Genotypic and phenotypic analysis of familial male breast cancer shows under representation of the HER2 and basal subtypes in BRCA-associated carcinomas

Male Breast Cancer: Imaging Considerations for Diagnosis and Surveillance

Male breast cancer accounts for less than 1% of all breast cancer cases. The important risk factors for the development of male breast cancer are family history, genetic mutations, obesity, liver disease, alcoholism, exogenous estrogen administration, and radiation exposure to the chest area. Despite its rarity, numerous studies have investigated the data on imaging considerations (mammogram, ultrasound, and magnetic resonance imaging (MRI)), but have addressed only certain aspects of male breast cancer. A comprehensive approach on the imaging characteristics, timing of imaging, prognostication based on imaging characteristics, and follow-up strategies in male breast cancer are still lacking. The purpose of this review article was to provide a comprehensive overview of the imaging findings, optimal timing to obtain imaging, and the appropriate follow-up strategies in male breast cancer survivors. This article also describes how imaging modalities can aid in determining prognosis. By addressing this knowledge gap, the article provides valuable insights for clinicians managing this uncommon yet clinically significant disease.

Gender-Specific Genetic Predisposition to Breast Cancer: BRCA Genes and Beyond

Among neoplastic diseases, breast cancer (BC) is one of the most influenced by gender. Despite common misconceptions associating BC as a women-only disease, BC can also occur in men. Additionally, transgender individuals may also experience BC. Genetic risk factors play a relevant role in BC predisposition, with important implications in precision prevention and treatment. The genetic architecture of BC susceptibility is similar in women and men, with high-, moderate-, and low-penetrance risk variants; however, some sex-specific features have emerged. Inherited high-penetrance pathogenic variants (PVs) in BRCA1 and BRCA2 genes are the strongest BC genetic risk factor. BRCA1 and BRCA2 PVs are more commonly associated with increased risk of female and male BC, respectively. Notably, BRCA-associated BCs are characterized by sex-specific pathologic features. Recently, next-generation sequencing technologies have helped to provide more insights on the role of moderate-penetrance BC risk variants, particularly in PALB2, CHEK2, and ATM genes, while international collaborative genome-wide association studies have contributed evidence on common low-penetrance BC risk variants, on their combined effect in polygenic models, and on their role as risk modulators in BRCA1/2 PV carriers. Overall, all these studies suggested that the genetic basis of male BC, although similar, may differ from female BC. Evaluating the genetic component of male BC as a distinct entity from female BC is the first step to improve both personalized risk assessment and therapeutic choices of patients of both sexes in order to reach gender equality in BC care. In this review, we summarize the latest research in the field of BC genetic predisposition with a particular focus on similarities and differences in male and female BC, and we also discuss the implications, challenges, and open issues that surround the establishment of a gender-oriented clinical management for BC.

Trichorhinophalangeal syndrome type 1 (TRPS1) expression in male breast carcinoma

Currently, there is a paucity of highly specific and sensitive markers to identify breast carcinoma in male patients. Immunohistochemical stains commonly used for unmasking primary breast carcinomas include estrogen receptor (ER) and GATA3. However, these markers are commonly expressed in carcinomas originating from other organ systems and can be reduced in breast carcinomas with higher histologic grades. Androgen receptor (AR) may be used to highlight primary male breast cancer, but this marker can also be expressed in other carcinomas. We evaluated TRPS1, a highly sensitive and specific marker for female breast carcinoma, in cases of male breast carcinoma. Through an institutional database search, we identified 72 cases of primary invasive breast carcinoma in male patients. Among ER/progesterone receptor (PR)-positive cancers, 97% showed intermediate or high positivity for both TRPS1 and GATA3. Among HER2-positive cancers, 100% showed intermediate or high positivity for TRPS1 and GATA3. One case of triple-negative breast cancer was collected, showing high positivity for TRPS1 and negativity for GATA3. AR staining was non-specific and heterogeneous: 76% showed high positivity, but the remaining 24% showed low or intermediate positivity. Additionally, among 29 cases of metastatic carcinoma to male breast tissue, 93% were negative for TRPS1, and the remaining 2 cases (7%), which were carcinomas from salivary gland primary tumors, were intermediate positive. TRPS1 is a sensitive and specific marker in the unmasking of male primary invasive breast carcinoma across different subtypes. Additionally, TRPS1 is not expressed in metastatic carcinomas of multiple primaries, with the exception of salivary gland primaries.

Outcomes of Rural Men with Breast Cancer: A Multicenter Population Based Retrospective Cohort Study

Background: Breast cancer is rare in men. This population-based study aimed to determine outcomes of male breast cancer in relation to residence and other variables. Methods: In this retrospective cohort study, men diagnosed with breast cancer in Saskatchewan during 2000–2019 were evaluated. Cox proportional multivariable regression analyses were performed to determine the correlation between survival and clinicopathological and contextual factors. Results: One hundred-eight eligible patients with a median age of 69 years were identified. Of them, 16% had WHO performance status ≥ 2 and 61% were rural residents. The stage at diagnosis was as follows: stage 0, 7%; I, 31%; II, 42%; III, 11%; IV, 8%. Ninety-eight percent had hormone receptor-positive breast cancer. The median disease-free survival of urban patients was 97 (95% CI: 50–143) vs. 64 (46–82) months of rural patients (p = 0.29). The median OS of urban patients was 127 (94–159) vs. 93 (32–153) months for rural patients (p = 0.27). On multivariable analysis, performance status ≥ 2, hazard ratio (HR) 2.82 (1.14–6.94), lack of adjuvant systemic therapy, HR 2.47 (1.03–5.92), and node-positive disease, HR 2.32 (1.22–4.40) were significantly correlated with inferior disease-free survival in early-stage invasive breast cancer. Whereas stage IV disease, HR 7.8 (3.1–19.5), performance status ≥ 2, HR 3.25 (1.57–6.71), and age ≥ 65 years, HR 2.37 (1.13–5.0) were correlated with inferior overall survival in all stages. Conclusions: Although residence was not significantly correlated with outcomes, rural men had numerically inferior survival. Poor performance status, node-positive disease, and lack of adjuvant systemic therapy were correlated with inferior disease-free survival.

