Founder BRCA1/2 mutations among male patients with breast cancer in Israel

Feasibility of targeted therapies in the adjuvant setting of early breast cancer in men: real-world data from a population-based registry

BACKGROUND

Following the positive iDFS and OS results of the phase III clinical trials monarchE, NATALEE and OlympiA, new oral anticancer agents (the CDK4/6 inhibitors abemaciclib, ribociclib as well as the PARP inhibitor olaparib) have recently been introduced into the treatment of high-risk early breast cancer (eBC). However, only few male patients were included in these trials (0.4%, 0.6% and 0.3%, respectively). The objective of this real-world analysis was to determine the proportion of male patients with eBC fulfilling the clinical high-risk criteria of above-mentioned trials.

PATIENTS AND METHODS

We conducted a data inquiry and analysis with the Cancer Registry of Baden-Württemberg of men with breast cancer diagnosed between January 1, 2015 and December 31, 2021. Men with eBC were identified and the number of patients at clinical high-risk according to the inclusion criteria of monarchE, NATALEE and OlympiA was assessed.

RESULTS

Of 397 men with eBC, 354 (89.1%) had a HR + /Her2- and 4 (1.0%) a triple-negative subtype. 84 patients (21.2%) met the clinical high-risk criteria according to the monarchE, 189 (47.6%) those according to the NATALEE and 50 (12.6%) those according to the OlympiA trial.

CONCLUSION

In a large real-world sample, more men with eBC are at clinical high risk according to the inclusion criteria of monarchE, NATALEE and OlympiA than would be expected in women. This is most likely due to more advanced stages at initial diagnosis in men. To evaluate whether CDK4/6 and PARP inhibitors improve prognosis also in men should be the topic of future real- world analyses.

Difficulties of gender affirming treatment in trans women with BRCA1+ mutation: A case report

Gender affirming treatment in transgender women is based on a combination of antiandrogens and estrogens, with the latter maintained over the long term. When prescribing these treatments, we must consider the possibility of developing estrogen-dependent breast cancer. In transgender women, a breast cancer incidence of 4.1 per 100,000 has been estimated, which would increase the risk by 46% in relation to cisgender men but decrease it by 70% in relation to cisgender women. It is known that certain gene mutations such as BRCA1 imply an increased risk of breast cancer, but at present the risk in transgender women with BRCA1 treated with estrogens is not well established. We present the case of a transgender woman with a family history of breast cancer and BRCA1 mutation and the therapeutic decisions made in a multidisciplinary team. Following this case, we review and discuss the published literature.

Preventive population genomics: The model of BRCA related cancers

Preventive population genomics offers the prospect of population stratification for targeting screening and prevention and tailoring care to those at greatest risk. Within cancer, this approach is now within reach, given our expanding knowledge of its heritable components, improved ability to predict risk, and increasing availability of effective preventive strategies. Advances in technology and bioinformatics has made population-testing technically feasible. The BRCA model provides 30 years of insight and experience of how to conceive of and construct care and serves as an initial model for preventive population genomics. Population-based BRCA-testing in the Jewish population is feasible, acceptable, reduces anxiety, does not detrimentally affect psychological well-being or quality of life, is cost-effective and is now beginning to be implemented. Population-based BRCA-testing and multigene panel testing in the wider general population is cost-effective for numerous health systems and can save thousands more lives than the current clinical strategy. There is huge potential for using both genetic and non-genetic information in complex risk prediction algorithms to stratify populations for risk adapted screening and prevention. While numerous strides have been made in the last decade several issues need resolving for population genomics to fulfil its promise and potential for maximizing precision prevention. Healthcare systems need to overcome significant challenges associated with developing delivery pathways, infrastructure expansion including laboratory services, clinical workforce training, scaling of management pathways for screening and prevention. Large-scale real world population studies are needed to evaluate context specific population-testing implementation models for cancer risk prediction, screening and prevention.

Differences in Ovarian and Other Cancers Risks by Population and BRCA Mutation Location

Hereditary breast and ovarian cancer is caused by a germline mutation in BRCA1 or BRCA2 genes. The frequency of germline BRCA1/2 gene mutation carriers and the ratio of germline BRCA1 to BRCA2 mutations in BRCA-related cancer patients vary depending on the population. Genotype and phenotype correlations have been reported in BRCA mutant families, however, the correlations are rarely used for individual risk assessment and management. BRCA genetic testing has become a companion diagnostic for PARP inhibitors, and the number of families with germline BRCA mutation identified is growing rapidly. Therefore, it is expected that analysis of the risk of developing cancer will be possible in a large number of BRCA mutant carriers, and there is a possibility that personal and precision medicine for the carriers with specific common founder mutations will be realized. In this review, we investigated the association of ovarian cancer risk and BRCA mutation location, and differences of other BRCA-related cancer risks by BRCA1/2 mutation, and furthermore, we discussed the difference in the prevalence of germline BRCA mutation in ovarian cancer patients. As a result, although there are various discussions, there appear to be differences in ovarian cancer risk by population and BRCA mutation location. If it becomes possible to estimate the risk of developing BRCA-related cancer for each BRCA mutation type, the age at risk-reducing salpingo-oophorectomy can be determined individually. The decision would bring great benefits to young women with germline BRCA mutations.

