Hereditary breast cancer: a review

Multiple carcinomas in a woman with HIV infection: a case report and literature review

Non-acquired immunodeficiency syndrome-defining cancers (NADCs) are malignancies in persons living with human immunodeficiency virus (PLWHIV) and are not primarily due to the host's immunodeficiency. There is renewed clinical interest in long-term morbidities in PLWHIV as well as malignancies that occur in this population. We herein describe a 36-year-old woman with a 2-year history of an anal wound and right breast mass. She had been diagnosed with HIV infection prior to the development of these lesions. Clinical and laboratory evaluations led to diagnoses of breast and anal cancers. Chemotherapy and antiretroviral therapy were begun, but the patient discontinued these treatments early and was lost to follow-up. NADCs will continue to be a major clinical issue as the global population ages. This presentation of two NADCs (breast and anal cancers) in a PLWHIV further highlights the burden of multiple malignancies on the depleted health of HIV-infected patients. Early identification and treatment of HIV upon patients' presentation to cancer care sites and screening for NADCs at HIV/AIDS care sites are recommended for improved outcomes.

Identifying a BRCA2 c.5722_5723del mutation in a Han-Chinese family with breast cancer

Breast cancer (BC) is the most common female cancer found worldwide. It is responsible for 25% of all cancer patients in females. Hereditary BC accounts for about 5–10% of all BC cases. The breast cancer 1 gene (BRCA1) and the breast cancer 2 gene (BRCA2) are the two most-studied BC susceptibility genes. Genetic testing for disease-causing mutations in BRCA1, BRCA2, and other BC susceptibility genes is strongly recommended for members of families having a BC family history. The present study found a heterozygous c.5722_5723del mutation in the BRCA2 exon 11 of a large Han-Chinese BC family using whole exome sequencing and Sanger sequencing. It may cause DNA double-strand breaks repair dysfunction by disturbing homologous recombination, further resulting in BC. The study findings may help supplement and further improve genetic testing strategies and BC risk estimation methodologies in China.

The BRCA1 and BRCA2 Genes in Early-Onset Breast Cancer Patients

Approximately 5-10% of breast cancers are attributable to genetic susceptibility. Mutations in the BRCA1 and BRCA2 genes are the best known genetic factors to date. The goal of this study was to determine the structure and distribution of haplotypes of the BRCA1 and BRCA2 genes in early-onset breast cancer patients. We enrolled 70 patients diagnosed with early-onset breast cancer. A total of 21 SNPs (11 on BRCA1 and 10 on BRCA2) and 1 dinucleotide deletion on BRCA1 were genotyped using nested allele-specific PCR methods. Linkage disequilibrium (LD) analysis was conducted, and haplotypes were deduced from the genotype data. Two tightly linked LD blocks were observed on each of the BRCA1 and BRCA2 genes. Variant-free haplotypes (TAT-AG for BRCA1 and ATA-AAT for BRCA2) were observed at a frequency of more than 50% on each gene along with variable frequencies of derived haplotypes. The variant 3'-subhaplotype CGC displayed strong LD with 5'-subhaplotypes GA, AA, and GG on BRCA1 gene. Haplotypes ATA-AGT, ATC-AAT, and ATA-AAC were the variant haplotypes frequent on BRCA2 gene. Although the clinical significance of these derived haplotypes has not yet been established, it is expected that some of these haplotypes, especially the less frequent subhaplotypes, eventually will be shown to be indicative of a predisposition to early-onset breast cancer.

BRCA1 promoter methylation in peripheral blood cells and predisposition to breast cancer

Early onset breast cancer is a common malignancy and cause of death among young women in KSA. In addition, the data from women have demonstrated that most patients present late with an advanced stage. The early detection of this disease would not only save patients' lives but would also have the potential to reduce the budget and the time required for treating and nursing advanced breast cancer patients. This review highlights the risk of developing breast cancer in women with the methylated BRCA1 promoter in their white blood cells and proposes the potential use of this epigenetic modification as a powerful molecular marker for the early detection of breast cancer.

