The histologic phenotypes of breast carcinoma occurring before age 40 years in women with and without BRCA1 or BRCA2 germline mutations

Clinical Impact of Constitutional Genomic Testing on Current Breast Cancer Care

The most commonly diagnosed cancer in women worldwide is cancer of the breast. Up to 20% of familial cases are attributable to pathogenic mutations in high-penetrance (BReast CAncer gene 1 [BRCA1], BRCA2, tumor protein p53 [TP53], partner and localizer of breast cancer 2 [PALB2]) or moderate-penetrance (checkpoint kinase 2 [CHEK2], Ataxia-telangiectasia mutated [ATM], RAD51C, RAD51D) breast-cancer-predisposing genes. Most of the breast-cancer-predisposing genes are involved in DNA damage repair via homologous recombination pathways. Understanding these pathways can facilitate the development of risk-reducing and therapeutic strategies. The number of breast cancer patients undergoing testing for pathogenic mutations in these genes is rapidly increasing due to various factors. Advances in multigene panel testing have led to increased detection of pathogenic mutation carriers at high risk for developing breast cancer and contralateral breast cancer. However, the lack of long-term clinical outcome data and incomplete understanding of variants, particularly for moderate-risk genes limits clinical application. In this review, we have summarized the key functions, risks, and prognosis of breast-cancer-predisposing genes listed in the National Health Service (NHS) England National Genomic Test Directory for inherited breast cancer and provide an update on current management implications including surgery, radiotherapy, systemic treatments, and post-treatment surveillance.

Expression- and splicing-based multi-tissue transcriptome-wide association studies identified multiple genes for breast cancer by estrogen-receptor status

BACKGROUND

Although several transcriptome-wide association studies (TWASs) have been performed to identify genes associated with overall breast cancer (BC) risk, only a few TWAS have explored the differences in estrogen receptor-positive (ER+) and estrogen receptor-negative (ER-) breast cancer. Additionally, these studies were based on gene expression prediction models trained primarily in breast tissue, and they did not account for alternative splicing of genes.

METHODS

In this study, we utilized two approaches to perform multi-tissue TWASs of breast cancer by ER subtype: (1) an expression-based TWAS that combined TWAS signals for each gene across multiple tissues and (2) a splicing-based TWAS that combined TWAS signals of all excised introns for each gene across tissues. To perform this TWAS, we utilized summary statistics for ER + BC from the Breast Cancer Association Consortium (BCAC) and for ER- BC from a meta-analysis of BCAC and the Consortium of Investigators of Modifiers of BRCA1 and BRCA2 (CIMBA).

RESULTS

In total, we identified 230 genes in 86 loci that were associated with ER + BC and 66 genes in 29 loci that were associated with ER- BC at a Bonferroni threshold of significance. Of these genes, 2 genes associated with ER + BC at the 1q21.1 locus were located at least 1 Mb from published GWAS hits. For several well-studied tumor suppressor genes such as TP53 and CHEK2 which have historically been thought to impact BC risk through rare, penetrant mutations, we discovered that common variants, which modulate gene expression, may additionally contribute to ER + or ER- etiology.

CONCLUSIONS

Our study comprehensively examined how differences in common variation contribute to molecular differences between ER + and ER- BC and introduces a novel, splicing-based framework that can be used in future TWAS studies.

Breast Cancer Screening for Women at Higher-Than-Average Risk: Updated Recommendations From the ACR

Early detection decreases breast cancer death. The ACR recommends annual screening beginning at age 40 for women of average risk and earlier and/or more intensive screening for women at higher-than-average risk. For most women at higher-than-average risk, the supplemental screening method of choice is breast MRI. Women with genetics-based increased risk, those with a calculated lifetime risk of 20% or more, and those exposed to chest radiation at young ages are recommended to undergo MRI surveillance starting at ages 25 to 30 and annual mammography (with a variable starting age between 25 and 40, depending on the type of risk). Mutation carriers can delay mammographic screening until age 40 if annual screening breast MRI is performed as recommended. Women diagnosed with breast cancer before age 50 or with personal histories of breast cancer and dense breasts should undergo annual supplemental breast MRI. Others with personal histories, and those with atypia at biopsy, should strongly consider MRI screening, especially if other risk factors are present. For women with dense breasts who desire supplemental screening, breast MRI is recommended. For those who qualify for but cannot undergo breast MRI, contrast-enhanced mammography or ultrasound could be considered. All women should undergo risk assessment by age 25, especially Black women and women of Ashkenazi Jewish heritage, so that those at higher-than-average risk can be identified and appropriate screening initiated.

BRCA Mutations-The Achilles Heel of Breast, Ovarian and Other Epithelial Cancers

Two related tumor suppressor genes, BRCA1 and BRCA2, attract a lot of attention from both fundamental and clinical points of view. Oncogenic hereditary mutations in these genes are firmly linked to the early onset of breast and ovarian cancers. However, the molecular mechanisms that drive extensive mutagenesis in these genes are not known. In this review, we hypothesize that one of the potential mechanisms behind this phenomenon can be mediated by Alu mobile genomic elements. Linking mutations in the BRCA1 and BRCA2 genes to the general mechanisms of genome stability and DNA repair is critical to ensure the rationalized choice of anti-cancer therapy. Accordingly, we review the literature available on the mechanisms of DNA damage repair where these proteins are involved, and how the inactivating mutations in these genes (BRCAness) can be exploited in anti-cancer therapy. We also discuss a hypothesis explaining why breast and ovarian epithelial tissues are preferentially susceptible to mutations in BRCA genes. Finally, we discuss prospective novel therapeutic approaches for treating BRCAness cancers.

PLA2G7/PAF-AH as Potential Negative Regulator of the Wnt Signaling Pathway Mediates Protective Effects in BRCA1 Mutant Breast Cancer

Past studies have confirmed that aberrant activation of the Wnt/β-catenin signaling is associated with tumorigenesis and metastasis in breast cancer, while the role of platelet-activating factor acetylhydrolase (PLA2G7/PAF-AH) in this signaling pathway remains unclear. In this study, we analyze the functional impact of PAF-AH on BRCA1 mutant breast cancer and explore its relationship to the Wnt signaling pathway. By performing immunohistochemistry, PAF-AH expression and β-catenin expression were examined in both BRCA1 WT and BRCA1 mutant breast cancer specimens. The BRCA1 mutant breast cancer cell line HCC1937 was used for in vitro experiments to assess the impact of PAF-AH on cellular functions. The intracellular distribution of β-catenin depending on PLA2G7/PAF-AH expression was investigated by immunocytochemistry. Significantly higher nuclear expression levels of PAF-AH were found in BRCA1 mutant tissue specimens than in BRCA1 WT samples. Cell viability, proliferation, and the motility rate of HCC1937 were significantly enhanced after PLA2G7 silencing, which indicated a protective role of PAF-AH in breast cancer. Nuclear PAF-AH expressed correlatedly with membranous β-catenin. PLA2G7 silencing provoked the β-catenin translocation from the membrane to the nucleus and activated Wnt signaling downstream genes. Our data showed a protective effect of high PAF-AH expression in BRCA1 mutant breast cancer. PAF-AH may achieve its protective effect by negatively regulating the Wnt pathway. In conclusion, our research sheds new light on the regulatory pathways in BRCA1 mutant breast cancer.

Controversies and Open Questions in Management of Cancer-Free Carriers of Germline Pathogenic Variants in BRCA1/BRCA2

Females harboring germline BRCA1/BRCA2 (BRCA) P/LPV are offered a tight surveillance scheme from the age of 25−30 years, aimed at early detection of specific cancer types, in addition to risk-reducing strategies. Multiple national and international surveillance guidelines have been published and updated over the last two decades from geographically diverse countries. We searched for guidelines published between 1 January 2015 and 1 May 2022. Differences between guidelines on issues such as primary prevention, mammography screening in young (<30 years) carriers, MRI screening in carriers above age 65 years, breast imaging (if any) after risk-reducing bilateral mastectomy, during pregnancy, and breastfeeding, and hormone-replacement therapy, are just a few notable examples. Beyond formal guidelines, BRCA carriers’ concerns also focus on the timing of risk-reducing surgeries, fertility preservation, management of menopausal symptoms in cancer survivors, and pancreatic cancer surveillance, issues that, for some, there are no data to support evidence-based recommendations. This review discusses these unsettled issues, emphasizing the importance of future studies to enable global guideline harmonization for optimal surveillance strategies. Moreover, it raises the unmet need for personalized risk stratification and surveillance in BRCA P/LPV carriers.

