptions of genetic counseling and testing for BRCA mutations. The specific aims of this study were to describe (1) OJ thought leaders' views on genetic counseling and testing for BRCA mutation status and (2) insights into this high-risk faith-based minority group and their beliefs about counseling and testing for BRCA mutations.

METHODS

In-depth focus groups and demographic questionnaires were used in this descriptive, qualitative study, which was performed in the cancer center of a 750-bed community teaching hospital in Brooklyn, New York. Participants included 17 OJ thought leaders in a large metropolitan area in the northeastern United States.

RESULTS

Four themes emerged that describe the key components of the views of OJ thought leaders regarding genetic counseling and testing for BRCA mutation carriers. There was a high level of concern about cancer, recognition that community norms shift, acknowledgment of the role of the rabbi in medical decision making, and concern about the balance between determinism and personal responsibility in utilizing this health care service.

CONCLUSION

The identification of social contributors to the utilization of genetic counseling and testing, as well as identification of solutions to optimize utilization of BRCA testing, supports the philosophic premise or conceptual model that faith-based leaders are crucial to the promotion of culturally sensitive health care delivery. Incorporating faith-based leaders early in health care strategic planning and implementation can translate into communities better utilizing health-related services.

Chemopreventive Effects of ROS Targeting in a Murine Model of BRCA1-Deficient Breast Cancer

There remains great interest in practical strategies to limit the elevated risks of familial breast and ovarian cancers driven by BRCA1 mutation. Here, we report that limiting the production of reactive oxygen species (ROS) is sufficient to reduce DNA lesions and delay tumorigenesis in a murine model of BRCA1-deficient breast cancer. We documented a large amount of endogenous estrogen oxidative metabolites in the mammary gland of the model, which induced DNA adducts and apurinic/apyrimidinic sites associated with DNA double-strand breaks and genomic instability. Repressing estrogen oxidation via antioxidant treatments reduced oxidative DNA lesions and delayed the onset of mammary tumors. Overall our work suggests an answer to the long-standing question of why germline BRCA1 mutations cause tissue-specific tumors, in showing how tissue-specific, ROS-induced DNA lesions create a nongenetic force to promote mammary tumors in BRCA1-deficient mice. Our findings create a rationale for evaluating suitable antioxidant modalities as a chemopreventive strategy for familial breast cancer. Cancer Res; 77(2); 448-58. ©2016 AACR.

Genomic Biomarkers for Breast Cancer Risk

Clinical risk assessment for cancer predisposition includes a three-generation pedigree and physical examination to identify inherited syndromes. Additionally genetic and genomic biomarkers may identify individuals with a constitutional basis for their disease that may not be evident clinically. Genomic biomarker testing may detect molecular variations in single genes, panels of genes, or entire genomes. The strength of evidence for the association of a genomic biomarker with disease risk may be weak or strong. The factors contributing to clinical validity and utility of genomic biomarkers include functional laboratory analyses and genetic epidemiologic evidence. Genomic biomarkers may be further classified as low, moderate or highly penetrant based on the likelihood of disease. Genomic biomarkers for breast cancer are comprised of rare highly penetrant mutations of genes such as BRCA1 or BRCA2, moderately penetrant mutations of genes such as CHEK2, as well as more common genomic variants, including single nucleotide polymorphisms, associated with modest effect sizes. When applied in the context of appropriate counseling and interpretation, identification of genomic biomarkers of inherited risk for breast cancer may decrease morbidity and mortality, allow for definitive prevention through assisted reproduction, and serve as a guide to targeted therapy .

Subjective and Objective Risks of Carrying a BRCA1/2 Mutation in Individuals of Ashkenazi Jewish Descent

This repeated measures study examines (1) the change in subjective risk of mutations pre- to postcounseling, (2) the accuracy of BRCAPRO estimates of mutations, and (3) the discrepancy between subjective risk and BRCAPRO estimates of mutations before and after genetic counseling. Ninety-nine Ashkenazi Jewish individuals pursued testing for BRCA1/2 mutations. Most had a personal cancer history (N = 51; family only: N = 48); and received uninformative negative results (N = 66; positives: N = 23; informative negative: N = 10). The coping strategy of defensive pessimism predicts that individuals will believe the worst case scenario to better cope with a potential negative outcome. Consistent with this, most felt they would have a mutation, if not mutations in both genes. The BRCAPRO model appeared to overestimate risk of having a mutation in this sample (p < .001). BRCAPRO overestimates notwithstanding, genetic counseling increased accuracy of subjective risk (p < .01). Individuals with a family-only cancer history had the least accurate estimates of risk (p < .05) and may need further intervention to either manage anxiety or improve knowledge.

A practice guideline from the American College of Medical Genetics and Genomics and the National Society of Genetic Counselors: referral indications for cancer predisposition assessment

DISCLAIMER

The practice guidelines of the American College of Medical Genetics and Genomics (ACMG) and the National Society of Genetic Counselors (NSGC) are developed by members of the ACMG and NSGC to assist medical geneticists, genetic counselors, and other health-care providers in making decisions about appropriate management of genetic concerns, including access to and/or delivery of services. Each practice guideline focuses on a clinical or practice-based issue and is the result of a review and analysis of current professional literature believed to be reliable. As such, information and recommendations within the ACMG and NSGC joint practice guidelines reflect the current scientific and clinical knowledge at the time of publication, are current only as of their publication date, and are subject to change without notice as advances emerge. In addition, variations in practice, which take into account the needs of the individual patient and the resources and limitations unique to the institution or type of practice, may warrant approaches, treatments, and/or procedures that differ from the recommendations outlined in this guideline. Therefore, these recommendations should not be construed as dictating an exclusive course of management, nor does the use of such recommendations guarantee a particular outcome. Genetic counseling practice guidelines are never intended to displace a health-care provider's best medical judgment based on the clinical circumstances of a particular patient or patient population. Practice guidelines are published by the ACMG or the NSGC for educational and informational purposes only, and neither the ACMG nor the NSGC "approve" or "endorse" any specific methods, practices, or sources of information.Cancer genetic consultation is an important aspect of the care of individuals at increased risk of a hereditary cancer syndrome. Yet several patient, clinician, and system-level barriers hinder identification of individuals appropriate for cancer genetics referral. Thus, the purpose of this practice guideline is to present a single set of comprehensive personal and family history criteria to facilitate identification and maximize appropriate referral of at-risk individuals for cancer genetic consultation. To develop this guideline, a literature search for hereditary cancer susceptibility syndromes was conducted using PubMed. In addition, GeneReviews and the National Comprehensive Cancer Network guidelines were reviewed when applicable. When conflicting guidelines were identified, the evidence was ranked as follows: position papers from national and professional organizations ranked highest, followed by consortium guidelines, and then peer-reviewed publications from single institutions. The criteria for cancer genetic consultation referral are provided in two formats: (i) tables that list the tumor type along with the criteria that, if met, would warrant a referral for a cancer genetic consultation and (ii) an alphabetical list of the syndromes, including a brief summary of each and the rationale for the referral criteria that were selected. Consider referral for a cancer genetic consultation if your patient or any of their first-degree relatives meet any of these referral criteria.

