Identification of twenty-nine novel germline unclassified variants of BRCA1 and BRCA2 genes in 1400 Italian individuals

ObjectivesBreast and/or ovarian cancers are complex multifactorial diseases caused by interaction of both genetic and non-genetic factors and characterized by predisposition to inheritance. BRCA1 and BRCA2 genes are the most clinically involved with these kinds of cancer and the spectrum of variants affecting these genes is very wide. In fact, point variants, large or small insertions/deletions, genomic rearrangements can be found in these patients, although a large number of variants with uncertain biological and clinical significance continues to be identified. Next-generation sequencing (NGS) technology is actually the most powerful tool for the discovering of causative mutations and novel disease genes, moreover it allows to make a rapid diagnosis of genetic variants giving fast, inexpensive and detailed genetic information.Material and methodsIn this study, we report the screening of BRCA1 and BRCA2 genes on 1400 consecutive Caucasian patients with breast and/or ovarian cancer history or family risk, attending the oncogenetic ambulatory at the Foundation Policlinico Agostino Gemelli in Rome.ResultsWe describe twenty-nine novel BRCA1 and BRCA2 variants detected in Italian individuals suffering from hereditary breast and ovarian cancer syndrome (HBOC).ConclusionData regarding novel variants can provide useful information not only at epidemiological but also at clinical level, allowing for the better managing of breast and ovarian cancer patients and their family members.     

Practical aspects of genetic counseling in breast cancer: Lights and shadows

In unselected populations, less than 10% of breast cancers are associated with germline mutations in predisposing genes. Breast cancer type 1 and 2 (BRCA1 and BRCA2) susceptibility genes are the most common involved genes and confer a 10–30 times higher risk of developing the disease compared to the general population. A personal or family history suggestive of inherited breast cancer syndrome may be further evaluated to assess the risk of genetic predisposition and the presence of a genetic mutation. Breast cancer genetic counseling should include a careful risk assessment with associated psychosocial evaluation and support, possible molecular testing, personalized discussion of results. Knowledge of BRCA status can influence individualized cancer risk-reduction strategies. i.e. active surveillance, prophylactic surgery and/or pharmacoprevention.     

Challenges in Interpreting Germline Mutations in BARD1 and ATM in Breast and Ovarian Cancer Patients

Next‐generation sequencing promotes identification of mutations in non‐BRCA1/2 genes in hereditary cancer families. The contribution of mutations in moderate penetrance genes to hereditary cancer risk is not well established. Here, we report a family with early onset breast and fallopian tube cancer that was identified as carrying germline mutations in BARD1 and ATM genes. Loss of heterozygosity studies suggest a causative role of the BARD1 mutation in the development of primary peritoneal cancer, but fail to confirm an association between germline ATM mutations and breast cancer development in this family. Complexities in interpreting implications of mutations in moderate‐risk cancer susceptibility genes are discussed.     

Genetic testing for breast cancer predisposition

The recent identification of the BRCA1 and BRCA2 genes has improved our understanding of the association between breast and ovarian cancers in certain families. Carriers of predisposing germline mutations must decide on different options for management, including close follow-up or prophylactic surgery. Further studies are needed to elucidate the optimal management of these patients and to identify the factors that modify their risk for developing breast cancer. Finally, we must work to prevent any form of discrimination against those who, following genetic testing, are found to be at increased risk for breast cancer.     

Overestimation of hereditary breast cancer risk.