The Homologous Recombination Deficiency Scar in Advanced Cancer: Agnostic Targeting of Damaged DNA Repair

BRCA1 and BRCA2 are the most recognized tumor-suppressor genes involved in double-strand DNA break repair through the homologous recombination (HR) system. Widely known for its role in hereditary cancer, HR deficiency (HRD) has turned out to be critical beyond breast and ovarian cancer: for prostate and pancreatic cancer also. The relevance for the identification of these patients exceeds diagnostic purposes, since results published from clinical trials with poly-ADP ribose polymerase (PARP) inhibitors (PARPi) have shown how this type of targeted therapy can modify the long-term evolution of patients with HRD. Somatic aberrations in other HRD pathway genes, but also indirect genomic instability as a sign of this DNA repair impairment (known as HRD scar), have been reported to be relevant events that lead to more frequently than expected HR loss of function in several tumor types, and should therefore be included in the current diagnostic and therapeutic algorithm. However, the optimal strategy to identify HRD and potential PARPi responders in cancer remains undefined. In this review, we summarize the role and prevalence of HRD across tumor types and the current treatment landscape to guide the agnostic targeting of damaged DNA repair. We also discuss the challenge of testing patients and provide a special insight for new strategies to select patients who benefit from PARPi due to HRD scarring.

Comparing breast cancer imaging characteristics of CHEK2 with BRCA1 and BRCA2 gene mutation carriers

PURPOSE

Breast cancer gene (BRCA) 1 and 2 mutations are frequently studied gene mutations (GM); the incidence of checkpoint kinase 2 (CHEK2) is increasing. We describe the imaging features of breast cancer (BC) in CHEK2 mutations, compared to BRCA 1 and 2 using mammography, ultrasound (US) and magnetic resonance imaging (MRI).

METHOD

Inclusion criteria were primary BC in GM carriers, treated in the same hospital. Age at diagnosis, histology, hormone receptor and human epidermal growth factor receptor 2 (HER2) status were retrieved. Mammography descriptors were mass, asymmetry and suspicious microcalcifications. The enhancement pattern (MRI), shape and border, architectural distortion, the presence of a hyperechoic rim and cystic complex structure (US) were documented. Analyses were performed using SAS software (version 9.4). Fishers' exact test was used to test associations between two categorical variables.

RESULTS

In 191 women, 233 malignant lesions were diagnosed (78 in BRCA1, 109 in BRCA2, 46 in CHEK2). In CHEK2 carriers, mammographically, suspicious microcalcifications (54%) were more prevalent (BRCA2 (48%) and BRCA1 carriers (33%)) (p-value = 0.057) compared to mass lesions (35%). On US, lesions were most frequently ill-defined (86%) (p = 0.579) and irregular (94.5%) (p = 0.098) compared to BRCA2 (77% and 80% resp.) and BRCA1 carriers (71% and 72% resp.). On MRI, mass lesions showed a type 3 curve in CHEK2 (67%) compared to BRCA1 (36%) and BRCA2 (50%) (p = 0.056).

CONCLUSIONS

Malignant radiological characteristics of breast cancer, more specifically suspicious microcalcifications, were more frequently seen in CHEK2 and BRCA2 compared to BRCA1 mutation carriers (without a significant difference) indicating the importance of mammography in follow-up of CHEK2 carriers.

The role of pathologists in recognition of morphologic and biologic features of genetically mutated breast cancer

The recent introduction of genomic medicine and emphasis on optimizing breast cancer risk reduction mortalities has provided opportunities for pathologists to partner with clinicians in advancing the diagnosis and management of breast cancer patients. The discovery of breast cancer genes BRCA1, BRCA2, and other breast cancer genes is considered a major breakthrough in the understanding of hereditary breast cancer. These discoveries have contributed to investigate the nature of tumorigenesis and the genetic and molecular pathology in multistep tumor development, as well as their relationship to endocrine and environmental factors. The recognition of unique morphologic and biological features associated with genetically mutated breast cancer by pathologists may have an impact on appropriate follow-up management of breast cancer patients.

Recommendations for the management of breast cancer patients during the COVID-19 pandemic from the Japan Breast Cancer Society

The novel coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 remains a major global crisis and continues to spread relentlessly around the world. In Japan, the number of infected people has incrementally increased since April 2020. The COVID-19 pandemic has exerted a major impact not only on our daily lives but also on healthcare. As the infection continues to spread, many medical institutions have devoted all efforts to minimize the risk of infection not only for patients but also for medical personnel by prioritizing medical care, reserving treatment, and extending consultation intervals. Cancer treatment is one of the priorities for medical care even during an epidemic infection as there is a concern of decreasing curability or therapeutic effect from postponement. As the COVID-19 situation evolves rapidly, we created an informative triage to provide appropriate medical treatment to breast cancer patients. In this triage, we offer guidance on preparing for the impact of the COVID-19 pandemic in breast cancer patients, prioritizing triage and diagnostic procedures, and providing advice on surgical, radiation, and oncological treatments.

BRCAness as a prognostic indicator in patients with early breast cancer

BRCAness is defined as a phenotypic copy of germline BRCA mutations, which describes presence of homologous recombination defects in sporadic cancers. We detected BRCAness by multiplex ligation-dependent probe amplification (MLPA) and explored whether BRCAness can be used as a predictor of prognosis. BRCAness status was classified for total 121 breast cancer patients. Forty-eight patients (39.7%) were identified as BRCAness positive. Tumors of BRCAness were more likely to be hormone receptors negative (95.8% vs. 50.7%, P < 0.001), nuclear grade III (76.1% vs. 48.4%, P = 0.001) and triple-negative breast cancer subtype (91.6% vs. 42.5%, P < 0.001). Five-year disease free survival (DFS) (54.0% vs. 88.0%, P < 0.001) and overall survival (OS) (76.3% vs. 93.1%, P = 0.002) were significantly lower in BRCAness patients. In neoadjuvant chemotherapy subgroup analysis, clinical response rate for taxane-based regimen was significantly lower in BRCAness patients (58.3% vs. 77.8%, P = 0.041). Cox regression multivariate analysis showed that BRCAness was the independent prognostic factor for DFS (HR 2.962, 95%CI 1.184–7.412, P = 0.020), but not for OS (HR 2.681, 95%CI 0.618–11.630, P = 0.188). BRCAness is associated with specific characteristics and may suggest resistance to taxane-based chemotherapy. BRCAness can be used as a negative prognostic indicator for breast cancer.

Identification of Novel BRCA1 and RAD50 Mutations Associated With Breast Cancer Predisposition in Tunisian Patients

Background

Deleterious mutations on BRCA1/2 genes are known to confer high risk of developing breast and ovarian cancers. The identification of these mutations not only helped in selecting high risk individuals that need appropriate prevention approaches but also led to the development of the PARP-inhibitors targeted therapy. This study aims to assess the prevalence of the most frequent BRCA1 mutation in Tunisia, c.211dupA, and provide evidence of its common origin as well as its clinicopathological characteristics. We also aimed to identify additional actionable variants using classical and next generation sequencing technologies (NGS) which would allow to implement cost-effective genetic testing in limited resource countries.

Patients and Methods

Using sanger sequencing, 112 breast cancer families were screened for c.211dupA. A set of patients that do not carry this mutation were investigated using NGS. Haplotype analysis was performed to assess the founder effect and to estimate the age of this mutation. Correlations between genetic and clinical data were also performed.

Results

The c.211dupA mutation was identified in 8 carriers and a novel private BRCA1 mutation, c.2418dupA, was identified in one carrier. Both mutations are likely specific to North-Eastern Tunisia. Haplotype analysis supported the founder effect of c.211dupA and showed its recent origin. Phenotype-genotype correlation showed that both BRCA1 mutations seem to be associated with a severe phenotype. Whole Exome Sequencing (WES) analysis of a BRCA negative family revealed a Variant of Unknown Significance, c.3647C > G on RAD50. Molecular modeling showed that this variant could be classified as deleterious as it is responsible for destabilizing the RAD50 protein structure. Variant prioritization and pathway analysis of the WES data showed additional interesting candidate genes including MITF and ANKS6.

Conclusion

We recommend the prioritization of BRCA1-c.211dupA screening in high risk breast cancer families originating from the North-East of Tunisia. We also highlighted the importance of NGS in detecting novel mutations, such as RAD50-c.3647C > G. In addition, we strongly recommend using data from different ethnic groups to review the pathogenicity of this variant and reconsider its classification in ClinVar.