Next-generation sequencing for inherited breast cancer risk: counseling through the complexity

Next-generation sequencing technology affords an unprecedented opportunity to analyze multiple breast cancer susceptibility genes simultaneously. With the incarnation of gene panels that combine testing for moderate- and high-penetrance genes, this technology has given birth to a paradigm shift in clinical genetic test offerings. A transformation in genetic counseling for cancer susceptibility will necessarily follow, with a shift from the traditional approach of single-gene testing to considerations of testing by multi-gene panels. At the same time, however, the opportunity to identify rare lesions underlying hereditary susceptibility has introduced new challenges. Available cancer risk estimates for genes included in panel tests may not be supported by evidence, and there is increased risk of identifying variants of uncertain significance (VUS). Management of individuals with rare pathogenic mutations may be unclear. We provide a summary of available evidence for breast cancer risks conferred by pathogenic mutations in genes commonly included in breast cancer susceptibility panels, as well as a review of limitations and counseling points.

BRCA1 and BRCA2 Gene Mutations Screening In Sporadic Breast Cancer Patients In Kazakhstan

BACKGROUND

A large number of distinct mutations in the BRCA1 and BRCA2 genes have been reported worldwide, but little is known regarding the role of these inherited susceptibility genes in breast cancer risk among Kazakhstan women.

AIM

To evaluate the role of BRCA1/2 mutations in Kazakhstan women presenting with sporadic breast cancer.

METHODS

We investigated the distribution and nature of polymorphisms in BRCA1 and BRCA2 entire coding regions in 156 Kazakhstan sporadic breast cancer cases and 112 age-matched controls using automatic direct sequencing.

RESULTS

We identified 22 distinct variants, including 16 missense mutations and 6 polymorphisms in BRCA1/2 genes. In BRCA1, 9 missense mutations and 3 synonymous polymorphisms were observed. In BRCA2, 7 missense mutations and 3 polymorphisms were detected. There was a higher prevalence of observed mutations in Caucasian breast cancer cases compared to Asian cases (p<0.05); higher frequencies of sequence variants were observed in Asian controls. No recurrent or founder mutations were observed in BRCA1/2 genes. There were no statistically significant differences in age at diagnosis, tumor histology, size of tumor, and lymph node involvement between women with breast cancer with or without the BRCA sequence alterations.

CONCLUSIONS

Considering the majority of breast cancer cases are sporadic, the present study will be helpful in the evaluation of the need for the genetic screening of BRCA1/2 mutations and reliable genetic counseling for Kazakhstan sporadic breast cancer patients. Evaluation of common polymorphisms and mutations and breast cancer risk in families with genetic predisposition to breast cancer is ongoing in another current investigation.

Prevalence of 185delAG and 5382insC mutations in BRCA1, and 6174delT in BRCA2 in women of Ashkenazi Jewish origin in southern Brazil

Certain mutations in BRCA1 and BRCA2 genes are frequent in the Ashkenazi Jewish population. Several factors contribute to this increased frequency, including consanguineous marriages and an event known as a "bottleneck", which occurred in the past and caused a drastic reduction in the genetic variability of this population. Several studies were performed over the years in an attempt to elucidate the role of BRCA1 and BRCA2 genes in susceptibility to breast cancer. The aim of this study was to estimate the carrier frequency of certain common mutations in the BRCA1 (185delAG and 5382insC) and BRCA2 (6174delT) genes in an Ashkenazi Jewish population from Porto Alegre, Brazil. Molecular analyses were done by PCR followed by RFLP (ACRS). The carrier frequencies for BRCA1 185delAG and 5382insC were 0.78 and 0 respectively, and 0.4 for the BRCA2 6174deT mutation. These findings are similar to those of some prior studies but differ from others, possibly due to excluding individuals with a personal or family history of cancer. Our sample was drawn from the community group and included individuals with or without a family or personal history of cancer. Furthermore, increased dispersion among Ashkenazi subpopulations may be the result of strong genetic drift and/or admixture. It is therefore necessary to consider the effects of local admixture on the mismatch distributions of various Jewish populations.

Prevalence of BRCA1 and BRCA2 mutations in Ashkenazi Jewish families with breast and pancreatic cancer

BACKGROUND

Germline mutations in the BRCA2 cancer susceptibility gene are associated with an increased risk of pancreatic cancer (PC). Breast-pancreas cancer families with BRCA1 mutations have also been observed. The influence of a family history (FH) of PC on BRCA mutation prevalence in patients with breast cancer (BC) is unknown.

METHODS

A clinical database review (2000-2009) identified 211 Ashkenazi Jewish (AJ) BC probands who 1) underwent BRCA1/2 mutation analysis by full gene sequencing or directed testing for Ashkenazi founder mutations (BRCA1: 185delAG and 5382insC; BRCA2: 6174delT) and 2) had a FH of PC in a first-, second-, or third-degree relative. For each proband, the pretest probability of identifying a BRCA1/2 mutation was estimated using the Myriad II model. The observed-to-expected (O:E) mutation prevalence was calculated for the entire group.