Breast cancer development and progression: Risk factors, cancer stem cells, signaling pathways, genomics, and molecular pathogenesis

As the most commonly occurring cancer in women worldwide, breast cancer poses a formidable public health challenge on a global scale. Breast cancer consists of a group of biologically and molecularly heterogeneous diseases originated from the breast. While the risk factors associated with this cancer varies with respect to other cancers, genetic predisposition, most notably mutations in BRCA1 or BRCA2 gene, is an important causative factor for this malignancy. Breast cancers can begin in different areas of the breast, such as the ducts, the lobules, or the tissue in between. Within the large group of diverse breast carcinomas, there are various denoted types of breast cancer based on their invasiveness relative to the primary tumor sites. It is important to distinguish between the various subtypes because they have different prognoses and treatment implications. As there are remarkable parallels between normal development and breast cancer progression at the molecular level, it has been postulated that breast cancer may be derived from mammary cancer stem cells. Normal breast development and mammary stem cells are regulated by several signaling pathways, such as estrogen receptors (ERs), HER2, and Wnt/β-catenin signaling pathways, which control stem cell proliferation, cell death, cell differentiation, and cell motility. Furthermore, emerging evidence indicates that epigenetic regulations and noncoding RNAs may play important roles in breast cancer development and may contribute to the heterogeneity and metastatic aspects of breast cancer, especially for triple-negative breast cancer. This review provides a comprehensive survey of the molecular, cellular and genetic aspects of breast cancer.

Mutational analysis of candidate genes in Israeli male breast cancer cases

PURPOSE

To define the mutational spectrum of several candidate gene mutations in Israeli male breast cancer cases.

METHODS

MBC cases counselled at the Oncogenetics unit, Sheba Medical Center from January 1998 to June 2017 were included. Relevant clinical and oncological data and cancer phenotype were retrieved. All participants were genotyped for the predominant Jewish BRCA1 and BRCA2 germline mutations using a chip-based assay. Those who tested negative were further genotyped for three recurring mutations in CHEK2 (c.1100delC, p.S428F, p.I157T), and single mutations in the FANCM (c.5791C>T), and RAD51D (c.556C>T) genes, by direct sequencing. The ethics committee approved the study.

RESULTS

Overall, 61 MBC were identified and genotyped, 41 (67.2%) were Ashkenazim, age at diagnosis was 58.1 ± 12.6 years, and 31 (50.8%) had a family history of cancer. Of genotyped individuals, one (1.6%) harboured the 185delAG* BRCA1 mutation, 7 (11.4%) the 6174delT*BRCA2 mutation and 2 (3.2%) other recurring mutations in BRCA2 (overall 10/61-16.4% BRCA1/BRCA2 mutation carriers). Of BRCA-negative cases, 3/51 (5.9%) carried the p.S428F *CHEK2 mutation. None was a carrier of the other genotyped mutations in CHEK2, FANCM or RAD51D.

CONCLUSION

BRCA1, BRCA2 and CHEK2 germline mutations contribute to inherited predisposition to MBC in Israel.

The Epidemiology of Male Breast Cancer

Male breast cancer is a rare disease, accounting for only 1% of breast cancer diagnoses in the USA. The current literature suggests that genetic factors including BRCA2 mutations, family history, age, androgen/estrogen imbalance, and environmental exposures may predispose to male breast cancer. In this manuscript, we will review known and possible risk factors for male breast cancer, as well as describe the clinical patterns of the disease.

Molecular profiling of male breast cancer - lost in translation?

Breast cancer is the most common cancer form in women and it has been extensively studied on the molecular level. Male breast cancer (MBC), on the other hand, is rare and has not been thoroughly investigated in terms of transcriptional profiles or genomic aberrations. Most of our understanding of MBC has therefore been extrapolated from knowledge of female breast cancer. Although differences in addition to similarities with female breast cancer have been reported, the same prognostic and predictive markers are used to determine optimal management strategies for both men and women diagnosed with breast cancer. This review is focused on prognosis for MBC patients, prognostic and predictive factors and molecular subgrouping; comparisons are made with female breast cancer. Information was collected from relevant literature on both male and female breast cancer from the MEDLINE database between 1992 and 2014. MBC is a heterogeneous disease, and on the molecular level many differences compared to female breast cancer have recently been revealed. Two distinct subgroups of MBC, luminal M1 and luminal M2, have been identified which differ from the well-established intrinsic subtypes of breast cancer in women. These novel subgroups of breast cancer therefore appear unique to MBC. Furthermore, several studies report inferior survival for men diagnosed with breast cancer compared to women. New promising prognostic biomarkers for MBC (e.g. NAT1) deserving further attention are reviewed. Further prospective studies aimed at validating the novel subgroups and recently proposed biomarkers for MBC are warranted to provide the basis for optimal patient management in this era of personalized medicine. This article is part of a Directed Issue entitled: Rare Cancers.

Male breast cancer: risk factors, biology, diagnosis, treatment, and survivorship

BACKGROUND

The causes, optimal treatments, and medical/psychosocial sequelae of breast cancer in men are poorly understood.

DESIGN

A systematic review of the English language literature was conducted to identify studies relevant to male breast cancer between 1987 and 2012 and including at least 20 patients. Searches were carried out on PubMed using the title terms 'male breast cancer' or 'male breast carcinoma'.

RESULTS

Relevant published data regarding risk factors, biological characteristics, presentation and prognosis, appropriate evaluation and treatment, and survivorship issues in male breast cancer patients are presented. BRCA2 mutations, age, conditions that alter the estrogen/androgen ratio, and radiation are proven risk factors. Disease biology is distinct in men, but diagnostic approaches and treatments for men are generally extrapolated from those in women due to inadequate research in men. Survivorship issues in men may include sexual and hormonal side-effects of endocrine therapies as well as unique psychosocial impacts of the disease.

CONCLUSION

Further research is needed to address gaps in knowledge pertaining to care of male breast cancer patients and survivors.