Clinicopathological characteristics of BRCA-associated breast cancer in Asian patients

BRCA1/2 germline mutations account for the majority of hereditary breast cancers. Since the identification of the BRCA genes, several attempts have been made to define the clinicopathological characteristics of BRCA-associated breast cancer in comparison with sporadic breast cancer. Asians constitute 60% of the world population, and although the incidence of breast cancer in Asia remains low compared to the West, breast cancer is the most prevalent female cancer in the region. The epidemiological aspects of breast cancer are different between Asians and Caucasians. Asian patients present with breast cancer at a younger age than Western patients. The contributions of BRCA1/2 mutations to breast cancer incidence are expected to differ between Asians and Caucasians, and the different genetic backgrounds among races are likely to influence the breast cancer phenotypes. However, most large-scale studies on the clinicopathological characteristics of BRCA-associated breast cancer have been on Western patients, while studies on Asian populations were small and sporadic. In this review, we provide an overview of the clinical and pathological characteristics of BRCA-associated breast cancer, incorporating findings on Asian patients.

Recommendations for prioritization, treatment, and triage of breast cancer patients during the COVID-19 pandemic. the COVID-19 pandemic breast cancer consortium

The COVID-19 pandemic presents clinicians a unique set of challenges in managing breast cancer (BC) patients. As hospital resources and staff become more limited during the COVID-19 pandemic, it becomes critically important to define which BC patients require more urgent care and which patients can wait for treatment until the pandemic is over. In this Special Communication, we use expert opinion of representatives from multiple cancer care organizations to categorize BC patients into priority levels (A, B, C) for urgency of care across all specialties. Additionally, we provide treatment recommendations for each of these patient scenarios. Priority A patients have conditions that are immediately life threatening or symptomatic requiring urgent treatment. Priority B patients have conditions that do not require immediate treatment but should start treatment before the pandemic is over. Priority C patients have conditions that can be safely deferred until the pandemic is over. The implementation of these recommendations for patient triage, which are based on the highest level available evidence, must be adapted to current availability of hospital resources and severity of the COVID-19 pandemic in each region of the country. Additionally, the risk of disease progression and worse outcomes for patients need to be weighed against the risk of patient and staff exposure to SARS CoV-2 (virus associated with the COVID-19 pandemic). Physicians should use these recommendations to prioritize care for their BC patients and adapt treatment recommendations to the local context at their hospital.

Recurrent Germline BRCA2 Gene Mutation in Lithuanian Family

Approximately 10% of all breast cancer (BC) cases are familial and caused by inheritance of mutant BRCA1, BRCA2, or some other genes from the same DNA reparation pathway. Genetic counseling in families with cancer history is a powerful means for early cancer detection and active risk reduction through preventive interventions. This is the first report of the rare inherited BRCA2 frameshift-deletion mutation c.3847_3848delGT in one Lithuanian pedigree with the intense familial history of BC. Three BRCA2-positive blood relatives with BC of different biological types were identified in this pedigree with the same type mutation. All three cases were diagnosed with advanced stage ductal carcinoma. Markedly, polymorphic cells and numerous mitoses were identified in BC from the cases. Two patients from the family were diagnosed with the triple negative tumors, while one case had early onset of the hormone positive BC. Despite the variation in clinical and biological presentation of BC, all cases showed a good response to conventional treatment. In conclusion, the strong influence of BRCA2 mutation on the onset of BC of various biological types reveals the complexity of genetic counselling in families with BC history.

Risk-Based Screening Mammography for Women Aged <40: Outcomes From the National Mammography Database

OBJECTIVE

There is insufficient large-scale evidence for screening mammography in women <40 years at elevated risk. This study compares risk-based screening of women aged 30 to 39 with risk factors versus women aged 40 to 49 without risk factors in the National Mammography Database (NMD).

METHODS

This retrospective, HIPAA-compliant, institutional review board-exempt study analyzed data from 150 NMD mammography facilities in 31 states. Patients were stratified by 5-year age intervals, availability of prior mammograms, and specific risk factors for breast cancer: family history of breast cancer, personal history of breast cancer, and dense breasts. Four screening performance metrics were calculated for each age and risk group: recall rate (RR), cancer detection rate (CDR), and positive predictive values for biopsy recommended (PPV₂) and biopsy performed (PPV₃).

RESULTS

Data from 5,986,131 screening mammograms performed between January 2008 and December 2015 in 2,647,315 women were evaluated. Overall, mean CDR was 3.69 of 1,000 (95% confidence interval: 3.64-3.74), RR was 9.89% (9.87%-9.92%), PPV₂ was 20.1% (19.9%-20.4%), and PPV₃ was 28.2% (27.0%-28.5%). Women aged 30 to 34 and 35 to 39 had similar CDR, RR, and PPVs, with the presence of the three evaluated risk factors associated with significantly higher CDR. Moreover, compared with a population currently recommended for screening mammography in the United States (aged 40-49 at average risk), incidence screening (at least one prior screening examination) of women aged 30 to 39 with the three evaluated risk factors has similar cancer detection rates and recall rates.

DISCUSSION

Women with one or more of these three specific risk factors likely benefit from screening commencing at age 30 instead of age 40.

Functional analysis of clinical BARD1 germline variants

Germline pathogenic variants in BRCA1/2 account for one-third of familial breast cancers. The majority of BRCA1 function requires heterodimerization with BARD1. In contrast to BRCA1, BARD1 is a low-penetrance gene with an unclear clinical relevance, partly because of limited functional evidence. Using patient-derived lymphoblastoid cells, we functionally characterized two pathogenic variants (c.1833dupT, c.2099delG) and three variants of uncertain significance (VUSs) (c.73G>C, c.1217G>A, c.1918C>A). Three of these patients had breast cancers, whereas the remaining had colorectal cancers (n = 3). Both patients with pathogenic variants (c.1833dupT, c.2099delG) developed breast cancers with aggressive disease phenotypes such as triple-negative breast cancer and high cancer grades. As BARD1 encompasses multiple functional domains, including those of apoptosis and homologous recombination repair, we hypothesized that the function being impaired would correspond with the domain where the variant was located. Variants c.1918C>A, c.1833dupT, c.1217G>A, and c.2099delG, located within and proximal to apoptotic domains of ankyrin and BRCT, were associated with impaired apoptosis. Conversely, apoptosis function was preserved in c.73G>C, which was distant from the ankyrin domain. All variants displayed normal BRCA1 heterodimerization and RAD51 colocalization, consistent with their location being distal to BRCA1—and RAD51-binding domains. In view of deficient apoptosis, VUSs (c.1217G>A and c.1918C>A) may be pathogenic or likely pathogenic variants. In summary, functional analysis of BARD1 VUSs requires a combination of assays and, more importantly, the use of appropriate functional assays with consideration to the variant's location.

Mortality after breast cancer as a function of time since diagnosis by estrogen receptor status and age at diagnosis

Our aim was to estimate how long-term mortality following breast cancer diagnosis depends on age at diagnosis, tumor estrogen receptor (ER) status, and the time already survived. We used the population-based Australian Breast Cancer Family Study which followed-up 1,196 women enrolled during 1992-1999 when aged <60 years at diagnosis with a first primary invasive breast cancer, over-sampled for younger ages at diagnosis, for whom tumor pathology features and ER status were measured. There were 375 deaths (median follow-up = 15.7; range = 0.8-21.4, years). We estimated the mortality hazard as a function of time since diagnosis using a flexible parametric survival analysis with ER status a time-dependent covariate. For women with ER-negative tumors compared with those with ER-positive tumors, 5-year mortality was initially higher (p < 0.001), similar if they survived to 5 years (p = 0.4), and lower if they survived to 10 years (p = 0.02). The estimated mortality hazard for ER-negative disease peaked at ~3 years post-diagnosis, thereafter declined with time, and at 7 years post-diagnosis became lower than that for ER-positive disease. This pattern was more pronounced for women diagnosed at younger ages. Mortality was also associated with lymph node count (hazard ratio (HR) per 10 nodes = 2.52 [95% CI:2.11-3.01]) and tumor grade (HR per grade = 1.62 [95% CI:1.34-1.96]). The risk of death following a breast cancer diagnosis differs substantially and qualitatively with diagnosis age, ER status and time survived. For women who survive >7 years, those with ER-negative disease will on average live longer, and more so if younger at diagnosis.

Evaluation of tumor-infiltrating lymphocytes and association with prognosis in BRCA-mutated breast cancer

BACKGROUND

Patients with a BRCA1 or BRCA2 mutation (BRCA-mutated breast cancer) are frequently diagnosed with low differentiated and highly proliferating breast cancer characterized by high amounts of tumor-infiltrating lymphocytes (Tils). Stromal Tils (sTils) are highly prognostic in sporadic triple-negative and HER2 positive breast cancer however, their prognostic importance in BRCA-mutated breast cancers is unknown.