RESULTS

Of the 211 AJ BC probands with a FH of PC, 30 (14.2%) harbored a BRCA mutation. Fourteen (47%) of the mutations were in BRCA1 and 16 (53%) were in BRCA2. Patients diagnosed with BC at age ≤ 50 years were found to have a higher BRCA1/2 mutation prevalence than probands with BC who were diagnosed at age > 50 years (21.1% vs 6.9%; P = .003). In patients with a first-, second-, or third-degree relative with PC, mutation prevalences were 15.4%, 15.3%, and 8.6%, respectively (P = .58). In the overall group, the observed BRCA1/2 mutation prevalence was 14.2% versus an expected prevalence of 11.8% (O:E ratio, 1.21; P = .15).

CONCLUSIONS

BRCA1 and BRCA2 mutations are observed with nearly equal distribution in AJ breast-pancreas cancer families, suggesting that both genes are associated with PC risk. In this population, a FH of PC was found to have a limited effect on mutation prevalence.

Pathology of hereditary breast cancer

Background

Hereditary breast cancer runs in families where several members in different generations are affected. Most of these breast cancers are caused by mutations in the high penetrance genes BRCA1 and BRCA2 accounting for about 5% of all breast cancers. Other genes that include CHEK2, PTEN, TP53, ATM, STK11/LKB1, CDH1, NBS1, RAD50, BRIP1 and PALB2 have been described to be high or moderate penetrance breast cancer susceptibility genes, all contributing to the hereditary breast cancer spectrum. However, in still a part of familial hereditary breast cancers no relationship to any of these breast cancer susceptibility genes can be found. Research on new susceptibility genes is therefore ongoing.

Design

In this review we will describe the function of the today known high or moderate penetrance breast cancer susceptibility genes and the consequences of their mutated status. Furthermore, we will focus on the histology, the immunophenotype and genotype of breast cancers caused by mutations in BRCA1 and BRCA2 genes and the other high or moderate penetrance breast cancer susceptibility genes. Finally, an overview of the clinical implications of hereditary breast cancer patients will be provided.

Conclusion

This information leads to a better understanding of the morphological, immunohistochemical and molecular characteristics of different types of hereditary breast cancers. Further, these characteristics offer clues for diagnosis and new therapeutic approaches.

Hereditary breast and ovarian cancer due to mutations in BRCA1 and BRCA2

Hereditary breast and ovarian cancer due to mutations in the BRCA1 and BRCA2 genes is the most common cause of hereditary forms of both breast and ovarian cancer. The overall prevalence of BRCA1/2 mutations is estimated to be from 1 in 400 to 1 in 800 with a higher prevalence in the Ashkenazi Jewish population (1 in 40). Estimates of penetrance (cancer risk) vary considerably depending on the context in which they were derived and have been shown to vary within families with the same BRCA1/2 mutation. This suggests there is no exact risk estimate that can be applied to all individuals with a BRCA1/2 mutation. The likelihood of harboring a BRCA1 or BRCA2 mutation is dependent on one's personal and/or family history of cancer and can be estimated using various mutation probability models. For those individuals who have a BRCA1 or BRCA2 mutation, several screening and primary prevention options have been suggested, including prophylactic surgery and chemoprevention. Once a BRCA1 or BRCA2 mutation has been identified in a family, testing of at-risk relatives can identify those family members who also have the familial mutation and thus need increased surveillance and early intervention when a cancer is diagnosed.

Ethical issues related to BRCA gene testing in orthodox Jewish women

Persons exhibiting mutations in two tumor suppressor genes, BRCA1 and BRCA2, have a greatly increased risk of developing breast and/or ovarian cancer. The incidence of BRCA gene mutation is very high in Ashkenazi Jewish women of European descent, and many issues can arise, particularly for observant Orthodox women, because of their genetic status. Their obligations under the Jewish code of ethics, referred to as Jewish law, with respect to the acceptability of various risk-reducing strategies, may be poorly understood. In this article the moral direction that Jewish law gives to women regarding testing, confidentiality, and other issues is explored. The intent is to broaden nurses' knowledge of how a particular religious tradition could impact on decision making around genetics testing, with the aim of enhancing their understanding of culturally sensitive ethical care.

Breast cancer risk associated with BRCA1 and BRCA2 in diverse populations

Germline mutations in the BRCA1 or BRCA2 tumour-suppressor genes are strong predictors of breast and/or ovarian cancer development. The contribution of these mutations to breast cancer risk within any specific population is a function of both their prevalence and their penetrance. Mutation prevalence varies among ethnic groups and may be influenced by founder mutations. Penetrance can be influenced by mutation-specific phenotypes and the potential modifying effects of the patient's own genetic and environmental background. Although estimates of both mutation prevalence and mutation penetrance rates are inconsistent and occasionally controversial, understanding them is crucial for providing accurate risk information to each patient.

Localization of breast cancer susceptibility loci by genome-wide SNP linkage disequilibrium mapping

We studied the feasibility of a novel approach to localize breast cancer susceptibility genes, using a low-density genome-wide panel of single-nucleotide polymorphisms and taking advantage of large regions of linkage disequilibrium (LD) flanking Jewish disease genes in high-risk cases. With Affymetrix GeneChip arrays, we genotyped 8,576 polymorphisms in three sets of Ashkenazi Jewish breast cancer cases: a "validation" set of 27 breast cancer cases, all of whom carried the BRCA2*6174delT founder mutation; a "field" set of 19 breast cancer cases from male breast cancer kindreds, which simulated conditions for finding new genes; and a "test" set of 57 probands from breast cancer kindreds (4 or more cases/kindred), in which mutations in BRCA1 and BRCA2 had been excluded. To identify associations, we compared the frequency of genotypes and haplotypes in cases vs. controls by the Fisher's exact test and a maximum likelihood ratio test. In the "validation" set, we demonstrated the presence of a region of linkage disequilibrium on BRCA2*6174delT chromosomes that spanned over 5 million bases. In the "field" set, we showed that this large region of linkage disequilibrium flanking BRCA2 was detectable despite the presence of heterogeneity in the sample set. Finally, in the "test" set, at least three regions of interest emerged that could contain novel breast cancer genes, one of which had been identified previously by linkage analysis. While these results demonstrate the feasibility of genome-wide association strategies, further application of this approach will critically depend on optimizing the density and distribution of SNPs and the size and type of study design.

