Male breast cancer: genetics, epigenetics, and ethical aspects

Male breast cancer differs from female breast cancer in molecular features that affect prognoses and drug responses

BACKGROUND

Male breast cancer (MBC) is a rare malignancy with a worse prognosis than female breast cancer (FBC). Current MBC treatment strategies are based on those for FBC. However, molecular differences between MBC and FBC with respect to prognosis and drug responses remain unclear.

METHODS

After controlling for confounding factors with propensity score matching (PSM), differences between MBC and FBC were comprehensively analyzed using many types of data: survival, immune microenvironments, sex hormone responses, drug sensitivity, transcriptomes, genomes, epigenomes, and proteomes.

RESULTS

Overall survival (OS) and cancer-specific survival (CSS) were both worse for MBC than for FBC. Differentially expressed mRNAs were enriched in numerous cancer-related functions and pathways, with SPAG16 and STOX1 being as the most important prognosis-related mRNAs for MBC. Competing endogenous RNA (ceRNA) and transcription factor (TF)-mRNA regulatory networks contain potential prognostic genes. Nine genes had higher mutation frequencies in MBC than in FBC. MBC shows a comparatively poor response to immunotherapy, with five proteins that promote breast cancer progression being highly expressed in MBC. MBC may be more responsive than FBC to estrogen. We detected six United States Food and Drug Administration (FDA)-approved therapeutic target genes as being differentially expressed between MBC and FBC.

CONCLUSION

The poor prognosis of MBC compared to FBC is due to numerous molecular differences and resulting drug responses.

BRCA-associated hereditary male cancers: can gender affect the prevalence and spectrum of germline pathogenic variants?

Introduction

Although hereditary male neoplasms are quite rare, individuals harbouring germline BRCA1/2 pathogenic variants (PVs) may have a risk of developing tumours associated with Hereditary Breast and Ovarian Cancer (HBOC) syndrome, including male breast (MBC), prostate (PCa) and pancreatic (PC) cancers, and melanoma. Women and men showed a comparable genetic architecture of cancer susceptibility, but there are some gender-specific features. Since little is known about cancer genetic susceptibility in male population, our study was aimed at investigating the frequency of BRCA1/2 PVs in men with HBOC syndrome-associated tumors, in order to understand whether differences in gender may reflect in the prevalence and spectrum of germline alterations.

Patients and methods

We retrospectively collected and analysed clinical information of 352 HBOC-associated male cancer patients genetically tested for germline BRCA1/2 PVs by Next-Generation Sequencing analysis, enrolled, from February 2018 to January 2024, at the "Regional Center for the prevention, diagnosis and treatment of rare and heredo-familial tumors of adults" of the University-Hospital Policlinico "P. Giaccone" of Palermo (Italy).

Results

Our investigation revealed that 7.4% of patients was carrier of a germline BRCA PV, with an almost total prevalence of BRCA2 alterations. In particular, 65.4% of BRCA-positive patients developed MBC, 19.2% had PC, 11.6% developed PCa, and only 3.8% had melanoma. Specifically, MBC individuals showed a BRCA-associated genetic predisposition in 17% of cases, whereas patients with PCa or PC exhibited a lower frequency of BRCA2 PVs, taking into account the current national criteria for access to germline genetic testing.

Discussion

Our study showed a high heterogeneity in prevalence of germline BRCA2 PVs among men which could reflect a potential gender-specific genetic heterogeneity. Therefore, BRCA-associated male tumours could be due to BRCA2 PVs different from those usually detected in women. In the event that it is demonstrated, in future, that male cancers are genetically distinct entities from those female this could improve personalized risk evaluation and guide therapeutic choices for patients of both sexes, in order to obtain a gender equality in cancer care.

Biological Basis of Breast Cancer-Related Disparities in Precision Oncology Era

Precision oncology is based on deep knowledge of the molecular profile of tumors, allowing for more accurate and personalized therapy for specific groups of patients who are different in disease susceptibility as well as treatment response. Thus, onco-breastomics is able to discover novel biomarkers that have been found to have racial and ethnic differences, among other types of disparities such as chronological or biological age-, sex/gender- or environmental-related ones. Usually, evidence suggests that breast cancer (BC) disparities are due to ethnicity, aging rate, socioeconomic position, environmental or chemical exposures, psycho-social stressors, comorbidities, Western lifestyle, poverty and rurality, or organizational and health care system factors or access. The aim of this review was to deepen the understanding of BC-related disparities, mainly from a biomedical perspective, which includes genomic-based differences, disparities in breast tumor biology and developmental biology, differences in breast tumors' immune and metabolic landscapes, ecological factors involved in these disparities as well as microbiomics- and metagenomics-based disparities in BC. We can conclude that onco-breastomics, in principle, based on genomics, proteomics, epigenomics, hormonomics, metabolomics and exposomics data, is able to characterize the multiple biological processes and molecular pathways involved in BC disparities, clarifying the differences in incidence, mortality and treatment response for different groups of BC patients.

[News in breast oncology genetics for female and male population]

OBJECTIVES

Breast oncology genetics emerged almost 30 years ago with the discovery of the BRCA1 and BRCA2 genes. The evolution of analytical practices has progressively allowed access to tests whose results now have a considerable impact on the management of both female and male breast cancers. The Sénologie commission of the Collège national des gynécologues et obstétriciens français (CNGOF) asked five specialists in breast surgery, oncology and oncological genetics to draw up a summary of the oncogenetic testing criteria used and the clinical implications for the female and male population of the test results, with or without an identified causal variant. In the case of proven genetic risk, surveillance, risk-reduction strategies, and the specificities of surgical and medical management (with PARP inhibitors in particular) were updated.

METHODS

This summary was based on national and international guidelines on the monitoring and therapeutic management of genetic risk, and a recent review of the literature covering the last five years.

RESULTS

Despite successive technical developments, the probability of identifying a causal variant in a situation suggestive of a predisposition to breast and ovarian cancer remains around 10% in France. The risk of breast cancer in women with a causal variant of the BRCA1, BRCA2, PALB2, TP53, CDH1 and PTEN genes is estimated at between 35% and 85% at age 70. The presence of a causal variant in one of these genes is the subject of different recommendations for men and women, concerning both surveillance, the age of onset and imaging modalities of which vary according to the genes involved, and risk-reduction surgery, which is possible for women as soon as their risk level exceeds 30% and remains exceptionally indicated for men. In the case of breast cancer, PARP inhibitors are a promising new class of treatment for BRCA germline mutations.

CONCLUSION

A discipline resolutely focused on understanding molecular mechanisms, screening and preventive medicine/surgery, oncology genetics is currently also involved in new medical/surgical approaches, the long-term benefits/risks of which will need to be monitored.