OBJECTIVE: To find out how women with breast or ovarian cancer rate their chances of carrying hereditary factors for these cancers and to determine the extent to which they overestimate their risk. SUMMARY BACKGROUND DATA: BRCA1 and BRCA2 are genes that cause breast and ovarian cancer when they are inherited in families. Testing for disease-associated mutations in these genes is now available commercially. Previous studies have shown that women overestimate their chances of carrying mutations. However, women's perceptions of risk have not been compared to objective estimates or to actual BRCA1 and BRCA2 testing results. METHODS: This study examines estimates of carrying BRCA1 and BRCA2 mutations among women participating in a randomized trial comparing alternative precounseling educational materials. Estimates were provided by participants in a baseline mailed survey. Estimates given by participants were compared to those given by an expert panel and by a statistical model. Testing was offered free of charge and was done in an academic laboratory using standard techniques. Baseline estimates of participating women were compared to the estimates of the expert panel, to the carrier probability provided by the statistical model, and to actual testing results. RESULTS: Women who have a personal history of breast or ovarian cancer significantly overestimate their risk of carrying hereditary factors for breast and ovarian cancer. Self-estimates exceeded the estimates of experts and a statistical model. One hundred women completed testing, and 21 mutations in BRCA1 or BRCA2 were found. Many test-negative women also overestimated their hereditary risk. Some women with a high carrier probability were negative for BRCA1 and BRCA2 mutations. CONCLUSIONS: Overestimation of hereditary factors is common among affected women with a family history of cancer. Pretest education and counseling should reduce these high-risk perceptions. Better estimates of carrier probability will direct more intensive clinical services and research.     

The breast surgeon's role in BRCA1 and BRCA2 testing

Five percent to 10% of all women who develop breast cancer carry a hereditary mutation in the genes BRCA1 or BRCA2. Genetic testing is now clinically available, and the results of such testing can dramatically alter a patient's risks for an ipsilateral or contralateral primary breast cancer and ovarian cancer. Therefore, genetic testing will become integral in tailoring surveillance, chemoprevention, and surgical management plans for patients at risk for hereditary cancer syndromes. Such results will also impact the cancer risks for the patient's nuclear and extended family members. Surgeons will play a pivotal role in eliciting personal and family histories from patients, determining which of those histories is suggestive of a germline mutation, facilitating referrals for genetic counseling and testing, and incorporating the results of genetic testing into the patient's short- and long-term management plans.     

Hereditary breast cancer: part II. Management of hereditary breast cancer: implications of molecular genetics and pathology

Abstract:  Management of patients at high risk for hereditary breast cancer (HBC) must critically assess its phenotypic and genotypic heterogeneity, particularly evidenced by the varying spectra of cancer sites that are integral to the respective HBC syndromes. Targeted management must consider their biology, pathology, and molecular genetics, all in concert with their respective carcinogenic pathways, as they may differ significantly from one breast cancer syndrome to the next. A striking example of management differences pertains to BRCA1 and BRCA2 mutation-positive breast cancers wherein those with BRCA1 mutations are frequently estrogen receptor (ER)-negative in contrast to BRCA2 mutations which are more frequently ER-positive; therein, significant differences exist with respect to anti-estrogen therapy which will be more amenable to BRCA2 versus BRCA1 mutation carriers manifesting breast cancer. In turn, tumors that are negative for ER, PR, and Her2-neu, often referred to as "triple negative" tumors, may also harbor a unique basal-like gene expression profile and are characterized by poor prognosis wherein endocrine and/or Her2-neu-targeted therapies are not effective treatment options. A further confounder pertains to the lifetime risk for ovarian cancer, which differs strikingly between BRCA1 mutation carriers, who show a 40–60% lifetime risk, and their BRCA2 counterparts, who carry a lifetime risk of approximately 12–15% for ovarian cancer. It is clear that as we learn more about the biology and the molecular aspects of hereditary forms of breast cancer, it will be compelling for the clinician to integrate this knowledge with pharmacologic, radiologic, and surgical treatment options for these high-risk patients.     