Prognostic and Predictive Biomarkers in Familial Breast Cancer

Large numbers of breast cancers arise within a familial context, either with known inherited germline mutations largely within DNA repair genes, or with a strong family history of breast and/or ovarian cancer, with unknown genetic underlying mechanisms. These cancers appear to be different to sporadic cases, with earlier age of onset, increased multifocality and with association with specific breast cancer histological and phenotypic subtypes. Furthermore, tumours showing homologous recombination deficiency, due to loss of BRCA1, BRCA2, PALB2 and CHEK2 function, have been shown to be especially sensitive to platinum-based chemotherapeutics and PARP inhibition. While there is extensive research and data accrued on risk stratification and genetic predisposition, there are few data pertaining to relevant prognostic and predictive biomarkers within this breast cancer subgroup. The following is a review of such biomarkers in male and female familial breast cancer, although the data for the former are particularly sparse.

Characterization of the HER2 status in BRCA-mutated breast cancer: a single institutional series and systematic review with pooled analysis

BACKGROUND

Pathogenic variants (PVs) in BRCA1/2 genes account for ∼6% of breast and 20% of ovarian cancers. Most breast tumors developed by BRCA1 carriers are triple negative. BRCA2 tumors have similar rates of estrogen receptor positivity as sporadic controls but are less likely to be human epidermal growth factor receptor 2 (HER2)-positive. Prevalence of HER2 positivity among breast cancers (BCs) in BRCA1/2 mutation carriers is poorly and variably described, ranging from 0% to 10% and 0% to 13% in BRCA1 and BRCA2 carriers, respectively.

PATIENTS AND METHODS

We assessed the prevalence of HER2 positivity among a single institutional cohort of 398 BCs developed in carriers of BRCA1/2 PVs (240 BRCA1, 158 BRCA2). Subsequently, a systematic review of the literature and pooled analysis was carried out.

RESULTS

In our series we found a 7% HER2 positivity rate among all first BRCA1/2 BCs overall. In BRCA1 carriers, 5.4% of BCs were HER2-positive compared with 9.5% in BRCA2-mutated patients. Among bilateral BCs, HER2-positive cases were 15.2% in the BRCA1 group and 23.1% in the BRCA2 group. Notably, six BRCA1 and eight BRCA2 carriers showed discordant HER2 status between BC and bilateral BC (23.7%, 14/59). The systematic review included 21 083 BRCA1/2 patients from 73 eligible studies. The pooled rate of BRCAmut/HER2-positive BCs is 9.1% (95% confidence interval 7.3% to 11.2%). BRCA1 and BRCA2 when reported as separate data ranged from 0% to 33.3% (mean 8.3%) and from 0% to 86% (mean 10.3%), respectively.

CONCLUSIONS

As compared with sporadic cases, BCs occurring in BRCA1 and/or BRCA2 PVs carriers are less frequently HER2-positive. Prevalence of HER2 positivity in our series was consistent with pooled analysis and did not exceed 10%. Although not common, co-existence of BRCA mutations and HER2 overexpression and/or gene amplification should be acknowledged. More research is needed to better characterize this subgroup of patients who should not be excluded a priori from clinical trials of targeted therapy for BRCA1/2-driven cancers.

Analysis of the Clinical Advancements for BRCA-Related Malignancies Highlights the Lack of Treatment Evidence for BRCA-Positive Male Breast Cancer

Male breast cancer (MBC) is a rare disease that accounts for less than 1% of all breast cancers and male malignancies. Despite recognised clinico-pathological and molecular differences to female breast cancer (FBC), the clinical management of MBC follows established FBC treatment strategies. Loss of function mutations in the DNA damage response genes BRCA1 and BRCA2, have been strongly implicated in the pathogenesis of MBC. While there have been extensive clinical advancements in other BRCA-related malignancies, including FBC, improvements in MBC remain stagnant. Here we present a review that highlights the lack of treatment evidence for BRCA-related MBC and the required national and global collaborative effort to address this unmet need. In doing so, we summarise the transformative clinical advancements with poly(ADP-ribose) polymerase (PARP) inhibitors in other BRCA-related cancers namely, FBC and prostate cancer.

Male Breast Cancer: From Molecular Genetics to Clinical Management

MBC is a rare disease accounting for almost 1% of all cancers in men and less than 1% of breast cancer. Emerging data on the genetic drivers of predisposition for MBC are available and different risk factors have been associated with its pathogenesis. Genetic alterations, such as pathogenetic variants in BRCA1/2 and other moderate-/low-penetrance genes, along with non-genetic risk factors, have been recognized as pathogenic factors for MBC. Preventive and therapeutic implications could be related to the detection of alterations in predisposing genes, especially BRCA1/2, and to the identification of oncogenic drivers different from FBC. However, approved treatments for MBC remain the same as FBC. Cancer genetic counseling has to be considered in the diagnostic work-up of MBC with or without positive oncological family history. Here, we review the literature, reporting recent data about this malignancy with a specific focus on epidemiology, and genetic and non-genetic risk factors. We introduce the perspective of cancer genetic counseling for MBC patients and their healthy at-risk family members, with a focus on different hereditary cancer syndromes.

Prognostic difficulties of men with breast cancer

Most adequately powered studies confirm a worse prognosis for males versus matched females with breast cancer. There is in-stage migration for stage I cancers with a different ratio of tumor/normal breast tissue in males. Younger men have a better prognosis, largely the result of increased morbidity in the elderly, exacerbated by smoking, low socioeconomic differences, and ethnic disparity. BRCA2 carriers with MBC have a worse outcome than noncarriers as do men with amplification of EMSY. Men with tumors having a high cytosol level of plasminogen activator inhibitor 1 (PAI-1) may have more invasive cancers leading to earlier spread and hence a worse outcome. PREDICT+ is a useful prognostic model for MBC and multigene testing enables more specific systemic therapies to be used.