Treatments Targeting the Androgen Receptor and Its Splice Variants in Breast Cancer

Breast cancer is a major cause of death worldwide. The complexity of endocrine regulation in breast cancer may allow the cancer cells to escape from a particular treatment and result in resistant and aggressive disease. These breast cancers usually have fewer treatment options. Targeted therapies for cancer patients may offer fewer adverse side effects because of specificity compared to conventional chemotherapy. Signaling pathways of nuclear receptors, such as the estrogen receptor (ER), have been intensively studied and used as therapeutic targets. Recently, the role of the androgen receptor (AR) in breast cancer is gaining greater attention as a therapeutic target and as a prognostic biomarker. The expression of constitutively active truncated AR splice variants in breast cancer is a possible mechanism contributing to treatment resistance. Therefore, targeting both the full-length AR and AR variants, either through the activation or suppression of AR function, depending on the status of the ER, progesterone receptor, or human epidermal growth factor receptor 2, may provide additional treatment options. Studies targeting AR in combination with other treatment strategies are ongoing in clinical trials. The determination of the status of nuclear receptors to classify and identify patient subgroups will facilitate optimized and targeted combination therapies.

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.

Non-retroareolar male mucinous breast cancer without gynecomastia development in an elderly man: A case report

BACKGROUND

Male breast cancer (MBC) is an extremely rare condition and accounts for less than 1% of all breast cancers, and malignant tumors occur in less than 1% of the affected men. Mucinous breast cancer is extremely rare and accounts for 2% of all invasive breast cancers. Generally, MBC is accompanied by a retroareolar mass.

CASE SUMMARY

Herein, we report a case of male mucinous breast carcinoma (MMBC) without gynecomastia development and with mass localization outside the common retroareolar region, wherein the mass was a painless nodule in the right breast of a 64-year-old man. We also discuss the clinical and pathological characteristics of this unusual tumor. The excised breast specimen showed pure mucinous carcinoma. The patient had strong expression of estrogen and progesterone receptors, a low Ki-67 proliferation index of the tumor cells, and negative pathological axillary lymph nodes. The patient underwent modified radical mastectomy and axillary lymph node dissection, followed by tamoxifen hormone therapy.

CONCLUSION

To the best of our knowledge, this is the first case report of MMBC in the non-retroareolar region of the nipple without gynecomastia development. Mucinous tumors are easily missed during diagnosis, and the incidence of axillary lymph node metastases of chest mucinous tumors has increased.

Defining genomic, transcriptomic, proteomic, epigenetic, and phenotypic biomarkers with prognostic capability in male breast cancer: a systematic review

Although similar phenotypically, there is evidence that male and female breast cancer differ in their molecular landscapes. In this systematic review, we consolidated all existing prognostic biomarker data in male breast cancer spanning genetics, transcriptomics, proteomics, and epigenetics, and phenotypic features of prognostic value from articles published over a 29-year period (March 16, 1992, to May 1, 2021). We identified knowledge gaps in the existing literature, discussed limitations of the included studies, and outlined potential approaches for translational biomarker discovery and validation in male breast cancer. We also recognised STC2, DDX3, and DACH1 as underexploited markers of male-specific prognostic value in breast cancer. Finally, beyond describing the cumulative knowledge on the extensively researched markers oestrogen receptor-α, progesterone receptor, HER2, androgen receptor, and BRCA2, we highlighted ATM, CCND1, FGFR2, GATA3, HIF1-α, MDM2, TP53, and c-Myc as well studied predictors of poor survival that also aligned with several hallmarks of cancer.

Potential of histone deacetylase inhibitors in the control and regulation of prostate, breast and ovarian cancer

Histone deacetylases (HDACs) are enzymes that play a role in chromatin remodeling and epigenetics. They belong to a specific category of enzymes that eliminate the acetyl part of the histones' -N-acetyl lysine, causing the histones to be wrapped compactly around DNA. Numerous biological processes rely on HDACs, including cell proliferation and differentiation, angiogenesis, metastasis, gene regulation, and transcription. Epigenetic changes, specifically increased expression and activity of HDACs, are commonly detected in cancer. As a result, HDACi could be used to develop anticancer drugs. Although preclinical outcomes with HDACs as monotherapy have been promising clinical trials have had mixed results and limited success. In both preclinical and clinical trials, however, combination therapy with different anticancer medicines has proved to have synergistic effects. Furthermore, these combinations improved efficacy, decreased tumor resistance to therapy, and decreased toxicity. In the present review, the detailed modes of action, classification of HDACs, and their correlation with different cancers like prostate, breast, and ovarian cancer were discussed. Further, the different cell signaling pathways and the structure-activity relationship and pharmaco-toxicological properties of the HDACi, and their synergistic effects with other anticancer drugs observed in recent preclinical and clinical studies used in combination therapy were discussed for prostate, breast, and ovarian cancer treatment.

Development and validation of a nomogram to predict survival for advanced male breast cancer

Male breast cancer is a rare disease. Many experiences of male breast cancer were derived of female breast cancer. However, there are huge differences between two groups. We conducted this study to find a reliable prognostic model for advanced male breast cancer. The cohort was selected from the Surveillance, Epidemiology, and End Results database. The enrolled patients were randomly divided into training and validation group. The univariate and multivariate analyses were used for prognostic assessment and a nomogram was built. Calibration curves and concordance index were compiled to determine predictive and discriminatory capacity. The time-dependent receiver operating curves and the decision curve analysis was used to verify the model's ability. Two hundred and eighty individuals were enrolled. The cumulative rates of 1-, 3- and 5-year overall survival (OS) rates were 98.6%, 72% and 57.9%. The C-indexes for OS were 0.835 (95%CI, 0.777-0.893) in the training group and 0.765 (95%CI, 0.668-0.862) in the validation group. The calibration curves confirmed the consistency of the nomogram both in the training and validation group. The time-dependent receiver operating curves and decision curve analysis demonstrated that the nomogram had better prediction capacity than TNM stage system for advanced male breast cancer. The nomogram we built was a reliable and solid predictive model.

Hormones and Sex-Specific Medicine in Human Physiopathology

A prodigious increment of scientific evidence in both preclinical and clinical studies is narrowing a major gap in knowledge regarding sex-specific biological responses observed in numerous branches of clinical practices. Some paradigmatic examples include neurodegenerative and mental disorders, immune-related disorders such as pathogenic infections and autoimmune diseases, oncologic conditions, and cardiovascular morbidities. The male-to-female proportion in a population is expressed as sex ratio and varies eminently with respect to the pathophysiology, natural history, incidence, prevalence, and mortality rates. The factors that determine this scenario incorporate both sex-associated biological differences and gender-dependent sociocultural issues. A broad narrative review focused on the current knowledge about the role of hormone regulation in gender medicine and gender peculiarities across key clinical areas is provided. Sex differences in immune response, cardiovascular diseases, neurological disorders, cancer, and COVID-19 are some of the hints reported. Moreover, gender implications in occupational health and health policy are offered to support the need for more personalized clinical medicine and public health approaches to achieve an ameliorated quality of life of patients and better outcomes in population health.