Risk for breast cancer and management of unaffected individuals with non‐BRCA hereditary breast cancer

About 5%‐10% of breast cancer is hereditary with BRCA1 and BRCA2 being the most common genes associated with hereditary breast cancer (HBC). Several additional genes have recently been associated with HBC. These genes can be classified as highly or moderately penetrant genes with lifetime risk >30% or 17%‐30%, respectively. Highly penetrant genes associated with HBC include TP53, PTEN, CDH1, STK11, and PALB2. While, moderately penetrant genes include CHEK2, ATM, BARD1, BRIP1, NBN, NF1, RAD51D, and MSH6. Breast cancer risk and recommendations for screening and risk‐reduction vary by gene. In general, screening breast MRI is recommended for women at >20% lifetime risk, which includes women with mutations in highly penetrant genes and the majority (but not all) moderately penetrant genes. Consideration of chemoprevention is recommended for women with mutations in high and moderately penetrant genes. Risk‐reducing mastectomy does reduce the risk of breast cancer to the greatest extent and can be considered for women with highly penetrant genes. However, this procedure is associated with significant morbidities that should be considered, especially given the benefit of using screening breast MRI for high‐risk women. BSO is only recommended for women with mutations in genes associate with increased risk for ovarian cancer and not as a breast cancer risk‐reducing strategy. As more women undergo testing, additional genes may be identified and risk estimates for current genes and management recommendations may be modified.     

BRCA1 and BRCA2 germ-line mutations and oral contraceptives: to use or not to use

Approximately 10% of the cases of breast cancer and invasive ovarian cancer are hereditary, occurring predominantly in women with germ-line mutations in the BRCA1 or BRCA2 gene. In deciding whether women with germ-line mutations in the BRCA1 gene should use oral contraceptives a possible increase in the risk of breast cancer needs to be weighed against the convenience of this means of birth control and its potential to reduce the risk of ovarian cancer. In women with BRCA2 mutations, oral contraceptive use has not been associated with an increased risk of breast cancer and does have the potential to reduce the risk of ovarian cancer. Prophylactic surgical options and intensified surveillance should, of course, be discussed with these patients.     

Emerging Concepts in Gastric Neoplasia: Heritable Gastric Cancers and Polyposis Disorders

Hereditary gastric cancer is a relatively rare disease with specific clinical and histopathologic characteristics. Hereditary gastric cancer of the diffuse type is predominantly caused by germline mutations in CDH1. The inherited cause of familial intestinal gastric cancer is unknown. Gastric adenocarcinoma and proximal polyposis of the stomach is a hereditary cancer syndrome caused by germline mutations in promoter 1B of APC. Other well-defined cancer syndromes, such as Lynch, Li-Fraumeni, and hereditary breast or ovarian cancer syndromes, are associated with increased risk of gastric cancer. This article reviews important histopathologic features and emerging concepts regarding gastric carcinogenesis in these syndromes.     

Common mutations in BRCA1 and BRCA2 do not contribute to early prostate cancer in Jewish men.

BACKGROUND: Families with a high incidence of hereditary breast cancer, and subsequently shown to have terminating mutations in BRCA1 or BRCA2, appear to have a higher incidence of prostate cancer among male relatives. We aimed to determine whether the common germline mutations of BRCA1 or BRCA2 in Ashkenazi Jewish men predisposed them to prostate cancer. METHODS: We examined genomic DNA from 83 (for BRCA1 185delAG) or 82 (for BRCA2 6174delT) Ashkenazi Jewish prostate cancer patients, most of whom were treated at a relatively young age, for the most common germline mutation in each gene seen in the Ashkenazi population. RESULTS: Our study should have been able to detect a 4-5-fold increase in the risk of prostate cancer due to mutation of BRCA1 or BRCA2. However, only one (1.15%; 95% confidence interval, 0-3.6%) of the patients was heterozygous for the BRCA1 mutant allele, and only two were heterozygous for the BRCA2 mutation (2.4%; 95% confidence interval, 0-6.2%). CONCLUSIONS: The incidence of each of the germline mutations in these prostate cancer patients closely matched their incidence (about 1%) in the general Ashkenazi Jewish population. This suggests that unlike cases of breast and ovarian cancers, mutations in BRCA1 or BRCA2 do not significantly predispose men to prostate cancer.     