Male breast cancer: an update

Male breast cancer (MBC) is rare, accounting for less than 1% of all breast cancer but the incidence has increased worldwide. Risk factors include increased longevity, obesity, testicular diseases and tumours, and germline mutations of BRCA2. BRCA2 carriers have 80 times the risk of the general population. Men generally present with breast cancer at an older age compared with women. Histologically, MBC is often of grade 2, hormone receptor positive, HER2 negative, and no special type carcinoma although in situ and invasive papillary carcinomas are common. Reporting and staging are similar to female breast cancer. Metastatic lesions to the male breast do occur and should be differentiated from primary carcinomas. Until recently, MBC was thought to be similar to the usual ER positive post-menopausal female counterpart. However, advances in MBC research and trials have highlighted significant differences between the two. This review provides an up to date overview of the biology, genetics, and histology of MBC with comparison to female breast cancers and differential diagnosis from histological mimics.

Genetic Landscape of Male Breast Cancer

Male breast cancer (MBC) is now considered molecularly different from female breast cancer (FBC). Evidence from studies indicates that common genetic and epigenetic features of FBC are not shared with those diagnosed in men. Genetic predisposition is likely to play a significant role in the tumorigenesis of this rare disease. Inherited germline variants in BRCA1 and BRCA2 account for around 2% and 10% of MBC cases, respectively, and the lifetime risk of breast cancer for men harboring BRCA1 and BRCA2 mutations is 1.2% and 6.8%. As for FBC, pathogenic mutations in other breast cancer genes have also been recently associated with an increased risk of MBC, such as PALB2 and CHEK2 mutations. However, while multigene germline panels have been extensively performed for BC female patients, the rarity of MBC has resulted in limited data to allow the understanding of the magnitude of risk and the contribution of recently identified moderate penetrance genes of FBC for MBC predisposition. This review gathers available data about the germline genetic landscape of men affected by breast cancer, estimated risk associated with these genetic variants, and current guidelines for clinical management.

Genetic testing results in Slovenian male breast cancer cohort indicate the BRCA2 7806-2A > G founder variant could be associated with higher male breast cancer risk

PURPOSE

To analyze the prevalence of pathogenic/likely pathogenic variants (P/LPVs) in BRCA1 and BRCA2 genes in the largest cohort of Slovenian male breast cancer (MBC) patients to date and to explore a possible correlation between the Slovenian founder variant BRCA2:c.7806-2A > G and predisposition to MBC.

METHODS

We performed a retrospective analysis of 81 MBC cases who underwent genetic counseling and/or testing between January 1999 and May 2020. To explore a possible genotype-phenotype correlation, we performed additional analyses of 203 unrelated families with P/LPVs in BRCA2 and 177 cases of female breast cancer (FBC) in carriers of P/LPVs in BRCA2.

RESULTS

Detection rate of P/LPVs in the BRCA1 and BRCA2 genes was 24.7% (20/81) with 95% of them in BRCA2 gene. The only two recurrent P/LPVs were BRCA2:c.7806-2A > G and BRCA2:c.3975_3978dupTGCT (9 and 5 MBC cases, respectively). In families with BRCA2:c.7806-2A > G, the incidence of MBC cases was higher compared to families with other P/LPVs in BRCA2; however, the difference did not reach statistical significance (17.8% vs. 8.9%, p = 0.105). BRCA2:c.7806-2A > G was detected in both families with multiple cases of MBC. This splice-site variant represented a significantly higher proportion of all BRCA2 P/LPVs detected in MBC carriers compared to FBC carriers (47.4% vs. 26%, p = 0.049).

CONCLUSION

We observed a high mutation detection rate and conclude this may be due to the prevalent BRCA2:c.7806-2A > G variant in Slovenia. Our results indicate a possible association between this variant and higher risk of breast cancer in males compared to other identified P/LPVs in BRCA2.

Carvacrol Promotes Cell Cycle Arrest and Apoptosis through PI3K/AKT Signaling Pathway in MCF-7 Breast Cancer Cells

OBJECTIVE

To examine the role of carvacrol in modulating PI3K/AKT signaling involved in human breast cancer pathogenesis using in vitro experimental model MCF-7 cells.

METHODS

MTT and lactate dehydrogenase assays were performed with cells treated with different doses of carvacrol (0-250 p mol/L) at different time points (24 and 48 h). The nuclear morphology was assessed in MCF-7 cells with propidium iodide (PI) and acridine orange/ethidium bromide (AO/EB) staining and analyzed by fluorescence microscopy. Events like cell cycle arrest, apoptosis was observed by flow cytometric analysis and expressions of p-Rb, cyclin D1, cyclin-dependent kinase 4 (CDK4), CDK6, Bax, Bcl-2, PI3K/p-AKT was analyzed by immunoblot.

RESULTS

Carvacrol significantly reduced cell viability with the half maximal inhibitory concentration value of 200 µmol/L at 24 and 48 h (P<0.05). importantly, there was a significant increase in the accumulation of the G₀/G₁ phase upon treatment with carvacrol in MCF-7 cells (P<0.05 or P<0.01). A remarkable decrease in protein expressions of p-Rb, cyclin D1, CDK4 and CDK6 denotes cell cycle arrest (P<0.05 or P<0.01). In addition, carvacrol treatment significantly inhibited PI3K/p-AKT protein expressions leading to induction of apoptosis mediated by decreased Bcl2 and increased Bax protein expressions. Further, Annexin V/PI staining by FACS analysis, dual staining by AO/EB and PI staining studies suggests induction of apoptosis by carvacrol through PI3K/Akt signaling pathway in MCF-7 cells.

CONCLUSION

Carvacrol significantly inhibited the breast cancer MCF-7 cell proliferation and induced apoptosis via suppressing PI3/AKT signaling pathway.

The 21-Gene Recurrence Score in Male Breast Cancer

BACKGROUND

Given the limited data, systemic treatment of male breast cancer has been extrapolated from female patients. The 21-gene recurrence score (RS) assay estimates the risk of distant recurrence and chemotherapy benefit in early-stage, ER+/HER2- female breast cancer. We assessed the association between RS and type of treatment in male breast cancer.