Breast and Prostate Cancer Risks for Male BRCA1 and BRCA2 Pathogenic Variant Carriers Using Polygenic Risk Scores

BACKGROUND

Recent population-based female breast cancer and prostate cancer polygenic risk scores (PRS) have been developed. We assessed the associations of these PRS with breast and prostate cancer risks for male BRCA1 and BRCA2 pathogenic variant carriers.

METHODS

483 BRCA1 and 1318 BRCA2 European ancestry male carriers were available from the Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA). A 147-single nucleotide polymorphism (SNP) prostate cancer PRS (PRSPC) and a 313-SNP breast cancer PRS were evaluated. There were 3 versions of the breast cancer PRS, optimized to predict overall (PRSBC), estrogen receptor (ER)-negative (PRSER-), or ER-positive (PRSER+) breast cancer risk.

RESULTS

PRSER+ yielded the strongest association with breast cancer risk. The odds ratios (ORs) per PRSER+ standard deviation estimates were 1.40 (95% confidence interval [CI] =1.07 to 1.83) for BRCA1 and 1.33 (95% CI = 1.16 to 1.52) for BRCA2 carriers. PRSPC was associated with prostate cancer risk for BRCA1 (OR = 1.73, 95% CI = 1.28 to 2.33) and BRCA2 (OR = 1.60, 95% CI = 1.34 to 1.91) carriers. The estimated breast cancer odds ratios were larger after adjusting for female relative breast cancer family history. By age 85 years, for BRCA2 carriers, the breast cancer risk varied from 7.7% to 18.4% and prostate cancer risk from 34.1% to 87.6% between the 5th and 95th percentiles of the PRS distributions.

CONCLUSIONS

Population-based prostate and female breast cancer PRS are associated with a wide range of absolute breast and prostate cancer risks for male BRCA1 and BRCA2 carriers. These findings warrant further investigation aimed at providing personalized cancer risks for male carriers and informing clinical management.

Successful treatment of refractory lung adenocarcinoma harboring a germline BRCA2 mutation with olaparib: A case report

BACKGROUND

In recent years, targeted therapy and immunotherapy have become important treatment strategies for patients with non-small cell lung cancer (NSCLC). However, the clinical evidence for successful off-label use of targeted drugs for patients with NSCLC following progression on multiple lines of treatment is still lacking.

CASE SUMMARY

We describe a 62-year-old male patient with a right lung adenocarcinoma who harbored an EGFR exon 19 deletion mutation. He received gefitinib combined with six cycles of vinorelbine, cisplatin, and recombinant human endostatin as the first-line therapy. Then gefitinib was administered in combination with recombinant human endostatin as maintenance therapy, resulting in a progression-free survival (PFS) of 14 mo. Chemoradiotherapy was added following progression (enlarged brain metastases) on maintenance treatment. Unfortunately, the brain lesions were highly refractory and progressed again after 15 mo, at which time next-generation sequencing (NGS) of 1021 cancer-related genes was performed using peripheral blood to identify potential actionable mutations. NGS revealed that the patient harbored a BRCA2 germline mutation, the EGFR exon 19 deletion mutation disappeared, and no additional targetable genetic variant was detected. Therefore, the patient received olaparib combined with gefitinib and recombinant human endostatin, with a rapid and long-lasting clinical response (PFS = 13.5 mo).

CONCLUSION

This is a rare case of lung adenocarcinoma in a patient with a BRCA2 germline mutation who had long-term benefit from olaparib combination treatment, suggesting that NGS-based genetic testing may render the possibility of long-term survival in NSCLC patients after disease progression.

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.

A novel germline BRCA2 mutation in a Chinese patient with prostate cancer sensitive to platinum chemotherapy: a case report

Background

Germline BRCA2 mutation is associated with an aggressive prostate cancer phenotype and indicates higher risk for hereditary cancer. Recently, numerous studies have attempted to identify the genomic landscape of prostate cancer to better understand the genomic drivers of this disease and look for the molecular targets to guide treatment selection.

Case presentation

We report a 67-year-old patient diagnosed with prostate cancer who experienced rapid disease progression after androgen deprivation therapy and subsequent docetaxel treatment. The patient had a strong family history of malignancy as his mother was diagnosed with breast cancer and his father was died of lung cancer. Next generation sequencing demonstrated a novel pathogenic germline BRCA2 mutation (p.Gly2181Glufs*10) in the patient. His mother with breast cancer and his son were found to have the same BRCA2 mutation. The patient experienced impressive and durable responses to carboplatin treatment.

Conclusions

This case demonstrated that the carboplatin could have a dramatic antitumor effect on patients with prostate cancer with germline BRCA2 mutations and family history will help to ensure that patients and their families can be provided with proper genetic counseling.

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.

DNA methylation variations in familial female and male breast cancer

In total, ~25% of familial breast cancer (BC) is attributed to germline mutations of the BRCA1 and BRCA2 genes, while the rest of the cases are included in the BRCAX group. BC is also known to affect men, with a worldwide incidence of 1%. Epigenetic alterations, including DNA methylation, have been rarely studied in male breast cancer (MBC) on a genome-wide level. The aim of the present study was to examine the global DNA methylation profiles of patients with BC to identify differences between familial female breast cancer (FBC) and MBC, and according to BRCA1, BRCA2 or BRCAX mutation status. The genomic DNA of formalin-fixed paraffin-embedded tissues from 17 women and 7 men with BC was subjected to methylated DNA immunoprecipitation and hybridized on human promoter microarrays. The comparison between FBC and MBC revealed 2,846 significant differentially methylated regions corresponding to 2,486 annotated genes. Gene Ontology enrichment analysis revealed molecular function terms, such as the GTPase superfamily genes (particularly the GTPase Rho GAP/GEF and GTPase RAB), and cellular component terms associated with cytoskeletal architecture, such as 'cytoskeletal part', 'keratin filament' and 'intermediate filament'. When only FBC was considered, several cancer-associated pathways were among the most enriched KEGG pathways of differentially methylated genes when the BRCA2 group was compared with the BRCAX or BRCA1+BRCAX groups. The comparison between the BRCA1 and BRCA2+BRCAX groups comprised the molecular function term 'cytoskeletal protein binding'. Finally, the functional annotation of differentially methylated genes between the BRCAX and BRCA1+BRCA2 groups indicated that the most enriched molecular function terms were associated with GTPase activity. In conclusion, to the best of our knowledge, the present study was the first to compare the global DNA methylation profile of familial FBC and MBC. The results may provide useful insights into the epigenomic subtyping of BC and shed light on a possible novel molecular mechanism underlying BC carcinogenesis.

Comprehensive analysis of germline mutations in northern Brazil: a panel of 16 genes for hereditary cancer-predisposing syndrome investigation

BACKGROUND

Next generation sequencing (NGS) has been a handy tool in clinical practice, mainly due to its efficiency and cost-effectiveness. It has been widely used in genetic diagnosis of several inherited diseases, and, in clinical oncology, it may enhance the discovery of new susceptibility genes and enable individualized care of cancer patients. In this context, we explored a pan-cancer panel in the investigation of germline variants in Brazilian patients presenting clinical criteria for hereditary cancer syndromes or familial history.