Preventive mastectomy in patients at breast cancer risk due to genetic alterations in the<Emphasis Type="Italic"> BRCA1</Emphasis> and<Emphasis Type="Italic"> BRCA2</Emphasis> gene

BACKGROUND: The availability of genetic testing for inherited mutations in the BRCA1 and BRCA2 gene provides potentially valuable information to women at high risk of breast and ovarian cancer. METHODS AND FOCUS: We review the literature on the value of prophylactic surgical strategies in patients with hereditary predisposition to develop breast cancer and discuss the surgical options available in high-risk cancer patients, decision analyses, and possible complications. RESULTS: Preventive surgical interventions to reduce cancer risk in high-risk patients are often strongly recommended. A patient's life-time risk to develop breast cancer in the presence of BRCA1 and BRCA2 mutations is 50-90%. Despite the reduction in the risk of developing breast cancer, prophylactic mastectomy often leads to significant physical and psychological sequelae.     

Breast cancer and ovarian cancer genetics

Breast and ovarian cancers are the second and fifth leading causes of cancer death, respectively, among women in the United States. Individuals with breast cancer have a 20--30% chance of having at least one relative with the disease. However, only 5--10% of the cases are a direct result of germline mutations in highly penetrable genes, such as BRCA1 and BRCA2 (BRCA1/2) as well as genes TP53 and PTEN. Since 1996, genetic testing for these mutations has been clinically available. A strategy for the management of women at increased familial risk of breast and ovarian cancers is described, which includes genetic assessment, chemoprevention, radiologic screening, and clinical and self-examination. Genetic testing should occur within a cancer genetic clinic after genetic counseling. A blood sample allows determination of the presence of the BRCA1 and BRCA2 genes, the TP53 gene, the PTEN gene, and the ATM gene. Tumor examination has identified a growth factor receptor gene, human epidermal growth factor receptor (HER-2).With regard to diet and lifestyle, women at increased risk of breast cancer could be advised to reduce dietary fat, avoid obesity, decrease alcohol consumption, and take regular exercise. Although chemoprotection is a valuable consideration, it is important to emphasize that the use of Tamoxifen in BRCA1 and BRCA2 mutation carriers is not established, nor is the optimum duration of benefit. An overview of the main outcomes of the current published studies confirms a 38% decrease in breast cancer incidence with Tamoxifen but recommends its use be restricted to women at high risk of breast cancer and low risk for potential side effects. The role of bilateral risk-reducing mastectomy or prophylactic mastectomy has been controversial for several reasons, including the psychosocial significance of the breast in Western cultures, the wide acceptance of breast conservation in surgery for early breast cancer, and the previous lack of data on its efficacy. The surgical procedure should aim to remove substantially all at-risk breast tissue. However, there is a balance between reduction of cancer risk and cosmetic outcome. Bilateral prophylactic oophorectomy can significantly decrease ovarian cancer risk in women who carry BCRA1 mutations. Oophorectomy lowers the risk of breast cancer, even in women who have previously used hormone replacement therapy. There are no published randomized controlled trials examining the effectiveness of mammographic screening in women under 50 years of age with a family history of breast cancer. However, the published studies do suggest that mammographic screening of a high-risk group of women under 50 years of age may detect cancer at a rate equivalent to that seen in women 10 years older with normal risk. Other initial studies also support MRI as having a greater sensitivity than mammography in high-risk women. Breast clinical and self-examination is often advocated, but its effectiveness is unproved, and only one randomized study has been undertaken in women at risk. On the basis of this study as well as one nonrandomized study, it can be concluded that clinical examination as well as mammography are essential in detecting breast cancer. under 50 years of age with a family history of breast cancer. However, the published studies do suggest that mammographic screening of a high-risk group of women under 50 years of age may detect cancer at a rate equivalent to that seen in women 10 years older with normal risk. Other initial studies also support MRI as having a greater sensitivity than mammography in high-risk women. Breast clinical and self-examination is often advocated, but its effectiveness is unproved, and only one randomized study has been undertaken in women at risk. On the basis of this study as well as one nonrandomized study, it can be concluded that clinical examination as well as mammography are essential in detecting breast cancer.     