Haplotype structure in Ashkenazi Jewish BRCA1 and BRCA2 mutation carriers

Three founder mutations in BRCA1 and BRCA2 contribute to the risk of hereditary breast and ovarian cancer in Ashkenazi Jews (AJ). They are observed at increased frequency in the AJ compared to other BRCA mutations in Caucasian non-Jews (CNJ). Several authors have proposed that elevated allele frequencies in the surrounding genomic regions reflect adaptive or balancing selection. Such proposals predict long-range linkage disequilibrium (LD) resulting from a selective sweep, although genetic drift in a founder population may also act to create long-distance LD. To date, few studies have used the tools of statistical genomics to examine the likelihood of long-range LD at a deleterious locus in a population that faced a genetic bottleneck. We studied the genotypes of hundreds of women from a large international consortium of BRCA1 and BRCA2 mutation carriers and found that AJ women exhibited long-range haplotypes compared to CNJ women. More than 50% of the AJ chromosomes with the BRCA1 185delAG mutation share an identical 2.1 Mb haplotype and nearly 16% of AJ chromosomes carrying the BRCA2 6174delT mutation share a 1.4 Mb haplotype. Simulations based on the best inference of Ashkenazi population demography indicate that long-range haplotypes are expected in the context of a genome-wide survey. Our results are consistent with the hypothesis that a local bottleneck effect from population size constriction events could by chance have resulted in the large haplotype blocks observed at high frequency in the BRCA1 and BRCA2 regions of Ashkenazi Jews.

Mutations in BRCA2 and PALB2 in male breast cancer cases from the United States

Male breast cancer (MBC) is an uncommon disease with a frequency of approximately one in 1000. Due to the rarity of MBC, it is understudied and its etiology is poorly understood. Our objectives are to determine the frequency of pathogenic mutations in BRCA2 and PALB2 in MBC cases and to investigate the correlations between mutation status and cancer phenotypes. Single strand conformation polymorphism analysis, direct sequencing, and multiplex ligation-dependent probe amplification were employed to screen for mutations in the BRCA2 gene, followed by direct sequencing of the PALB2 gene in BRCA2-negative MBC cases. Pathogenic BRCA2 mutations were identified in 18 of the 115 MBC cases, including four of the ten cases (40%) from breast cancer families and 14 of the 105 cases (13%) unselected for family history of breast cancer. The difference in BRCA2-mutation frequencies between cases with and without family history of breast cancer was not statistically significant (P = 0.145), suggesting that family history is not a strong predictor of carrying a mutation in males. We observed a highly significant association of carrying a pathogenic BRCA2 mutation with high tumor grade (P < 0.001) and a weak association with positive lymph nodes (P < 0.02). Of the 97 BRCA2-negative MBC cases, we identified one PALB2 mutation with confirmed pathogenicity and one mutation predicted to be pathogenic, a prevalence of pathogenic PALB2-mutation of 1-2%. Based on our results and previous studies, genetic testing for BRCA2 should be recommended for any diagnosed MBC case, regardless of family history of breast cancer.

How old is this mutation? - a study of three Ashkenazi Jewish founder mutations

BACKGROUND

Several founder mutations leading to increased risk of cancer among Ashkenazi Jewish individuals have been identified, and some estimates of the age of the mutations have been published. A variety of different methods have been used previously to estimate the age of the mutations. Here three datasets containing genotype information near known founder mutations are reanalyzed in order to compare three approaches for estimating the age of a mutation. The methods are: (a) the single marker method used by Risch et al., (1995); (b) the intra-allelic coalescent model known as DMLE, and (c) the Goldgar method proposed in Neuhausen et al. (1996), and modified slightly by our group. The three mutations analyzed were MSH2*1906 G->C, APC*I1307K, and BRCA2*6174delT.

RESULTS

All methods depend on accurate estimates of inter-marker recombination rates. The modified Goldgar method allows for marker mutation as well as recombination, but requires prior estimates of the possible haplotypes carrying the mutation for each individual. It does not incorporate population growth rates. The DMLE method simultaneously estimates the haplotypes with the mutation age, and builds in the population growth rate. The single marker estimates, however, are more sensitive to the recombination rates and are unstable. Mutation age estimates based on DMLE are 16.8 generations for MSH2 (95% credible interval (13, 23)), 106 generations for I1037K (86-129), and 90 generations for 6174delT (71-114).

CONCLUSIONS

For recent founder mutations where marker mutations are unlikely to have occurred, both DMLE and the Goldgar method can give good results. Caution is necessary for older mutations, especially if the effective population size may have remained small for a long period of time.

Genetic counseling and testing for common hereditary breast cancer syndromes: a paper from the 2007 William Beaumont hospital symposium on molecular pathology

Throughout the past 15 years, the identification of several genes associated with hereditary breast cancer has fueled the growth of clinical genetic counseling and testing services. In addition, increased knowledge of the genetic and molecular pathways of the known hereditary breast cancer genes, as well as an increased understanding of the impact of testing on individuals has added to the ability to identify, manage, and provide psychosocial support for mutation carriers. This review provides an overview of the clinical features, cancer risks, causative genes, and management for hereditary breast and ovarian cancer syndrome, Cowden syndrome, and Li-Fraumeni syndrome. This article summarizes the genetic counseling process and genetic test result interpretation, including a review of the key elements involved in the provision of risk assessment and informed consent, as well as a review of the risks, benefits, and limitations of cancer susceptibility genetic testing.