MATERIAL AND METHODS

Formalin-fixed paraffin-embedded primary tumor tissue from 411 patients with a germline BRCA1 or BRCA2 mutation and diagnosed with early breast cancer was included. The percentage of sTils was quantified on full HE sections according to guidelines proposed by the Immuno-Oncology Biomarker in Breast Cancer Working Group. Distribution of sTils and associates with patient and tumor characteristics were assessed according to categorical sTils groups defined as low (<10%), intermediate (10-59%) and high (≥60%). Prognostic associations of sTils were evaluated as a continuous variable in univariate and multivariate models. Only follow-up time beyond date of BRCA mutation test was included.

RESULTS

A large proportion had high sTils (27% in the full cohort, 36% in BRCA1-mutated, and 44% in ER negative breast cancers). Higher sTils were associated with BRCA1, ER negative breast cancer, high histological grade and medullary histology. In combined analysis for BRCA1 and BRCA2-mutated breast cancers, increasing sTils in 10% intervals were significantly associated with OS (HR 0.92, 95% CI 0.84-1.00, p = .05). For each 10% increment of sTils in BRCA1 breast cancers, a 10% reduction of mortality (adjusted HR 0.90 95% CI 0.81-0.99, p = .03) and a 13% reduction in risk of DFS-event (HR 0.87 95% CI 0.76-1.00, p = .05) was observed even after adjustment for ER status. No significant association with survival was of observed in the BRCA2 subgroup. Test for interaction of sTils and BRCA status was not statistically significant (p = .3).

CONCLUSIONS

Breast cancer patients with a germline BRCA mutation had higher sTils than previously reported in sporadic breast cancers, and sTils were associated with favorable survival among BRCA carriers.

High Frequency of ERBB2 Activating Mutations in Invasive Lobular Breast Carcinoma with Pleomorphic Features

Background: Characterisation of molecular alterations of pleomorphic lobular carcinoma (PLC), an aggressive subtype of invasive lobular carcinoma (ILC), have not been yet completely accomplished. Methods: To investigate the molecular alterations of invasive lobular carcinoma with pleomorphic features, a total of 39 tumour samples (in situ and invasive lesions and lymph node metastases) from 27 patients with nuclear grade 3 invasive lobular carcinomas were subjected to morphological, immunohistochemical and massive parallel sequencing analyses. Results: Our observations indicated that invasive lobular carcinomas with pleomorphic features were morphologically and molecularly heterogeneous. All cases showed absence or aberrant expression of E-cadherin and abnormal expression of β-catenin and p120. CDH1 (89%), PIK3CA (33%) and ERRB2 (26%) were the most common mutated genes. ERBB2 mutations preferentially affected the tyrosine-kinase activity domain, being the most frequent the targetable mutation p.L755S (57%). We also observed higher frequency of mutations in ARID1B, KMT2C, MAP3K1, TP53 and ARID1A in PLC than previously reported in classic ILC. Alterations related to progression from in situ to invasive carcinoma and/or to lymph node metastases included TP53 mutation, amplification of PIK3CA and CCND1 and loss of ARID1A expression. Conclusions: The high frequency of ERBB2 mutations observed suggests that ERBB2 mutation testing should be considered in all invasive lobular carcinomas with nuclear grade 3.

Genome-wide DNA methylation assessment of 'BRCA1-like' early-onset breast cancer: Data from the Australian Breast Cancer Family Registry

Breast cancers arising in women carrying a germline mutation in BRCA1 are typically high-grade, early-onset and have distinct morphological features (BRCA1-like). However, the majority of early-onset breast cancers of this morphological type are not associated with germline BRCA1 mutations or constitutional BRCA1 promoter methylation. We aimed to assess DNA methylation across the genome for associations with the "BRCA1-like" morphology. Genome-wide methylation in blood-derived DNA was measured using the Infinium HumanMethylation450K BeadChip assay for women under the age of 40 years participating in the Australian Breast Cancer Family Study (ABCFS) diagnosed with: i) BRCA1-like breast cancer (n = 30); and ii) breast cancer without BRCA1-like morphological features (non BRCA1-like; n = 30), and age-matched unaffected women (controls; n = 30). Corresponding tumour-derived DNA from 43 of the affected women was also assessed. Methylation of blood-derived DNA was found to be elevated across 17 consecutive marks in the BRCA1 promoter region and decreased at several other genomic regions (including TWIST2 and CTBP1) for 7 women (23%) diagnosed with BRCA1-like breast cancer compared with women in the other groups. Corresponding tumour-derived DNA available from 5 of these 7 women had elevated methylation within the BRCA1 and SPHK2 promoter region and decreased methylation within the ADAP1, IGF2BP3 and SPATA13 promoter region when compared with the other breast tumours. These methylation marks could be biomarkers of risk for BRCA1-like breast cancer, and could be responsible in part for their distinctive morphological features and biology. As such, they may assist with prevention and targeted therapies for this cancer subtype.

Molecular Classification of Breast Cancer

Breast cancer is a heterogeneous disease, observed traditionally by morphology and protein expression but, more recently with the advent of modern molecular technologies, at the genomic and transcriptomic level. This review describes the association between the different molecular subtypes with the histologic subtypes of breast cancer alongside some of their major genomic characteristics and illustrates how these subtypes may affect the appearance of tumors on imaging studies. The authors aim to show how molecular stratification can be used to augment traditional methods to improve our understanding of breast cancers and their clinical management.

Heritable DNA methylation marks associated with susceptibility to breast cancer

Mendelian-like inheritance of germline DNA methylation in cancer susceptibility genes has been previously reported. We aimed to scan the genome for heritable methylation marks associated with breast cancer susceptibility by studying 25 Australian multiple-case breast cancer families. Here we report genome-wide DNA methylation measured in 210 peripheral blood DNA samples provided by family members using the Infinium HumanMethylation450. We develop and apply a new statistical method to identify heritable methylation marks based on complex segregation analysis. We estimate carrier probabilities for the 1000 most heritable methylation marks based on family structure, and we use Cox proportional hazards survival analysis to identify 24 methylation marks with corresponding carrier probabilities significantly associated with breast cancer. We replicate an association with breast cancer risk for four of the 24 marks using an independent nested case-control study. Here, we report a novel approach for identifying heritable DNA methylation marks associated with breast cancer risk.

Novel and reported pathogenic variants in exon 11 of BRCA2 gene in a cohort of Sri Lankan young breast cancer patients

Women with breast carcinoma diagnosed before 40 years of age with a strong familial risk have a greater prevalence of germline BRCA1 or BRCA2 variants than late onset breast cancer. Previously germline variants in BRCA1 and BRCA2 genes were characterized in a cohort of Sri Lankan breast cancer patients unselected for age of onset. This study focused on young breast cancer patients who were screened for previously identified hotspot regions in BRCA2 gene. A total of 48 young breast cancer patients with family history of cancer and 25 healthy controls were studied. Direct sequencing was used to detect pathogenic and other sequence variants in the hotspot regions of BRCA2 gene. Thirty-six sequence variants including seven pathogenic (c.2411_2412delAA/p.Glu804Valfs*2, c.2500_2501insG/p.Leu834Cysfs*4, c.3881T>G/p.Leu1294*, c.4768A>T/p.Lys1590*, c.5645C>G/p.Ser1882*, c.5747delC/p.His1916Phefs*3, c.6728C>T/p.Ser2243Phe) and two likely pathogenic (c.1922C>T and c.3378A>T) variants, two intronic variants of unknown significance (c.1910-74T>C, c.1910-51G>T), two variants of uncertain significance (c.2324C>T c.5104C>T) and 23 benign variants were detected. Among them, seven were novel (pathogenic 5 and likely pathogenic 2). Prevalence of pathogenic and likely pathogenic variants in the hotspots regions of BRCA2 was 23 and 6.3 % respectively in this cohort. This justifies BRCA2 variant testing in young breast cancer patients with family history of cancer in Sri Lanka.

Clinical and molecular characterization of BRCA-associated breast cancer: results from the DBCG

BACKGROUND

In breast cancer (BC) patients a cancer predisposing BRCA1/2 mutation is associated with adverse tumor characteristics, risk assessment and treatment allocation. We aimed to estimate overall- (OS) and disease-free survival (DFS) according to tumor characteristics and treatment among women who within two years of definitive surgery for primary BC were shown to carry a mutation in BRCA1/2 .