A new germline mutation in BRCA1 gene in a sicilian family with ovarian cancer

A group of 103 sicilian patients with hereditary and familiar breast and/or ovarian cancer were screened for Breast Cancer 1 gene (BRCA1) mutations by direct sequencing PCR products spanning the coding region and partial intronic regions of the BRCA1 gene. In this study, we report a new germline mutation in BRCA1 gene, not previously reported in the BIC database, in a woman with ovarian cancer at 46 years old. Mother's proband has been diagnosed the same histotype of ovarian cancer at 42 age. The mutational analyses that shown a 4843delC frameshift mutation in exon 16 of BRCA1 gene was extended to other family members including the proband's brother and her two sons. Direct automatic sequencing of DNA extracted from the lymphocytes showed exactly the same 4843delC frameshift mutation only in the brother. In conclusion, the characterization of this mutation could help in the identification of a founder mutation of sicilian area and this may provide significant advantages for genetic counselling.

Mutational analysis of the BRCA1 gene in 30 Czech ovarian cancer patients

Ovarian cancer is one of the most severe of oncological diseases. Inherited mutations in cancer susceptibility genes play a causal role in 5-10% of newly diagnosed tumours. BRCA1 and BRCA2 gene alterations are found in the majority of these cases. The aim of this study was to analyse the BRCA1 gene in the ovarian cancer risk group to characterize the spectrum of its mutations in the Czech Republic. Five overlapping fragments amplified on both genomic DNA and cDNA were used to screen for the whole protein-coding sequence of the BRCA1 gene. These fragments were analysed by the protein truncation test (PTT) and direct sequencing. Three inactivating mutations were identified in the group of 30 Czech ovarian cancer patients: the 5382insC mutation in two unrelated patients and a deletion of exons 21 and 22 in another patient. In addition, we have found an alternatively spliced product lacking exon 5 in two other unrelated patients. The 5382insC is the most frequent alteration of the BRCA1 gene in Central and Eastern Europe. The deletion of exons 21 and 22 affects the BRCT functional domain of the BRCA1 protein. Although large genomic rearragements are known to be relatively frequent in Western European populations, no analyses have been performed in our region yet.

Highly penetrant hereditary cancer syndromes

The past two decades have brought many important advances in our understanding of the hereditary susceptibility to cancer. Approximately 5-10% of all cancers are inherited, the majority in an autosomal dominant manner with incomplete penetrance. While this is a small fraction of the overall cancer burden worldwide, the molecular genetic discoveries that have resulted from the study of families with heritable cancer have not only changed the way these families are counselled and managed, but have shed light on molecular regulatory pathways important in sporadic tumour development as well. In this review, we consider 10 of the more highly penetrant cancer syndromes, with emphasis on those predisposing to breast, colon, and/or endocrine neoplasia. We discuss the prevalence, penetrance, and tumour spectrum associated with these syndromes, as well as their underlying genetic defects.

Psychological Impact of Genetic Testing for Breast Cancer Susceptibility in Women of Ashkenazi Jewish Background: A Prospective Study

The recognition that the prevalence of three founder mutations in the BRCA1 and BRCA2 genes is over 2% in Ashkenazi Jews has resulted in numerous epidemiological research studies of this ethno-religious group. To determine the effects of incorporating research into clinical practice, a psychological impact study of women participating in an epidemiological study was conducted. Sixty women of Ashkenazi Jewish background who underwent genetic testing for founder mutations were assessed using mailed, self-administered questionnaires with validated measures of psychological outcome. Forty-three women elected to learn their results and 17 women declined to do so. Women who elected to learn their results were also assessed 7-10 days, 4 months, and 12 months after results disclosure. Women who chose to learn their results had significantly higher baseline breast cancer anxiety, compared to those who elected not to learn their results (z = -2.27; p = 0.023). Unaffected women who elected to learn their results showed a significant decrease in breast cancer anxiety 4 months (z = -2.37, p = 0.018) and 12 months (z = -3.06, p = 0.002) post-notification compared to baseline. Genetic testing for mutations common in Ashkenazi Jewish women with result disclosure does not lead to adverse psychological outcomes.

Frequency of BRCA1 and BRCA2 mutations in unselected Ashkenazi Jewish patients with colorectal cancer

Mutations in BRCA1 and BRCA2 that predispose to breast and ovarian cancer are detected in approximately 2.5% of the Ashkenazi Jewish population. To explore whether carriers of Ashkenazi founder mutations in BRCA1 or BRCA2 have an increased risk for colorectal cancer, we screened 586 unselected Ashkenazi Jewish case patients with colorectal cancer for the three common founder mutations in BRCA1 and BRCA2. We identified six carriers (1.02%) among these case patients. After adjusting for age at diagnosis and sex by use of logistic regression analysis, we compared the incidence of carriers in this group of 586 case patients with that of 5012 Ashkenazi Jewish control subjects without a known history of colorectal cancer. The presence of a founder BRCA mutation was not associated with the risk of colorectal cancer (relative risk = 0.50, 95% confidence interval = 0.22 to 1.14). We thus recommend that counseling for colorectal cancer screening and prevention in individuals with BRCA mutations be based on the personal and family history of colorectal cancer or associated syndromic malignancies.

Mutational screening of breast cancer susceptibility gene 1 from early onset, bi-lateral, and familial breast cancer patients in Taiwan

The BRCA1 gene has been shown to be strongly associated with the occurrence of familial breast cancer. The spectrum of BRCA1 gene mutations in breast cancer patients in various populations has been investigated. In this study, patients in Central Taiwan with breast cancer were screened for BRCA1 mutations by sequencing PCR products spanning the coding region and partial intronic regions of the BRCA1 gene. Twelve polymorphisms in four exons and three introns were found. One mutation was found in one patient with familial breast cancer. Two patients showed LOH at the locus of BRCA1. Also found in the Taiwanese population were two common haplotypes and one rare haplotype of BRCA1. These results suggest that the mutation of BRCA1 contributes little to the occurrence of breast cancer in the Taiwanese population.