Levels of DNA Methylation Vary at CpG Sites across the BRCA1 Promoter, and Differ According to Triple Negative and "BRCA-Like" Status, in Both Blood and Tumour DNA

Triple negative breast cancer is typically an aggressive and difficult to treat subtype. It is often associated with loss of function of the BRCA1 gene, either through mutation, loss of heterozygosity or methylation. This study aimed to measure methylation of the BRCA1 gene promoter at individual CpG sites in blood, tumour and normal breast tissue, to assess whether levels were correlated between different tissues, and with triple negative receptor status, histopathological scoring for BRCA-like features and BRCA1 protein expression. Blood DNA methylation levels were significantly correlated with tumour methylation at 9 of 11 CpG sites examined (p<0.0007). The levels of tumour DNA methylation were significantly higher in triple negative tumours, and in tumours with high BRCA-like histopathological scores (10 of 11 CpG sites; p<0.01 and p<0.007 respectively). Similar results were observed in blood DNA (6 of 11 CpG sites; p<0.03 and 7 of 11 CpG sites; p<0.02 respectively). This study provides insight into the pattern of CpG methylation across the BRCA1 promoter, and supports previous studies suggesting that tumours with BRCA1 promoter methylation have similar features to those with BRCA1 mutations, and therefore may be suitable for the same targeted therapies.

The molecular significance of methylated BRCA1 promoter in white blood cells of cancer-free females

BACKGROUND

BRCA1 promoter methylation has been detected in DNA from peripheral blood cells of both breast cancer patients and cancer-free females. However, the pathological significance of this epigenetic change in white blood cells (WBC) remains an open question. In this study, we hypothesized that if constitutional BRCA1 methylation reflects an elevated risk for developing breast cancer (BC), WBC that harbor methylated BRCA1 in both cancer-free females and BC patients should exhibit similar molecular changes.

METHODS

BRCA1 promoter methylation was examined by methylation-specific PCR in WBC from 155 breast cancer patients and 143 cancer-free females. The Human Breast Cancer EpiTect Methyl II Signature PCR Array and The Human Breast Cancer RT2 Profiler™ PCR Array were used to study the methylation status and the expression profile of several breast cancer-related genes, respectively. In addition, we used label-free MS-based technique to study protein expression in plasma.

RESULTS

We have shown that 14.2% of BC patients and 9.1% of cancer-free females (carriers) harbored methylated BRCA1 promoter in their WBC. Interestingly, 66.7% of patients harbored methylated BRCA1 promoter in both WBC and tumors. Importantly, we have shown the presence of epigenetic changes in 9 other BC-related genes in WBC of both patients and carriers. Additionally, BRCA1 and 15 other important cancer -related genes were found to be differentially expressed in WBC from patients and carriers as compared to controls. Furthermore, we have shown that the carriers exhibited a unique plasma protein pattern different from those of BC patients and controls, with 10 proteins similarly differentially expressed in patients and carriers as compared to controls.

CONCLUSIONS

The present results suggest the presence of a strong link between aberrant methylation of the BRCA1 promoter in WBC and breast cancer -related molecular changes, which indicate the potential predisposition of the carriers for developing breast cancer. This informs the potential use of the aberrant methylation of BRCA1 promoter in WBC as a powerful non-invasive molecular marker for detecting predisposed individuals at a very early age.

Birth characteristics and childhood carcinomas

Background:

Carcinomas in children are rare and have not been well studied.

Methods:

We conducted a population-based case–control study and examined associations between birth characteristics and childhood carcinomas diagnosed from 28 days to 14 years during 1980–2004 using pooled data from five states (NY, WA, MN, TX, and CA) that linked their birth and cancer registries. The pooled data set contained 57 966 controls and 475 carcinoma cases, including 159 thyroid and 126 malignant melanoma cases. We used unconditional logistic regression to calculate odds ratios (ORs) and 95% confidence intervals (CIs).

Results:

White compared with ‘other’ race was positively associated with melanoma (OR=3.22, 95% CI 1.33–8.33). Older maternal age increased the risk for melanoma (OR_{per 5-year age increase}=1.20, 95% CI 1.00–1.44), whereas paternal age increased the risk for any carcinoma (OR=1.10_{per 5-year age increase}, 95% CI 1.01–1.20) and thyroid carcinoma (OR_{per 5-year age increase}=1.16, 95% CI 1.01–1.33). Gestational age <37 vs 37–42 weeks increased the risk for thyroid carcinoma (OR=1.87, 95% CI 1.07–3.27). Plurality, birth weight, and birth order were not significantly associated with childhood carcinomas.

Conclusion:

This exploratory study indicates that some birth characteristics including older parental age and low gestational age may be related to childhood carcinoma aetiology.

