Absence of genomic BRCA1 and BRCA2 rearrangements in Ashkenazi breast and ovarian cancer families

A substantial proportion of Ashkenazi Jewish (AJ) breast and ovarian cancer families carry one of three founder mutations in BRCA1 (185delAG, 5382InsC) and BRCA2 (6174delT). Non-founder mutations are identified in another 2–4% of such families. The extent to which major genomic rearrangements in BRCA contribute to breast and ovarian cancer in the Ashkenazim is not well understood. We identified AJ individuals with breast and/or ovarian cancer undergoing hereditary breast/ovarian cancer risk assessment since 2006 without evidence of a deleterious mutation on BRCA gene sequencing who were screened for major gene rearrangements in BRCA1 and BRCA2. For each proband, the pre-test probability of identifying a deleterious BRCA mutation was estimated using the Myriad II model. We identified 108 affected individuals who underwent large rearrangement testing (80 breast cancer, 19 ovarian cancer, nine both breast and ovarian cancer). The mean estimated AJ specific pre-test probability of a deleterious mutation in BRCA1 and BRCA2 was 24.7% (range: 4.4–88.9%). No genomic rearrangements were identified in either the entire group or in the 26 subjects with pre-test mutation prevalence estimates exceeding 30%. Major gene rearrangements involving the BRCA1 and BRCA2 genes appear to contribute little to the burden of inherited predisposition to breast and ovarian cancer in the Ashkenazim.     

Proven non-carriers in BRCA families have an earlier age of onset of breast cancer

BackgroundRisk estimates for proven non-carriers in BRCA mutation families are inconsistent for breast cancer and lacking for ovarian cancer. We aimed to assess the age-related risks for breast and ovarian cancer for proven non-carriers in these families.MethodsA consecutive cohort study ascertained 464 proven non-carriers who had a first-degree relative with a pathogenic BRCA mutation. Kaplan–Meier analyses were used to estimate the age-related cancer risks, and we calculated standardised incidence ratios.ResultsIn the 464 non-carriers, 17 breast cancers and two ovarian cancers were detected at a mean age of 47 years (95% confidence interval (CI) 32–61) and 49 years (95% CI 32–67), respectively. Overall, by the age of 50, the breast and ovarian cancer risks among non-carriers were 6.4% (95% CI 2.9–9.8%) and 0.4% (95% CI 0–1.3%), of which the breast cancer risk was statistically significantly higher than the risk in the general population. In particular, the number of breast cancers among non-carriers in BRCA1 families was higher than expected for the general population (standardised incidence ratio (SIR) 2.0, 95% CI 1.1–3.3). In the BRCA1 cohort, the mean number of breast cancer cases was higher in families in which non-carriers were diagnosed before the age of 50 (p = 0.04).ConclusionThe age at diagnosis of breast cancer in non-carriers in BRCA mutation families is younger than expected, yielding an increased risk in the fifth decade. This effect is most evident in BRCA1 families. If our results are confirmed by others, this could affect the advice given on breast cancer screening to proven non-carriers between the age of 40 and 50 in such families.     

BRCA1 and BRCA2 Mutations in Breast and Ovarian Cancer Syndrome: Reflection on the Creighton University Historical Series of High Risk Families

Over the last four decades, Henry Lynch has collected pedigrees and samples from high risk breast and/or ovarian cancer families, generating a unique resource for the study of breast cancer susceptibility. These families have made a major contribution to increasing our knowledge in the cancer genetic susceptibility field, allowing the discovery of a genetic association between breast and ovarian cancer predisposition, contributing to the mapping of the BRCA1 and BRCA2 genes, advancing the idea of the existence of other breast cancer susceptibility genes, allowing the evaluation of BRCA-associated cancer risks and psychosocial aspects of BRCA testing and so on. Ten years after the cloning of BRCA1 and BRCA2, we report the current status of these families and compare the observed BRCA1/2 mutation detection rate with the estimations obtained by linkage analysis of the Breast Cancer Linkage Consortium families.     