METHODS

We identified male patients with ER+/HER2- breast cancer and available RS results treated at our institution in 2006-2016. We collected data on clinicopathologic features, treatment, and outcome. The Institutional Review Board approved the study.

RESULTS

The study cohort consists of 38 male breast cancer patients with a median age of 70 years. Median tumor size was 1.6 cm, and 81.6% (31) were node-negative. RS was low (≤ 17) in 26 (68.4%) cases, intermediate (18-30) in 9 (23.7%) cases, and high (≥ 31) in 3 (7.9%) cases, comparable to that in female patients at our institution. All patients underwent total mastectomy, and one received radiotherapy. Thirty-four (89.5%) patients received adjuvant endocrine therapy, mostly tamoxifen (81.6%; 31). Five (13.2%) patients with intermediate or high RS were treated with adjuvant chemotherapy. No locoregional recurrence was observed, and one patient developed distant recurrence (median follow-up 34 months).

CONCLUSIONS

The RS distribution in male breast cancers was similar to that in females treated at our institution. With limited follow-up, patients with low RS were spared chemotherapy and did not develop recurrence. Our results suggest that the RS may have a clinical utility in male breast cancer patients.

BRCA2 carriers with male breast cancer show elevated tumour methylation

Background

Male breast cancer (MBC) represents a poorly characterised group of tumours, the management of which is largely based on practices established for female breast cancer. However, recent studies demonstrate biological and molecular differences likely to impact on tumour behaviour and therefore patient outcome. The aim of this study was to investigate methylation of a panel of commonly methylated breast cancer genes in familial MBCs.

Methods

60 tumours from 3 BRCA1 and 25 BRCA2 male mutation carriers and 32 males from BRCAX families were assessed for promoter methylation by methylation-sensitive high resolution melting in a panel of 10 genes (RASSF1A, TWIST1, APC, WIF1, MAL, RARβ, CDH1, RUNX3, FOXC1 and GSTP1). An average methylation index (AMI) was calculated for each case comprising the average of the methylation of the 10 genes tested as an indicator of overall tumour promoter region methylation. Promoter hypermethylation and AMI were correlated with BRCA carrier mutation status and clinicopathological parameters including tumour stage, grade, histological subtype and disease specific survival.

Results

Tumours arising in BRCA2 mutation carriers showed significantly higher methylation of candidate genes, than those arising in non-BRCA2 familial MBCs (average AMI 23.6 vs 16.6, p = 0.01, 45% of genes hypermethylated vs 34%, p < 0.01). RARβ methylation and AMI-high status were significantly associated with tumour size (p = 0.01 and p = 0.02 respectively), RUNX3 methylation with invasive carcinoma of no special type (94% vs 69%, p = 0.046) and RASSF1A methylation with coexistence of high grade ductal carcinoma in situ (33% vs 6%, p = 0.02). Cluster analysis showed MBCs arising in BRCA2 mutation carriers were characterised by RASSF1A, WIF1, RARβ and GTSP1 methylation (p = 0.02) whereas methylation in BRCAX tumours showed no clear clustering to particular genes. TWIST1 methylation (p = 0.001) and AMI (p = 0.01) were prognostic for disease specific survival.

Conclusions

Increased methylation defines a subset of familial MBC and with AMI may be a useful prognostic marker. Methylation might be predictive of response to novel therapeutics that are currently under investigation in other cancer types.

Electronic supplementary material

The online version of this article (10.1186/s12885-017-3632-7) contains supplementary material, which is available to authorized users.

LRH-1 expression patterns in breast cancer tissues are associated with tumour aggressiveness

The significance and regulation of liver receptor homologue 1 (LRH-1, NR5A2), a tumour-promoting transcription factor in breast cancer cell lines, is unknown in clinical breast cancers. This study aims to determine LRH-1/NR5A2 expression in breast cancers and relationship with DNA methylation and tumour characteristics. In The Cancer Genome Atlas breast cancer cohort NR5A2 expression was positively associated with intragenic CpG island methylation (1.4-fold expression for fully methylated versus not fully methylated, p=0.01) and inversely associated with promoter CpG island methylation (0.6-fold expression for fully methylated versus not fully methylated, p=0.036). LRH-1 immunohistochemistry of 329 invasive carcinomas and ductal carcinoma in situ (DCIS) was performed. Densely punctate/coarsely granular nuclear reactivity was significantly associated with high tumour grade (p<0.005, p=0.033 in invasive carcinomas and DCIS respectively), negative estrogen receptor status (p=0.008, p=0.038 in overall cohort and invasive carcinomas, respectively), negative progesterone receptor status (p=0.003, p=0.013 in overall cohort and invasive carcinomas, respectively), HER2 amplification (overall cohort p=0.034) and non-luminal intrinsic subtype (p=0.018, p=0.038 in overall cohort and invasive carcinomas, respectively). These significant associations of LRH-1 protein expression with tumour phenotype suggest that LRH-1 is an important indicator of tumour biology in breast cancers and may be useful in risk stratification.

Characterisation of male breast cancer: a descriptive biomarker study from a large patient series

Male breast cancer (MBC) is rare. We assembled 446 MBCs on tissue microarrays and assessed clinicopathological information, together with data from 15 published studies, totalling 1984 cases. By immunohistochemistry we investigated 14 biomarkers (ERα, ERβ1, ERβ2, ERβ5, PR, AR, Bcl-2, HER2, p53, E-cadherin, Ki67, survivin, prolactin, FOXA1) for survival impact. The main histological subtype in our cohort and combined analyses was ductal (81%, 83%), grade 2; (40%, 44%), respectively. Cases were predominantly ERα (84%, 82%) and PR positive (74%, 71%), respectively, with HER2 expression being infrequent (2%, 10%), respectively. In our cohort, advanced age (>67) was the strongest predictor of overall (OS) and disease free survival (DFS) (p = 0.00001; p = 0.01, respectively). Node positivity negatively impacted DFS (p = 0.04). FOXA1 p = 0.005) and AR p = 0.009) were both positively prognostic for DFS, remaining upon multivariate analysis. Network analysis showed ERα, AR and FOXA1 significantly correlated. In summary, the principle phenotype of MBC was luminal A, ductal, grade 2. In ERα+ MBC, only AR had prognostic significance, suggesting AR blockade could be employed therapeutically.