Clinical considerations in the management of individuals at risk for hereditary breast and ovarian cancer

BACKGROUND

Hereditary predisposition to breast and ovarian cancer, most commonly due to germline mutations in BRCA1 and BRCA2, has been recognized for many years. The optimal clinical management of individuals with such a predisposition is not yet completely defined.

METHODS

The current literature regarding the clinical management of individuals at risk for hereditary breast and ovarian cancer was reviewed.

RESULTS

Women with germline BRCA1 or BRCA2 mutations are at substantially increased risk for breast and ovarian cancer, although the risks may not be as high as originally reported. Current surveillance options are restricted in their effectiveness by both host and tumor factors as well as limitations of the techniques. Surgical prevention options, while effective, may be complicated by physical or psychological morbidity. Nonsurgical prevention options are under development.

CONCLUSIONS

The ability to define women as being at hereditary risk for breast and ovarian cancer facilitates the use of specialized surveillance and prevention strategies. Genetic testing, which plays a role in defining risk, requires careful pre- and post-test counseling to discuss the limitations of testing itself and available management strategies.

Analysis of BRCA1, TP53, and TSG101 germline mutations in German breast and/or ovarian cancer families

About 5%-10% of breast cancers are considered to be hereditary and associated with germline mutations of specific genes. As yet, the most frequently affected genes identified are BRCA1 and BRCA2, but also other genes such as TP53 are supposed to influence the predisposition toward breast cancer. In the present study, we analyzed patients of 19 German families with early onset breast cancer and/or a family history of breast and/or ovarian cancer for the presence of mutations in BRCA1 and TP53. In addition, we screened for germline mutations in the putative tumor suppressor gene TSG101. For this purpose we used direct sequence analysis of the entire coding regions for all three genes and, in the case of BRCA1, single-strand conformation polymorphism analysis and protein transcription-translation assays. We identified eight previously described polymorphisms and several aberrations in BRCA1: 1 unclassified missense mutation, 3 small protein truncating mutations, 1 novel pseudoexon, and 5 splicing variants. No mutation was detected in TP53. Analysis of TSG101 transcripts revealed an aberrant transcript in two breast cancer patients belonging to the same family, suggesting TSG101 as a predisposing gene in hereditary breast cancer.

The genetics of ovarian cancer

A family history of ovarian cancer confers an increased risk of ovarian cancer. We review the literature quantifying the familial risks associated with ovarian cancer and assess the evidence that the familial clustering of ovarian cancer is genetically determined. We then describe the known high-penetrance genes, the ovarian cancer risks attached to them and their contribution to ovarian cancer in families and in the general population. The evidence for the existence of other ovarian cancer genes is then considered.

Outcome of conservatively managed early-onset breast cancer by BRCA1/2 status

BACKGROUND

Management of early-stage breast cancer in young women with mutations in BRCA1 or BRCA2 remains controversial. This study assessed the long-term risks of ipsilateral and contralateral breast cancer in a cohort of young women who underwent breast-conserving surgery followed by radiotherapy.

METHODS

Between 1975 and 1998, 290 women with breast cancer diagnosed at age 42 years or younger underwent lumpectomy followed by radiotherapy at our hospital. We recruited 127 of these women for complete sequencing of BRCA1 and BRCA2. Demographic, clinical, pathological, and outcome data were recorded. The primary endpoints were rates of ipsilateral and contralateral breast cancer, in relation to germline BRCA1/2 status.

FINDINGS

105 women were classified as having sporadic disease (94 with wild-type or known polymorphisms and 11 with variants of unclear significance) and 22 as having genetic predisposition (deleterious mutations in BRCA1 [15] or BRCA2 [seven]). At 12 years of follow-up, the genetic group had significantly higher rates of ipsilateral (49% vs 21%, p=0.007) and contralateral events (42% vs 9%, p=0.001) than the sporadic group. The majority of events were classified as second primary tumours. No patient in the genetic group had undergone oophorectomy or was taking prophylactic agents such as tamoxifen.

INTERPRETATION

Patients with germline mutations in BRCA1 or BRCA2 have a high risk of developing late ipsilateral and contralateral second primary tumours. With breast-conserving therapy, chemoprophylaxis or other interventions to reduce the rate of second cancers may be valuable. Alternatively, bilateral mastectomy may be considered, to minimise the risk of second tumours in the breasts.

Breast cancer susceptibility genes: Options for those carrying BRCA1 mutations

The discovery of the association between breast and ovarian cancer and the BRCA genes and the development of methods for genetic testing made it possible to screen women for genetic predisposition to develop hereditary breast cancer (HBC). Parallelly, prevention strategies, including clinical surgical and medical interventions become available in order to reduce cancer risk. In a meantime, we became aware of limitations of genetic testing from the aspect of BRCA gene penetrance, negative result interpretation etc. All of these, together with data that invasive prevention strategies such as prophylactic surgery demonstrate better results in risk reduction than regimens including self and clinical-examination, face BRCA mutation carriers with difficult choice for risk reduction options. Therefore, the patients at high risk of HBC can best make informed decisions when guided by a multidisciplinary genetic counseling team.

Founder BRCA1 and BRCA2 mutations in early-onset French Canadian breast cancer cases unselected for family history

Recently, founder BRCA1 and BRCA2 mutations were identified in Canadian breast cancer and breast-ovarian cancer families of French ancestry. The presence of a breast cancer case diagnosed at younger than 36 years of age was strongly predictive of the presence of any founder mutation screened. Here we report the occurrence of founder BRCA1 and BRCA2 mutations in a series of 61 French Canadian women with invasive breast cancer diagnosed at age 40 or younger, unselected for family history of breast and ovarian cancer. Germline mutations in BRCA1 (n = 4) and BRCA2 (n = 4) were identified in 8 of 61 (13%) cases. All BRCA1 mutations were found in invasive ductal carcinomas, the most common histologic type of tumor in this series. In contrast, the BRCA2 mutations were found in tumors of various histologic types: two ductal carcinomas, a tumor containing both ductal and lobular histologic types and an invasive lobular carcinoma. Of the 37 women with at least one first-, second- or third-degree relative with breast or ovarian cancer and the 24 women with no history of these cancers, 7 (19%) and 1 (4%), respectively, were mutation carriers. The seven mutation carriers with a family history of cancer had at least one first-, second- or third-degree relative with a breast cancer diagnosis at less than 51 years of age. The identification of founder BRCA1 and BRCA2 mutations in young-onset breast cancer cases unselected for family history can facilitate carrier detection when the expected yield of a comprehensive screen may be low.

