Can harmful lifestyle, obesity and weight changes increase the risk of breast cancer in BRCA 1 and BRCA 2 mutation carriers? A Mini review.

BACKGROUND AND AIM: The BRCA 1 and BRCA 2 genes are associated with an inherited susceptibility to breast cancer with a cumulative risk of 60% in BRCA 1 mutation carriers and of 30% in BRCA 2 mutation carriers. Several lifestyle factors could play a role in determining an individual's risk of breast cancer. Obesity, changes in body size or unhealthy lifestyle habits such as smoking, alcohol consumption and physical inactivity have been evaluated as possible determinants of breast cancer risk. The aim of this study was to explore the current understanding of the role of harmful lifestyle and obesity or weight change in the development of breast cancer in female carriers of BRCA 1/2 mutations. METHODS: Articles were identified from MEDLINE in October 2020 utilizing related keywords; they were then read and notes, study participants, measures, data analysis and results were used to write this review. RESULTS: Studies with very large case series have been carried out but only few of them have shown consistent results. Additional research would be beneficial to better determine the actual role and impact of such factors.

Immune checkpoint inhibitor associated vitiligo and its impact on survival in patients with metastatic melanoma: an Italian Melanoma Intergroup study.

BACKGROUND: Checkpoint inhibitors in melanoma can lead to self-immune side-effects such as vitiligo-like depigmentation (VLD). Beyond the reported association with favorable prognosis, there are limited data regarding VLD patient features and their echo on the therapeutic outcomes. METHODS: To assess the association between VLD and a series of clinical and biological features as well as therapeutic outcomes, we built an observational cohort study by recruiting patients who developed VLD during checkpoint inhibitors. RESULTS: A total of 148 patients from 15 centers (101 men, median age 66 years, BRAF mutated 23%, M1c 42%, Eastern Cooperative Oncology Group (ECOG) status 0/1 99%, normal lactate dehydrogenase 74%) were enrolled. VLD was induced by ipilimumab, programmed cell death-1 (PD-1) inhibitors, and their combination in 32%, 56%, and 12%, respectively. The median onset was 26 weeks and it was associated with other skin and nonskin toxicities in 27% and 28%, respectively. After 3 years of VLD onset, 52% (95% confidence interval 39% to 63%) were progression free and 82% (95% confidence interval 70% to 89%) were still alive. The overall response rate was 73% with 26% complete response. Univariable analysis indicated that BRAF V600 mutation was associated with a better overall survival (P = 0.028), while in multivariable analysis a longer progression-free survival was associated with BRAF V600 (P = 0.093), female sex (P = 0.008), and M stage other than 1a (P = 0.024). When VLD occurred, there was a significant decrease of white blood cell (WBC) count (P = 0.05) and derived WBC-to-lymphocytes ratio (dWLR; P = 0.003). A lower monocyte count (P = 0.02) and dWLR (P = 0.01) were also reported in responder patients. CONCLUSIONS: Among VLD population, some features might help to identify patients with an effective response to immunotherapy, allowing clinicians to make more appropriate choices in terms of therapeutic options and duration.

BRCA germline mutation test for all woman with ovarian cancer?

BACKGROUND: Delivering widespread BRCA testing to patients with ovarian cancer has been suggested by several scientists, recommended by professional societies and solicited by patients organizations. However, based on the lack of studies clearly demonstrating the cost-effectiveness of such approach compared to standard practice, we evaluated the possibility to better select subgroups of ovarian cancer (OC) patients with higher probability to be a BRCA mutation carrier'. METHODS: We analyzed the database of 2222 germline BRCA analyses from OC patients recently published by Song et al. (Song 2014) by applying multivariate and conditional inference regression tree-analyses. RESULTS: Overall, 178/2192 (8.1%) evaluable OC women showed pathogenic germline mutations in BRCA genes (84 BRCA1;94 BRCA2). BRCA mutations resulted significantly more frequent in Epithelial tumors (10.7%), less differentiated tumours (11.0%) and younger subjects (13.4%). Regression tree analysis permitted to individualize a subset of 66% OC patients with particularly low risk (3.5%) to carry a BRCA mutation vs a subgroup (24% of the series), with a probability higher than 17% to carry a pathogenic mutation. Younger age, OC and Breast Cancer family history were confirmed powerful factors in selecting subgroups of patients with significantly different BRCA mutation probability. CONCLUSIONS: Our regression tree-analysis can represent an innovative approach taking into consideration all main clinical pathological information to select OC patients to be candidated for BRCA test.