BRCA1 and BRCA2 germline mutations in Uruguayan breast and breast-ovarian cancer families. Identification of novel mutations and unclassified variants

The aim of the present study was to analyze BRCA1 and BRCA2 mutations in Uruguayan families with breast and breast/ovarian cancer. Probands from 42 families with at least three cases of female breast cancer (BC) or two cases and subcriteria (paternal transmission, ovarian cancer, bilateral BC, male BC, Ashkenazi Jewish ancestry) in the same lineage, at least one diagnosed before age 50, were screened for germline mutations. PCR amplification of all exons and intron-exon boundaries were performed, followed by protein truncation test, heteroduplex analysis, and direct sequencing. We identified seven different truncating mutations in seven families, five in BRCA2 (three in site-specific BC families and two in breast-ovarian cancer families) and two in BRCA1 (one in a site-specific BC family and the other in a breast-ovarian cancer family). Both BRCA1 mutations (5583insT and 2687T>G) and one of the five BRCA2 mutations (3829insTdel35) were not previously reported. We also detected ten sequence variants of unknown significance, five of them not described before. The low frequency of BRCA1/2 mutations (0.17) is in agreement with that reported in studies which included families with similar selection criteria. However, the observed predominance of BRCA2 (0.12) over BRCA1 mutations (0.05) is in contrast with the higher proportion of BRCA1 mutations communicated for most previous studies, even those with a predominance of site-specific BC families. Meanwhile, it has been described in one Chilean and some Spanish and Italian reports, highlighting the strong dependence between the mutational spectra and the ethnicity of the population analyzed.

The origins and evolution of genetic disease risk in modern humans

Patterns and risks of human disease have evolved. In this article, I review evidence regarding the importance of recent adaptive evolution, positive selection, and genomic conflicts in shaping the genetic and phenotypic architectures of polygenic human diseases. Strong recent selection in human populations can create and maintain genetically based disease risk primarily through three processes: increased scope for dysregulation from recent human adaptations, divergent optima generated by intraspecific genomic conflicts, and transient or stable deleterious by-products of positive selection caused by antagonistic pleiotropy, ultimately due to trade-offs at the levels of molecular genetics, development, and physiology. Human disease due to these processes appears to be concentrated in three sets of phenotypes: cognition and emotion, reproductive traits, and life-history traits related to long life-span. Diverse, convergent lines of evidence suggest that a small set of tissues whose pleiotropic patterns of gene function and expression are under especially strong selection-brain, placenta, testis, prostate, breast, and ovary-has mediated a considerable proportion of disease risk in modern humans.

Possible DNA viral factors of human breast cancer

Viruses are considered to be one of the high-risk factors closely related to human breast cancer. However, different studies of viruses in breast cancer present conflicting results and some of these works remain in dispute. DNA viruses, such as specific types of human papillomaviruses (HPV), Epstein–Barr virus (EBV), human cytomegalovirus (HCMV), herpes simplex virus (HSV), and human herpes virus type 8 (HHV-8), have emerged as causal factors of some human cancers. These respective exogenous viruses and the possibility of multiple viral factors are discussed in this review.

Promoter hypermethylation of TMS1, BRCA1, ERalpha and PRB in serum and tumor DNA of invasive ductal breast carcinoma patients

Breast cancer is fast emerging as the leading cancer amongst females, especially in younger age group in India; a large proportion of these tumors are often aggressive and ER and/or PR negative. Promoter methylation of genes involved in DNA repair and hormonal regulation may, in part, account for this behavior. To test this hypothesis methylation status of tumor suppressor genes TMS1, BRCA1, ERalpha and PRB was determined in invasive ductal carcinoma of breast and paired serum DNA. Of the 50 breast cancer patients investigated, 36/50 (72%) tumors and 32/50 (64%) paired sera showed methylation of at least one of these genes, while 17/50 (34%) tumors and 12/50 (24%) sera showed methylation of three genes. Methylation frequencies ranged from 24% for TMS1 to 63% for ERalpha. Significant association was observed between ERalpha and PRB methylation (p< or =0.001) and there was concordance between DNA methylation in tumor and serum for each gene. Immunohistochemical analysis showed no detectable expression of ERalpha, PRB and BRCA1 in 21/36 (58%), 20/36 (56%) and 23/36 (64%) tumors respectively; significant correlation was observed between promoter methylation and loss of protein expression confirming our hypothesis that promoter methylation is an important mechanism for transcriptional silencing of these genes in breast cancer in this population. This study also underscores the potential utility of DNA methylation based screening of serum (a surrogate for tumor DNA methylation) as a tool for detection of breast cancer.