BRCA2 gene mutations in Slovenian male breast cancer patients

Male breast cancer (MBC) is a rare disease, comprising less than 1% of breast cancer patients in Slovenia. Some inherited cases are due to the mutations of BRCA1 or BRCA2 genes. There is no information available about the frequency of BRCA gene mutations in Slovenian MBC population. The purpose of this study was to characterize BRCA germline mutations in Slovenian MBC patients. Forty-one patients who were diagnosed with breast cancer at the Institute of Oncology Ljubljana between 1970 and 2006 were proposed to take part in this study. Of them, 27 agreed to follow a genetic counseling session and 25 patients agreed to provide a blood sample for genetic testing. The BRCA1 and BRCA2 genes from the MBC patients were screened for four highly recurrent mutations in the Slovenian population. When an additional breast cancer case or an ovarian cancer was present in the family, a more extended analysis was performed. No BRCA1 mutations were found. A BRCA2 gene mutation was identified in four MBC patients. Three of them carried the Slovenian founder mutation IVS16-2A>G. All four mutations were confined to the patients with a family history of breast cancer. Among the MBC patients with a family history of breast cancer in the first- or second-degree relatives, the frequency of BRCA2 gene mutation was 50%. The median age of the patients with a BRCA2 gene mutation was 60 years, not significantly different from those without a mutation. The BRCA2 mutations were diagnosed in 16% of our MBC patients.

Second cancers in patients with male breast cancer: a literature review

PURPOSE

The risk of second malignancies among female breast cancer patients has been studied for decades. In contrast, very little is known about second primary tumors in men. Risk factors for breast cancer in men, including genetic, hormonal and environmental factors, provide parallels to the etiology of breast cancer in women. This review considers the literature related to the risk of developing a second cancer in patients with male breast cancer.

MATERIALS AND METHODS

A systematic review of the literature between 1966 and 2007 was conducted and acceptable articles used for analysis. All retrieved articles were screened to identify any papers that had been missed. Studies were included if they discussed the risk of subsequent malignancy in patients with male breast cancer.

RESULTS

Patients with history of male breast cancer have an increased risk of a second ipsilateral, or contralateral breast cancer (standardized incidence ratio 30-110). The risk of subsequent contralateral breast cancer was highest in men under 50 years of age at the time of the diagnosis of the initial cancer. The data on non-breast second primary cancers is diverse. One study has suggested an increased incidence of cancers of the small intestine, prostate, rectum and pancreas, and of non-melanoma skin cancer and myeloid leukaemia. Other investigators did not find an increase in the overall risk of subsequent cancer development in men diagnosed initially with primary breast cancer. Although sarcoma, lung and esophageal cancers are well recognized complications of radiation therapy for female breast cancer, there is no evidence for the association of these cancers following radiation therapy in male breast cancer.

CONCLUSIONS

Although the incidence of second primary cancer in patients with primary male breast cancer requires further study, male breast cancer survivors should probably undergo periodic screening for the early detection of second breast cancers and other adverse health effects.

Breast cancer risk among male BRCA1 and BRCA2 mutation carriers

Men who carry germline mutations in the BRCA2 gene have a higher risk of developing breast carcinoma than men in the general population. Men who carry germline mutations in the BRCA1 gene may also be at a higher risk for breast carcinoma, but this association is not as well established. We evaluated the risks of developing breast carcinoma for male BRCA1 and BRCA2 mutation carriers in the US population based on data from 1939 families with 97 male subjects with breast carcinoma that were collected from eight centers across the National Cancer Institute's Cancer Genetics Network. At all ages, the cumulative risks of male breast cancer were higher in both BRCA1 and BRCA2 mutation carriers than in noncarriers. The relative risks of developing breast cancer were highest for men in their 30s and 40s and decreased with increasing age. Both the relative and cumulative risks were higher for BRCA2 mutation carriers than for BRCA1 mutation carriers. The estimated cumulative risk of breast carcinoma for male BRCA1 mutation carriers at age 70 years was 1.2% (95% confidence interval [CI] = 0.22% to 2.8%) and for BRCA2 mutation carriers, 6.8% (95% CI = 3.2% to 12%).

Similar prevalence of founder BRCA1 and BRCA2 mutations among Ashkenazi and non-Ashkenazi men with breast cancer: evidence from 261 cases in Israel, 1976-1999

To evaluate the potential contribution of mutations in the BRCA1 and BRCA2 genes to male breast cancer (MBC), we expanded a previous study to screen a total of 261 Israeli men diagnosed with breast carcinoma. A total of 21 BRCA2 6174delT and 8 BRCA1 185delAG mutations were found. Similar frequencies of BRCA1 and BRCA2 mutation carriers were found among Ashkenazi (12.8%) and non-Ashkenazi Jews (9.1%). The combined prevalence of BRCA1/BRCA2 founder mutations among Ashkenazi Jewish men is slightly higher than for women, due to a higher frequency of BRCA2 mutations.

Large genomic rearrangement in BRCA1 and BRCA2 and clinical characteristics of men with breast cancer in the United States

PURPOSE

Male breast cancer has been linked extensively to mutations of BRCA2 and, to a lesser extent, BRCA1. The aim of this study was to perform a comprehensive analysis of point mutations and genomic rearrangements in the BRCA1 and BRCA2 genes in 41 men with breast cancer.

PATIENTS AND METHODS

Deleterious point mutations were identified in 15 men (37%): 4 (10%) and 11 (27%) in BRCA1 and BRCA2, respectively. In the remaining 26 men, we screened for large genomic rearrangements in BRCA1 and BRCA2 using multiplex ligation-dependent probe amplification.

RESULTS

We did not detect any large genomic rearrangements. Men with BRCA1 or BRCA2 mutations were more likely to have a family history of prostate cancer (P = 0.025). Three of 4 male breast tumors with BRCA1 mutations (75%) were estrogen receptor positive. Whereas some studies have reported an 8%-0 rate of large BRCA2 genomic rearrangement in familial male breast cancer cases, we did not detect any such genomic rearrangements in BRCA1 or BRCA2 for our cohort.