BRCAPRO 6.0 Model Validation in Male Patients Presenting for BRCA Testing

Background.

BRCAPRO is a risk assessment model to estimate the risk of carrying a BRCA mutation. BRCA mutation carriers are at higher risk of developing breast, ovarian, pancreatic, and prostate cancer. BRCAPRO was developed for women and found to be superior to other risk assessment models. The present study evaluated the validity of BRCAPRO at predicting the risk of male patients carrying a BRCA mutation.

Patients and Methods.

A total of 146 men who presented for genetic counseling and testing from February1997 to September 2011, and their test results were included in the present study. BRCAPRO risk assessment for all patients was calculated using the BRCAPRO clinical CancerGene assessment software.

Results.

The mean age at presentation was 57 years. Of the 146 patients, 48 had breast cancer, 18 had pancreatic cancer, 39 had prostate cancer, 27 had other primary cancers, and 37 had no cancer. Fifty patients (34%) tested positive for a BRCA mutation (22 BRCA1, 27 BRCA2, and 1 BRCA1 and BRCA2). The mean BRCAPRO score for all patients was 24.96%. The BRCAPRO score was significantly higher for patients who tested positive for a BRCA mutation (46.19% vs. 13.9%, p < .01). The area under the receiver operating characteristics curve was 0.83 for all patients for the BRCAPRO score to predict the risk of carrying a BRCA mutation. At a cutoff point of 30.02%, the sensitivity, specificity, positive predictive value, and negative predictive value were 0.74, 0.81, 0.67, and 0.86, respectively.

Conclusion.

BRCAPRO appears to be a valid risk assessment tool for determining the risk of carrying a BRCA mutation in men.

Implications for Practice:

Men carrying genetic mutations in the BRCA gene have a greater risk than the general population of developing certain types of cancer, including breast, pancreatic, and prostate cancer. BRCAPRO is a risk assessment model that predicts the risk of carrying a BRCA mutation. The present study aimed at validating BRCAPRO for use with men seen for genetic counseling, whether affected by cancer or not. The data available for 146 patients revealed that BRCAPRO was effective at identifying patients at risk of BRCA mutation. These findings could help in identifying a subset of high-risk patients who should proceed to genetic testing.     

Associations between BRCA Mutations in High-Risk Breast Cancer Patients and Familial Cancers Other than Breast or Ovary

Purpose

We investigated the relationship between BRCA mutations and the distribution of familial cancers other than breast or ovary in high-risk breast cancer patients.

Methods

Patients with breast cancer who had at least one of the following risk factors were enrolled: reported family history of breast or ovarian cancer; 40 years of age or younger age at diagnosis; bilateral breast cancer; or male gender. Genetic testing for BRCA mutation and questionnaires about personal and family histories of malignancies were performed.

Results

Among the 238 eligible patients, 49 (20.6%) patients had BRCA1/2 mutations, which were more frequent in patients with multiple risk factors (p<0.0001). There were 271 members of 156 (65.5%) families who had histories of other primary cancer. The distribution of the families was 119 (63.0%) and 37 (75.5%) in the BRCA-negative and positive group, respectively (p=0.0996). Multiple familial cancers occurred in 70 families, which were significantly more frequent in BRCA-positive families (p=0.0034). By ordinal logistic regression, the occurrence of multiple familial cancers was associated with BRCA mutations (p=0.0045), not with other risk factors. The most common site of disease was the stomach, which is the most common in nationwide. And the proportional incidence of pancreatic cancer (6.8%) was significantly higher than that of nationwide cancer statistics (2.4%, p=0.0137).

Conclusion

BRCA mutations in high-risk breast cancer patients were associated with multiple risk factors and multiple family members with other primary cancers. Genetic counseling based on accurate information should be provided to families with BRCA mutation carriers.     