Epigenetic silencing and deletion of the BRCA1 gene in sporadic breast cancer

INTRODUCTION

BRCA1 or BRCA2 germline mutations increase the risk of developing breast cancer. Tumour cells from germline mutation carriers have frequently lost the wild-type allele. This is predicted to result in genomic instability where cell survival depends upon dysfunctional checkpoint mechanisms. Tumorigenic potential could then be acquired through further genomic alterations. Surprisingly, somatic BRCA mutations are not found in sporadic breast tumours. BRCA1 methylation has been shown to occur in sporadic breast tumours and to be associated with reduced gene expression. We examined the frequency of BRCA1 methylation in 143 primary sporadic breast tumours along with BRCA1 copy number alterations and tumour phenotype.

METHODS

Primary sporadic breast tumours were analysed for BRCA1alpha promoter methylation by methylation specific PCR and for allelic imbalance (AI) at BRCA1 and BRCA2 loci by microsatellite analysis and TP53 (also known as p53) mutations by constant denaturing gel electrophoresis. The BRCA1 methylated tumours were analysed for BRCA1 copy alterations by fluorescence in situ hybridisation and BRCA1 expression by immunostaining.

RESULTS

BRCA1 methylation was found in 13/143 (9.1%) sporadic breast tumours. The BRCA1 methylated tumours were significantly associated with estrogen receptor (ER) negativity (P = 0.0475) and displayed a trend for BRCA1 AI (P = 0.0731) as well as young-age at diagnosis (< or = 55; P = 0.0898). BRCA1 methylation was not associated with BRCA2 AI (P = 0.5420), although a significant association was found between BRCA1 AI and BRCA2 AI (P < 0.0001).Absent/markedly reduced BRCA1 expression was observed in 9/13 BRCA1 methylated tumours, most of which had BRCA1 deletion. An elevated TP53 mutation frequency was found among BRCA1 methylated tumours (38.5%) compared with non-methylated tumours (17.2%). The BRCA1 methylated tumours were mainly of tumour grade 3 (7/13) and infiltrating ductal type (12/13). Only one methylated tumour was of grade 1.

CONCLUSION

BRCA1 methylation is frequent in primary sporadic breast tumours. We found an indication for BRCA1 methylation to be associated with AI at the BRCA1 locus. Almost all BRCA1 methylated tumours with absent/markedly reduced BRCA1 expression (8/9) displayed BRCA1 deletion. Thus, epigenetic silencing and deletion of the BRCA1 gene might serve as Knudson's two 'hits' in sporadic breast tumorigenesis. We observed phenotypic similarities between BRCA1 methylated and familial BRCA1 tumours, based on BRCA1 deletion, TP53 mutations, ER status, young age at diagnosis and tumour grade.

Four primary malignancies successively occurred in a BRCA2 mutation carrier: a case report

Carriers of BRCA2 germline mutation have a significantly increased lifetime risk of breast and ovarian cancer compared to non carriers. Several other carcinomas seem to be associated with BRCA2 mutations: pancreas, prostate, larynx, gallbladder, bile duct cancer, and malignant melanoma. We described a case of a 67-year-old BRCA2 mutation carrier of Caucasian, non-Jewish, ethnic origin who successively developed 4 primary malignancies in 30 months: breast ductal carcinoma, chronic lymphatic leukemia, ovarian serous papillary carcinoma, and endocervical adenocarcinoma. This is the first case of 4 primary malignancies in a BRCA mutation carrier, also occurred in such a short observation period. Chronic lymphatic leukemia and endocervical adenocarcinoma have not been yet associated to BRCA2 germline mutation.

[Psychological stress, immune function and disease development. The psychoneuroimmunologic perspective]

Interdisciplinary psychoneuroimmunological (PNI) research increasingly demonstrates clinically relevant interrelations between psychological stressors and the onset or progression of chronic diseases. Disturbances of the bi-directional interaction between the nervous system, the immune system and the endocrine system have been hypothesized to be implicated in several diseases. Here, we review evidence from psychoneuroimmunology within the theoretical framework of allostatic load to conceptualize some of these associations. Interdisciplinary PNI research investigating the importance of psychological stress for the higher incidence of infections, decreased responses to vaccinations and delayed wound healing is reviewed. Furthermore, the literature supporting similar associations with regard to progression of oncological diseases and autoimmune disorders is reviewed with a focus on breast cancer and multiple sclerosis. The accumulating evidence regarding the importance of neuroendocrine-immune interaction in these diseases may thus lead to novel insights into pathogenetic mechanisms and could contribute to the development of novel preventive and therapeutic strategies.