Dissection of DLBCL microenvironment provides a gene expression-based predictor of survival applicable to formalin-fixed paraffin-embedded tissue.

Background: Gene expression profiling (GEP) studies recognized a prognostic role for tumor microenvironment (TME) in diffuse large B-cell lymphoma (DLBCL), but the routinely adoption of prognostic stromal signatures remains limited. Patients and methods: Here, we applied the computational method CIBERSORT to generate a 1028-gene matrix incorporating signatures of 17 immune and stromal cytotypes. Then, we carried out a deconvolution on publicly available GEP data of 482 untreated DLBCLs to reveal associations between clinical outcomes and proportions of putative tumor-infiltrating cell types. Forty-five genes related to peculiar prognostic cytotypes were selected and their expression digitally quantified by NanoString technology on a validation set of 175 formalin-fixed, paraffin-embedded DLBCLs from two randomized trials. Data from an unsupervised clustering analysis were used to build a model of clustering assignment, whose prognostic value was also assessed on an independent cohort of 40 cases. All tissue samples consisted of pretreatment biopsies of advanced-stage DLBCLs treated by comparable R-CHOP/R-CHOP-like regimens. Results: In silico analysis demonstrated that higher proportion of myofibroblasts (MFs), dendritic cells, and CD4+ T cells correlated with better outcomes and the expression of genes in our panel is associated with a risk of overall and progression-free survival. In a multivariate Cox model, the microenvironment genes retained high prognostic performance independently of the cell-of-origin (COO), and integration of the two prognosticators (COO + TME) improved survival prediction in both validation set and independent cohort. Moreover, the major contribution of MF-related genes to the panel and Gene Set Enrichment Analysis suggested a strong influence of extracellular matrix determinants in DLBCL biology. Conclusions: Our study identified new prognostic categories of DLBCL, providing an easy-to-apply gene panel that powerfully predicts patients' survival. Moreover, owing to its relationship with specific stromal and immune components, the panel may acquire a predictive relevance in clinical trials exploring new drugs with known impact on TME.

Homoarginine and inhibition of human arginase activity: kinetic characterization and biological relevance.

The inhibition of arginase, resulting in higher arginine (ARG) availability for nitric oxide synthesis, may account for the putative protective effect of homoarginine (HOMOARG) against atherosclerosis and cardiovascular disease. However, uncertainty exists regarding the significance of HOMOARG-induced arginase inhibition in vivo. A novel UPLC-MS method, measuring the conversion of ARG to ornithine (ORN), was developed to determine arginase 1 and arginase 2 inhibition by HOMOARG, lysine (LYS), proline (PRO), agmatine (AG), asymmetric dimethylarginine (ADMA), symmetric dimethylarginine (SDMA), and NG-Monomethyl-L-arginine (L-NMMA). Plasma HOMOARG, ARG and ORN concentrations were further measured in 50 healthy older adults >65 years (27 males and 23 females). HOMOARG inhibited arginase 1 with IC50 and Ki values of 8.14 ± 0.52 mM and 6.1 ± 0.50 mM, and arginase 2 with IC50 and Ki values of 2.52 ± 0.01 mM and 1.73 ± 0.10 mM, respectively. Both arginase isoforms retained 90% activity vs. control when physiological HOMOARG concentrations (1-10 µM) were used. In partial correlation analysis, plasma HOMOARG was not associated with ARG (P = 0.38) or ARG/ORN ratio (P = 0.73) in older adults. Our results suggest that arginase inhibition is unlikely to play a significant role in the reported cardio-protective effects of HOMOARG.