The prevalence of BRCA mutations among familial breast cancer patients in Korea: results of the Korean Hereditary Breast Cancer study

The primary aim of this study was to estimate the prevalence of BRCA1/2 mutations among familial breast cancer (BC) patients in Korea. We analyzed 775 familial BC patients who were enrolled in the Korean Hereditary Breast Cancer (KOHBRA) study and treated at 36 institutions between May 2007 and May 2010. Patients with familial BC were defined as BC patients with family histories of BC or ovarian cancer (OC) in any relatives. All probands received genetic counseling and BRCA genetic testing was performed after obtaining informed consent. The mean age of BC diagnosis was 43.6 years. The numbers of probands with family histories of BC only and OC only were 682 and 93, respectively. The overall prevalence of the BRCA mutation among familial BC patients was 21.7 % (BRCA1 9.3 % and BRCA2 12.4 %). Subgroup analyses observed prevalences of the BRCA mutation as follows: 19.6 % among patients with BC family history only (BRCA1 7.6 % and BRCA2 12.0 %) and 36.6 % among patients with OC family history only (BRCA1 21.5 % and BRCA2 15.1 %). Most of the subgroups satisfied the 10 % probability criteria to undergo BRCA testing. However, the prevalence of the BRCA mutations among subgroups that had 2 BC patients in a family with both age at diagnosis of more than 50 years old did not reach the 10 % criteria (4.1 %). Korean familial BC patients are good candidates for BRCA testing even when they have family histories of single breast cancers. However, proband age at diagnosis should be carefully considered when selecting patients for testing.     

Clinical aspects of familial ovarian cancer - current status and issues in Japan

Familial ovarian cancer occurs as part of two genetically distinct syndromes: hereditary breast and ovarian cancer (HBOC) and hereditary nonpolyposis colorectal cancer (HNPCC). HBOC caused by inherited mutations of BRCA1/2 and HNPCC caused by mismatch-repair genes are considered responsible for about 65 to 75% and 10 to 15% of familial ovarian cancers, respectively. Germline mutations of BRCA1 are considered responsible for about 50% of ovarian cancer families and 80% of breast-ovarian cancer families. BRCA2 mutations are less common than BRCA1 mutations in ovarian cancer families. A high proportion of serous adenocarcinomas at an advanced stage has been reported with BRCA-related ovarian cancers in several studies. It is controversial whether BRCA-related ovarian cancer patients carry a better prognosis despite the aggressive tumor-pathological characteristics of their disease, compared to sporadic cases. However, a good therapeutic response may be attributable to platinum-based chemotherapy. Recently in Japan, gene testing of BRCA1/2 has been available as a routine clinical test for diagnosing ovarian cancer families. Because the mutation spectrum of BRCA1/2 in Japanese was different from that of non-Ashkenazi individuals, the clinical application of BRCA1/2 gene testing for Japanese has been advocated. Approximately 1-5% of ovarian cancer patients in Japan are thought to have a family history of breast and/or ovarian cancer. The prevalence of deleterious mutations of BRCA1/2 in Japanese was reportedly significantly higher than that of non-Ashkenazi individuals despite the low frequency of familial cases in Japan. Although the age at diagnosis of ovarian cancers with BRCA1/2 mutation in the United States was earlier than those of the sporadic cases, there were no differences among Japanese. These results suggest that clinical and genetic aspects of BRCA-related ovarian cancer of the Japanese are different from those of Caucasians. A serious issue in this field is how the results will lead to a basis for the clinical application of a cancer prevention strategy targeting BRCA mutation carriers in Japanese.     

The Korean Hereditary Breast Cancer (KOHBRA) study: protocols and interim report

Aims

The primary aims of the Korean Hereditary Breast Cancer (KOHBRA) study are to estimate the prevalence of BRCA1/2 mutations and ovarian cancer among a high-risk group of patients with hereditary breast cancer and their families.

Materials and methods

The KOHBRA study is a prospective multicentre cohort identifying cases and their families. Between May 2007 and May 2010, the KOHBRA study enrolled up to 2000 subjects. All participants received genetic counselling and BRCA genetic testing; the clinical information and blood samples for blood banking were collected. An interim analysis of the prevalence of BRCA1/2 mutations and ovarian cancer in Korean subjects was determined from the initial 975 patients who presented to 33 centres.