Increased risk of second malignancies after in situ breast carcinoma in a population-based registry

Among 1276 primary breast carcinoma in situ (BCIS) patients diagnosed in 1972-2002 in the Southern Netherlands, 11% developed a second cancer. Breast carcinoma in situ patients exhibited a two-fold increased risk of second cancer (standardised incidence ratios (SIR): 2.1, 95% confidence interval (CI): 1.7-2.5). The risk was highest for a second breast cancer (SIR: 3.4, 95% CI: 2.6-4.3; AER: 66 patients per 10,000 per year) followed by skin cancer (SIR: 1.7, 95% CI: 1.1-2.6; AER: 17 patients per 10,000 per year). The increased risk of second breast cancer was similar for the ipsilateral (SIR: 1.9, 95% CI: 1.3-2.7) and contralateral (SIR: 2.0, 95% CI: 1.4-2.8) breast. Risk of second cancer was independent of age at diagnosis, type of initial therapy, histologic type of BCIS and period of diagnosis. Standardised incidence ratios of second cancer after BCIS (SIR: 2.3, 95% CI: 1.8-2.8) resembled that after invasive breast cancer (SIR: 2.2, 95% CI: 2.1-2.4). Surveillance should be directed towards second (ipsi- and contra-lateral) breast cancer.

BRCA1 promoter methylation in sporadic breast cancer is associated with reduced BRCA1 copy number and chromosome 17 aneusomy

To explore the molecular mechanisms for the similarities between inherited and noninherited forms of breast cancer, we tested the hypothesis that inactivation of BRCA1 by promoter hypermethylation is associated with reduced gene copy number and chromosome 17 aneusomy as observed in tumors from BRCA1 mutation carriers. Using a combination of methylation-specific PCR analysis and fluorescence in situ hybridization, we observed varying degrees of promoter methylation in 39 of 131 (29.8%) primary tumors. Despite significant tumor heterogeneity, mean copy numbers of BRCA1 and CEP17 per cell were lower in methylated cases compared with unmethylated cases [1.78 versus 2.30 (P = 0.001) and 1.85 versus 2.29 (P = 0.005), respectively]. Methylation was more frequently observed in younger women (P = 0.05) with high-grade (P = 0.001), estrogen receptor-negative (P = 0.04), and progesterone receptor-negative (P = 0.01) tumors. Moreover, methylation was associated with reduced or absent BRCA1 transcripts, which was reversible in the heavily BRCA1-methylated cell line UACC3199 following treatment with 5-aza-2'-deoxycytidine and trichostatin A. We identified five CpGs at positions -533, -355, -173, -21, and +44 as critical in the reexpression of BRCA1. We conclude that BRCA1 methylation contributes to a subset of sporadic breast cancers with the resulting molecular and clinicopathologic phenotype similar to that of hereditary BRCA1-associated breast cancers. Our data support a model of carcinogenesis in which BRCA1 promoter methylation may serve as a "first hit," much like an inherited germ line mutation, and promote tumor progression down a restricted set of molecular pathways.

Evaluation of the needs and concerns of partners of women at high risk of developing breast/ovarian cancer

This exploratory study investigates the experience of partners of women at high risk of developing breast/ovarian cancer and reports on the partners' views concerning their relationship, communication, future planning, children and childbearing, involvement in decision-making regarding screening and prophylactic measures, and information and support needs. In-depth interviews were conducted with 15 partners. Of these, seven were partners of women who were BRCA1/2 mutation carriers, five were partners of women with unknown mutation status, and three were partners of women who were non-carriers. None of the women had a previous diagnosis of breast or ovarian cancer. Partners of carriers and women with unknown mutation status were found to be more distressed than partners of non-carriers, with partners of mutation carriers reporting the most difficulties. Factors associated with better adjustment and coping for partners included dealing with this situation as a team with their wife, greater involvement in decision-making, satisfaction with their supportive roles and being optimistic. Decision-making difficulties in relation to prophylactic measures, concerns about their children possibly being at increased cancer risk, as well as the need to receive information directly from health professionals and the wish to meet other partners were also discussed.

Risks of second primary breast and urogenital cancer following female breast cancer in the south of The Netherlands, 1972–2001

A cohort of 9919 breast cancer patients from the population-based Eindhoven Cancer Registry was followed for vital status and development of second cancer. Person-year analysis was applied to determine the risk of second primary breast or urogenital cancer among breast cancer patients and to assess its correlation with age, treatment and time since the first breast cancer diagnosis. Women with previous breast cancer have an elevated risk of overall second breast or urogenital cancer. The largest relative risk was observed for second breast cancer (SIR (standardised incidence ratio) 3.5; 95% confidence interval (CI) 3.2-3.8) and second ovarian cancer (SIR 1.7; 95% CI 1.2-2.3). The absolute excess risk was highest for second breast cancer (64/10,000 patients/year). However, breast cancer has an inverse relationship to risk of cervical cancer. Changes in behavioural risk factors are important for lowering the risk of second cancer after breast cancer.