Sex Differences in the Associations between L-Arginine Pathway Metabolites, Skeletal Muscle Mass and Function, and their Responses to Resistance Exercise, in Old Age.

OBJECTIVES: The current study was designed to explore the associations between L-arginine metabolites and muscle mass and function in old age, which are largely unknown. DESIGN: The study used a randomised, double-blind, placebo-controlled design. SETTING: The study was carried out in a laboratory setting. PARTICIPANTS: 50 healthy older adults [median age 70 years (IQR 67-73); 27 males]. INTERVENTION: Participants undertook an 18-week resistance exercise program, and a nutritional intervention (fish oil vs. placebo). MEASUREMENTS: Serum homoarginine, ornithine, citrulline, asymmetric dimethylarginine (ADMA), NG-monomethyl-L-arginine (L-NMMA), and symmetric dimethylarginine (SDMA), maximal voluntary contraction (MVC) and isokinetic torque of the knee extensors at 30° s-1 (MIT), muscle cross sectional area (MCSA) and quality (MQ) were measured at baseline and after the intervention. RESULTS: No significant exercise-induced changes were observed in metabolite concentrations. There were significant sex differences in the associations between metabolites and muscle parameters. After adjusting for age, glomerular filtration rate and fish oil intervention, citrulline (P=0.002) and ornithine (P=0.022) were negatively associated with MCSA at baseline in males but not females. However, baseline citrulline was negatively correlated with exercise-induced changes in MVC (P=0.043) and MQ (P=0.026) amongst females. Furthermore, amongst males, baseline homoarginine was positively associated with exercise-induced changes in MVC (P=0.026), ADMA was negatively associated with changes in MIT (P=0.026), L-NMMA (p=0.048) and ornithine (P<0.001) were both positively associated with changes in MCSA, and ornithine was negatively associated with changes in MQ (P=0.039). CONCLUSION: Therefore, barring citrulline, there are significant sex differences in the associations between L-arginine metabolites and muscle mass and function in healthy older adults. These metabolites might enhance sarcopenia risk stratification, and the success of exercise programs, in old age.

Human dimethylarginine dimethylaminohydrolase 1 inhibition by proton pump inhibitors and the cardiovascular risk marker asymmetric dimethylarginine: in vitro and in vivo significance.

Proton pump inhibitor (PPI)-induced inhibition of dimethylarginine dimethylaminohydrolase 1 (DDAH1), with consequent accumulation of the nitric oxide synthase inhibitor asymmetric dimethylarginine (ADMA), might explain the increased cardiovascular risk with PPI use. However, uncertainty exists regarding whether clinical PPI concentrations significantly inhibit DDAH1 under linear initial rate conditions, and whether PPI-induced DDAH1 inhibition significantly increases ADMA in humans. DDAH1 inhibition by esomeprazole, omeprazole, pantoprazole, lansoprazole and rabeprazole was determined by quantifying DDAH1-mediated L-citrulline formation in vitro. Plasma ADMA was measured in PPI users (n = 134) and non-users (n = 489) in the Hunter Community Study (HCS). At clinical PPI concentrations (0.1-10 µmol/L), DDAH1 retained >80% activity vs. baseline. A significant, reversible, time-dependent inhibition was observed with lansoprazole (66% activity at 240 min, P = 0.034) and rabeprazole (25% activity at 240 min, P < 0.001). In regression analysis, PPI use was not associated with ADMA in HCS participants (beta 0.012, 95% CI -0.001 to 0.025, P = 0.077). Furthermore, there were no differences in ADMA between specific PPIs (P = 0.748). At clinical concentrations, PPIs are weak, reversible, DDAH1 inhibitors in vitro. The lack of significant associations between PPIs and ADMA in HCS participants questions the significance of DDAH1 inhibition as a mechanism explaining the increased cardiovascular risk reported with PPI use.