Cancer risks for Australian women with a BRCA1 or a BRCA2 mutation

One of the primary purposes of genetic testing for mutations in the BRCA1 and BRCA2 genes in patients with familial breast/ovarian cancer has been to provide accurate advice to at-risk relatives. The provision of such advice has been hampered by a lack of appropriate data regarding the cancer risks. Chen and colleagues recently provided precise estimates of the relative risks of breast and ovarian cancer in almost 2000 kindreds with such mutations ascertained through familial cancer clinics across USA. The baseline incidence of breast cancer is lower in Australia than in North America. The relative risks derived from the study have been combined with Australian baseline incidence data to estimate the absolute short-term and long-term risks of breast and ovarian cancers for Australian carriers of different ages. The results are presented as a series of graphs that may be useful in counselling an unaffected carrier of a specified age. It is of note that the incidence of breast cancer in carriers is high in premenopausal women, but approaches the population incidence in postmenopausal women. Conversely, the incidence of ovarian cancer continues to increase from the age of 40 years. Among carriers of BRCA1 or BRCA2 mutations, the cumulative lifetime risk of developing breast cancer is 50-60% and the equivalent risk of ovarian cancer is 20-40%. An unaffected carrier aged 60 years is at greater risk of developing ovarian cancer than breast cancer. These observations have important implications for genetic counselling and decisions regarding prophylactic surgery.     

Germline mutation screening of the Saethre-Chotzen-associated genes TWIST1 and FGFR3 in families with BRCA1/2-negative breast cancer

Saethre-Chotzen syndrome is one of the most common craniosynostosis syndromes. It is an autosomal dominantly inherited disorder with variable expression that is caused by germline mutations in the TWIST1 gene or more rarely in the FGFR2 or FGFR3 genes. We have previously reported that patients with Saethre-Chotzen syndrome have an increased risk of developing breast cancer. Here we have analysed a cohort of 26 women with BRCA1/2-negative hereditary breast cancer to study whether a proportion of these families might have mutations in Saethre-Chotzen-associated genes. DNA sequence analysis of TWIST1 showed no pathogenic mutations in the coding sequence in any of the 26 patients. MLPA (multiplex ligation-dependent probe amplification)-analysis also showed no alterations in copy numbers in any of the craniofacial disorder genes MSX2, ALX4, RUNX2, EFNB1, TWIST1, FGFR1, FGFR2,FGFR3, or FGFR4. Taken together, our findings indicate that mutations in Saethre-Chotzen-associated genes are uncommon or absent in BRCA1/2-negative patients with hereditary breast cancer.     

Influence of Race/Ethnicity on Genetic Counseling and Testing for Hereditary Breast and Ovarian Cancer

Abstract:  Risk assessment coupled with genetic counseling and testing for the cancer predisposition genes BRCA1 and BRCA2 ( BRCA1/2 ) has become an integral element of comprehensive patient evaluation and cancer risk management in the United States for individuals meeting high-risk criteria for hereditary breast and ovarian cancer (HBOC). For mutation carriers, several options for risk modification have achieved substantial reductions in future cancer risk. However, several recent studies have shown lower rates of BRCA1/2 counseling and testing among minority populations. Here, we explore the role of race/ethnicity in cancer risk assessment, genetic counseling and genetic testing for HBOC and the BRCA1/2 cancer predisposition genes. Barriers to genetic services related to race/ethnicity and underserved populations, including socioeconomic barriers (e.g., time, access, geographic, language/cultural, awareness, cost) and psychosocial barriers (e.g., medical mistrust, perceived disadvantages to genetic services), as well as additional barriers to care once mutation carriers are identified, will be reviewed.     