MATERIAL AND METHODS

From the clinical database of the Danish Breast Cancer Group we included 141 BRCA1 and 96 BRCA2 BC patients. Estrogen receptor and HER2 status were centrally reviewed on paraffin-embedded tumor tissue. Information on risk reducing surgery was obtained from the Danish Pathology and Patient Registries and included as time-dependent variables in Cox proportional hazard models.

RESULTS

Ten-year OS and DFS for BRCA1 BC patients were 78% (95% CI 69-85) and 74% (95% CI 64-81). Ten-year OS and DFS for BRCA2 BC were 88% (95% CI 78-94) and 84% (95% CI 74-91). BRCA1 BC patients as compared to BRCA2 BC patients had a higher risk of BC relapse or non-breast cancer within ten years of follow-up, independent of ER status (adjusted HR 2.78 95% CI 1.28-6.05, p = .01), but BRCA mutation was not associated with OS (adjusted HR 1.98, 95% CI 0.87-4.52, p = .10). In multivariate analysis, including both BRCA1 and BRCA2 carriers, no chemotherapy was associated with a higher risk of death (adjusted OS HR 3.58, 95% CI 1.29-9.97, p = .01) and risk reducing contralateral mastectomy (RRCM) was associated with a significantly reduced risk of death (adjusted OS HR 0.42, 95% CI =0.21-0.84, p = .01).

CONCLUSION

Difference in OS between BRCA1 and BRCA2 BC patients could be ascribed to tumor-biology. BRCA1 BC patients may have a shorter ten-year DFS than BRCA2 BC patients. Chemotherapy and risk reducing contralateral mastectomy reduce mortality for both BRCA1 and BRCA2 BC patients.

Clinicopathological characteristics and survival outcomes in pleomorphic lobular breast carcinoma of the breast: a SEER population-based study

The purpose of this study was to explore the clinicopathological features and survival outcome of pleomorphic lobular carcinoma (PLC) of breast, we identified 131 PLC patients and 460,109 invasive ductal carcinoma (IDC) patients in the Surveillance, Epidemiology, and End Result (SEER) database. PLCs presented with increased lymph node involvement, older age, higher AJCC stage and grade, and lower median survival months (PLC 84 ± 51.03 vs. IDC 105.2 ± 64.39 P < 0.01). Compared to IDC patients, PLC patients were more inclined to be treated with mastectomy. In univariate analysis, PLC patients showed a worse disease-specific survival (DSS) than that of IDC patients (hazard ratio = 0.691, 95% confidence interval 0.534-0.893, P < 0.01). In multivariate analysis, we took into account other prognostic factors and found that the histology types were no longer an independent prognostic factor (P = 0.120). DSS have no difference between matched IDC and PLC groups (P = 0.615). This result may be due to PLCs presenting higher tumor stage, higher tumor grade, and higher rate of LN metastasis than IDCs. Our conclusion is that PLC and IDC have many different characteristics, but there is not enough difference on the DSS.

Effect of BRCA germline mutations on breast cancer prognosis: A systematic review and meta-analysis

BACKGROUND

The contribution of BRCA germline mutational status to breast cancer patients' prognosis is unclear. We aimed to systematically review and perform meta-analysis of the available evidence of effects of BRCA germline mutations on multiple survival outcomes of breast cancer patients as a whole and in specific subgroups of interest, including those with triple negative breast cancer, those with Ashkenazi Jewish ancestry, and patients with stage I-III disease.

METHODS

Sixty studies met all inclusion criteria and were considered for this meta-analysis. These studies involved 105,220 breast cancer patients, whose 3588 (3.4%) were BRCA mutations carriers. The associations between BRCA genes mutational status and overall survival (OS), breast cancer-specific survival (BCSS), recurrence-free survival (RFS), and distant metastasis-free survival (DMFS) were evaluated using random-effect models.

RESULTS

BRCA1 mutation carriers have worse OS than BRCA-negative/sporadic cases (hazard ratio, HR 1.30, 95% CI: 1.11-1.52) and worse BCSS than sporadic/BRCA-negative cases among patients with stage I-III breast cancer (HR 1.45, 95% CI: 1.01-2.07). BRCA2 mutation carriers have worse BCSS than sporadic/BRCA-negative cases (HR 1.29, 95% CI: 1.03-1.62), although they have similar OS. Among triple negative breast cancer, BRCA1/2 mutations carriers had better OS than BRCA-negative counterpart (HR 0.49, 95% CI: 0.26-0.92). Among Ashkenazi Jewish women, BRCA1/2 mutations carriers presented higher risk of death from breast cancer (HR 1.44, 95% CI: 1.05-1.97) and of distant metastases (HR 1.82, 95% CI: 1.05-3.16) than sporadic/BRCA-negative patients.

CONCLUSION

Our results support the evaluation of BRCA mutational status in patients with high risk of harboring BRCA germline mutations to better define the prognosis of breast cancer in these patients.

Simulation-based parameter estimation for complex models: a breast cancer natural history modelling illustration

Simulation-based parameter estimation offers a powerful means of estimating parameters in complex stochastic models. We illustrate the application of these ideas in the setting of a natural history model for breast cancer. Our model assumes that the tumor growth process follows a geometric Brownian motion; parameters are estimated from the SEER registry. Our discussion focuses on the use of simulation for computing the maximum likelihood estimator for this class of models. The analysis shows that simulation provides a straightforward means of computing such estimators for models of substantial complexity.

Dissimilarity between sporadic, non-BRCA1/2 families and hereditary breast cancer, linked to BRCA genes, in the Tunisian population

BACKGROUND

Most breast cancers (90 %) are sporadic. Only 5-10 % of all cancer cases can be attributed to genetic defects. BRCA genes are strongly incriminated in the hereditary predisposition to the disease. The purpose of our study was to provide more efficient approach to identify pathogenic BRCA mutation carriers and to determine subgroups within the non-BRCA tumor class.

METHODS

Different clinicopathological features, reproductive factors, as well as psychosocial ones were compared in women carrying mutations in the BRCA1/BRCA2 genes (12 cases) with non-BRCA1/2 family tumors (36 cases) and age-matched sporadic cases, unselected for family history (44 cases).

RESULTS

A BRCA-related class was yielded based on age at diagnosis (age ≤ 35 years; p = 0.1), molecular subtypes(the triple-negative subtype was predominant: 43 % of cases; p = 0.025) and age at menarche (p = 0.04). Furthermore, a "probably sporadic" class was distinguished using hormonal contraceptive use (through 30-40 years of age; p = 0.039), the number of full-term pregnancies (age ≥40 years; p = 0.01), age at menopause(age > 50 years; p = 0.04) and psychosocial factors (age ≥ 40 years; p = 0.01). However, analysis of non-BRCA1/2 family tumors indicated that they constitute a heterogeneous class, showing few perceptible differences with sporadic group, but distinct from BRCA1/2 tumors.

CONCLUSIONS

In Tunisian population, breast cancer can be classified with a high level of accuracy as sporadic or related to BRCA germline mutations by combining different clinicopathological features and reproductive factors. This can be clinically useful in genetic counseling and decision making for BRCA genetic test.

BRCA-mutated Invasive Breast Carcinomas: Immunohistochemical Analysis of Insulin-like Growth Factor II mRNA-binding Protein (IMP3), Cytokeratin 8/18, and Cytokeratin 14

To evaluate the expression of insulin-like growth factor II mRNA-binding protein (IMP3), CK8/18, and CK14 in BRCA mutated and sporadic invasive breast carcinoma. Immunohistochemistry for IMP3, CK8/18, and CK14 was performed on 39 cases of invasive breast carcinomas with BRCA mutation (24 BRCA1, 14 BRCA2, and 1 dual BRCA1/BRCA2) and 54 cases of sporadic invasive breast carcinomas. The relationship between the IMP3, CK8/18, and CK14 and the tumor grade and molecular phenotypes were analyzed. IMP3, CK8/18, and CK14 positivity were present in 20 (51%), 22 (56%), and 14 (36%) of 39 BRCA-mutated breast carcinomas, and 11 (20%), 53 (98%), and 24 (44%) of 54 sporadic breast carcinomas respectively. The rates of IMP3 expression and absence of CK8/18 (44% versus 2%) in BRCA-mutated breast carcinomas was significantly higher than the sporadic breast carcinomas (p = 0.002 and p < 0.001). No significant difference was observed for CK14 among the two groups (p = 0.408). No significant difference was observed among BRCA1-related and BRCA2-related breast carcinomas in the immunoprofile for IMP3, CK8/18, and CK14. No significant correlation was identified between the expression of IMP3 and CK8/18 and the tumor grade in both BRCA-mutated and sporadic breast carcinomas (p > 0.05). In cases with luminal A and B phenotypes, the rates of expression of IMP3 and loss of CK8/18 were significantly higher in BRCA-mutated as compared to sporadic breast carcinoma (p < 0.001). In cases with basal-like phenotype, the absence of CK8/18 expression was significantly higher in BRCA-mutated breast carcinomas (54% versus 0%, p = 0.001), while no difference was observed for IMP3 expression (p = 0.435). Regardless of mutation type, histologic grade, or molecular phenotype, the absence of CK8/18 expression and presence of IMP3 expression are seen at much higher rate in BRCA mutated breast carcinomas.