Hereditary and non-hereditary branches of family eligible for BRCA test: cancers in other sites.

BACKGROUND: The analysis of relationships of BRCA alterations with cancer at sites other than breast/ovary may provide innovative information concerning BRCA pathogenic role and support additional clinical decisions. Aim of this study is to compare presence of cancers in other sites in members of hereditary (H) and not-hereditary (nH) branches of families of patients eligible to BRCA test. METHODS: We retrospectively analyzed the incidence of cancer in other sites in members of 136 families eligible for hereditary breast/ovarian cancer genetic counseling at Centro Studi Tumori Eredo-familiari of our Institute; we compared the frequency of other cancer types in 1156 members of the H-branch with respect to 1062 members of nH-Branch. The families belonging to a proband case and with informative members in at least three generation entered the present study. RESULTS: The frequency of other Cancers in members of H-branch was significantly higher than that in members of nH-branch (161 vs 75 cancers; p < 0.0001). In specific, members of H-branch had a significantly higher probability to have more lung cancer (38 vs 9;p < 0.0006), kidney cancer (23 vs 5;p < 0.0005), liver cancer (13 vs 3;p < 0.02) and larynx cancer (14 vs 4;p < 0.03). Interestingly, to belong to H-branch resulted significantly associated with a higher probability of lung cancer (OR 4.5; 2.15-9.38 95%C.I.), liver cancer (OR: 4.02; 1.14-14.15 95% C.I.) and larynx cancer (OR:3.4; 1.12-10.39 95%C.I.) independently from Gender and Age. CONCLUSIONS: Members belonging to the H-branch of families of patients eligible to BRCA test have a higher risk of tumors in lung, larynx and liver. Clinicians should consider the increased risk for these cancers to activate prevention/early diagnosis practices in members of families with breast/ovarian familial cancer syndrome.

u-PAR expression in cancer associated fibroblast: new acquisitions in multiple myeloma progression.

BACKGROUND: Multiple Myeloma (MM) is a B-cell malignancy in which clonal plasma cells progressively expand within the bone marrow (BM) as effect of complex interactions with extracellular matrix and a number of microenvironmental cells. Among these, cancer-associated fibroblasts (CAF) mediate crucial reciprocal signals with MM cells and are associated to aggressive disease and poor prognosis. A large body of evidence emphasizes the role of the urokinase plasminogen activator (u-PA) and its receptor u-PAR in potentiating the invasion capacity of tumor plasma cells, but little is known about their role in the biology of MM CAF. In this study, we investigated the u-PA/u-PAR axis in MM-associated fibroblasts and explore additional mechanisms of tumor/stroma interplay in MM progression. METHODS: CAF were purified from total BM stromal fraction of 64 patients including monoclonal gammopathy of undetermined significance, asymptomatic and symptomatic MM, as well as MM in post-treatment remission. Flow cytometry, Real Time PCR and immunofluorescence were performed to investigate the u-PA/u-PAR system in relation to the level of activation of CAF at different stages of the disease. Moreover, proliferation and invasion assays coupled with silencing experiments were used to prove, at functional level, the function of u-PAR in CAF. RESULTS: We found higher activation level, along with increased expression of pro-invasive molecules, including u-PA, u-PAR and metalloproteinases, in CAF from patients with symptomatic MM compared to the others stages of the disease. Consistently, CAF from active MM as well as U266 cell line under the influence of medium conditioned by active MM CAF, display higher proliferative rate and invasion potential, which were significantly restrained by u-PAR gene expression inhibition. CONCLUSIONS: Our data suggest that the stimulation of u-PA/u-PAR system contributes to the activated phenotype and function of CAF during MM progression, providing a biological rationale for future targeted therapies against MM.

miRNA profiling in serum and tissue samples to assess noninvasive biomarkers for NSCLC clinical outcome.