Breast cancer mortality among Ashkenazi Jewish women in São Paulo and Porto Alegre, Brazil

BACKGROUND

Increased BRCA1 and BRCA2 germline mutation rates have been reported in Ashkenazi Jewish women in North America, Europe and Israel, and have been mentioned as possibly related to a higher incidence of breast and ovarian cancer among these communities. The present study was carried out with the aim of obtaining evidence on the magnitude of breast cancer as a cause of death among Ashkenazi women in Brazil.

METHODS

We reviewed all death certificates archived in the Jewish Burial Societies of São Paulo (1971-1997) and Porto Alegre (1948-1997), two of the main and oldest Jewish communities in Brazil. Breast cancer observed deaths were compared with expected deaths according to breast cancer mortality in the general population.

RESULTS

The observed ratios were approximately quite close to unity, suggesting a similar breast cancer mortality pattern among the Ashkenazi population and the general population in both cities. These results maintain similar behavior regardless of whether analyzed before or after the mid-1980s, when mammography came to be increasingly performed in Brazil. Cancer proportional mortality ratios were 1.04 (0.83-1.29) in São Paulo and 1.16 (0.84-1.57) in Porto Alegre before 1985, and 1.17 (1.00-1.44) and 1.21 (0.81-1.79), respectively, between 1985 and 1997. Some evidence of the maintenance of protective risk factors such as high parity has been observed among Ashkenazi women in São Paulo.

CONCLUSION

A quite similar breast cancer mortality pattern was observed between Ashkenazi Jewish women and the general population in São Paulo and Porto Alegre, Brazil. These results may suggest an environmental role on germ mutation expression reported in this ethnic group.

Prevalence and penetrance of BRCA1 and BRCA2 mutations in a population-based series of breast cancer cases. Anglian Breast Cancer Study Group

Estimates of the contribution of BRCA1 and BRCA2 to breast cancer incidence in outbred populations have been based on studies that are either small or have selected for cases diagnosed at an early age. Only one of these has reported an estimate of the breast cancer risk associated with a mutation in these genes, and there is no published ovarian cancer risk estimate derived from a population-based case series. We screened a population-based series of breast cancer cases diagnosed before the age of 55 for mutations in BRCA1 and BRCA2. Pedigree information from the mutation carriers was used to estimate penetrance and the proportion of familial risk of breast cancer due to BRCA1 and BRCA2. We identified eight (0.7%) BRCA1 and 16 (1.3%) BRCA2 mutation carriers in 1220 breast cancer cases (actual sample size 1435 adjusted for 15% polymerase chain reaction failure rate). Mutation prevalence was substantially higher in cases diagnosed before 35 years-of-age and with increasing number of relatives affected with breast or ovarian cancer. However, most mutation carriers were diagnosed in the older age groups, and a minority reported a first-degree relative with breast cancer. Breast cancer penetrance by age 80 was estimated to be 48% (95% CI 7-82%) for BRCA1 mutation carriers and 74% (7-94%) for BRCA2 mutation carriers. Ovarian cancer penetrance for BRCA1 and BRCA2 combined was 22% (6-65%) by age 80. 17% of the familial risk of breast cancer was attributable to BRCA1 and BRCA2. At birth, the estimated prevalence of BRCA1 mutation carriers was 0.07% or 0.09% depending on the penetrance function used for the calculation. For BRCA2, the birth prevalence estimates were 0.14% and 0.22%. Mutations in the genes BRCA1 and BRCA2 are rare in the population and account for a small fraction of all breast cancer in the UK. They account for less than one fifth of the familial risk of breast cancer. Eligibility criteria for BRCA1 and BRCA2 mutation testing based on family history and age of onset will identify only a small proportion of mutation carriers.

Patients with double primary tumors in the breast and ovary- clinical characteristics and BRCA1-2 mutations status

OBJECTIVE

The aim of this study was to define the prevalence, clinical characteristics, and BRCA1-2 mutation carrier status of ovarian cancer (OvC) patients with a previous primary malignancy in the breast (PPMBr).

METHODS

The study population comprised 1240 consecutive Jewish Israeli women with pathologically confirmed epithelial OvC diagnosed between March 1, 1994, and December 31, 1997. Demographic and clinical data were obtained from medical files and from a detailed questionnaire taken through a nationwide epidemiological case-control study on OvC. Blood samples and tumor tissues were collected for analysis of the three predominant germline BRCA1-2 Jewish founder mutations (185delAG, 5382insC, and 6174delT).

RESULTS

Fifty nine (4.7%) patients with OvC had a PPMBr. The median age at diagnosis of OvC was 60 years. The mean interval between the two diagnoses was 104 months (range 0-363 months). In the majority of the patients (n = 53), the diagnosis of breast cancer (BrC) preceded the OvC by more than 1 year. The ovarian tumors were diagnosed in 47% of the cases following investigation of patients' symptoms. In 41%, diagnosis was made as a consequence of check-up exams performed during the routine follow-up of BrC survivors. Patients with PPMBr were more likely to present with FIGO ovarian stage III-IV, compared to women with solitary OvC (73% vs 60. 3%, P < 0.05), and less likely to have borderline tumors (3.4% vs 17. 9%, P = 0.007). Family history of OvC/BrC was recorded in 26% of this group of patients compared to 10.5% among patients with solitary OvC (P = 0.003). Patients with PPMBr had an exceptionally high prevalence of BRCA1-2 mutations (57%), irrespective of family history.

CONCLUSIONS

Patients with PPMBr present with more advanced disease and invasive-type epithelial ovarian tumors when compared to cases associated with solitary OvC. The rate of BRCA1-2 mutations in Jewish women with OvC who had PPMBr is at least twice as high as in Jewish women with OvC as the solitary disease.