CONCLUSION

Despite this negative finding, our study, to the best of our knowledge, is one of the first to comprehensively screen for mutations, including large genomic rearrangement mutations, in BRCA1 and BRCA2 in men with breast cancer in the United States.

BRCA1 genetic testing in 106 breast and ovarian cancer families from Southern Italy (Sicily): a mutation analyses

PURPOSE

To evaluate the contribution of germline BRCA1 mutations in the incidence of hereditary and familial Breast Cancer (BC) and/or Ovarian Cancer (OC) in patients from Southern Italy (in the region of Sicily) and to identify a possible association between the higher frequency of BRCA1 mutations and a specific familial profile.

EXPERIMENTAL DESIGN

A consecutive series of 650 patients with BC and/or OC diagnosed between 1999 and 2005 were recruited from the Southern Italian region of Sicily, after interview at the "Regional Reference Centre for the Characterization and Genetic Screening of Hereditary Tumors" at the University of Palermo. Genetic counselling allowed us to recruit a total of 106 unrelated families affected with breast and/or ovarian cancer screened for mutations occurring in the whole BRCA1 gene by automatic direct sequencing.

RESULTS

Germline BRCA1 mutations were found in 17 of 106 (16%) Sicilian families. The HBOC profile had a major frequency (66%) of mutations (P < 0.01). A total of 28 sequence variants was identified. Seven of these were pathogenic, 5 unknown biological variant (UV) and 16 polymorphisms. We also identified a pathological mutation (4843delC) as a possible Sicilian founder mutation.

CONCLUSIONS

The present study is the first BRCA1 disease-associated mutations analysis in Southern Italian families. The early age of onset of such tumors and the association with the HBOC familial profile could be two valid screening factors for the identification of BRCA1 mutation carriers. Finally, we identified a BRCA1 mutation with a possible founder effect.

BRCA2 mutations in 154 finnish male breast cancer patients

The etiology and pathogenesis of male breast cancer (MBC) are poorly known. This is due to the fact that the disease is rare, and large-scale genetic epidemiologic studies have been difficult to carry out. Here, we studied the frequency of eight recurrent Finnish BRCA2 founder mutations in a large cohort of 154 MBC patients (65% diagnosed in Finland from 1967 to 1996). Founder mutations were detected in 10 patients (6.5%), eight of whom carried the 9346(-2) A>G mutation. Two novel mutations (4075 delGT and 5808 del5) were discovered in a screening of the entire BRCA2 coding region in 34 samples. However, these mutations were not found in the rest of the 120 patients studied. Patients with positive family history of breast and/or ovarian cancer were often BRCA2 mutation carriers (44%), whereas those with no family history showed a low frequency of involvement (3.6%; P < .0001). Finally, we found only one Finnish MBC patient with 999 del5, the most common founder mutation in Finnish female breast cancer (FBC) patients, and one that explains most of the hereditary FBC and MBC cases in Iceland. The variation in BRCA2 mutation spectrum between Finnish MBC patients and FBC patients in Finland and breast cancer patients in Iceland suggests that modifying genetic and environmental factors may significantly influence the penetrance of MBC and FBC in individuals carrying germline BRCA2 mutations in some populations.

Epidemiology of Male Breast Cancer

Breast cancer in men is a rare disease, accounting for ∼1% of all breast cancer cases. Although the epidemiologic literature regarding female breast cancer is extensive, relatively little is known about the etiology of male breast cancer (MBC). This review is intended to summarize the existing body of evidence on genetic and epidemiologic risk factors for breast cancer in men. Overall, the epidemiology of MBC presents similarities with the epidemiology of female breast cancer. Major genetic factors associated with an increased risk of breast cancer for men include BRCA2 mutations, which are believed to account for the majority of inherited breast cancer in men, Klinefelter syndrome, and a positive family history. Suspected genetic factors include AR gene mutations, CYP17 polymorphism, Cowden syndrome, and CHEK2. Epidemiologic risk factors for MBC include disorders relating to hormonal imbalances, such as obesity, testicular disorders (e.g., cryptorchidism, mumps orchitis, and orchiectomy), and radiation exposure. Suspected epidemiologic risk factors include prostate cancer,prostate cancer treatment, gynecomastia, occupational exposures (e.g., electromagnetic fields, polycyclic aromatic hydrocarbons, and high temperatures), dietary factors (e.g., meat intake and fruit and vegetable consumption), and alcohol intake.

Cancer risks for male carriers of germline mutations in BRCA1 or BRCA2: a review of the literature

Major risks conferred by BRCA1 and BRCA2 in women are for cancers of the breast, ovary, fallopian tube, and peritoneum. Male carriers of mutations in BRCA1 or BRCA2 are also susceptible to cancer; however, their risks remain poorly understood and their optimal clinical management has not yet been defined. This article reviews studies that estimate risk associated with mutations in BRCA1 or BRCA2, with a focus on the cancer sites most relevant to men. Male BRCA1 mutation carriers are at increased risk of cancers of the prostate and breast. Evidence supporting increased susceptibility to colon cancer is limited. In contrast to women, who have a greater lifetime risk of cancer with mutations of the BRCA1 gene, BRCA2 is the more important gene for men. The spectrum of cancers is wide for BRCA2 and some studies report that the overall cancer risk for male BRCA2 carriers exceeds the risk for female carriers. In particular, the relative risk to male BRCA2 mutation carriers is high before age 65 years, largely attributable to breast, prostate, and pancreatic cancers. BRCA2 mutation carriers are also at risk of stomach cancer and melanoma (of the skin and eye). Additional research into risks to male BRCA1 or BRCA2 mutation carriers is necessary, specifically to determine the magnitude of excess cancer risk among BRCA2 carriers and to increase our understanding of the basis for the observed site-specificity in cancer development.