In NSCLC, the altered expression of some miRNAs in primary tumor tissues has been correlated with diagnosis and prognosis, while the role of circulating miRNAs as cancer biomarkers is currently emerging. MiRNA expression profile through miRNA Affymetrix array was evaluated on a training set formed by the tumor component (n = 30 NSCLC serum, n = 11/30 tumor tissues) and the control component (n = 10 healthy serum and n = 11/30 noncancerous counterparts). Statistical analyses highlighted the following: a = 55 miRNAs deregulated in tumor serum, b = 27 miRNAs deregulated in tumor tissues, and c = 2 miRNAs deregulated both in tumor serum and in tumor tissues. MiRwalk tool and enrichment pathway analyses selected some miRNAs whose target genes are correlated with the main pathways involved in NSCLC tumorigenesis. The altered expression of the selected miR-486-5p (a), miR-29c* (b), and miR-133a (c) was confirmed in the validation set (n = 40). MiR-486-5p had a higher expression in tumor serum than in tumor tissues (P = 0.004), and miR-29c* showed a lower expression in tumor tissues than in tumor serum (P < 0.001). MiR-133a had a not different expression in both tumor serum and tumor tissues (P = 0.07). The low level of miR-486-5p expression in the serum of affected patients was associated with a worse time to progression of disease (P = 0.010), and serum level of miR-486-5p was a significant prognostic indicator of NSCLC (adjusted hazard ratio = 0.179, P = 0.019). These data suggest the possibility to monitor affected patients through serum and/or tissue samples, analyzing the altered expression of specific miRNAs, in order to detect prognostic biomarkers in the NSCLC.

Sporadic melanoma in South-Eastern Italy: the impact of melanocortin 1 receptor (MC1R) polymorphism analysis in low-risk people and report of three novel variants.

Environmental and genetic risk factors are involved in the development of melanoma. The role of the melanocortin 1 receptor (MC1R) gene has been investigated and differences according to geographic areas have been described. To evaluate the role of some clinical and genetic risk factors in melanoma development, we performed a case-control study involving 101 melanoma patients and 103 controls coming from South-Eastern Italy (Puglia), after achieving informed consent. We confirmed the role of known clinical risk factors for melanoma. Furthermore, 42 MC1R polymorphisms were observed. Three of these variants (L26V, H232L, D294Y) were not previously reported in the literature. Their predicted impact on receptor function was evaluated using bioinformatic tools. We report an overall frequency of MC1R variants in our population higher than in Northern or Central Italy. The most common polymorphism found was V60L, that has been recently reported to spread among South Mediterranean population. This variant influenced phenotypic characteristics of our population while it did not impinge on melanoma risk. An increased risk of melanoma was associated with two or more MC1R variants, when at least one was RHC, compared to people carrying the MC1R consensus sequence or a single MC1R polymorphism. Interestingly, we observed an increased risk of melanoma in subjects with darker skin and lower nevus count, usually considered at low risk, when carrying MC1R polymorphisms.

MicroRNA expression profiling in male and female familial breast cancer.

BACKGROUND: Gender-associated epigenetic alterations are poorly investigated in male and female familial breast cancer (fBC). MicroRNAs may contribute to the different biology in men and women particularly related to RASSF1A pathways. METHODS: Microarray technology was used to evaluate miRNA profile in 24 male and 43 female fBC. Key results were validated using RT-qPCR in an external samples set. In vitro studies were carried out to verify microRNA-target gene interaction. RESULTS: Pathway enrichment analysis with the 287 differentially expressed microRNAs revealed several signalling pathways differently regulated in male and female cases. Because we previously hypothesised a peculiar involvement of RASSF1A in male fBC pathogenesis, we focussed on the MAPK and the Hippo signalling pathways that are regulated by RASSF1A. Male miR-152 and miR-497 upregulation and RASSF1A and NORE1A interacting gene downregulation were observed, confirming a possible indirect interaction between miRNAs and the two genes. CONCLUSIONS: For the first time, a different microRNA expression pattern in male and female fBC has been shown. Moreover, the importance of RASSF1A pathway in male fBC carcinogenesis has been confirmed, highlighting a possible role for miR-152 and miR-497 in controlling MAPK and Hippo signalling pathways, regulated by RASSF1A.