METHODS

Seventy-one individuals diagnosed or with familial history of hereditary cancer syndromes were submitted to custom pan-cancer panel including 16 high and moderate penetrance genes previously associated with hereditary cancer syndromes (APC, BRCA1, BRCA2, CDH1, CDKN2A, CHEK2, MSH2, MSH6, MUTYH, PTEN, RB1, RET, TP53, VHL, XPA and XPC). All pathogenic variants were validated by Sanger sequencing.

RESULTS

We identified a total of eight pathogenic variants among 12 of 71 individuals (16.9%). Among the mutation-positive subjects, 50% were diagnosed with breast cancer and had mutations in BRCA1, CDH1 and MUTYH. Notably, 33.3% were individuals diagnosed with polyposis or who had family cases and harbored pathogenic mutations in APC and MUTYH. The remaining individuals (16.7%) were gastric cancer patients with pathogenic variants in CDH1 and MSH2. Overall, 54 (76.05%) individuals presented at least one variant uncertain significance (VUS), totalizing 81 VUS. Of these, seven were predicted to have disease-causing potential.

CONCLUSION

Overall, analysis of all these genes in NGS-panel allowed the identification not only of pathogenic variants related to hereditary cancer syndromes but also of some VUS that need further clinical and molecular investigations. The results obtained in this study had a significant impact on patients and their relatives since it allowed genetic counselling and personalized management decisions.

Clinical and Molecular Characterization of Fanconi Anemia Patients in Turkey

Fanconi anemia (FA) is a rare multigenic chromosomal instability syndrome that predisposes patients to life-threatening bone marrow failure, congenital malformations, and cancer. Functional loss of interstrand cross-link (ICL) DNA repair system is held responsible, though the mechanism is not yet fully understood. The clinical and molecular findings of 20 distinct FA cases, ages ranging from perinatal stage to 32 years, are presented here. Pathogenic variants in FANCA were found responsible in 75%, FANCC, FANCE, FANCJ/BRIP1, FANCL in 5%, and FANCD1/BRCA2 and FANCN/PALB2 in 2.5% of the subjects. Altogether, 25 different variants in 7 different FA genes, including 10 novel mutations in FANCA, FANCN/PALB2, FANCE, and FANCJ/BRIP1, were disclosed. Two compound heterozygous germline cases were mosaic for one allele, revealing that the incidence of reverse mutations may not be uncommon in FA. Another case with de novo FANCD1/BRCA2 and paternally inherited FANCN/PALB2 pathogenic alleles at first glance suggested a digenic inheritance, because the presence of a second pathogenic variant in the unexamined regions of FANCD1/BRCA2 and FANCN/PALB2 were exluded by sequencing and deletion/duplication analysis. A better understanding of the complexity of the FA genotype may provide further access to undiscovered ICL components and apparently dispensable cellular pathways where FA proteins may play important roles.

Identification of novel candidate genes by exome sequencing in Tunisian familial male breast cancer patients

Male Breast Cancer (MBC) is a rare and aggressive disease that is associated with genetic factors. Mutations in BRCA1 and BRCA2 account for 10% of all MBC cases suggesting that other genetic factors are involved. The aim of the present study is to screen whole BRCA1 and BRCA2 exons using the Ampliseq BRCA panel in Tunisian MBC patients with family history. Furthermore, we performed exome sequencing using the TruSight One sequencing panel on an early onset BRCA negative patient. We showed that among the 6 MBC patients, only one (MBC-F1) harbored a novel frameshift mutation in exon 2 of the BRCA2 gene (c.17-20delAAGA, p.Lys6Xfs) resulting in a short BRCA2 protein of only 6 amino-acids. We selected 9 rare variants after applying several filter steps on the exome sequencing data. Among these variants, and based on their role in breast carcinogenesis, we retained 6 candidate genes (MSH5, DCC, ERBB3, NOTCH3, DIAPH1, and DNAH11). Further studies are needed to confirm the association of the selected genes with family MBC.

Characterization of the Cancer Spectrum in Men With Germline BRCA1 and BRCA2 Pathogenic Variants: Results From the Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA)

Importance

The limited data on cancer phenotypes in men with germline BRCA1 and BRCA2 pathogenic variants (PVs) have hampered the development of evidence-based recommendations for early cancer detection and risk reduction in this population.

Objective

To compare the cancer spectrum and frequencies between male BRCA1 and BRCA2 PV carriers.

Design, Setting, and Participants

Retrospective cohort study of 6902 men, including 3651 BRCA1 and 3251 BRCA2 PV carriers, older than 18 years recruited from cancer genetics clinics from 1966 to 2017 by 53 study groups in 33 countries worldwide collaborating through the Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA). Clinical data and pathologic characteristics were collected.

Main Outcomes and Measures

BRCA1/2 status was the outcome in a logistic regression, and cancer diagnoses were the independent predictors. All odds ratios (ORs) were adjusted for age, country of origin, and calendar year of the first interview.

Results

Among the 6902 men in the study (median [range] age, 51.6 [18-100] years), 1634 cancers were diagnosed in 1376 men (19.9%), the majority (922 of 1,376 [67%]) being BRCA2 PV carriers. Being affected by any cancer was associated with a higher probability of being a BRCA2, rather than a BRCA1, PV carrier (OR, 3.23; 95% CI, 2.81-3.70; P < .001), as well as developing 2 (OR, 7.97; 95% CI, 5.47-11.60; P < .001) and 3 (OR, 19.60; 95% CI, 4.64-82.89; P < .001) primary tumors. A higher frequency of breast (OR, 5.47; 95% CI, 4.06-7.37; P < .001) and prostate (OR, 1.39; 95% CI, 1.09-1.78; P = .008) cancers was associated with a higher probability of being a BRCA2 PV carrier. Among cancers other than breast and prostate, pancreatic cancer was associated with a higher probability (OR, 3.00; 95% CI, 1.55-5.81; P = .001) and colorectal cancer with a lower probability (OR, 0.47; 95% CI, 0.29-0.78; P = .003) of being a BRCA2 PV carrier.

Conclusions and Relevance

Significant differences in the cancer spectrum were observed in male BRCA2, compared with BRCA1, PV carriers. These data may inform future recommendations for surveillance of BRCA1/2-associated cancers and guide future prospective studies for estimating cancer risks in men with BRCA1/2 PVs.

Male Breast Cancer: Results of the Application of Multigene Panel Testing to an Italian Cohort of Patients

Male breast cancer (MBC) is a rare tumor, accounting for less than 1% of all breast cancers. In MBC, genetic predisposition plays an important role; however, only a few studies have investigated in depth the role of genes other than BRCA1 and BRCA2. We performed a Next-Generation Sequencing (NGS) analysis with a panel of 94 cancer predisposition genes on germline DNA from an Italian case series of 70 patients with MBC. Moreover, we searched for large deletions/duplications of BRCA1/2 genes through the Multiplex Ligation-dependent Probe Amplification (MLPA) technique. Through the combination of NGS and MLPA, we identified three pathogenic variants in the BRCA1 gene and six in the BRCA2 gene. Besides these alterations, we found six additional pathogenic/likely-pathogenic variants in PALB2, CHEK2, ATM, RAD51C, BAP1 and EGFR genes. From our study, BRCA1 and BRCA2 emerge as the main genes associated with MBC risk, but also other genes seem to be associated with the disease. Indeed, some of these genes have already been implicated in female breast cancer predisposition, but others are known to be involved in other types of cancer. Consequently, our results suggest that novel genes could be involved in MBC susceptibility, shedding new light on their role in cancer development.