Results

By April 2009, a total of 167 mutation carriers among 853 probands were identified. The prevalence of the BRCA mutation was as follows: 24.8% (106/428) for breast cancer patients with a family history of breast/ovarian cancers; 11.3% (24/212) for patients with early-onset (<35 years) breast cancer without a family history; 22.1% (15/68) for patients with bilateral breast cancer; male breast cancer in 8.3% (1/12); and 33.4% (1/3) for patients with breast and ovarian cancer.

Conclusions

The results of this study suggest that the prevalence of BRCA mutations in Korean subjects is similar to the prevalence reported among Western cohorts. However, weak family history and non-familial early-onset of breast cancer were significant factors associated with carrying the BRCA mutation in Korean breast cancer patients. Completion of the KOHBRA study is needed to confirm these findings.     

Consideration of hereditary nonpolyposis colorectal cancer in BRCA mutation‐negative familial ovarian cancers

BACKGROUND:

Inherited mutations account for approximately 10% of all epithelial ovarian cancers. Breast cancer (BRCA1 and BRACA2) gene mutations are responsible for up to 85% of inherited breast and/or ovarian cancer. Another condition that has been associated with ovarian cancer is hereditary nonpolyposis colorectal cancer syndrome (HNPCC), which carries a lifetime risk of up to 13% for ovarian cancer. The objective of this study was to determine the incidence of HNPCC‐related gene mutations in patients with familial ovarian cancer who previously tested negative for BRCA1 and BRCA2 gene mutations.

METHODS:

Seventy‐seven probands were identified who had familial ovarian cancer and negative BRCA gene mutation testing. Their pedigrees were analyzed for HNPCC syndrome. DNA samples underwent gene sequencing and Southern blot analysis for mutations in the 3 most common HNPCC‐associated genes: mutL homolog 1 (MLH1) and mutS homolog 2 (MSH2) with reflex testing for MSH6 if tests for the first 2 genes were negative.

RESULTS:

None of the probands met Amsterdam criteria for the clinical diagnosis of HNPCC. DNA testing revealed 2 patients (2.6%) with deleterious mutations in the MSH2 gene. An additional 8 patients (10.4%) had substitutions in either the MLH1 gene or the MSH2 gene that were classified as variants of uncertain significance. If Amsterdam criteria were expanded to include ovarian cancer, then 15 of 77 patients (19.5%) would have met these expanded criteria. One deleterious mutation was noted in this group, yielding a mutation incidence of 6.7%. This percentage may be even higher if any of the identified variants of uncertain significance are confirmed to be deleterious.

CONCLUSIONS:

HNPCC should be considered when evaluating patients with suspected hereditary ovarian cancer who have had negative BRCA mutation testing. Cancer 2009. © 2009 American Cancer Society.     

Limited significance of family history for presence of BRCA1 gene mutation in Polish breast and ovarian cancer cases

It is estimated that about 5–10% of ovarian and 2–5% of all breast cancer patients are carriers of a germline BRCA1 or BRCA2 gene mutation. Most families with detected BRCA1 or BRCA2 gene mutation are qualified for molecular testing on the basis of family history of breast or ovarian cancers. The purpose of our study was to establish the frequency of positive family history of cancer in a series of Polish consecutive breast and ovarian cancer patients in two groups, with and without the BRCA1 gene mutations. We analysed the prevalence of four of the most common BRCA1 mutations: 5382insC (c.5266dupC), 300T>G (p.181T>G), 185delAG (c.68_69delAG) and 3819del5 (c.3700_3704del5). The patient group consisted of 1,845 consecutive female breast and 363 ovarian cancer cases. 19 out of 37 (51%) of BRCA1-positive ovarian cancer patients and 21 out of 55 (39%) BRCA1-positive breast cancer had negative family history of breast and/or ovarian cancer among first- and second-degree relatives. In ovarian cancer patients, negative family history was more frequent in those with 300T>G BRCA1 gene mutation than in 5382insC carriers. This finding indicates the necessity of searching for 300T>G mutation in families with a single diagnosis of ovarian cancer in family. The high frequency of mutations detected in breast cancer patients lacking obvious family history shows that breast cancer patients should be qualified for genetic testing on the basis of wide clinical and pathological criteria.     