The predictive value of BRCA1 and BRCA2 mutation testing

Genetic testing for mutations in BRCA1 and BRCA2, two genes predisposing to breast and ovarian cancers, is available to women with a relevant family history. The aim of this study was to estimate the positive and negative predictive value of clinical sequence analysis of these genes. A reference graph showing positive and negative predictive values over a range of pre-test risk was derived, taking into account the sensitivity and specificity of a full-sequence analysis test. High positive and negative predictive values were found for women with pre-test risk between 4% and 40%, a range of risk commonly seen in clinical testing. The predictive value of full sequence and single-site analysis of BRCA1 and BRCA2, therefore, compares favorably with other diagnostic medical tests. Our results provide a numerical estimate of the predictive value of BRCA testing, and as such, provide a valuable tool to healthcare providers and families as they interpret BRCA1 and BRCA2 test results.

Constant denaturant gel electrophoresis (CDGE) in BRCA1 mutation screening

Screening for mutations in the breast and ovarian cancer susceptibility gene, BRCA1, is complicated by the wide spectrum of mutations found in this large gene. In the present study a constant denaturant gel electrophoresis (CDGE) mutation screening strategy was established for approximately 80% of the genomic coding sequence (exons 2, 11, 13-16, 20, 24). This strategy was applied to screen genomic DNA from 50 familial breast and/or ovarian cancer patients who had previously been examined for BRCA1 mutations by SSCP. A total of 14 carriers of 12 distinct disease-associated mutations and 7 carriers of 6 distinct rare substitutions leading to amino acid substitutions were identified. The SSCP failed to detect 40% of the different deletions/insertions (4/10) and 75% (6/8) of the different base substitutions leading to terminating codons or rare amino acid changes. SSCP did, however, identify one rare base substitution that could not be detected in the CDGE screening. To evaluate the CDGE mutation screening strategy further, 25 unrelated patients from Norwegian breast and/or ovarian cancer families were examined for BRCA1 mutations using a combined genomic DNA/cDNA approach covering the entire coding sequence of the gene. A total of six mutation carriers were detected, all of whom had cases of ovarian cancer in their families. Three patients from independent families carried an 1135insA mutation in exon 11, two others had a Gly484ter and an 1675delA mutation, respectively, and the sixth carried a splice mutation (5194-2 a-->c) causing deletion of exon 18. CDGE may become an efficient tool in diagnostic and population based screening for BRCA1 mutations.

Future possibilities in the prevention of breast cancer: intervention strategies in BRCA1 and BRCA2 mutation carriers

The development of intervention strategies for carriers of mutations in the BRCA1 and BRCA2 genes has several considerations. The first are primary prevention and secondary prevention in unaffected carriers using medical/surgical or lifestyle strategies to prevent cancer development, or screening methods to detect cancers at an earlier stage. The options available are determined by the magnitude and age at onset, risk profile of cancer in carriers (the penetrance function of the gene) and the different cancer sites involved. The management of affected individuals who are BRCA1 and BRCA2 mutation carriers may be altered by their carrier status, because the tumour histology, efficacy of treatment and risk of subsequent cancer development is determined by the BRCA1 and BRCA2 germline status. Carriers of BRCA1 and BRCA2 mutations are relatively rare, so the strategies for management should be determined by international multicentre studies.

Establishment and characterization of a breast cell strain containing a BRCA1 185delAG mutation

OBJECTIVE

The aim of this study was to examine whether cells containing the heterozygous form of a BRCA1 185delAG mutation would exhibit abnormal growth or an altered response to DNA damage.

METHODS

A primary culture of human mammary epithelial cells (90P) was obtained from the nontumor breast tissue of a 35-year-old patient who had undergone a mastectomy for removal of a breast tumor. These cells were immortalized (90PE6E7) following retroviral infection with HPV-16 viral E6/E7. genes. Both the 90P cell strain and the cell line were characterized for their ability to grow in culture, form colonies in soft agar, and produce tumors in athymic nude mice compared to normal breast epithelial cells containing wild-type BRCA1. 90P cells were also analyzed for cellular response to gamma radiation and H(2)O(2).

RESULTS

These cells were confirmed to contain a frameshift mutation, 185delAG, of the BRCA1 gene. Despite being heterozygous for wild-type BRCA1, the 220-kDa full-size BRCA1 protein was abundantly expressed. 90P and 90PE6E7 cells grew at a similar rate and were anchorage dependent. 90PE6E7 also failed to form tumors in athymic nude mice. Finally, 90P cells exhibited a survival response similar to that of normal mammary epithelial cells to radiation damage and exposure to oxidative stress.

CONCLUSION

To our knowledge the 90P cells and the 90PE6E7 cells are the first characterized, non-tumor-derived breast epithelial cells that are heterozygous for the BRCA1 germline mutation 185delAG. Our conclusion is that these BRCA1 mutant cells appear to have growth and stress response characteristics similar to those of normal human breast cells, which is consistent with the hypothesis that loss of heterozygosity must occur to impair putative BRCA1 function.

Screening for hereditary cancer and genetic testing, epitomized by breast cancer

The new genetics is having an impact on many areas of healthcare. Diversity in the genetic code accounts for differences in phenotypes between populations and it is becoming apparent that genetic differences may have a role in predisposition to and behaviour of disease. Genetic models suggest that there are two types of genetic predisposition to disease: the so-called high and low penetrance genes. At present, most of the impact on medicine has been from highly penetrant genes, and genetic testing for disease predisposition, particularly for diseases of late onset (e.g. certain cancers) is in its infancy. As a general statement, approximately 5-10% of common cancers are due to such highly penetrant genes. The category of genes that will become of increasing interest is that of the low penetrance genes. Often these are normal variations in genes that result in a slightly increased risk of disease. These are analogous to high blood pressure carrying an increased risk of cardiovascular disease. Once rapid genetic analysis is available for these types of genes, such analysis would be analogous to taking someone's blood pressure in a general practitioner's (GP's) surgery to identify individuals at increased risk of cardiovascular disease. This will produce a revolutionary change in the way we practise medicine. Genetic analysis will become faster and may therefore be more commonplace. It is possible to envisage an era when genetic analysis will become a routine part of primary care to identify changes in low penetrance genes that will confer a 'risk profile' for patients. This will then enable their primary care physicians to advise about primary prevention and even prescribe certain preventive drugs to decrease the risk of certain diseases occurring. This proactive rather than reactive style of practising medicine is potentially exciting, however it carries with it ethical, legal and social implications for how we deal with this new knowledge.