Nunes S, Silva F, Henrique R, Félix A, Jerónimo C. Analysis of Epigenetic Alterations in Homologous Recombination DNA Repair Genes in Male Breast Cancer

Background: Male breast cancer (BC) is a distinct neoplasm with low but rising incidence, frequently diagnosed as advanced stage disease. Considering the relevance of altered homologous recombination repair (HRR) in male BC, we aimed to explore the biomarker potential of aberrant promoter methylation of ATM, BRCA1, PALB2, RAD51B, and XRCC3. Methods: Formalin-fixed paraffin-embedded (FFPE) tissue samples from 128 male BC patients, paired adjacent normal tissue and 19 gynecomastia cases were collected and assessed by quantitative methylation-specific PCR (qMSP). Non-parametric tests were used to compare methylation levels between tumor and non-tumor samples and to seek for associations with clinicopathological variables. Results: Only RAD51B and XRCC3 disclosed significant differences between tumor and gynecomastia (p < 0.0001 and p = 0.020, respectively). Assembled in a panel, RAD51B and XRCC3 promoter methylation discriminated male BC from gynecomastia with 91.5% sensitivity, 89.5% specificity, and 91.2% accuracy. Moreover, promoter methylation levels were lower in paired non-tumor tissues, comparing to tumor samples. No associations were found between epigenetic alterations and clinicopathological features, as well as with RAD51 and XRCC3 immunoexpression and methylation levels. Conclusion: Quantitative promoter methylation of RAD51B and XRCC3 constitutes a promising and accurate biomarker for male BC. Validation in larger series and in liquid biopsies is warranted to confirm its usefulness in detection and monitoring settings.

Epidemiology and biological characteristics of male breast cancer in Italy

AIM

To evaluate the epidemiology of male breast cancer (MBC) in Italy and to describe incidence and survival data in relation to age, morphology, year of incidence, geographic area, and possible association with other cancers compared with female BC.

METHODS

Cases were extracted from 40 Italian Cancer Registries. Standardized incidence rates (SIR), age-specific rates, and 5-year survival were calculated. The association with second tumors was also evaluated. All data were compared with data from female BCs.

RESULTS

In the 2000-2014 period, 2175 new cases of MBC were registered, with an SIR of 1.7 × 100,000. The incidence showed a slight upward trend and increased with increasing age. The 5-year survival was 82% in the first two periods (2000-2004, 2005-2009), lower than in females (87%). The most frequent morphology was the ductal carcinoma (84%). Stage at diagnosis was 39.5% stage I, 33.1% stage II, 20.9% in stage III, and 6.4% in stage IV. Concerning receptor status, 96.4% had ER+ and 82.5% PR+; 46.5% had high Ki67 and 14.7% HER2 amplified. The risk of BC increased if the man had already had a previous tumor in any site (excess absolute risk, EAR = 2.7) and especially if he had had prostate cancer (EAR = 5.1). Instead, males with a previous diagnosis of BC had an increased risk of testicular, kidney and lung cancer.

CONCLUSIONS

MBC requires more attention in terms of diagnosis and treatment as clinicians tend to follow the guidelines that have been developed for female BC management.

Molecular Mechanisms of PALB2 Function and Its Role in Breast Cancer Management

Partner and localizer of BRCA2 (PALB2) is vital for homologous recombination (HR) repair in response to DNA double-strand breaks (DSBs). PALB2 functions as a tumor suppressor and participates in the maintenance of genome integrity. In this review, we summarize the current knowledge of the biological roles of the multifaceted PALB2 protein and of its regulation. Moreover, we describe the link between PALB2 pathogenic variants (PVs) and breast cancer predisposition, aggressive clinicopathological features, and adverse clinical prognosis. We also refer to both the opportunities and challenges that the identification of PALB2 PVs provides in breast cancer genetic counseling and precision medicine.

Male breast cancer: a closer look at patient and tumor characteristics and factors that affect survival using the National Cancer Database

OBJECTIVE

To comprehensively describe the tumor and clinical characteristics of breast cancer in a cohort of male patients and to assess the factors that affect survival.

BACKGROUND

Much of the standard care of male breast cancer is based on the diagnosis and treatment strategies of female breast cancer. However, important clinical differences between the two have been elucidated, which suggests the need for unique attention to male breast cancer.

METHODS

We evaluated the records of male patients who were diagnosed with breast cancer between 2004 and 2015 using the National Cancer Database (NCDB). Data obtained were demographic characteristics, clinical and tumor data, type of therapy, as well as survival data. We used descriptive statistics to characterize our study population. We then performed a survival and Cox proportional hazards analysis.

RESULTS

We identified 16,498 patients (median age: 63 years). Several treatment modalities were used, of which surgery was the most common (14,882 [90.4%]). The total follow-up time was 13 years (156 months). Five-year survival was 77.7% (95% CI 76.9-78.4) and 10-year survival was 60.7%. In a Cox proportional hazards model, mastectomy was associated with the greatest survival (hazard ratio [HR] 0.49; p < 0.001).

CONCLUSION

We report what is to our knowledge the largest national population-based cohort of male breast cancer patients. Importantly, our data suggests that similar to female patients, several treatment modalities are significantly associated with improved survival in male patients, particularly surgery. Increasing age, black race, government insurance, more comorbidities, and higher tumor stages are associated with decreased survival.

Mechanisms of resistance to estrogen receptor modulators in ER+/HER2- advanced breast cancer

Endocrine therapy represents a mainstay adjuvant treatment of estrogen receptor-positive (ER+) breast cancer in clinical practice with an overall survival (OS) benefit. However, the emergence of resistance is inevitable over time and is present in one-third of the ER+ breast tumors. Several mechanisms of endocrine resistance in ER+/HER2- advanced breast cancers, through ERα itself, receptor tyrosine signaling, or cell cycle pathway, have been identified to be pivotal in endocrine therapy. The epigenetic alterations also contribute to ensuring tumor cells' escape from endocrine therapies. The strategy of combined hormone therapy with targeted pharmaceutical compounds has shown an improvement of progression-free survival or OS in clinical practice, including three different classes of drugs: CDK4/6 inhibitors, selective inhibitor of PI3Kα and mTOR inhibitors. Many therapeutic targets of cell cycle pathway and cell signaling and their combination strategies have recently entered clinical trials. This review focuses on Cyclin D-CDK4/6-RB axis, PI3K pathway and HDACs. Additionally, genomic evolution is complex in tumors exposed to hormonal therapy. We highlight the genomic alterations present in ESR1 and PIK3CA genes to elucidate adaptive mechanisms of endocrine resistance, and discuss how these mutations may inform novel combinations to improve clinical outcomes in the future.