BRIP1/FANCJ Mutation Analysis in a Family with History of Male and Female Breast Cancer in India

Male breast cancer (MBC) is a rare and poorly studied disease that is a growing global health problem. Interestingly, both the molecular basis of MBC and its histological profile are often quite distinct from the far more prevalent female breast cancer, emphasizing the need for increased focus on MBC. Here, we present a case report of an MBC patient from India with a strong familial history of breast cancer. This patient was normal for BRCA1/2 and many other common breast cancer-associated genes. However, upon further analysis, the individual was found to possess two mutations in the DNA helicase and tumor suppressor gene BRIP1, including a silent mutation at residue 879 as well as a P919S variant. Other family members were also screened for these mutations. To the best of our knowledge, this is the first report of BRIP1 mutation in MBC in the Indian population.

Male Breast Cancer

Objectives

A clinicopathologic study with an emphasis on tumor immunohistochemical profile is presented.

Methods

Sixty-one cases of male invasive breast cancers were studied. Median age of the cohort was 65 years.

Results

Ninety-seven percent were estrogen receptor positive+ and 10% human epidermal growth factor receptor 2 positive. The individual diagnostic marker positivity was 98% for GATA-binding protein 3, 95% for androgen receptor, 90% for progesterone receptor, 88% for deleted in pancreatic cancer 4, 75% for gross cystic disease fluid protein 15, 72% for cytokeratin 7, 55% for mammaglobin, and 15% for vimentin and Wilms tumor protein 1. Caudal type homeobox 2 protein, cytokeratin 20, Napsin A, paired box gene 8, prostate-specific antigen, thyroid transcription factor 1, and uroplakin II were negative in all cases. Survival analyses showed tumor stage, receptor status, and Nottingham prognostic index to be prognostic. The overall survival was 70%, but the breast cancer–specific survival was 92% (mean follow-up, 59 months); 33% developed second malignancy. The immunohistochemistry profile was similar to female breast cancers.

Conclusions

The second malignancies in this cohort affected overall survival and suggest the possibility of other germline mutations in addition to BRCA2 in male patients with breast cancer.

The cancer genetics and pathology of male breast cancer

Male breast cancer (MBC) is an uncommon and poorly understood disease. Recent molecular studies have shown important differences from female breast cancer which are likely to influence treatment strategies from the current female-based management towards a more tailored approach. Significantly more MBCs than female breast cancers arise with an underlying germline cancer predisposition, and display a vastly different penetrance compared with females. Furthermore, the genophenotypical association of basal-like cancer with BRCA1 present in female breast cancer is not observed in male breast cancer. Differences in somatic changes between male and female breast cancer have also been reported, with particular enrichment of PIK3CA mutations and a paucity of TP53 mutations. In general, chromosomal-based changes, in particular regions of gains, are seen more frequently in male than female breast cancer and methylation is seen less frequently. Clinically, several molecular subtypes with prognostic relevance have been described, including chromosomal complex high and methylation high groups, and subgroups with profiling signatures pertaining to epithelial mesenchymal transition and hormonal therapy insensitivity. As with female breast cancer, attention to male specific multicentre trials based on the individual characteristics are needed, together with establishment of reliable preclinical models to understand more clearly the pathogenesis of male breast cancer and improve the general poor outcome of this disease.

BRCA1 and BRCA2 mutations in males with familial breast and ovarian cancer syndrome. Results of a Spanish multicenter study

Male breast cancer (MBC) is a rare disease that represents <1% of all breast cancers (BCs). We analyze the results of a multicenter study performed in Spanish familial MBC including family history of hereditary breast and ovarian cancer syndrome (HBOCS) and clinicopathological features. We also study the relationship between BRCA1/BRCA2 mutational status in male relatives affected with cancer (MAC) and, family history and tumor types. The study included 312 men index cases with family history of HBOCS and 61 MAC BRCA1/2 mutation-carriers. Family history, histological grade (HG), clinicopathological and immunohistochemistry data were collected. BRCA1/2 mutation analyses were performed by direct sequencing or screening methods and the large rearrangements by multiplex ligation dependent probe amplification. We found 49 mutation-carriers (15.7%), 95.9% with BRCA2 mutations. BRCA2 mutation-carriers were associated with families with at least one MBC and one BC in female (type II; p = 0.05). Strong association were found between the presence of pathogenic mutations in MBCs and the advanced HG (p = 0.003). c.658_659delTG, c.2808_2811delACAA, c.6275_6276delTT and c.9026_9030delATCAT were the most prevalent mutations. In 61 MAC we found 20 mutations in BRCA1 and 41 in BRCA2. For MAC we show that mutational status was differentially associated with family history (p = 0.018) and tumor type, being BRCA2 mutations linked with BC and prostatic cancer (p = 0.018). MBC caused by BRCA1/2 mutations define two types of MBCs. The most frequent caused by BRCA2 mutation linked to type II families and the rarest one attributed to BRCA1 mutation. Tumor associated with MAC suggest that only BRCA2 mutations have to do with a specific type of cancer (BC and prostatic cancer); but the linkage to tumors is questionable for BRCA1 mutations .