Association of SULT1A1 Arg²¹³His polymorphism with male breast cancer risk: results from a multicenter study in Italy.

Male breast cancer (MBC) is rare and poorly understood. Like female breast cancer (FBC), MBCs are highly sensitive to hormonal changes, and hyperestrogenism, specifically, represents a major risk factor for MBC. MBC is considered similar to late-onset, post-menopausal estrogen/progesteron receptors positive FBC (ER+/PR+). Sulfotransferase 1A1 (SULT1A1) is an enzyme involved in the metabolism of estrogens. Recently, SULT1A1 common functional polymorphism Arg(213)His (638G>A) variant has been found to be associated with increased breast cancer (BC) risk, particularly in post-menopausal women. For this reason, we decided to explore whether SULT1A1 Arg(213)His could exert an effect on MBC development. The primary aim of this study was to evaluate the influence of the SULT1A1 Arg(213)His polymorphism on MBC risk. The secondary aim was to investigate possible associations with relevant clinical-pathologic features of MBC. A total of 394 MBC cases and 786 healthy male controls were genotyped for SULT1A1 Arg(213)His polymorphism by PCR-RFLP and high-resolution melting analysis. All MBC cases were characterized for relevant clinical-pathologic features. A significant difference in the distribution of SULT1A1 Arg(213)His genotypes was found between MBC cases and controls (P < 0.0001). The analysis of genotype-specific risk showed a significant increased MBC risk in individuals with G/A (OR 1.97, 95% CI 1.50-2.59; P < 0.0001) and A/A (OR 3.09, 95% CI 1.83-5.23; P < 0.0001) genotypes in comparison to wild-type genotype, under co-dominant model. A significant association between SULT1A1 risk genotypes and HER2 status emerged. Results indicate that SULT1A1 Arg(213)His may act as a low-penetrance risk allele for developing MBC and could be associated with a specific tumor subtype associated with HER2 overexpression.

Expression of base excision repair key factors and miR17 in familial and sporadic breast cancer.

Understanding of BRCA1/2 interaction with the base excision repair (BER) pathway could improve therapy based on 'synthetic lethality', whose effectiveness is based on homologous recombination deficiency in cells lacking functional BRCA genes. However, poly (ADP-ribose) polymerase (PARP) inhibitors failed in some patients and for this reason we explored BER key enzyme expression. In this study, the expression of BER enzymes (redox factor 1/apurinic-apyrimidinic endonuclease 1 (REF1/APEX1), NTH endonuclease III-like 1 (NTHL1), 8-oxoguanine DNA glycosylase (OGG1), PARP1) and of the scaffold protein XRCC1 (X-ray repair complementing defective repair in Chinese hamster cells 1) were investigated in familial (BRCA-related and not) and sporadic breast cancer cases. Furthermore, miR17 expression was measured because of its role in the epigenetic regulation of BRCA1. Gene expression was evaluated in BRCA1-mutated cell lines, SUM149PT and SUM1315MO2, and in a BRCA1-proficient triple-negative MDA-MB-231 cell line. A cohort of 27 familial and 16 sporadic breast cancer patients was then examined to confirm results obtained from the cell line model. APEX1/REF1 was found to be upregulated in familial BRCA-wild-type and sporadic cases, indicating this enzyme as a potential therapeutic target. Furthermore, XRCC1 was overexpressed in BRCAX patients; consequently, we suggest to test the effectiveness of inhibitors targeting two different BER components in preclinical studies. XRCC1, which is also involved in the non-homologous end-joining pathway, was found to be downregulated in BRCA2-related patients concurrently with no change in PARP1 expression. Interestingly, no difference in PARP1 and miR17 expression was found in BRCA-related and sporadic breast cancer cases. PARP1 and miR17 could therefore be further investigated as molecular biomarkers of 'BRCAness' phenotype, indicating patients which could really benefit from PARP inhibitor therapies.