Sex Disparity Observed for Oncotype DX Breast Recurrence Score in Predicting Mortality Among Patients with Early Stage ER-Positive Breast Cancer

PURPOSE

Prognostic value of Oncotype DX Breast Recurrence Score (RS) in male patients with breast cancer is understudied. We evaluated associations of RS with overall mortality in male patients with breast cancer and compared it with female counterparts.

EXPERIMENTAL DESIGN

With a cohort of 848 male and 110,898 female patients with breast cancer identified from the National Cancer Database (2010-2014), we estimated HRs and 95% confidence intervals (CI) for overall mortality associated with RS using Cox regression models. RS was evaluated continuously, as well as by categorization following respective traditional (≤17, 18-30, and ≥31) and TAILORx (≤10, 11-25, and ≥26) cutoffs.

RESULTS

RS was positively associated with mortality in male patients (HR = 1.13; 95% CI, 1.02-1.26 per unit RS increment) up to RS > 21, after which the risk plateaued. Among female patients, mortality began to increase with RS only when RS > 23 (HR = 1.02; 95% CI, 1.01-1.02 per unit of RS increment). The intermediate- (HR = 5.37; 95% CI, 1.79-16.11) and high-risk diseases (HR = 4.28; 95% CI, 1.22-14.97) defined by TAILORx, but not traditional cutoffs established for female patients, were associated with elevated mortality risk in men even after adjustment for demographic, clinical characteristics, and treatments, except chemotherapy.

CONCLUSIONS

RS is associated with mortality in male patients with breast cancer at a much lower threshold than that for female patients. Studies are needed to establish specific guidelines for RS thresholds for male patients with breast cancer.

A prognostic nomogram for overall survival in male breast cancer with histology of infiltrating duct carcinoma after surgery

Objective

The study was designed to construct and validate a nomogram for predicting overall survival (OS) of male breast cancer (MBC) patients with infiltrating duct carcinoma (IDC).

Methods

The cohort was selected from the Surveillance, Epidemiology, and End Results (SEER) database between January 1, 2004 and December 31, 2013. Univariate and multivariate Cox proportional hazard (PH) regression models were performed. A nomogram was developed based on the significant prognostic indicators of OS. The discriminatory and predictive capacities of nomogram were assessed by Harrell's concordance index (C-index), calibration plots, area under the curve (AUC) and the decision curve analysis (DCA).

Results

The median and maximal survival time of 1862 eligible patients were 49 and 131 months, respectively. Multivariate analysis showed that age (P < 0.0001), marital status (P = 0.002), T stage (P < 0.0001), N stage (P = 0.021), M stage (P < 0.0001), progesterone receptor (PR) (P = 0.046), human epidermal growth factor receptor-2 (HER2) (P = 0.009), and chemotherapy (P = 0.003) were independent prognostic indicators of IDC of MBC. The eight variables were then combined to construct a 3-and 5-year nomogram. The C-indexes of the nomogram were0.740 (95% confidence interval [CI] [0.709-0.771]) and 0.718 (95% CI [0.672-0.764]) for the internal validation and external validation, respectively. A better discriminatory capacity was observed in the nomogram compared with the SEER summary stage (P < 0.001) and AJCC TNM staging systems (6th edition; P < 0.001) with respect to OS prediction. Good consistency was detected between the nomogram prediction and actual findings, as indicated by calibration curves. The AUC for 3-and 5-year OS was 0.739 (95% CI [0.693-0.786]) and 0.764 (95% CI [0.725-0.803]) in the training cohort and 0.737 (95% CI [0.671-0.803]) and 0.735 (95% CI [0.678-0.793]) in the validation cohort, respectively. The DCA demonstrated that the survival nomogram was clinically useful.

Conclusions

The nomogram was able to more accurately predict 3-and 5-year OS of MBC patients with IDC histology than were existing models.

Germline investigation in male breast cancer of DNA repair genes by next-generation sequencing

PURPOSE

In order to better define the breast cancer (BC) genetic risk factors in men, a germline investigation was carried out on 81 Male BC cases by screening the 24 genes involved in BC predisposition, genome stability maintenance and DNA repair mechanisms by next-generation sequencing.

METHODS

Germline DNAs were tested in a custom multi-gene panel focused on all coding exons and exon-intron boundaries of 24 selected genes using two amplicon-based assays on PGM-Ion Torrent (ThermoFisher Scientific) and MiSeq (Illumina) platforms. All variants were recorded and classified by using a custom pipeline.

RESULTS

Clinical pathological data and the family history of 81 Male BC cases were gathered and analysed, revealing the average age of onset to be 61.3 years old and that in 35 cases there was a family history of BC. Our genetic screening allowed us to identify a germline mutation in 22 patients (23%) in 4 genes: BRCA2, BRIP1, MUTYH and PMS2. Moreover, 12 variants of unknown clinical significance (VUS) in 9 genes (BARD1, BRCA1, BRIP1, CHEK2, ERCC1, NBN, PALB2, PMS1, RAD50) were predicted as potentially pathogenic by in silico analysis bringing the mutation detection rate up to 40%.

CONCLUSION

As expected, a positive family history is a strong predictor of germline BRCA2 mutations in male BC. Understanding the potential pathogenicity of VUS represents an extremely urgent need for the management of BC risk in Male BC cases and their own families.

Evaluation of CYP17A1 and CYP1B1 polymorphisms in male breast cancer risk

Breast cancer in men is a rare and still poorly characterized disease. Inherited mutations in BRCA1, BRCA2 and PALB2 genes, as well as common polymorphisms, play a role in male breast cancer genetic predisposition. Male breast cancer is considered a hormone-dependent tumor specifically related to hyperestrogenism. Polymorphisms in genes involved in estrogen biosynthesis and metabolism pathways, such as CYP17A1 and CYP1B1, have been associated with breast cancer risk. Here, we aimed to investigate the role of CYP17A1 and CYP1B1 polymorphisms in male breast cancer risk. A series of 597 male breast cancer cases and 1022 male controls, recruited within the Italian Multicenter Study on male breast cancer, was genotyped for CYP17A1 rs743572, CYP1B1 rs1056836 and rs1800440 polymorphisms by allelic discrimination real-time PCR with TaqMan probes. Associations with male breast cancer risk were estimated using logistic regression. No statistically significant associations between male breast cancer risk and the three analyzed polymorphisms emerged. Similar results were obtained also when BRCA1/2 mutational status was considered. No significant differences in the distribution of the genotypes according to estrogen receptor status emerged. In conclusion, our study, based on a large series of male breast cancer cases, is likely to exclude a relevant role of CYP17A1 and CYP1B1 polymorphisms in male breast cancer predisposition. Overall, these results add new data to the increasing evidence that polymorphisms in these genes may not be associated with breast cancer risk.