Primary Malignancy after Primary Female Breast Cancer in the South of the Netherlands, 1972–2001

OBJECTIVES

To assess the risk of second primary cancers among women with previous breast cancer and calculate the excess burden of second cancer in the population.

METHODS

A population-based longitudinal study was conducted using the Eindhoven cancer registry data on 9919 breast cancer patients diagnosed in the period 1972-2000 and followed until 2001. Standardised incidence ratios (SIR) and absolute excess risks (AER) were calculated.

RESULTS

In total, 1298 (13%) women developed a second primary cancer. The risk of overall second cancer was higher among breast cancer patients compared to the general population (SIR: 2.8; 95% CI: 2.6-2.9), with an AER of 115 second cancers for every 10,000 breast cancer patients per year. High SIR and AER were observed for breast cancer (SIR: 4.1; 95% CI: 3.8-4.4; AER: 64/10,000 patients/year) and ovarian cancer (SIR: 2.0; 95% CI: 1.5-2.7; AER: 4.5/10,000 patients/year).

CONCLUSIONS

Our recent data show that women with previous breast cancer have an elevated risk of developing a second cancer compared to the general population. Excess burden for the population is especially high for second cancers of the breast, ovary and colon. Screening may only be justified for breast, ovary and colon cancer in certain groups of patients.

Contribution of the Defective BRCA1, BRCA2 and CHEK2 Genes to the Familial Aggregation of Breast Cancer: a Simulation Study Based on the Swedish Family-Cancer Database

The known breast cancer susceptibility genes only account for 20% to 25% of the excess familial risk of the disease [1]. The present study assessed the contribution of BRCA1/2 mutations and CHEK2 variants to the relative risk of breast cancer for women with affected mothers or sisters. The familial relative risks were estimated by Poisson regression based on the Swedish Family-Cancer Database. The Database was also used to calculate the distribution of life expectancy, the number of daughters per family and the age specific cumulative risk of female breast cancer. This information, together with the penetrances of BRCA1, BRCA2 and CHEK2 from the literature, was used to simulate the familial clustering of breast cancer under different scenarios. The excess risk explained by BRCA1, BRCA2 and CHEK2 decreased steeply with the age at diagnosis of the cancers. Around 40% of the familial risk for cases diagnosed before the age of 50 years was associated with BRCA1/2 mutations. In contrast, roughly 85% of the familial risk of breast cancer diagnosed before the age of 69 years remained unexplained. The contribution of CHEK2 to familial breast cancer was small.

MYC Is Amplified in BRCA1-Associated Breast Cancers

PURPOSE

Germ-line mutations in the BRCA1 tumor suppressor gene predispose to early onset breast cancers with a distinct phenotype characterized by high tumor grade, aneuploidy, high proliferation rate, and estrogen receptor-negativity. The molecular mechanisms and cooperative oncogenes contributing to multistep tumor progression in cells lacking BRCA1 are not well defined. To examine whether C-MYC (MYC), a transforming oncogene associated with genetic instability, contributes to multistep tumor progression in BRCA1-associated breast cancer, we have analyzed tumors from women with hereditary BRCA1-mutated and sporadic breast cancers.

EXPERIMENTAL DESIGN

We performed fluorescence in situ hybridization using a MYC:CEP8 assay on formalin-fixed paraffin-embedded tumor tissues from 40 women with known deleterious germ-line BRCA1 mutations and 62 sporadic cases, including 20 cases with hypermethylation of the BRCA1 gene promoter.

RESULTS

We observed a MYC:CEP8 amplification ratio >/=2 in 21 of 40 (53%) BRCA1-mutated tumors compared with 14 of 62 (23%) sporadic tumors (P = 0.003). Of the 14 sporadic cases with MYC amplification, 8 (57%) were BRCA1-methylated. In total, MYC amplification was found in a significantly higher proportion of tumors with BRCA1 dysfunction (29 of 60, 48% versus 6 of 42, 14%; P = 0.0003). In a multivariable regression model controlling for age, tumor size, and estrogen receptor status, BRCA1-mutated tumors demonstrated significantly greater mean MYC:CEP8 ratio than sporadic tumors (P = 0.02).

CONCLUSIONS

Our data indicate that MYC oncogene amplification contributes to tumor progression in BRCA1-associated breast cancers. Thus, we conclude that the aggressive histopathological features of BRCA1-associated tumors are in part due to dysregulated MYC activity.