Prevalence of the BRCA1 founder mutation c.5266dupin Brazilian individuals at-risk for the hereditary breast and ovarian cancer syndrome

About 5-10% of breast and ovarian carcinomas are hereditary and most of these result from germline mutations in the BRCA1 and BRCA2 genes. In women of Ashkenazi Jewish ascendance, up to 30% of breast and ovarian carcinomas may be attributable to mutations in these genes, where 3 founder mutations, c.68_69del (185delAG) and c.5266dup (5382insC) in BRCA1 and c.5946del (6174delT) in BRCA2, are commonly encountered. It has been suggested by some authors that screening for founder mutations should be undertaken in all Brazilian women with breast cancer. Thus, the goal of this study was to determine the prevalence of three founder mutations, commonly identified in Ashkenazi individuals in a sample of non-Ashkenazi cancer-affected Brazilian women with clearly defined risk factors for hereditary breast and ovarian cancer (HBOC) syndrome. Among 137 unrelated Brazilian women from HBOC families, the BRCA1c.5266dup mutation was identified in seven individuals (5%). This prevalence is similar to that encountered in non-Ashkenazi HBOC families in other populations. However, among patients with bilateral breast cancer, the frequency of c.5266dup was significantly higher when compared to patients with unilateral breast tumors (12.1% vs 1.2%, p = 0.023). The BRCA1 c.68_69del and BRCA2 c.5946del mutations did not occur in this sample. We conclude that screening non-Ashkenazi breast cancer-affected women from the ethnically heterogeneous Brazilian populations for the BRCA1 c.68_69del and BRCA2 c.5946del is not justified, and that screening for BRCA1c.5266dup should be considered in high risk patients, given its prevalence as a single mutation. In high-risk patients, a negative screening result should always be followed by comprehensive BRCA gene testing. The finding of a significantly higher frequency of BRCA1 c.5266dup in women with bilateral breast cancer, as well as existence of other as yet unidentified founder mutations in this population, should be further assessed in a larger well characterized high-risk cohort.     

Germline BRCA1/2 mutation testing is indicated in every patient with epithelial ovarian cancer: A systematic review

The presence of a germline BRCA1/2 mutation improves options for tailored risk-reducing strategies and treatment in both breast and ovarian cancer patients and their relatives. Currently, referral for germline BRCA1/2 mutation testing of women with epithelial ovarian cancer (EOC) varies widely, based on different criteria, such as age of onset, family history of breast and/or ovarian cancer and histological type of EOC. The overall probability of a germline BRCA1/2 mutation in women with EOC is above 10%, and a substantial part of the germline BRCA1/2 mutation carriers is missed when applying these criteria for referral. Therefore, we strongly recommend referral of all women with EOC for genetic counselling and DNA analysis.     

Screening for common mutations in BRCA1 and BRCA2 genes: interest in genetic testing of Tunisian families with breast and/or ovarian cancer