Invasive Pleomorphic Lobular Carcinoma of the Breast: Pathologic, Clinical, and Therapeutic Considerations

Pleomorphic lobular carcinoma is an uncommon form of breast cancer and a subtype of invasive lobular carcinoma. It has unique histopathologic features that translate to a more aggressive phenotype with an associated poor prognosis. Unlike classical invasive lobular carcinoma, it can lose estrogen and progesterone receptor expression and demonstrate HER-2/neu amplification. It remains to be determined, however, whether the pleomorphic histology independently predicts a worse outcome or whether other known associated negative prognostic factors such as larger tumor size, increased metastatic disease, and associated worse molecular subtypes commonly present in pleomorphic carcinoma account for the poor prognosis. Here we present an updated review of the unique pathologic and clinical features of pleomorphic lobular carcinoma needed to guide management for women with this subtype of cancer.

Histologic features of melanoma associated with CDKN2A genotype

BACKGROUND

Inherited susceptibility genes have been associated with histopathologic characteristics of tumors.

OBJECTIVE

We sought to identify associations between histology of melanomas and CDKN2A genotype.

METHODS

This was a case-control study design comparing 28 histopathologic tumor features among individuals with sporadic melanomas (N = 81) and cases from melanoma families with (N = 123) and without (N = 120) CDKN2A germline mutations.

RESULTS

Compared with CDKN2A(-) cases, mutation carriers tended to have histologic features of superficial spreading melanoma subtype including higher pigmentation (Ptrend = .02) and increased pagetoid scatter (Ptrend = .07) after adjusting for age at diagnosis, sex, and American Joint Committee on Cancer thickness category. Similar associations were observed when comparing mutation carriers with a combined group of CDKN2A(-) (wild type) and sporadic melanomas. The presence of spindle cell morphology in the vertical growth phase was also an important predictor of genotype. Of the 15 cases with this phenotype, none were observed to harbor a CDKN2A mutation.

LIMITATIONS

Our study examined rare mutations and may have been underpowered to detect small, but biologically significant associations between histology and genotype.

CONCLUSION

Familial melanomas with CDKN2A mutations preferentially express a histologic phenotype of dense pigmentation, high pagetoid scatter, and a non-spindle cell morphology in the vertical growth phase.

Refined histopathological predictors of BRCA1 and BRCA2 mutation status: a large-scale analysis of breast cancer characteristics from the BCAC, CIMBA, and ENIGMA consortia

INTRODUCTION

The distribution of histopathological features of invasive breast tumors in BRCA1 or BRCA2 germline mutation carriers differs from that of individuals with no known mutation. Histopathological features thus have utility for mutation prediction, including statistical modeling to assess pathogenicity of BRCA1 or BRCA2 variants of uncertain clinical significance. We analyzed large pathology datasets accrued by the Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA) and the Breast Cancer Association Consortium (BCAC) to reassess histopathological predictors of BRCA1 and BRCA2 mutation status, and provide robust likelihood ratio (LR) estimates for statistical modeling.

METHODS

Selection criteria for study/center inclusion were estrogen receptor (ER) status or grade data available for invasive breast cancer diagnosed younger than 70 years. The dataset included 4,477 BRCA1 mutation carriers, 2,565 BRCA2 mutation carriers, and 47,565 BCAC breast cancer cases. Country-stratified estimates of the likelihood of mutation status by histopathological markers were derived using a Mantel-Haenszel approach.

RESULTS

ER-positive phenotype negatively predicted BRCA1 mutation status, irrespective of grade (LRs from 0.08 to 0.90). ER-negative grade 3 histopathology was more predictive of positive BRCA1 mutation status in women 50 years or older (LR = 4.13 (3.70 to 4.62)) versus younger than 50 years (LR = 3.16 (2.96 to 3.37)). For BRCA2, ER-positive grade 3 phenotype modestly predicted positive mutation status irrespective of age (LR = 1.7-fold), whereas ER-negative grade 3 features modestly predicted positive mutation status at 50 years or older (LR = 1.54 (1.27 to 1.88)). Triple-negative tumor status was highly predictive of BRCA1 mutation status for women younger than 50 years (LR = 3.73 (3.43 to 4.05)) and 50 years or older (LR = 4.41 (3.86 to 5.04)), and modestly predictive of positive BRCA2 mutation status in women 50 years or older (LR = 1.79 (1.42 to 2.24)).

CONCLUSIONS

These results refine likelihood-ratio estimates for predicting BRCA1 and BRCA2 mutation status by using commonly measured histopathological features. Age at diagnosis is an important variable for most analyses, and grade is more informative than ER status for BRCA2 mutation carrier prediction. The estimates will improve BRCA1 and BRCA2 variant classification and inform patient mutation testing and clinical management.

Methylation of the BRCA1 promoter in peripheral blood DNA is associated with triple-negative and medullary breast cancer

It has been proposed that methylation signatures in blood-derived DNA may correlate with cancer risk. In this study, we evaluated whether methylation of the promoter region of the BRCA1 gene detectable in DNA from peripheral blood cells is a risk factor for breast cancer, in particular for tumors with pathologic features characteristic for cancers with BRCA1 gene mutations. We conducted a case-control study of 66 breast cancer cases and 36 unaffected controls. Cases were triple-negative or of medullary histology, or both; 30 carried a constitutional BRCA1 mutation and 36 did not carry a mutation. Blood for DNA methylation analysis was taken within three months of diagnosis. Methylation of the promoter of the BRCA1 gene was measured in cases and controls using methylation-sensitive high-resolution melting (MS-HRM). A sample with any detectable level of methylation was considered to be positive. Methylation of the BRCA1 promoter was detected in 15 of 66 cases and in 2 of 36 controls (OR 5.0, p = 0.03). Methylation was present in 15 of 36 women with breast cancer and without germline BRCA1 mutation, but in none of 30 women with breast cancer and a germline mutation (p < 0.01). The association between methylation and breast cancer was restricted to women with no constitutional BRCA1 mutation (OR 12.1, p = 0.0006). Methylation of the promoter of the BRCA1 gene detectable in peripheral blood DNA may be a marker of increased susceptibility to triple-negative or medullary breast cancer.

Invasion patterns of metastatic high-grade serous carcinoma of ovary or fallopian tube associated with BRCA deficiency

High-grade serous carcinomas of the uterine adnexa with BRCA1 deficiency (high-grade serous carcinomas-BRCA) have recently been described to demonstrate characteristic histopathological features. We hypothesize that metastatic high-grade serous carcinomas-BRCA cases exhibit characteristic morphological features as well. We studied 102 high-grade serous carcinomas with known BRCA1 and BRCA2 genotype from the archives of the Department of Pathology at Memorial Sloan-Kettering Cancer Center. The primary site morphological characteristics of these cases were reported previously; we now focus solely on tumor morphology in sites other than the uterine adnexa (ie, metastatic sites). The study group consisted of the following case types: 13 BRCA1 germline mutations; 5 BRCA1 somatic mutations; 10 BRCA1 promoter methylation; 4 BRCA2 germline mutations; 1 BRCA2 somatic mutation; 11 lacking BRCA1 or BRCA2 abnormality; 58 cases lacking BRCA1 or BRCA2 germline mutation. Two observers independently scored invasion patterns and microscopic tumor architecture while blinded to genotype. Concordance between observers and correlations between metastatic patterns and the following indices were studied: genotype, primary site tumor characteristics, and BRCA1 immunohistochemistry. Concordance between observers was excellent (κ values >0.9). All cases with BRCA1 or 2 abnormalities showed either pushing pattern metastases (76%) or infiltrative metastases composed only of micropapillae (24%). In contrast, all cases lacking BRCA1 or 2 abnormalities showed infiltrative metastases that contained combinations of papillary, glandular, and, rarely, cribriform and micropapillary architecture (P<0.0001 for comparison with pushing metastasis and P<0.001 for comparison with purely micropapillary architecture). Morphological assessment of metastatic carcinomas, a highly reproducible exercise, accurately correlated with BRCA1 status in every case, unlike morphological assessment of primary site adnexal high-grade serous carcinomas or BRCA1 immunohistochemistry. Metastatic high-grade serous carcinomas-BRCAs exhibit characteristic morphological features that appear more sensitive and specific for BRCA mutations than two other morphologically based prediction systems and should be easier to apply in practice. These findings should be validated prospectively in an independent cohort.