BRCA1/BRCA2 germline mutations in locally recurrent breast cancer patients after lumpectomy and radiation therapy: implications for breast-conserving management in patients with BRCA1/BRCA2 mutations

PURPOSE

Breast cancer patients treated conservatively with lumpectomy and radiation therapy (LRT) have an estimated lifetime risk of local relapse (ipsilateral breast tumor recurrence [IBTR]) of 10% to 15%. For breast cancer patients carrying BRCA1 or BRCA2 (BRCA1/2) mutations, the outcome of treatment with LRT with respect to IBTR has not been determined. In this study, we estimate the frequency of BRCA1/2 mutations in a study of breast cancer patients with IBTR treated with LRT.

PATIENTS AND METHODS

Between 1973 and 1994, there were 52 breast cancer patients treated with LRT who developed an IBTR within the prior irradiated breast and who were willing to participate in the current study. From our database, we also identified 52 control breast cancer patients treated with LRT without IBTR. The control patients were individually matched to the index cases with respect to multiple clinical and pathologic parameters. Lymphocyte DNA specimens from all 52 locally recurrent patients and 15 of the matched control patients under age 40 were used as templates for polymerase chain reaction amplification and dye-primer sequencing of exons 2 to 24 of BRCA1, exons 2 to 27 of BRCA2, and flanking intron sequences.

RESULTS

After LRT, eight (15%) of 52 breast cancer patients had IBTR with deleterious BRCA1/2 mutations. By age, there were six (40%) of 15 patients with IBTR under age 40 with BRCA1/2 mutations, one (9.0%) of 11 between ages 40 and 49, and one (3.8%) of 26 older than age 49. In comparison to the six (40%) of 15 of patients under age 40 with IBTR found to have BRCA1/2 mutations, only one (6.6%) of 15 matched control patients without IBTR and had a BRCA1/2 mutation (P =.03). The median time to IBTR for patients with BRCA1/2 mutations was 7.8 years compared with 4.7 years for patients without BRCA1/2 mutations (P =.03). By clinical and histologic criteria, these relapses represented second primary tumors developing in the conservatively treated breast. All patients with BRCA1/2 mutations and IBTR underwent successful surgical salvage mastectomy at the time of IBTR and remain alive without evidence of local or systemic progression of disease.

CONCLUSION

In this study, we found an elevated frequency of deleterious BRCA1/2 mutations in breast cancer patients treated with LRT who developed late IBTR. The relatively long time to IBTR, as well as the histologic and clinical criteria, suggests that these recurrent cancers actually represent new primary breast cancers. Early onset breast cancer patients experiencing IBTR have a disproportionately high frequency of deleterious BRCA1/2 mutations. This information may be helpful in guiding management in BRCA1 or BRCA2 patients considering breast-conserving therapy.

Genetic screening of targeted subpopulations: the role of communal discourse in evaluating sociocultural implications

Targeting socially identifiable subpopulations for genetic screening entails the risk of stigmatizing them. The potential for such harm should be considered before programs are initiated. There is an emerging consensus that targeted subpopulations should be actively involved in evaluating these risks. A process of communal discourse engages the community in discussions that reflect both public and private sociocultural contexts in which individual decisions about screening will be made. This allows the subpopulation to address the collective implications of testing in a culturally appropriate way. Communal discourse was used to evaluate the collective implications of genetic testing in two Native American communities. We found that private social units were more influential than public units in reaching communal consensus, that local sociocultural issues were of more concern than were general issues such as employment and insurance discrimination, and that heterogeneity within a subpopulation may be just as significant a consideration in designing a targeted screening program as diversity between subpopulations. Heterogeneity is constructed by using a dichotomy between community-specific and biomedical health representations and practices. How genetic screening is socially constructed using a community's existing dichotomy may be central to its success.

Prevalence and penetrance of BRCA1 and BRCA2 gene mutations in unselected Ashkenazi Jewish women with breast cancer

BACKGROUND

Approximately 2.0%-2.5% of Ashkenazi Jewish women carry one of three founding mutations in the BRCA1 and BRCA2 genes, and each mutation is associated with a high lifetime risk of invasive breast cancer. We investigated the extent to which these three mutations contribute to breast cancer incidence in the Ashkenazi Jewish population.

METHODS

We ascertained 457 Jewish women with prevalent cases of breast cancer who were unselected for age or family history of the disease; 412 of these women were tested for the three founder mutations (case patients). Control subjects consisted of 360 non-Jewish women with breast cancer (control patients) and 380 healthy Jewish women with no history of cancer (control subjects).

RESULTS

Mutations were found in 48 (11.7%) of 412 Jewish case patients. Forty-six of 48 mutations occurred in women with early-onset breast cancer (<50 years) or a history of ovarian or early-onset breast cancer in a first-, second-, or third-degree relative. The estimated penetrance to age 70 years for breast cancer was 59.9% for the BRCA1 gene mutations and 28.3% for the BRCA2 gene mutation. Compared with Jewish control subjects, the relative risk (RR) of breast cancer for first-degree relatives of mutation carriers was 5.16 (95% confidence interval [CI] = 3.14-8. 48), but risk was also increased for relatives of noncarriers (RR = 1.66; 95% CI = 1.18-2.33). The RR of prostate cancer for first-degree relatives of Jewish case patients was 3.36 (95% CI = 1. 49-7.56).

CONCLUSIONS

Approximately 12% of breast cancers in the Ashkenazi Jewish population are attributable to mutations in the BRCA1 or BRCA2 gene. Genetic testing may be useful when Jewish women with breast cancer are diagnosed before age 50 years or have a close relative with ovarian or early-onset breast cancer. An association between breast and prostate cancers was observed in our study population.