Educational Review: Role of the Surgeon in Hereditary Breast Cancer

Up to 10% of the breast cancers detected in the United States are related to an inherited germline mutation, usually in the BRCA1 or BRCA2 genes, and the majority of these patients will at some point require surgical evaluation and/or treatment. Women who harbor a genetic predisposition for breast cancer face an increased risk for early onset disease, bilateral tumors, and other non-breast malignancies, such as ovarian cancer. These issues raise questions regarding the appropriate surveillance regimen, and the potential efficacy of risk reduction strategies that should be considered. Once a breast cancer diagnosis has been established, the prognosis appears to be similar to stage-controlled sporadic breast cancer, despite an increased prevalence of adverse primary tumor features. However, the role of breast conservation therapy for these patients and the optimal means of addressing the substantially increased risk for contralateral tumors is not yet defined. The reported literature in this area, including a discussion of the value of genetic counseling and genetic testing, is reviewed.     

Male breast cancer: history, epidemiology, genetic and histopathology

Breast carcinoma is a rare disease in men. The incidence is 1 per cent of the incidence in women. Relative hyperestrogenemia and environmental factors seem to be important for the development of the disease. In recent years, germline mutations have been observed in male breast carcinoma patients in several genes, BRCA2, the androgene receptor gene and PTEN. Suspected genetic factors include the cell-cycle checkpoint kinase (CHEK)2 protein truncating mutation 1100delC that has been shown to confer a 10-fold increase of breast cancer risk in men. The c.1-34T > C 5' promoter region polymorphism in cytochrome P450c17 (CYP17), a key enzyme in the biosynthesis of estrogen, has been associated with male breast cancer risk, hemochromatosis gene (HFE) mutations, the mismatch repair genes (hMSH2, hMLH1,hPMS1,hPMS2) and PTEN mutations (Cowden syndrome) are associated with male breast cancer. The majority of tumors is seen retromamillarly. Ductal carcinoma in situ comprises 5-10 % of all cancers. In case of invasive growth, 85-90 % are invasive ductal carcinomas (NOS), 2.5 % are papillary tumors; lobular cancers are exceptionally rare. About 3/4 of all cancers express estrogen and progesterone receptor with increasing positivity with increasing patient age. HER-2 / neu overexpression is seen in the same frequency as in female breast cancer. Poor prognostic factors are tumor size > 2 cm, poorly differentiated tumors, receptor negativity, axillary lymph node involvement and more than four affected nodes.     

No evidence for a role of BRCA1 or BRCA2 mutations in Ashkenazi Jewish families with hereditary prostate cancer.

BACKGROUND: Two genes responsible for hereditary breast cancer (BRCA1 and BRCA2) have been identified, and predisposing mutations identified. Several studies have provided evidence that germline mutations in BRCA1 and BRCA2 confer an increased risk of prostate cancer. Based on these findings, one might expect to find an increased frequency of mutations in these genes in family clusters of prostate cancer. The Ashkenazi Jewish population is unique in that it has an approximate 2% incidence of specific founder BRCA1 and BRCA2 mutations (i.e., 185delAG and 5382insC in BRCA1, and 6174delT in BRCA2). METHODS: To address the question of whether or not mutations in either of these genes were overrepresented in prostate cancer families, we searched for these mutations in germline DNA samples collected from affected and unaffected members of 18 Ashkenazi Jewish families, each having at least 3 first-degree relatives affected with prostate cancer. RESULTS: No mutations were found in the BRCA1 gene in any of the 47 individuals tested. One individual possessed a BRCA2 mutation (6174delT). This individual was unaffected at the time of analysis, but had an affected paternal uncle, and an affected first cousin, neither of whom harbored the mutant gene. CONCLUSIONS: In this sample of Ashkenazi prostate cancer families, the frequency of founder BRCA1 and BRCA2 mutations was not elevated, suggesting that such mutations will account for only a small, perhaps minimal, fraction of familial prostate cancer.