Distinct claudin expression characterizes BRCA1-related breast cancer

AIMS

Members of the claudin family are involved in cancer progression and are differentially expressed in subtypes of breast cancer. Breast cancers in BRCA1 germ line mutation carriers have distinct clinicopathological characteristics. Biomarkers that discriminate between BRCA1-related and sporadic breast cancer cases are needed to improve early identification of mutation carriers. In this study we evaluated protein expression of five major claudins in BRCA1-related breast cancers in comparison with sporadic controls.

METHODS AND RESULTS

Forty breast cancers in BRCA1 mutation carriers and 40 age-matched sporadic breast cancers were immunohistochemically stained for claudins 1, 3, 4, 6 and 7. Total intratumoural expression levels were compared to those in the surrounding normal tissue. In addition, subcellular claudin expression was scored. Higher overexpression rates were observed for all five claudins in BRCA1-related breast cancers when compared to sporadic controls. In multivariate analysis, overexpression of claudin 3, 4, and 7 was mainly dependent on ER-status, whereas overexpression of claudin 6 and high membranous expression of claudin 1 were independent of other characteristics.

CONCLUSIONS

BRCA1-related breast cancers are characterized by frequent overexpression of claudins. Especially claudin 1 and 6 expression may help to discriminate mutation carriers from sporadic breast cancer cases.

Lobulitis in nonneoplastic breast tissue from breast cancer patients: association with phenotypes that are common in hereditary breast cancer

Lobular inflammation (lobulitis) has been demonstrated in benign breast tissue adjacent to in situ and invasive breast cancers and, more recently, in nonneoplastic tissue from prophylactic mastectomy specimens for hereditary high-risk breast carcinoma. The aim of this study is to investigate the incidence of lobulitis in benign breast tissue of patients with breast cancer and associated clinicopathologic features. We reviewed nonneoplastic breast tissue sections from 334 patients with invasive breast carcinoma to study lobulitis in normal breast tissue and to correlate its presence with clinicopathologic features of the associated tumor. Clinical information (age, menopausal status, and follow-up), tumor characteristics (type, grade, size, lymph node status, stage, estrogen and progesterone receptor, HER2), and survival were recorded. Characteristics of women with and without lobulitis were cross-classified with categories of clinical, pathologic, and histologic characteristics, and differences in distributions were tested in univariate and multivariate analysis. Lobulitis was found in 26 (8%) of 334 patients. The lymphocytic infiltrate was predominantly T-cell type. In a multivariate model, lobulitis in patients with breast cancer was significantly associated with younger age, triple (estrogen receptor, progesterone receptor, HER2)-negative cancers, and medullary phenotypes. Lobulitis in nonneoplastic breast tissue, away from tumor, is associated with clinicopathologic features more commonly seen in hereditary breast cancer.

Reproductive factors and risk of premenopausal breast cancer by age at diagnosis: are there differences before and after age 40?

We examined the relationship between reproductive factors and risk of premenopausal breast cancer among women less than age 40 compared with older premenopausal women. We documented 374 incident cases of breast cancer diagnosed before age 40, and 2,533 cases diagnosed at age 40 and older among premenopausal women in the Nurses' Health Study cohorts. Biennial questionnaires were used to determine age at menarche, age at first birth, parity, breastfeeding, and other reproductive factors. Multivariate relative risks (RR) and 95 % confidence intervals (CI) were calculated using Cox proportional hazards models within age at diagnosis groups. Tumors in younger women were significantly more likely to be higher grade, larger size, and hormone receptor negative than were tumors in older premenopausal women (p < 0.0001). There was no significant heterogeneity according to age in associations between reproductive factors and risk of premenopausal breast cancer. First birth at age 30 or older increased breast cancer risk in both age groups (age <40: RR 1.10, 95 % CI 0.80-1.50; age ≥ 40: RR 1.16, 95 % CI 1.02-1.32; p-heterogeneity = 0.44). Risk of premenopausal breast cancer decreased with each additional year of age at menarche in both age groups (age <40: RR 0.93, 95 % CI 0.87-0.99; p trend = 0.02; age ≥ 40: RR 0.94, 95 % CI 0.91-0.97; p trend = <0.0001). Among premenopausal parous women, breastfeeding was protective regardless of age at diagnosis (age <40: RR 0.84, 95 % CI 0.57-1.22; age ≥ 40: RR 0.85, 95 % CI 0.72-0.99; p-heterogeneity = 0.79). In the largest prospective examination of reproductive risk factors and risk of breast cancer before and after age 40, we found that younger women were more likely to develop tumors with less favorable prognostic characteristics. However, associations between reproductive factors and risk of breast cancer were similar regardless of age at diagnosis of premenopausal breast cancer.

Tumour morphology predicts PALB2 germline mutation status

Background:

Population-based studies of breast cancer have estimated that at least some PALB2 mutations are associated with high breast cancer risk. For women carrying PALB2 mutations, knowing their carrier status could be useful in directing them towards effective cancer risk management and therapeutic strategies. We sought to determine whether morphological features of breast tumours can predict PALB2 germline mutation status.

Methods:

Systematic pathology review was conducted on breast tumours from 28 female carriers of PALB2 mutations (non-carriers of other known high-risk mutations, recruited through various resources with varying ascertainment) and on breast tumours from a population-based sample of 828 Australian women diagnosed before the age of 60 years (which included 40 BRCA1 and 18 BRCA2 mutation carriers). Tumour morphological features of the 28 PALB2 mutation carriers were compared with those of 770 women without high-risk mutations.

Results:

Tumours arising in PALB2 mutation carriers were associated with minimal sclerosis (odds ratio (OR)=19.7; 95% confidence interval (CI)=6.0–64.6; P=5 × 10⁻⁷). Minimal sclerosis was also a feature that distinguished PALB2 mutation carriers from BRCA1 (P=0.05) and BRCA2 (P=0.04) mutation carriers.

Conclusion:

This study identified minimal sclerosis to be a predictor of germline PALB2 mutation status. Morphological review can therefore facilitate the identification of women most likely to carry mutations in PALB2.

Prevalence of BRCA1 and BRCA2 Germline Mutations in Breast Cancer Women of Multiple Ethnic Region in Northwest China

PURPOSE

The aim of this study is to further understand the status of BRCA1 and BRCA2 mutation among Chinese high-risk breast cancer patients in multiple-ethnic regions of China.

METHODS

A total of 79 blood samples of high-risk breast cancer patients from Xinjiang Uyghur autonomous region were analyzed by PCR-DHPLC sequencing analysis.

RESULTS

Analysis with full length of the two genes identified a total of 6 deleterious mutations (2073delA, 2394C-T [Q759X] and IVS16+1G>A in BRCA1; 1627A-T [K467X], 6873delCTCC and 9481delA in BRCA2) in this cohort. The prevalence of BRCA1/2 germline mutation was about 7.6% (6/79) in the Xinjiang multiple ethnic region of China. Among them, 3 novel deleterious mutations, 2073delA in BRCA1 (Han ethnic Chinese) and BRCA2 variants 6873delCTCC and 9481delA (both are Kazakh ethnic Chinese), were identified and they had never been reported in breast cancer information core (BIC) database before. 2394C-T (Q759X) and IVS16+1G>A, in BRCA1 and BRCA2 variants 1627A-T were previously reported in other populations but not Chinese. Among 6 of the BRCA-related tumors, three BRCA1- and one BRCA2-associated tumors were in triple negative (estrogen receptor, progesterone receptor, and HER2 negative expressed) status and exhibited a high tumor grade. So far none of these 6 deleterious mutations were reported in ethnic Han Chinese.

CONCLUSION

BRCA germline mutation in Chinese multiple ethnicity region may exhibit different genotypes compared to ethnic Han Chinese in other regions. These differences may arise from interaction of genetic background and environmental factors.