DNA methylation and miRNAs regulation in hereditary breast cancer: epigenetic changes, players in transcriptional and post- transcriptional regulation in hereditary breast cancer.

The genetic alterations associated with breast carcinogenesis are well known. On the contrary epigenetic alterations in hereditary breast cancer are a new field. Two epigenetic mechanisms have emerged as the most critical players in transcriptional regulation in breast cancer: the methylation of DNA and microRNA interference. In this review we will focus on recent findings on gene silencing caused by DNA methylation and microRNA to explore the potential role of these epigenetic changes in the understanding of hereditary breast cancer. Moreover we will describe the same alterations in basal-like breast cancer and in triple-negative breast cancer, since their phenotypes have similarities with BRCA1-mutated tumors. To underline the possibility that some epigenetic alterations could also be used as potential epigenetic biomarkers of drug sensitivity or resistance, we will discuss the more common therapies in hereditary breast cancer that could also be applied to breast cancer with basal-like or triple negative phenotypes.

BRCAness: a deeper insight into basal-like breast tumors.

The molecular scenario of breast cancer has become more complex in the last few years. Distinguishing between BRCA-associated, sporadic, HER2-enriched and triple-negative tumors is not sufficient to allow effective clinical management. Basal-like breast cancer, a subtype of triple-negative breast cancer, differs from others grouped under this heading. Commonalities between BRCA-related tumors and basal-like breast cancers (BRCAness phenotype) are highly relevant to ongoing clinical trials, in particular those investigating targeted therapies (e.g. PARP inhibitors) in sporadic breast tumors. The 'gold standard' to identify basal-like phenotype is DNA microarray, but integrated results could provide a panel of biomarkers helpful in identifying 'BRCAness' tumors (e.g. copy number aberrations, abnormal protein localization and altered transcriptional levels) and other molecular targets, such as APE1,the inhibition of which is emerging as an attractive breast cancer treatment in certain therapeutic settings.

Male breast cancer: genetics, epigenetics, and ethical aspects.

BACKGROUND AND STUDY DESIGN: Male breast cancer (MBC) is a rare disease compared with female BC and our current understanding regarding breast carcinogenesis in men has been largely extrapolated from the female counterpart. We focus on differences between the ethical issues related to male and female BC patients. A systematic literature search by using PubMed (http://www.ncbi.nlm.nih.gov/pubmed/), was carried out to provide a synopsis of the current research in the field of MBC genetics, epigenetics and ethics. Original articles and reviews published up to September 2012 were selected by using the following search key words to query the PubMed website: 'male breast cancer', 'male breast cancer and genetic susceptibility', 'male breast cancer and epigenetics', 'male breast cancer and methylation', 'male breast cancer and miRNA', 'male breast cancer and ethics'. RESULTS AND CONCLUSIONS: As in women, three classes of breast cancer genetic susceptibility (high, moderate, and low penetrance) are recognized in men. However, genes involved and their impact do not exactly overlap in female and male BC. Epigenetic alterations are currently scarcely investigated in MBC, however, the different methylation and miRNA expression profiles identified to date in female and male BCs suggest a potential role for epigenetic alterations as diagnostic biomarkers. Overall, much still needs to be learned about MBC and, because of its rarity, the main effort is to develop large consortia for moving forward in understanding MBC and improving the management of MBC patients on a perspective of gender medicine.