A study of mechanistic mapping of novel SNPs to male breast cancer

Alterations in BRCA2, PALB2, CHEK2, and p53 genes have been identified for their association with male breast cancer in various studies. The incidence of male breast cancer in India is consistent with its global rate. The present study was carried out with an aim to evaluate the genetic alterations in male breast cancer patients from Malwa region of Punjab, India. Four male breast cancer patients belonging to different families were recruited from Guru Gobind Singh Medical College and Hospital, Faridkot, India. A total of 51 genes reported with implications in the pathogenesis of breast cancer were screened using next generation sequencing. Germline variations were found in BRCA1, BRCA2, PMS2, p53, and PALB2 genes, previously reported to be associated with MBC as well as FBC. In addition to these, 13 novel missense alterations were detected in eight genes including STK11, FZR1, PALB2, BRCA2, NF2, BAP1, BARD1, and CHEK2. Impact of these missense alterations on structure and function of protein was also analyzed through molecular dynamics simulation. Structural analysis of these single nucleotide polymorphisms (SNPs) revealed significant impact on the encoded protein functioning.

Nomogram Predicting Cause-Specific Mortality in Nonmetastatic Male Breast Cancer: A Competing Risk Analysis

Introduction: Male breast cancer (MBC) is a rare tumor with few cases for research. Using the Surveillance, Epidemiology, and End Results program database, we carried out a competing risk analysis in patients with primary nonmetastatic MBC and built a predictive nomogram. Materials and Methods: We extracted primary nonmetastatic MBC patients according to the inclusion and exclusion criteria. Cumulative incidence function (CIF) and proportional subdistribution hazard model were adopted to explore risk factors for breast cancer-specific death (BCSD) and other cause-specific death (OCSD). Then we built a nomogram to predict the 3-year, 5-year and 8-year probabilities of BCSD and OCSD. C-indexes, Brier scores and calibration curves were chosen for validation. Results: We identified 1,978 nonmetastatic MBC patients finally. CIF analysis showed that the 3-year, 5-year and 8-year mortalities were 5.2%, 10.6% and 16.5% for BCSD, and 6.1%, 9.6% and 14.4% for OCSD. After adjustment of Fine and Gray models, black race, PR (-), advanced T/N/grade and no surgery were independently associated with BCSD. Meanwhile, elderly, unmarried status, advanced AJCC stage and no chemotherapy resulted in OCSD more possibly. A graphic nomogram was developed according to the coefficients from the Fine and Gray models. The calibration curves displayed exceptionally, with C-indexes nearly larger than 0.700 and Brier scores nearly smaller than 0.100. Conclusion: The competing risk nomogram showed good accuracy for predictive prognosis in nonmetastatic MBC patients. It was a useful implement to evaluate crude mortalities of BCSD and OCSD, and help clinicians to choose appropriate therapeutic plans.

Hormone signaling via androgen receptor affects breast cancer and prostate cancer in a male patient: A case report

Background

Male breast cancer (MBC) is rare, accounting for only around 1% of all breast cancers. Most MBCs are hormone-driven. Not only the estrogen receptor (ER), but also other steroid hormone receptors, including the androgen receptor (AR) and progesterone receptor (PgR) are expressed in MBC. AR activation in breast cancer cells facilitates downstream gene expression that drives tumorigenesis in a similar manner to ER. AR-mediated signalling works paradoxically in breast cancer and prostate cancer, and cancer cells expressing the AR are endocrine-sensitive.

Case presentation

We describe a case of double cancer of MBC and prostate cancer. A 69-year-old man was referred to our hospital with a lump in his left breast in the 1990s. The patient had cT3N3M0, stage IIIC breast cancer, and underwent a mastectomy and axillary lymph node dissection. Though adjuvant chemotherapy was administered, he experienced pleural metastasis 2 months after the surgery. Two years after the recurrence during endocrine therapy with oral 5-fluorouracil, he complained of frequent urination. Radiological and histological examinations revealed that the patient had cT3N0M0, stage III primary prostate cancer with a prostate-specific antigen (PSA) level of 40.5 ng/mL. Germline mutations in the BRCA1 and BRCA2 genes were not tested. He received multidisciplinary, continuous therapy for both breast and prostate cancer; however, 5 and 3 years after each diagnosis, respectively, he experienced a deep vein thrombosis in his right leg related to the endocrine therapy. Liver metastasis progressed after he stopped breast cancer therapy. However, long-term disease control had been achieved with anti-estrogen therapy for breast cancer and estrogen replacement therapy for prostate cancer.

Conclusions

Several studies have shown that estrogen exposure after estrogen depletion likely causes apoptosis of ER-positive breast cancer cells. Our findings indicate that this also applies to the environment in male body. AR dominant signaling prevents breast cancer recurrence and metastasis, especially in MBC patients.

Contribution of MUTYH Variants to Male Breast Cancer Risk: Results From a Multicenter Study in Italy

Inherited mutations in BRCA1, and, mainly, BRCA2 genes are associated with increased risk of male breast cancer (MBC). Mutations in PALB2 and CHEK2 genes may also increase MBC risk. Overall, these genes are functionally linked to DNA repair pathways, highlighting the central role of genome maintenance in MBC genetic predisposition. MUTYH is a DNA repair gene whose biallelic germline variants cause MUTYH-associated polyposis (MAP) syndrome. Monoallelic MUTYH variants have been reported in families with both colorectal and breast cancer and there is some evidence on increased breast cancer risk in women with monoallelic variants. In this study, we aimed to investigate whether MUTYH germline variants may contribute to MBC susceptibility. To this aim, we screened the entire coding region of MUTYH in 503 BRCA1/2 mutation negative MBC cases by multigene panel analysis. Moreover, we genotyped selected variants, including p.Tyr179Cys, p.Gly396Asp, p.Arg245His, p.Gly264Trpfs^*7, and p.Gln338His, in a total of 560 MBC cases and 1,540 male controls. Biallelic MUTYH pathogenic variants (p.Tyr179Cys/p.Arg241Trp) were identified in one MBC patient with phenotypic manifestation of adenomatous polyposis. Monoallelic pathogenic variants were identified in 14 (2.5%) MBC patients, in particular, p.Tyr179Cys was detected in seven cases, p.Gly396Asp in five cases, p.Arg245His and p.Gly264Trpfs^*7 in one case each. The majority of MBC cases with MUTYH pathogenic variants had family history of cancer including breast, colorectal, and gastric cancers. In the case-control study, an association between the variant p.Tyr179Cys and increased MBC risk emerged by multivariate analysis [odds ratio (OR) = 4.54; 95% confidence interval (CI): 1.17-17.58; p = 0.028]. Overall, our study suggests that MUTYH pathogenic variants may have a role in MBC and, in particular, the p.Tyr179Cys variant may be a low/moderate penetrance risk allele for MBC. Moreover, our results suggest that MBC may be part of the tumor spectrum associated with MAP syndrome, with implication in the clinical management of patients and their relatives. Large-scale collaborative studies are needed to validate these findings.