Hereditary breast cancer in Jews

A family history of breast cancer poses higher risks for Jewish versus non-Jewish women, particularly for early-onset breast cancer. This appears to be due in large part to the high prevalence (2.5%) of three BRCA1 and BRCA2 founder mutations in Ashkenazi Jews. About 4 to 8% of non-Jewish male breast cancer cases versus 19% of Jewish male breast cancer cases carry germline BRCA mutations. Jewish women are disproportionately impacted by BRCA mutations throughout life, with a 10% carrier rate for breast cancer diagnosed at any age and a 21 to 30% carrier rate for breast cancer diagnosed by age 40. Comparable rates in non-Jewish populations are 6.1% for breast cancer diagnosed before age 50. Lifetime penetrance estimates based on genotyping of probands have ranged widely in Jewish and non-Jewish populations. However, a study of 1008 Jewish women with breast cancer which extended genotyping to relatives found high penetrance rates with considerably smaller standard errors. This study and studies of early-onset incident breast cancer in non-Jews have found that at least half of high-risk cases would be missed by family history screening alone. While the carrier rate in non-Jewish populations is too low to consider genetic screening, the carrier rate in Ashkenazi Jews is high and genetic screening poses fewer technical barriers. The high genetic attributable cancer risks of Ashkenazi BRCA founder mutations, the sobering lethality of ovarian and early onset breast cancers, and the increasing clarity about effectiveness of medical interventions make imperative further dialogue and research to keep guidelines for genetic screening up to date.

Population attributes affecting the prevalence of BRCA mutation carriers in epithelial ovarian cancer cases in israel

OBJECTIVE

The objective was to evaluate the prevalence of BRCA1/2 mutations in selected categories of ovarian cancer patients in Israel.

METHODS

Blood samples and specimens of ovarian tumors were obtained in the course of a national case control study of women with ovarian cancer in Israel. Eight hundred ninety-six patients with epithelial ovarian cancer, 40 cases with nonepithelial ovarian cancer, and 68 with primary peritoneal cancer were tested for the BRCA mutations. Analysis of the three common BRCA mutations in Israel (185delAG, 5382insC in BRCA1, and 6174delT in BRCA2) was done using a multiplex polymerase chain reaction assay. A multivariate logistic regression model was used to assess the association of mutation carrier status and other factors (age, origin, family history, and clinical variables).

RESULTS

Of the 779 invasive epithelial ovarian cancer cases, 29.4% were mutation carriers. The prevalence of the mutations was higher among women below age 60 and in more advanced cases. The prevalence was low in mucinous tumors. There was almost a twofold excess of mutations among women with positive family history (45.7%), but still 26.5% of the family history negative cases were carriers. As expected, we found a higher rate of mutation carriers among the Ashkenazi group (34.2%) and 55% among Ashkenazi women with positive family history. No subjects born in North Africa were mutation positive.

CONCLUSION

BRCA mutations are strongly associated with ovarian cancer and they are present in variable rates in distinct age, ethnic, and histopathologic categories.

Frequency of BRCA mutations in primary peritoneal carcinoma in Israeli Jewish women

OBJECTIVE

The aim of the present study was to compare demographic and clinical characteristics of primary peritoneal carcinoma (PPC) to ovarian carcinoma (OvC) with regard to BRCA mutation frequencies.

METHODS

Incident cases of histologically confirmed cancer of the ovary or peritoneum diagnosed in Israeli Jewish women between March 1, 1994, and June 30, 1999, were identified within the framework of an ongoing nationwide epidemiological study of these neoplasms in Israel. The present study comprises 609 (81.5% of 747) Jewish women with epithelial stage III-IV OvC and 68 (77.3% of 88) Jewish women with PPC who were genetically tested for the BRCA mutations. Data from each patient were collected by the aid of a prestructured questionnaire and medical records. Blood samples or tumor tissue was tested for the 185delAG and 5382insC mutations in BRCA1 and the 6174delT mutations in BRCA2.

RESULTS

A carrier rate of 28% of any BRCA 1/2 mutation was observed among the PPC group and of 30% among the invasive stage III-IV OvC. No differences were found between PPC and OvC neither in the overall distribution of BRCA1/2 mutation carrier rates nor according to type of mutation, age, ethnic origin, and histologic subtype. Among women with a positive family history, a higher rate of mutation carriers was observed in the PPC group compared to the OvC group (72.7 vs 43.8%, respectively, P = 0.07).

CONCLUSIONS

The similar frequency distribution of BRCA1/2 mutations in PPC and OvC observed in the present study indicates that these mutations may predispose to PPC as well and that this neoplasm is part of the hereditary breast-ovarian cancer syndrome.

Risk assessment & genetic testing

Ovarian cancer is the fifth most common cause of cancer death in women in Western countries and family history is one of the strongest known risk factors. Approximately 5 to 13% of all ovarian cancer cases are caused by the inheritance of cancer predisposing genes with an autosomal pattern of transmission. The inherited fraction of ovarian cancer may differ between populations. Based on analysis of familial ovarian cancer pedigrees and other epidemiological studies, three hereditary ovarian cancer syndromes have been defined. The identification of the genes responsible for most hereditary ovarian cancers has open a new area of early detection methods and preventive procedures specifically dedicated to women identified as carrying ovarian cancer predisposing genes. Predictive oncology is best performed by a dedicated unit with professionals aware of all the issues surrounding genetic testing.

Male breast carcinoma in Israel: higher incident but possibly prognosis in Ashkenazi Jews

BACKGROUND

Little information is available regarding male breast carcinoma. However, cumulative data have suggested a propensity for the disease among Ashkenazi Jews. Because Ashkenazi Jews comprise one of the major ethnic groups in Israel, the authors conducted a local study to shed more light on the features of this rare disease.