Phosphopeptide binding specificities of BRCA1 COOH-terminal (BRCT) domains

Protein phosphorylation by protein kinases may generate docking sites for other proteins. It thus allows the assembly of signaling complexes in response to kinase activation. Several protein domains that bind phosphoserine or phosphothreonine residues have been identified, including the 14-3-3, PIN1, FHA, KIX, WD-40 domain, and polo box (Yaffe, M. B., and Elia, A. E. (2001) Curr. Opin. Cell Biol. 13, 131-138; Elia, A. E., Cantley, L. C., and Yaffe, M. B. (2003) Science 299, 1228-1231). The BRCA1 COOH-terminal (BRCT) domains are protein modules found in many proteins that regulate DNA damage responses (Koonin, E. V., Altschul, S. F., and Bork, P. (1996) Nat. Genet. 13, 266-268). Whether BRCT domains can mediate phosphorylation-dependent interactions has not been systematically investigated. We report here that the BRCT domains also recognize phosphopeptides. Oriented peptide library analysis indicated that the BRCT domains from BRCA1, MDC1, BARD1, and DNA Ligase IV preferred distinct phosphoserine-containing peptides. In addition, the interaction between BRCA1 and the BRCT binding motif of BACH1 was required for BACH1 checkpoint activity. Furthermore, BRCT domains of the yeast DNA repair protein Rad9 could bind phosphopeptides, suggesting that the BRCT domains represent a class of ancient phosphopeptide-binding modules. Potential targets of BRCT domains were identified through data base search. Structural analysis of BRCA1 BRCT repeats also predicted conserved residues that may form the phosphopeptide-binding pocket. Thus, the BRCT repeats are a new family of phosphopeptide-binding domains in DNA damage responses.

Psychosocial issues associated with genetic testing for breast and ovarian cancer risk: an integrative review

The identification of the BRCA1/2 genes, and their possible etiologic relationship with various forms of inherited cancer, has been recognized universally as a cornerstone in the search for cancer's genetic link and has made it possible to identify specific individuals and families who harbor a mutation in one of these predisposition genes. Genetic testing for breast and ovarian cancer susceptibility may pose unanticipated psychological and social problems. Because of the recent availability of predisposition genetic testing, research efforts have begun to investigate factors that may influence an individual's intention to undergo testing and the psychosocial sequelae associated with testing. The purpose of this article is to provide an integrative review of the literature that will delineate what is currently known about the psychosocial issues associated with genetic testing for breast and ovarian cancer risk. Important generalizations from the literature include: (a) a positive test for breast cancer susceptibility may ignite a psychological response similar to the diagnosis of breast cancer itself; (b) there is likely a subset of individuals at increased risk for hereditary breast and ovarian cancer who are also at risk for sustained psychosocial problems; (c) available literature challenges a common notion that only individuals with a positive test result will need psychosocial services; and (d) at-risk individuals are basing health care decisions on genetic testing information, thus they are making important decisions under conditions of uncertainty. Clinical issues and directions for future research were highlighted.

Evidence that BCL3 plays a role in the etiology of nonsyndromic oral clefts in Brazilian families

The BCL3 gene has been considered a susceptibility locus for nonsyndromic cleft lip with or without cleft palate (NSCL/P), based on association and linkage studies in some populations. We evaluated an intragenic marker at the BCL3 gene and the microsatellite D19S178 (1.1 cM distant from the BCL3 gene) among 98 infants born with NSCL/P and their parents, using the transmission disequilibrium test (TDT) and a method for haplotype analysis. Our analysis, based on BCL3 alleles, revealed the existence of a marginal association of allele 135pb of the BCL3 gene with NSCL/P (chi(2)=3.60; P=0.058; 1 df), with a major effect in female (chi(2)=5.77; P=0.016; 1 df) and in familial cases (chi(2)=3.79; P=0.051; 1 df). However, the haplotype analysis detected no significant segregation distortion, even if the alleles of the D19S178 were grouped into two classes. These findings support previous findings that BCL3 plays a role in the etiology of NSCL/P as an allele of low penetrance or as a modifier locus. We hypothesize that there might be more than one mutation in this gene associated with NSCL/P, or alternatively, that more than one mutation has arisen associated with the 135-bp allele. Genet. Epidemiol. 23:364-374, 2002