Pathologic features and immunophenotype of estrogen receptor-positive breast cancers in BRCA1 mutation carriers

Although most breast cancers in BRCA1 mutation carriers are estrogen receptor negative (ER-) with a basal-like phenotype, up to one third are ER positive (ER+). Little is known about the characteristics of this subgroup. To address this, we compared histologic and immunophenotypic features of 60 BRCA1-related ER+ breast cancers with those of 85 BRCA1-related ER- cancers and 174 matched ER+ sporadic cancers. ER+ BRCA1-related cancers were significantly less likely than ER- BRCA1-related cancers to be of pure invasive ductal type (P<0.001) and to be of histologic grade 3 (P<0.001), and less frequently to have a high mitotic rate (P<0.001), pushing (or unknown) margins (P<0.001), a moderate/marked lymphocytic infiltrate (P=0.003), or geographic necrosis/fibrotic focus (P<0.001). In addition, ER+ BRCA1-related cancers less often expressed CK5/6 (P<0.0001), CK14 (P<0.0001), and epidermal growth factor receptor (P<0.0001) and more often expressed progesterone receptor (P<0.0001). In contrast, when compared with ER+ sporadic cancers, ER+ BRCA1-related cancers were significantly more often of invasive ductal type (P=0.005) and of histologic grade 3 (P=0.006), more frequently had a high mitotic rate (P=0.0003), and were more often CK14+ (P=0.03). On unsupervised cluster analysis, some ER+ BRCA1 cancers clustered more closely with sporadic ER+ cancers, whereas others clustered more closely with ER- BRCA1-related cancers. Nuclear expression levels of poly(ADP) ribose polymerase 1 in ER+ BRCA1-related cancers were similar to those in ER- BRCA1-related cancers but significantly higher than in ER+ sporadic cancers. We conclude that ER+ BRCA1-related breast cancers show several morphologic and immunophenotypic differences from ER+ sporadic breast cancers as well as some similarities to ER- BRCA1-related cancers.

BRCA1 germ-line mutations and tumor characteristics in eastern Chinese women with familial breast cancer

Although several studies detected the BRCA1 germ-line mutations in Chinese women with familial breast cancer, most of them did not employ conventional full gene sequencing, especially in eastern China. In addition, the clinicopathological features of BRCA1-associated breast cancer in Chinese women were not well investigated. In this study, we screened the complete coding regions and exon-intron boundaries of BRCA1 by polymerase chain reaction (PCR)-sequencing assay. Immunohistochemistry analyses were performed on tumor samples to detect the expression of estrogen receptor (ER), progesterone receptor (PR), P53, and human epidermal growth factor receptor-2 (HER-2). Breast cancer patients having one or more affected relatives referred from the Zhejiang Cancer Hospital, eastern China during 2008-2011 were selected for the study. A total of 62 familial breast cancer patients received the BRCA1 germ-line mutation screening. Five deleterious mutations were detected in this cohort. The mutation rate was 11.3% (7/62). We found two novel mutations (3414delC and 5,280 C > T) and two recurrent mutations (5,273 G > A and 5589del8). BRCA1 mutation tumors tended to be negative for ER, PR, and HER-2, and exhibited high histological grade compared with tumors without BRCA1 mutations. Our study suggests that recurrent mutations may exist in eastern Chinese women with familial breast cancer and PCR-sequencing assay is a useful tool to screen these mutations. It also suggests that BRCA1-associated breast cancers in Chinese women exhibit an aggressive phenotype.

Prediction of BRCA1 germline mutation status in women with ovarian cancer using morphology-based criteria: identification of a BRCA1 ovarian cancer phenotype

Specific morphologic features that may predict BRCA1 germline mutation in ovarian cancer have neither been well described nor independently tested. We identified 5 morphologic features associated with BRCA1 mutation status in a series of 20 ovarian cancers from BRCA1 mutation carriers: (1) modified Nottingham grade 3; (2) serous/undifferentiated histology; (3) prominent intraepithelial lymphocytes; (4) marked nuclear atypia with giant/bizarre forms; and (5) abundant mitotic figures. These morphologic features were then tested on 325 ovarian tumors drawn from a population-based Greater Bay Area Cancer Registry and classified into 3 categories independent of the BRCA1 status: "Compatible with BRCA1," "Possibly compatible with BRCA1," and "Not compatible with BRCA1." All "Compatible with BRCA1" tumors were additionally investigated for presence of dominant adnexal mass, fallopian tube mucosal involvement, and uterine cornu involvement. The positive and negative predictive values for "Compatible with BRCA1" were 11/42 (26.2%) and 267/283 (94.3%), respectively, whereas combining the "Compatible with BRCA1" and "Possibly compatible with BRCA1" had positive and negative predictive values of 18/85 (21.2%) and 231/240 (96.3%), respectively. Although dominant adnexal mass and uterine cornu involvement did not add further predictive value, the likelihood of BRCA1 positivity increased to 42.9% when a tumor with "Compatible with BRCA1" histology was also associated with fallopian tube mucosal involvement. The combination of modified Nottingham grade 3 serous or undifferentiated histology, prominent intraepithelial lymphocytes, marked nuclear atypia with giant/bizarre nuclei, and high mitotic index should help to identify women for BRCA1 mutational analysis in the appropriate clinical setting. Ovarian tumors lacking this specific phenotype are unlikely to be associated with BRCA1 and should not undergo mutational analysis in the absence of other indications.

Tumour morphology of early-onset breast cancers predicts breast cancer risk for first-degree relatives: the Australian Breast Cancer Family Registry

Introduction

We hypothesised that breast cancer risk for relatives of women with early-onset breast cancer could be predicted by tumour morphological features.

Methods

We studied female first-degree relatives of a population-based sample of 452 index cases with a first primary invasive breast cancer diagnosed before the age of 40 years. For the index cases, a standardised tumour morphology review had been conducted for all; estrogen (ER) and progesterone receptor (PR) status was available for 401 (89%), and 77 (17%) had a high-risk mutation in a breast cancer susceptibility gene or methylation of the BRCA1 promoter region in peripheral blood DNA. We calculated standardised incidence ratios (SIR) by comparing the number of mothers and sisters with breast cancer with the number expected based on Australian incidence rates specific for age and year of birth.

Results

Using Cox proportional hazards modelling, absence of extensive sclerosis, extensive intraductal carcinoma, absence of acinar and glandular growth patterns, and the presence of trabecular and lobular growth patterns were independent predictors with between a 1.8- and 3.1-fold increased risk for relatives (all P <0.02). Excluding index cases with known genetic predisposition or BRCA1 promoter methylation, absence of extensive sclerosis, circumscribed growth, extensive intraductal carcinoma and lobular growth pattern were independent predictors with between a 2.0- and 3.3-fold increased risk for relatives (all P <0.02). Relatives of the 128 (34%) index cases with none of these four features were at population risk (SIR = 1.03, 95% CI = 0.57 to 1.85) while relatives of the 37 (10%) index cases with two or more features were at high risk (SIR = 5.18, 95% CI = 3.22 to 8.33).

Conclusions

This wide variation in risks for relatives based on tumour characteristics could be of clinical value, help discover new breast cancer susceptibility genes and be an advance on the current clinical practice of using ER and PR as pathology-based predictors of familial and possibly genetic risks.

Identification of fifteen novel germline variants in the BRCA1 3'UTR reveals a variant in a breast cancer case that introduces a functional miR-103 target site

Mutations in the BRCA1 gene confer a substantial increase in breast cancer risk, yet routine clinical genetic screening is limited to the coding regions and intron-exon boundaries, precluding the identification of mutations in noncoding and untranslated regions (UTR). As 3'UTR mutations can influence cancer susceptibility by altering protein and microRNA (miRNA) binding regions, we screened the BRCA1 3'UTR for mutations in a large series of BRCA-mutation negative, population and clinic-based breast cancer cases, and controls. Fifteen novel BRCA1 3'UTR variants were identified, the majority of which were unique to either cases or controls. Using luciferase reporter assays, three variants found in cases, c.* 528G>C, c.* 718A>G, and c.* 1271T>C and four found in controls, c.* 309T>C, c.* 379G>A, c.* 823C>T, and c.* 264C>T, reduced 3'UTR activity (P < 0.02), whereas two variants found in cases, c.* 291C>T and c.* 1139G>T, increased 3'UTR activity (P < 0.01). Three case variants, c.* 718A>G, c.* 800T>C, and c.* 1340_1342delTGT, were predicted to create new miRNA binding sites and c.* 1340_1342delTGT caused a reduction (25%, P = 0.0007) in 3'UTR reporter activity when coexpressed with the predicted targeting miRNA, miR-103. This is the most comprehensive identification and analysis of BRCA1 3'UTR variants published to date.