BackgroundIn the Tunisian population, as yet a limited number of BRCA1/2 germline mutations have been reported in hereditary breast and/or ovarian cancer. These mutations are located in a few exons of BRCA1/2. The aim of the present study was to search for these mutations in 66 unrelated patients with hereditary breast and/or ovarian cancer in order to assess the interest in such a targeted approach for genetic testing in Tunisia.Materials and MethodsBlood specimens from the 66 Tunisian patients, with family history of breast and/or ovarian cancer, were collected at the Salah Azaiz Cancer Institute of Tunis. The exons 5, 20 and part of exon 11 of BRCA1 as well as part of exons 10 and 11 of BRCA2 were analyzed by Sanger sequencing.Results12 patients had deleterious mutations in the BRCA1 or BRCA2 genes (18%), including a novel frame-shift mutation of BRCA1 (c.3751dup; 3780insT). Four distinct BRCA1 mutations were detected eight patients: c.5266dup (5382insC) and c.211dup (330insA) each in three patients, c.3751dup (3870insT) and c.4041_4042del (4160delAG) each in one patient. The four remaining cases all carried the same BRCA2 mutation, c.1310_1313del (1538delAAGA). Besides these deleterious mutations, eight polymorphisms and unclassified variants were detected, one of them being never reported (BRCA1c.3030T>G, p.Pro1010Pro).ConclusionIn this study, we show that targeting relevant exons in BRCA1 and BRCA2 genes allows detection of a substantial percentage of mutations in the Tunisian population. Therefore such an approach may be of interest in genetic testing of high-risk breast and ovarian cancer families in Tunisia.     

Risk of cancer at sites other than the breast in Swedish families eligible for BRCA1 or BRCA2 mutation testing.

BACKGROUND: Population-based data on the risk of cancer in families eligible for BRCA1/2 mutation testing may help to reach a consensus about the association of BRCA1/2 mutations with cancer at sites other than the breast and may reveal new, non-BRCA1/2 related components of the familial clustering of cancer in those families. PATIENTS AND METHODS: The families of the Swedish Family-Cancer Database with at least three generations (n = 944,723) were classified according to the criteria proposed by the German Consortium for Hereditary Breast and Ovarian Cancer. The cancer incidences in the classified families were compared with the incidences in the general population. The percentages of individuals with cancer in families eligible for BRCA1/2 mutation testing were compared with data in the literature to estimate the proportion of malignancies related to BRCA1/2 mutations. RESULTS: Families with two breast cancers before the age of 50 years showed increased risk of early onset pancreatic, prostate and ovarian cancers; families with ovarian and breast cancers presented increased incidences for ovarian and ocular cancers; families with two breast cancers, at least one of them under the age of 50 years, showed increased risks of prostate and primary liver cancers. Stomach cancer before age 70 years was twice as frequent in families with breast and ovarian cancers as in the general population. BRCA1/2 mutations probably explain most of the aggregation of ovarian cancer in families with male breast cancer, and in families with at least two breast cancers diagnosed before age 50 years. CONCLUSIONS: The association of BRCA1/2 mutations with ovarian, pancreatic, prostate and stomach cancers was confirmed at a population level. However, the clustering of early pancreatic cancer in families with two breast cancers under age 50 years, the aggregation of ovarian cancer in families with breast and ovarian cancers, and the increased incidence of early onset prostate cancer in families with male breast cancer seem to be due to other effects unrelated to BRCA1/2 mutations.     

The association between smoking and cancer incidence in BRCA1 and BRCA2 mutation carriers

Tobacco smoke is an established carcinogen, but the association between tobacco smoking and cancer risk in BRCA mutation carriers is not clear. The aim of this study was to evaluate prospectively the association between tobacco smoking and cancer incidence in a cohort of BRCA1 and BRCA2 mutation carriers. The study population consisted of unaffected BRCA mutation carriers. Information on lifestyle including smoking histories, reproductive factors, and past medical histories was obtained through questionnaires. Incident cancers were updated biennially via follow‐up questionnaires. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using time‐dependent Cox regression models. There were 700 incident cancers diagnosed over 26,711 person‐years of follow‐up. The most frequent cancers seen in BRCA mutation carriers were breast (n = 428; 61%) and ovarian (n = 109; 15%) cancer. Compared to nonsmokers, (ever) smoking was associated with a modest increased risk of all cancers combined (HR = 1.17; 95%CI 1.01–1.37). Women in the highest group of total pack‐years (4.3–9.8) had an increased risk of developing any cancer (HR = 1.27; 95%CI 1.04–1.56), breast cancer (HR = 1.33, 95%CI 1.02–1.75), and ovarian cancer (HR = 1.68; 95%CI 1.06–2.67) compared to never smokers. The associations between tobacco smoking and cancer did not differ by BRCA mutation type or by age at diagnosis. This prospective study suggests that tobacco smoking is associated with a modest increase in the risks of breast and ovarian cancer among women with BRCA1 or BRCA2 mutation.     