Male breast cancer is not congruent with the female disease

It has become customary to extrapolate from the results of treatment trials for female breastcancer and apply them to males with the disease. In the absence of results from national and international randomised trials for male breast cancer (MBC) this appears superficially to be an appropriate response. Closer examination of available data reveals that aspects of the aetiology and treatment of MBC do not fit the simplistic model that men usually have endocrine sensitive tumours which behave like those in postmenopausal women. Most females and males with breast cancer have none of the recognised risk factors, indicating the gaps in our knowledge of the epidemiology of this disease. Several studies have compared epidemiological risk factors for MBC and female breast cancer (FBC) but many have been blighted by small numbers. In comparison with FBC there is a larger proportion of BRCA2 tumours, (occurring in 10% of MBC), and underrepresentation of BRCA1 tumours (found in only 1%), suggesting significant differences in the genetic aetiology of MBC and FBC. Genome-wide association studies in FBC reported single nucleotide polymorphisms (SNPs) in 12 novel independent loci were consistently associated with disease but for MBC 2 SNPs had a significantly increased risk. Molecular profiles of matched cancers in males and females showed a gender-associated modulation of major processes including energy metabolism, regulation of translation, matrix remodelling and immune recruitment. Immunohistochemistry for kinase inhibitor proteins (KIPs) p27Kip1 and p21Waf1 indicate a significant difference in the immunostaining of tumours from male patients compared with females. MBC is almost always estrogen receptor positive (ER+ve) and so systemic treatment is usually endocrine. With evidence in FBC that aromatase inhibitors are more effective than tamoxifen in the postmenopausal it was seemingly logical that the same would be true for MBC. Results however suggest less efficacy with AIs and an increase in risk of mortality compared to tamoxifen. The overall survival in male breast cancer was significantly better after adjuvant treatment with tamoxifen compared to an aromatase inhibitor. These important biological differences point the way to the development of new therapies for MBC based on differences rather than similarities with FBC.

Male breast cancer in BRCA1 and BRCA2 mutation carriers: pathology data from the Consortium of Investigators of Modifiers of BRCA1/2

BACKGROUND

BRCA1 and, more commonly, BRCA2 mutations are associated with increased risk of male breast cancer (MBC). However, only a paucity of data exists on the pathology of breast cancers (BCs) in men with BRCA1/2 mutations. Using the largest available dataset, we determined whether MBCs arising in BRCA1/2 mutation carriers display specific pathologic features and whether these features differ from those of BRCA1/2 female BCs (FBCs).

METHODS

We characterised the pathologic features of 419 BRCA1/2 MBCs and, using logistic regression analysis, contrasted those with data from 9675 BRCA1/2 FBCs and with population-based data from 6351 MBCs in the Surveillance, Epidemiology, and End Results (SEER) database.

RESULTS

Among BRCA2 MBCs, grade significantly decreased with increasing age at diagnosis (P = 0.005). Compared with BRCA2 FBCs, BRCA2 MBCs were of significantly higher stage (P for trend = 2 × 10(-5)) and higher grade (P for trend = 0.005) and were more likely to be oestrogen receptor-positive [odds ratio (OR) 10.59; 95 % confidence interval (CI) 5.15-21.80] and progesterone receptor-positive (OR 5.04; 95 % CI 3.17-8.04). With the exception of grade, similar patterns of associations emerged when we compared BRCA1 MBCs and FBCs. BRCA2 MBCs also presented with higher grade than MBCs from the SEER database (P for trend = 4 × 10(-12)).

CONCLUSIONS

On the basis of the largest series analysed to date, our results show that BRCA1/2 MBCs display distinct pathologic characteristics compared with BRCA1/2 FBCs, and we identified a specific BRCA2-associated MBC phenotype characterised by a variable suggesting greater biological aggressiveness (i.e., high histologic grade). These findings could lead to the development of gender-specific risk prediction models and guide clinical strategies appropriate for MBC management.

Mutation Screening of BRCA Genes in 10 Iranian Males with Breast Cancer

Male breast cancer is a rare disease with an increasing trend. Due to limited information especially about the genetic basis of the disease in Iran and the lower age of its onset, the disease requires more attention. The aim of this study was to screen the male patients with breast cancer for BRCA mutations as well as tissue markers of estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor (HER-2) and cytokeratin 5/6 (CK5/6). Ten Iranian males with breast cancer were selected regardless of their histologic subtypes, age and family history from patients referred to Mehrad, Day and Parsian hospitals in Tehran, Iran, during a two-year period. Paraffin blocks of the tumoral regions were tested for ER, PR, HER-2 and CK5/6 immunostaining. DNA extraction was carried out on the EDTA blood samples followed by Sanger sequencing. Immunohistochemistry results for ER, and PR were negative in 2 out of 10 patients, while the results of HER-2 and CK5/6 were negative in all the cases. A missense mutation in exon 18 of BRCA1 and a nonsense mutation in exon 25 of in BRCA2 were detected in one patient each. Both patients belonged to luminal A subtype. Despite the low number of patients in this study, it could be concluded that mutations in BRCA1 and BRCA2 occur in male breast cancer patients of luminal A subtype. The negative status of the tissue markers could not be used for the prediction of BRCA mutations.

Increased risk of male cancer and identification of a potential prostate cancer cluster region in BRCA2

BACKGROUND

The risk of cancer in men from BRCA1 and BRCA2 families is relevant to define to motivate genetic testing and optimize recommendations for surveillance.

MATERIAL AND METHODS

We assessed the risk of cancer in male mutation carriers and their first-degree relatives in 290 BRCA1 and BRCA2 families with comparison to matched controls with the aim to motivate genetic testing and optimize recommendations for surveillance.

RESULTS

Mutation carriers in BRCA1 families were not at increased risk of cancer, whereas mutation carriers in BRCA2 families were at increased risk of male breast cancer and prostate cancer with cumulative risks of 12.5% and 18.8%, respectively. Breast cancer developed at a mean age of 59 years, typically as ER/PR positive ductal carcinomas. Prostate cancer developed at a mean age of 68 years, with Gleason scores ≥ 8 in 40% of the tumors. The hazard ratio for BRCA2-associated prostate cancer was 3.7 (p < 0.001) in mutation carriers and 3.1 (p = 0.001) in first-degree relatives. Of the 37 prostate cancers, 19 were linked to four BRCA2 mutations within a region defined by c.6373-c.6492. Individuals with mutations herein had a HR of 3.7 for prostate cancer compared to individuals with mutations outside of this region.