METHODS

From 1960 to 2000, 131 men with breast carcinoma were treated at the Rabin Medical Center or the Rambam Medical Center, and, from 1980 to 1997, 470 patients with this diagnosis were recorded in the Israel Cancer Registry. These two data bases were used to analyze the epidemiologic and clinicopathologic characteristics of male breast carcinoma in Israel.

RESULTS

Seventy-eight percent of the 131 Jewish patients were Ashkenazi. Most of their clinical characteristics were similar to those of their Sephardic counterparts. However, there was a statistically significant difference in the pattern of comorbidity between these groups (P = 0.000), and there was a trend toward a younger age at onset and more advanced tumor stage at the time of diagnosis for the Sephardim. It also was found that Sephardic origin was associated with poorer outcome (P = 0.03). Analysis of the Cancer Registry data base revealed an 80% increase in the risk of the disease for Ashkenazi Jews compared with Sephardic Jews (odds ratio, 1.8; 95% confidence interval, 1.4-2.3; P = 0.001). Survival analysis from this source suggested a poorer outcome for Sephardic Jews compared with Ashkenazi Jews (62% vs. 64.3% estimated 5-year survival rates, respectively; P = 0.08).

CONCLUSIONS

Analyses of two independent data bases, patient charts, and a cancer registry indicate that breast carcinoma seems to be more prevalent among Ashkenazi Jewish men. At the same time, affected Ashkenazi patients may have a more favorable outcome than their Sephardic counterparts.

Prevalence of the BRCA2 6174 del T mutation in Israeli uveal melanoma patients

Substantial differences exist in the incidence rates of uveal melanoma (UM) among Israeli Jewish subpopulations: high in immigrants from North America and Europe (Ashkenazic) and low in immigrants from Africa and Asia (Sepharadic). This trend persists in Israeli-born individuals when stratified by their ancestral place of birth. There have been several anecdotal reports of uveal melanoma occurring in breast cancer families with mutations in the BRCA2 gene as well as one systematic study reporting BRCA2 mutations in UM. A single BRCA2 mutation, 6174 del T, occurs in about 1% of the Ashkenazic population and rarely in non-Ashkenazic. To assess the contribution of this germline mutation to uveal melanoma in Jewish Israeli patients, we tested this relationship through analysis of blood samples from a series of UM patients. A total of 153 cases (84 female, 69 male) were available for study, which represents 30% of all cases of UM diagnosed in Israel during the period 1984-1999 (82% for the period 1992-1999). Of the 143 UM patients for which a result could be obtained (4 due to refusals, 6 due to damage to the blood sample), 4 (2.8%, 95% confidence interval [CI] 0-5.6) carried the 6174 del T mutation. Assuming a population frequency of the mutation of 1% as estimated among Ashkenazic Jews in the United States, the probability of observing 4 or more carriers with the 6174 del T mutation, assuming no relationship between uveal melanoma and BRCA2, is 0.057. Although our study confirms the relationship between uveal melanoma and BRCA2, it is clear that the 6174 del T mutation accounts for only a small fraction of all Israeli UM cases. Therefore, BRCA2 mutations are likely to account for an even smaller proportion in populations with low frequencies of BRCA2 alterations.

Effect of BRCA mutations on the length of survival in epithelial ovarian tumors

PURPOSE

To study the role of BRCA mutations in ovarian cancer survival.

PATIENTS AND METHODS

Blood samples and specimens of ovarian tumors (whenever blood samples were not available) at the time of the primary surgery were obtained in the course of a nationwide case-control study of women with ovarian cancer in Israel. The three common BRCA mutations in Israel (185delAG, 5382insC, and 6174delT) were analyzed with a multiplex polymerase chain reaction to amplify the exons containing the three mutations using fluor-labeled primers in a single reaction. Because each mutation is a small insertion or deletion, they can be detected as length polymorphisms. Patients were followed for up to 5 years (range, 20 to 64 months). Statistical analysis was performed using the Kaplan-Meier method and the log-rank test. Stepwise Cox regression analysis was used for determination of independent prognostic factors.

RESULTS

This report is based on 896 blood or tumor specimens analyzed for the presence of the BRCA mutations. Of these, 234 women (26.1%) were found to be positive. A significant difference in survival pattern was found between BRCA1/BRCA2 carriers and noncarriers among the women with invasive ovarian cancer (median survival, 53.4 months v. 37.8 months; 3-year survival, 65.8% v. 51.9%, respectively). These differences were independent of age at diagnosis or stage of the disease.

CONCLUSION

Our data indicate that the survival of patients with ovarian cancer is affected by BRCA germline mutation, at least in the early years after diagnosis.

BRCA1 and BRCA2 mutations in a population-based study of male breast cancer

BACKGROUND

The contribution of BRCA1 and BRCA2 to the incidence of male breast cancer (MBC) in the United Kingdom is not known, and the importance of these genes in the increased risk of female breast cancer associated with a family history of breast cancer in a male first-degree relative is unclear.

METHODS

We have carried out a population-based study of 94 MBC cases collected in the UK. We screened genomic DNA for mutations in BRCA1 and BRCA2 and used family history data from these cases to calculate the risk of breast cancer to female relatives of MBC cases. We also estimated the contribution of BRCA1 and BRCA2 to this risk.