The myc oncogene: MarvelouslY Complex

The activated product of the myc oncogene deregulates both cell growth and death check points and, in a permissive environment, rapidly accelerates the affected clone through the carcinogenic process. Advances in understanding the molecular mechanism of Myc action are highlighted in this review. With the revolutionary developments in molecular diagnostic technology, we have witnessed an unprecedented advance in detecting activated myc in its deregulated, oncogenic form in primary human cancers. These improvements provide new opportunities to appreciate the tumor subtypes harboring deregulated Myc expression, to identify the essential cooperating lesions, and to realize the therapeutic potential of targeting Myc. Knowledge of both the breadth and depth of the numerous biological activities controlled by Myc has also been an area of progress. Myc is a multifunctional protein that can regulate cell cycle, cell growth, differentiation, apoptosis, transformation, genomic instability, and angiogenesis. New insights into Myc's role in regulating these diverse activities are discussed. In addition, breakthroughs in understanding Myc as a regulator of gene transcription have revealed multiple mechanisms of Myc activation and repression of target genes. Moreover, the number of reported Myc regulated genes has expanded in the past few years, inspiring a need to focus on classifying and segregating bona fide targets. Finally, the identity of Myc-binding proteins has been difficult, yet has exploded in the past few years with a plethora of novel interactors. Their characterization and potential impact on Myc function are discussed. The rapidity and magnitude of recent progress in the Myc field strongly suggests that this marvelously complex molecule will soon be unmasked.

Prevention of cancer in the older person

Both primary and secondary cancer prevention may improve cancer control among older persons. Although chemoprevention of cancer is feasible, the agents currently used for chemoprevention have several complications. As a result, the use of these substances should be individualized based on risk-benefit ratio. It is reasonable to implement screening for cancer of the breast and of the large bowel in persons with a life expectancy of 5 years and longer. No definite recommendation may be issued at present related to screening for prostate, lung, and cervical cancer. Ongoing clinical trials may answer some of these questions.

Genetic insights into familial cancers-- update and recent discoveries

While the vast majority of cancers are believed to occur sporadically, most forms of cancer, both adult and paediatric, have a hereditary equivalent. In the case of adult malignancies, these include hereditary breast and ovarian cancer and syndromes such as the multiple endocrine neoplasias types 1 and 2 characterised by specific tumours of the endocrine gland system. In the case of paediatric malignancies, these include syndromes such as retinoblastoma and Wilms tumour. In a little over a single decade, we have seen a tremendous increase in the knowledge of the primary genetic basis of many of the familial cancer syndromes. The majority of familial syndromes are inherited as autosomal dominant traits including hereditary colon cancer and familial malignant melanoma, however, the genetics behind autosomal recessive disorders such as Bloom syndrome and Fanconi anaemia are also being elucidated. A third mode of inheritance less well understood in the setting of familial cancer is that of imprinting recently observed in a subset of families with inherited paraganglioma. In this review, we discuss 31 genes inherited in an autosomal dominant manner associated with 20 familial cancer syndromes. Genes inherited in an autosomal recessive manner linked to familial cancer syndromes are also discussed. The identification of genes associated with familial cancer syndromes has in some families enabled a 'molecular diagnosis' that complements clinical assessment and allows directed cancer surveillance for those individuals determined to be at-risk of disease.

Identification of BRCA1 and BRCA2 carriers by allele-specific gene expression (AGE) analysis

Mutations in BRCA1 and BRCA2 genes confer a high risk of breast and ovarian cancer. As such, their identification is essential to reduce the risk of disease in healthy carriers, as well as in carriers who have already developed the disease because they are at increased risk for a second malignancy; moreover, noncarriers of BRCA1 and BRCA2 mutated families can be spared anxiety and unnecessary medical interventions. A number of problems, including large gene size, complex mutational spectra and genetic heterogeneity of the disease, however, make genetic testing labor intensive and often inconclusive. We devised a new mutation detection strategy called AGE (allele-specific gene expression) analysis that relies on the detection of a "functional effect" of the mutation at the RNA level known as "nonsense-mediated RNA decay," thus avoiding several of the problems of BRCA1 and BRCA2 genetic testing. In particular, (i) AGE analysis discriminates among the predisposing genes and identifies mutation carriers with a single RT-PCR reaction; (ii) it relies on the effect of truncating mutations, which represent the large majority of cases and thus identifies mutation carriers regardless of the specific genomic alteration; and (iii) it is specific for cis-regulatory mutations that are missed at present by most of the methods. As AGE analysis has the potential to identify most of the BRCA1 and BRCA2 mutation carriers, it can be used as a preliminary screening method, thereby accelerating and increasing the sensitivity of the genetic testing process. Notably, other hereditary diseases whose genetic analysis is hampered by similar problems could benefit from this kind of approach.