CONCLUSIONS

Male mutation carriers and first-degree relatives in BRCA2 families are at an increased risk of breast cancer and prostate cancer with a potential prostate cancer cluster region within exon 11 of BRCA2.

Deregulation of the EGFR/PI3K/PTEN/Akt/mTORC1 pathway in breast cancer: possibilities for therapeutic intervention

The EGFR/PI3K/PTEN/Akt/mTORC1/GSK-3 pathway plays prominent roles in malignant transformation, prevention of apoptosis, drug resistance and metastasis. The expression of this pathway is frequently altered in breast cancer due to mutations at or aberrant expression of: HER2, ERalpha, BRCA1, BRCA2, EGFR1, PIK3CA, PTEN, TP53, RB as well as other oncogenes and tumor suppressor genes. In some breast cancer cases, mutations at certain components of this pathway (e.g., PIK3CA) are associated with a better prognosis than breast cancers lacking these mutations. The expression of this pathway and upstream HER2 has been associated with breast cancer initiating cells (CICs) and in some cases resistance to treatment. The anti-diabetes drug metformin can suppress the growth of breast CICs and herceptin-resistant HER2+ cells. This review will discuss the importance of the EGFR/PI3K/PTEN/Akt/mTORC1/GSK-3 pathway primarily in breast cancer but will also include relevant examples from other cancer types. The targeting of this pathway will be discussed as well as clinical trials with novel small molecule inhibitors. The targeting of the hormone receptor, HER2 and EGFR1 in breast cancer will be reviewed in association with suppression of the EGFR/PI3K/PTEN/Akt/mTORC1/GSK-3 pathway.

Mutational profiling of familial male breast cancers reveals similarities with luminal A female breast cancer with rare TP53 mutations

Background:

Male breast cancer (MBC) is still poorly understood with a large proportion arising in families with a history of breast cancer. Genomic studies have focused on germline determinants of MBC risk, with minimal knowledge of somatic changes in these cancers.

Methods:

Using a TruSeq amplicon cancer panel, this study evaluated 48 familial MBCs (3 BRCA1 germline mutant, 17 BRCA2 germline mutant and 28 BRCAX) for hotspot somatic mutations and copy number changes in 48 common cancer genes.

Results:

Twelve missense mutations included nine PIK3CA mutations (seven in BRCAX patients), two TP53 mutations (both in BRCA2 patients) and one PTEN mutation. Common gains were seen in GNAS (34.1%) and losses were seen in GNAQ (36.4%), ABL1 (47.7%) and ATM (34.1%). Gains of HRAS (37.5% vs 3%, P=0.006), STK11 (25.0% vs 0%, P=0.01) and SMARCB1 (18.8% vs 0%, P=0.04) and the loss of RB1 (43.8% vs 13%, P=0.03) were specific to BRCA2 tumours.

Conclusions:

This study is the first to perform high-throughput somatic sequencing on familial MBCs. Overall, PIK3CA mutations are most commonly seen, with fewer TP53 and PTEN mutations, similar to the profile seen in luminal A female breast cancers. Differences in mutation profiles and patterns of gene gains/losses are seen between BRCA2 (associated with TP53/PTEN mutations, loss of RB1 and gain of HRAS, STK11 and SMARCB1) and BRCAX (associated with PIK3CA mutations) tumours, suggesting that BRCA2 and BRCAX MBCs may be distinct and arise from different tumour pathways. This has implications on potential therapies, depending on the BRCA status of MBC patients.

Identification of a new BRCA2 large genomic deletion associated with high risk male breast cancer

BACKGROUND

Male breast cancer (MBC) is an uncommon disease that has been the focus of limited research. It is estimated that approximately 10% of men with breast cancer have a genetic predisposition, with BRCA2 being the most prevalent genetic mutation. Here we describe the case of MBC in a 64-year-old man who presented on physical examination a nodule in his left breast and declared to have an extensive family history of cancer.

METHODS AND RESULTS

The patient was firstly diagnosed with an invasive ductal carcinoma (IDC) with histological grade III, nuclear grade 3, pT4N2Mx and positive for hormonal receptors and HER2. Exome sequencing was performed by massive parallel sequencing which had detected a novel BRCA2 germline mutation that is a large genomic deletion of 3,492 nucleotides including BRCA2 exon 14, and this deletion is out of frame and is predicted to lead to a stop codon in exon 15 at codon 2,496.

CONCLUSION

Large rearrangements in BRCA1 and BRCA2 occur in a small percentage (<1%) of patients tested for hereditary breast and ovarian cancer. This is the first report of the mutation del3492 in BRCA2 exon 14, which leads to a truncated protein and therefore is clinically relevant. Mutation segregation analysis should be further done in the Brazilian population. Herein we highlight the importance of next-generation sequencing in the detection of large genomic deletions.

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 profiling of ductal carcinoma in situ and its relationship to histopathological features

Introduction

DNA methylation is a well-studied biomarker in invasive breast cancer, but its role in ductal carcinoma in situ (DCIS) is less well characterized. The aims of this study are to assess the methylation profile in DCIS for a panel of well-characterized genes that are frequently methylated in breast cancer, to investigate the relationship of methylation with pathological features, and to perform a proof-of-principle study to evaluate the practicality of methylation as a biomarker in diagnostic DCIS material.

Methods

Promoter CpG island methylation for a panel of 11 breast cancer-related genes was performed by methylation-sensitive high resolution melting (MS-HRM). Formalin-fixed, paraffin-embedded (FFPE) biopsies from 72 samples of pure DCIS (DCIS occurring in the absence of synchronous invasive carcinoma), 10 samples of mixed DCIS (DCIS adjacent to invasive carcinoma), and 18 samples of normal breast epithelium adjacent to a DCIS lesion were micro-dissected prior to DNA extraction.