A prior diagnosis of breast cancer is a risk factor for breast cancer in BRCA1 and BRCA2 carriers

Background

The risk of breast cancer in carriers of BRCA1 and BRCA2 mutations is influenced by factors other than the genetic mutation itself. Modifying factors include a woman’s reproductive history and family history of cancer. Risk factors are more likely to be present in women with breast cancer than in women without breast cancer, and therefore the risk of cancer in the two breasts should not be independent. It is not clear to what extent modifying factors influence the risk of a first primary or a contralateral breast cancer in BRCA carriers.

Methods

We conducted a matched case–control study of breast cancer among 3920 BRCA1 or BRCA2 mutation carriers. We asked whether a past history of breast cancer in the contralateral breast was a risk factor for breast cancer.

Results

After adjustment for age, country of residence, and cancer treatment, a previous cancer of the right breast was found to be a significant risk factor for cancer of the left breast among BRCA1 or BRCA2 carriers (relative risk: 2.1; 95% confidence interval: 1.4 to 3.0; p < 0.0001).

Conclusions

In a woman with a BRCA1 or BRCA2 mutation who is diagnosed with breast cancer, the risk of cancer in the contralateral breast depends on the first diagnosis. That observation supports the hypothesis that there are important genetic or non-genetic modifiers of cancer risk in BRCA carriers. Discovering risk modifiers might lead to greater personalization of risk assessment and management recommendations for BRCA-positive patients.     

The mutation landscape of multiple cancer predisposition genes in Chinese familial/hereditary breast cancer families

Objective:Approximately 5%–10% of breast cancer (BC) patients display familial traits that are genetically inherited among the members of a family. The purpose of this study was to profile the germline mutations in 43 genes with different penetration rates and their correlations with phenotypic traits in Chinese familial BC families.Methods:Ion Torrent S5™-based next generation sequencing was conducted on 116 subjects from 27 Chinese familial BC families.Results:Eighty-one germline mutations in 27 BC predisposition genes were identified in 82.8% (96/116) of the cases. Among these, 80.8% of the mutated genes were related to DNA damage repair. Fourteen possible disease-causing variants were identified in 13 of 27 BC families. Only 25.9% (7/27) of the BC families exhibited hereditary deficiency in BRCA1/2 genes, while 22.2% of the BC families exhibited defects in non-BRCA genes. In all, 41.7% (40/96) of the mutation carriers had BRCA mutations, 88.5% (85/96) had non-BRCA mutations, and 30.2% (29/96) had both BRCA and non-BRCA mutations. The BC patients with BRCA mutations had a higher risk of axillary lymph node metastases than those without mutations (P < 0.05). However, the BC patients with non-BRCA mutations frequently had a higher occurrence of benign breast diseases than those without mutations (P < 0.05).Conclusions:In addition to BRCA1/2, genetic variants in non-BRCA DNA repair genes might play significant roles in the development of familial/hereditary BC. Therefore, profiling of multiple BC predisposition genes should be more valuable for screening potential pathogenic germline mutations in Chinese familial/hereditary BC.     

Clinical and pathological characteristics of Hispanic BRCA-associated breast cancers in the American-Mexican border city of El Paso,TX