RESULTS

Nineteen cases (20%) reported a first-degree relative with breast cancer, of whom seven also had an affected second-degree relative. The breast cancer risk in female first-degree relatives was 2.4 times (95% confidence interval [CI] = 1.4-4.0) the risk in the general population. No BRCA1 mutation carriers were identified and five cases were found to carry a mutation in BRCA2. Allowing for a mutation detection sensitivity frequency of 70%, the carrier frequency for BRCA2 mutations was 8% (95% CI = 3-19). All the mutation carriers had a family history of breast, ovarian, prostate or pancreatic cancer. However, BRCA2 accounted for only 15% of the excess familial risk of breast cancer in female first-degree relatives.

CONCLUSION

These data suggest that other genes that confer an increased risk for both female and male breast cancer have yet to be found.

Parity, oral contraceptives, and the risk of ovarian cancer among carriers and noncarriers of a BRCA1 or BRCA2 mutation

BACKGROUND

Multiparity and the use of oral contraceptives reduce the risk of ovarian cancer, but their effects on this risk in women with a BRCA1 or BRCA2 mutation are unclear.

METHODS

We conducted a population-based case-control study of ovarian cancer among Jewish women in Israel. Women were tested for the two founder mutations in BRCA1 and the one founder mutation in BRCA2 that are known to be common among Jews. We estimated the effects of parity and oral-contraceptive use on the risk of ovarian cancer in carriers and noncarriers in separate analyses that included all control women, who did not have ovarian cancer.

RESULTS

Of 751 controls who underwent mutation analysis, 13 (1.7 percent) had a BRCA1 or BRCA2 mutation, whereas 244 of 840 women with ovarian cancer (29.0 percent) had a BRCA1 or BRCA2 mutation. Overall, each additional birth and each additional year of use of oral contraceptives were found to lower the risk of ovarian cancer, as expected. Additional births were protective in separate analyses of carriers and noncarriers, but oral-contraceptive use appeared to reduce the risk only in noncarriers; among carriers, the reduction in the odds of ovarian cancer was 12 percent per birth (95 percent confidence interval, 2.3 to 21 percent) and 0.2 percent per year of oral-contraceptive use (-4.9 to 5.0 percent).

CONCLUSIONS

The risk of ovarian cancer among carriers of a BRCA1 or BRCA2 mutation decreases with each birth but not with increased duration of use of oral contraceptives. These data suggest that it is premature to use oral contraceptives for the chemoprevention of ovarian cancer in carriers of such mutations.

The founder mutations in the BRCA1, BRCA2, and ATM genes in Moroccan Jewish women with breast cancer

To gain insight into the molecular mechanisms underlying the inherited predisposition to breast cancer in non-Ashkenazi Jews, we genotyped 54 Jewish Moroccan women with breast cancer, unselected for family history of cancer, for the predominant Jewish mutations in BRCA1, BRCA2, and ATM. One patient (2%) was found to have the 185de1AG BRCA1 mutation, none was a carrier of the 6174delT BRCA2 mutation, and 2/54 (4%) were heterozygous for the ATM mutation. These rates were not significantly different from the rates in the general non-Ashkenazi population. These preliminary data may indicate that the predominant Jewish mutations in BRCA1, BRCA2, and ATM genes contribute little, if any, to breast cancer predisposition and risk among Moroccan Jews.

Genetic analyses of male breast cancer in Israel

Male breast cancer is a rare disorder, and little is known about the molecular mechanisms associated with the tumorigenic process. We genotyped 31 Jewish Israeli males with breast cancer for the predominant Jewish BRCA1 (185delAG, 5382InsC) and BRCA2 (6174delT) germline mutations: 11 individuals from high-risk families and 20 patients unselected for family history of cancer. Two patients of the high-risk group (18.2%) displayed germline mutations: one harbored the 185delAG BRCA1 mutation, and the other the 6174delT mutation in BRCA2. None of the unselected patients displayed any mutation. In 2 patients, complete mutation analysis of the BRCA2 gene did not reveal any disease-associated mutations. We conclude that the predominant Jewish germline mutations in BRCA1/BRCA2 contribute to male breast cancer in Israel, primarily in Ashkenazi individuals with a family history of cancer.

The rate of the 6174delT founder Jewish mutation in BRCA2 in patients with non-colonic gastrointestinal tract tumours in Israel

Inherited predisposition occurs in 5-10% of all gastrointestinal (GI) cancer patients, but with the exception of colorectal cancer (CRC), the genes involved in conferring genetic susceptibility remain largely unknown. Indirect evidence indicates that germline mutations in BRCA2 might be associated with an increased risk for various GI malignancies. A single mutation (6174delT) occurs in the BRCA2 gene in high-risk breast ovarian cancer families of Jewish Ashkenazi origin, in about 1% of the general Ashkenazi population, and rarely in non-Ashkenazi Jews. In order to assess the contribution of this germline mutation to non-CRC GI cancer in Jewish Israeli patients, we tested 70 unselected, consecutive Jewish Ashkenazi patients with gastrointestinal malignancies for this mutation by PCR amplification and modified restriction enzyme digests. Patients' age range was 38-90 years (mean 65.8+/-11.8 years). The most common malignancies were gastric cancer (n = 35) and exocrine pancreatic cancer (n = 23). Overall, 6 mutation carriers were detected: 3/23 (13%) of the patients with pancreatic cancer, 2/35 (5.7%) of patients with gastric cancer and 1/4 (25%) of patients with bile duct cancer. The 8.6% mutation carrier rate among patients is a rate significantly higher than that of the general Ashkenazi population (1.16%, P = 0.0002). We conclude that the rate of the predominant Jewish BRCA2 mutation in patients with gastric and pancreatic cancer significantly differ from that of the general population of the same ethnic origin. Thus, BRCA2 mutations probably contribute to gastrointestinal tumorigenesis other then colon cancer, and the surveillance scheme for mutation carriers should incorporate this information.