Results

Methylation was seen for all the tested genes except BRCA1. RASSF1A was the most frequently methylated gene (90% of DCIS samples) and its methylation was associated with comedo necrosis (p = 0.018). Cluster analysis based on the methylation profile revealed four groups, the highly methylated cluster being significantly associated with high nuclear grade, HER2 amplification, negative estrogen receptor (ER) α status, and negative progesterone receptor (PgR) status, (p = 0.038, p = 0.018, p <0.001, p = 0.001, respectively). Methylation of APC (p = 0.017), CDH13 (p = 0.017), and RARβ (p <0.001) was associated with negative ERα status. Methylation of CDH13 (p <0.001), and RARβ (p = 0.001) was associated with negative PgR status. Methylation of APC (p = 0.013) and CDH13 (p = 0.026) was associated with high nuclear grade. Methylation of CDH13 (p = 0.009), and RARβ (p = 0.042) was associated with HER2-amplification.

Conclusions

DNA methylation can be assessed in FFPE-derived samples using suitable methodologies. Methylation of a panel of genes that are known to be methylated in invasive breast cancer was able to classify DCIS into distinct groups and was differentially associated with phenotypic features in DCIS.

Electronic supplementary material

The online version of this article (doi:10.1186/s13058-014-0423-9) contains supplementary material, which is available to authorized users.

Nuclear HIF1A expression is strongly prognostic in sporadic but not familial male breast cancer

Male breast cancer is poorly understood with a large proportion arising in the familial context particularly with the BRCA2 germline mutation. As phenotypic and genotypic differences between sporadic and familial male breast cancers have been noted, we investigated the importance of a hypoxic drive in these cancers as this pathway has been shown to be of importance in familial female breast cancer. Expression of two major hypoxia-induced proteins, the hypoxia-inducible factor-1α (HIF1A) and the carbonic anhydrase IX (CA9), examined within a large cohort including 61 familial (3 BRCA1, 28 BRCA2, 30 BRCAX) and 225 sporadic male breast cancers showed that 31% of all male breast cancers expressed either HIF1A (25%) and/or CA9 (8%) in the combined cohort. Expression of HIF1A correlated with an increased incidence of a second-major malignancy (P=0.04), histological tumor type (P=0.005) and basal phenotype (P=0.02). Expression of CA9 correlated with age (P=0.004) in sporadic cases and an increased tumor size (P=0.003). Expression of HIF1A was prognostic for disease-specific survival in sporadic male breast cancers (HR: 3.8, 95% CI: 1.5-9.8, P=0.006) but not within familial male breast cancer, whereas CA9 was only prognostic in familial male breast cancers (HR: 358.0, 95% CI: 9.3-13781.7, P=0.002) and not in sporadic male breast cancer. This study found that hypoxic drive is less prevalent in male breast cancer compared with female breast cancer, possibly due to a different breast microenvironment. The prognostic impact of HIF1A is greatest in sporadic male breast cancers with an alternate dominant mechanism for the oncogenic drivers suggested in high risk familial male breast cancers.

The 21-gene recurrence score assay (Oncotype DX™) in estrogen receptor-positive male breast cancer: experience in an Israeli cohort

OBJECTIVE

The 21-gene recurrence score (RS) assay has been widely adopted for use in early estrogen receptor (ER)-positive breast cancer to assess the risk for distant recurrence and the potential benefit of adjuvant chemotherapy. The primary aim of this study was to assess RS distribution in Israeli male breast cancer (MBC) patients.

METHODS

The study population included 65 newly diagnosed Israeli MBC patients. Clinical and pathologic data were collected at the time of referral. Pathologic examinations were conducted at the pathology departments of the referring centers. The RS assay (Oncotype DX™) was performed on paraffin-embedded tumor samples at Genomic Health laboratories.

RESULTS

The mean age of the patients was 65.1 years (range 38-88 years). Low-risk (RS<18), intermediate-risk (RS 18-30) and high-risk (RS≥31) scores were noted in 29 patients (44.6%), 27 patients (41.5%) and 9 patients (13.9%), respectively. The distribution of RS in male patients was similar to the distribution in 2,455 female patients from Israel referred during the same time period.

CONCLUSION

Our data suggest that the distribution of Oncotype DX RS in ER-positive MBC patients is similar to that of female breast cancer patients.

PIK3CA mutations are frequently observed in BRCAX but not BRCA2-associated male breast cancer

INTRODUCTION

Although a substantial proportion of male breast cancers (MBCs) are hereditary, the molecular pathways that are activated are unknown. We therefore examined the frequency and clinicopathological associations of the PIK3CA/mammalian target of rapamycin (mTOR) and mitogen-activated protein kinase (MAPK) pathways and their regulatory genes in familial MBC.

METHODS

High resolution melting analysis and confirmatory sequencing was used to determine the presence of somatic mutations in PIK3CA (exon 9 and 20), AKT1 (exon 4), KRAS (exon 2) and BRAF (exon 15) genes in 57 familial MBCs. Further analysis of the PIK3CA/mTOR pathway was performed using immunohistochemistry for the pAKT1, pS6 and p4EBP1 biomarkers.

RESULTS

PIK3CA somatic mutations were identified in 10.5% (6 of 57) of cases; there were no AKT1, KRAS or BRAF somatic mutations. PIK3CA mutations were significantly more frequent in cancers from BRCAX patients (17.2%, 5/29) than BRCA2 (0%, 0/25) carriers (P = 0.030). Two BRCAX patients had an E547K mutation which has only been reported in one female breast cancer previously. PIK3CA mutation was significantly correlated with positive pS6 (83.3% vs. 32.0%, P = 0.024) and negative p4EBP1 (100% vs. 38.0%, P = 0.006) expression, but not pAKT expression. Expression of nuclear p4EBP1 correlated with BRCA2 mutation carrier status (68.0% vs. 38.7%, P = 0.035).

CONCLUSIONS

Somatic PIK3CA mutation is present in familial male breast cancer but absent in BRCA2 carriers. The presence of two of the extremely rare E547K PIK3CA mutations in our cohort may have specific relevance in MBCs. Further study of PIK3CA in MBCs, and in particular BRCAX patients, may contribute to further establishing the relevance of specific PIK3CA mutations in MBC aetiology and in the identification of particular patient groups most likely to benefit from therapeutic targeting with the novel PIK3CA inhibitors that are currently in development.