Hispanics in El Paso, TX, a large American-Mexican border city constitute 85% of the population. Limited cancer research has been conducted in this population. We sought to study the prevalence of BRCA mutations among Hispanic patients of Mexican origin, identify reported Mexican founder or recurrent mutations, and study the breast cancer characteristics in mutation carriers. Methods: Hispanic women of Mexican descent with a personal history of breast cancer, who presented consecutively for genetic cancer risk assessment, were enrolled in an Institutional Review Board-approved registry and underwent BRCA testing based on national guidelines. The characteristics of tumors and patients with positive BRCA mutation were analyzed. Results: 88 patients were screened; 18 patients (20%) were BRCA carriers. Among BRCA carriers, 72% were diagnosed with breast cancer at younger than 50 years, 61% had “Triple negative disease”. BRCA carriers had a significantly higher Body Mass Index (BMI) than non-carriers. Thirteen patients had BRCA1 mutations and five had BRCA2 mutations. A total of 17 deleterious BRCA Mutations were observed. Seven have been previously reported as specific genes from Mexico as country of origin. Five new mutations in BRCA carriers of Mexican descent were identified. Conclusion: Hispanic breast cancer patients of Mexican origin present at a younger age, and have predominantly triple negative tumors and high BMI. We identified 5 new mutations not reported previously in Hispanic BRCA carriers of Mexican descent. Interestingly, 41% of BRCA mutations identified have been reported as recurrent mutations in Hispanic individuals from Mexico as the country of origin. A more cost-effective approach to initial screening of Hispanic individuals based on country of origin is desirable and would potentially decrease the number of cases requiring complete sequencing.     

Uptake of predictive testing among relatives of BRCA1 and BRCA2 families: a multicenter study in northeastern Spain

Identifying a BRCA mutation among families with hereditary breast and ovarian cancer enables distinguishing those who may benefit from a specific medical management. This study aimed to evaluate the uptake of predictive testing among close relatives of a proband in Spanish families with a BRCA1 or BRCA2 mutation, and to determine the associated demographic and clinical predictors. A retrospective cohort of families undergoing clinical genetic testing at four university hospitals in northeastern Spain was considered. From 108 unrelated BRCA1/2 families, 765 close relatives of probands were analyzed. Sixty percent of the first-degree and 28% of the second-degree relatives underwent predictive testing within a median time of 2 and 6 months, respectively, since the mutation disclosure to the proband. Relatives undergoing genetic testing were more likely to be female, first-degree, and belong to a family with a proband who had a high educational level. Relatives were also more likely to have offspring, a previous cancer diagnosis, and to be aged between 30 and 64 years. Among second-degree relatives, having a first-degree relative with cancer was highly correlated with uptake. In conclusion, uptake of BRCA1/2 predictive testing among close relatives was notably high and within a short period of time after disclosure of the mutation to the proband. Being female, a high educational level of the proband, and having a close relative with cancer were associated with uptake among relatives. Further studies are warranted to determine whether information is disseminated properly by probands and to learn about the reasons for those not undergoing testing.     

Occurrence of both breast and ovarian cancer in a woman is a marker for the BRCA gene mutations: a population-based study from Western Sweden

Aim: This study aimed to analyze whether the occurrence of both breast and ovarian cancer in a woman serves as a marker for BRCA gene mutations. Material and methods: This population-based study included 256 women in western Sweden who developed both invasive breast and ovarian tumors between 1958 and 1999. Archival paraffin tissue blocks of their tumors were retrieved for DNA-extraction to analyze the founder mutation, BRCA1 c.3171_3175dup (c.3171ins5), which is most common in this geographic area and four other common Scandinavian BRCA1 gene mutations and one BRCA2 mutation. Together, account these mutations for approximately 75% of the BRCA1/2 gene mutations in the clinical unit. Results: Ninteen percent (95% confidence interval (CI) 14–24%) of the women carried one of the analyzed BRCA1 gene mutations but none of the women were positive for the analyzed BRCA2 mutation. One-third of the women with both tumors before age 60 were mutation carriers. BRCA1 c.3171_3175dup (c.3171ins5) constituted 84% of all identified mutations. Although the majority of breast cancers were invasive ductal and atypical medullary types, a variety of other breast malignancies were seen among mutation carriers. Serous ovarian carcinomas predominated among ovarian tumors. A variety of other ovarian tumors, including three granulosa-theca cell tumors, were also observed among mutation carriers. Conclusions: The occurrence of both breast and ovarian cancer in a woman is associated with a high likelihood of a constitutional BRCA1 mutation. These women and their families might therefore be considered for mutation screening after appropriate genetic counselling.