Male accessory breast cancer on the abdominal wall: a case report and literature review

BACKGROUND

Accessory breast cancer is very rare, particularly in men. Male accessory breast cancer on the abdominal wall has not been documented in the scientific literature so far. We describe a case of male accessory breast cancer on the abdominal wall.

CASE PRESENTATION

We describe a male patient suffering a swelling and erosive, enlarged, and hardened abdominal wall mass with pain due to abdominal wall accessory breast cancer. The patient had no obvious disease history, and the initial clinical symptom was a small mass on the abdominal wall. B-ultrasound revealed a solid subcutaneous nodule in the right abdomen with a size of ~2.8 × 2.5 × 1.5 cm. The abdominal wall tumor resection was performed with local anesthesia. Pathological testing revealed a grade II infiltrating ductal carcinoma derived from the accessory mammary gland (right abdominal wall) with neuroendocrine characteristics, showing ER (100% strong positive), PR (100% strong positive), HER-2 (-), ki67 (40% positive), Syn (+), CgA (+), and GCDFP15 (+).

CONCLUSION

Nonaxillary accessory breast cancer in males is very rare, with no obvious clinical manifestations, and could be easily ignored. This disease requires great attention from clinicians.

Male breast cancer: a disease distinct from female breast cancer

PURPOSE

Male breast cancer (BC) is rare, representing approximately 1% of cancers that occur in men and approximately 1% of all BCs worldwide. Because male BC is rare, not much is known about the disease, and treatment recommendations are typically extrapolated from data available from clinical trials enrolling female BC patients.

METHODS

We review the epidemiology, risk factors, prognosis, and the varied molecular and clinicopathologic features that characterize male BC. In addition, we summarize the available data for the use of systemic therapy in the treatment of male BC and explore the ongoing development of targeted therapeutic agents for the treatment of this subgroup of BCs.

RESULTS

There are important biological differences between male and female BC. Male BC is almost exclusively hormone receptor positive (+), including the androgen receptor (AR), and is associated with an increased prevalence of BRCA2 germline mutations, especially in men with increased risk for developing high-risk BC. Additional research is warranted to better characterize male BC. To accomplish this, a multi-national consortium approach, such as the International Male Breast Cancer Program, is needed in response to the scarcity of patients. This approach allows the pooling of information from a large number of men with BC and the creation of registries for future therapeutic-focused clinical trials.

CONCLUSIONS

Given the unique biology of BC in men, promising new therapeutic targets are currently under investigation, including the use of poly-ADP-ribose polymerase inhibitors or AR-targeted agents either as monotherapy or in combination with other agents.

Male Breast Cancer: An Updated Surveillance, Epidemiology, and End Results Data Analysis

BACKGROUND

Male breast cancer is rare and understudied compared with female breast cancer. A current comparison with female breast cancer could assist in bridging this gap. Although conflicting data have been reported on male and female survival outcomes, data from 1973 through 2005 in the Surveillance, Epidemiology, and End Results (SEER) program have demonstrated that the improvement in breast cancer survival in men has fallen behind that of women. As treatment for breast cancer has improved significantly, an updated analysis using a contemporary population is necessary.

MATERIALS AND METHODS

An analysis of SEER data from patients with a diagnosis of primary breast cancer from 2005 to 2010 were included. A Cox regression model was used to examine the association between sex and breast cancer mortality after controlling for prognostic factors, including age, race, marital status, disease stage, estrogen and progesterone receptor status, lymph node involvement, tumor grade, surgery, and geography. Subgroup analyses were performed by race and stage.

RESULTS

We included a total of 289,673 breast cancer cases (2054 men) with a diagnosis from 2005 to 2010. The 5-year survival rate for male patients was lower than that for female patients (82.8% vs. 88.5%). After controlling for other factors, the risk of death in men was 43% greater than that in women during the follow-up period (hazard ratio, 1.43; 95% confidence interval, 1.26-1.61). Similar results were noted in the race and stage subgroup analyses.

CONCLUSION

In recent years, male breast cancer patients have had worse survival outcomes compared with those of female patients.

Marital Status and Survival of Patients with Hormone Receptor-Positive Male Breast Cancer: A Surveillance, Epidemiology, and End Results (SEER) Population-Based Study

Background

Although marital status has been reported as a prognostic factor in different cancer types, its prognostic effect on hormone receptor (HR) positive male breast cancer (MBC) is unclear. The objective of the present analysis was to assess the effects of marital status on survival in patients with HR positive MBC.

Material/Methods

Patients diagnosed with HR positive MBC from 1990 to 2014 in the Surveillance, Epidemiology, and End Results (SEER) database were included. Kaplan-Meier survival analysis and Cox proportional hazard regression were used to identify the effects of marital status on cancer-specific survival (CSS) and overall survival (OS).

Results

A total of 3612 cases were identified in this study. Married patients had better 5-year CSS and 5-year OS than unmarried men. In multivariate Cox regression models, unmarried patients also showed higher mortality risk for both CSS and OS, independent of age, race, grade, stage, PR status, HER2 status, and surgery. Subgroup survival analysis according to different ER/PR status showed that married patients had beneficial CSS results only in ER⁺/PR⁺ subtype, and CSS in the married and unmarried groups did not significantly differ by TNM stage. The results were further confirmed in the 1: 1 matched group.

Conclusions

Marital status was an important prognostic factor for survival in patients with HR positive MBC. Unmarried patients are at greater risk of death compared with married groups. The survival benefit for married patients remained even after adjustment, which indicates the importance of spousal support in MBC.

Somatic alterations of targetable oncogenes are frequently observed in BRCA1/2 mutation negative male breast cancers

Male breast cancer (MBC) is a rare disease. Due to its rarity, MBC research and clinical approach are mostly based upon data derived from its largely known female counterpart. We aimed at investigating whether MBC cases harbor somatic alterations of genes known as prognostic biomarkers and molecular therapeutic targets in female breast cancer.

We examined 103 MBC cases, all characterized for germ-line BRCA1/2 mutations, for somatic alterations in PIK3CA, EGFR, ESR1 and CCND1 genes.

Pathogenic mutations of PIK3CA were detected in 2% of MBCs. No pathogenic mutations were identified in ESR1 and EGFR. Gene copy number variations (CNVs) analysis showed amplification of PIK3CA in 8.1%, EGFR in 6.8% and CCND1 in 16% of MBCs, whereas deletion of ESR1 was detected in 15% of MBCs. Somatic mutations and gene amplification were found only in BRCA1/2 mutation negative MBCs.

Significant associations emerged between EGFR amplification and large tumor size (T4), ER-negative and HER2-positive status, between CCND1 amplification and HER2-positive and MIB1-positive status, and between ESR1 deletion and ER-negative status.

Our results show that amplification of targetable oncogenes is frequent in BRCA1/2 mutation negative MBCs and may identify MBC subsets characterized by aggressive phenotype that may benefit from potential targeted therapeutic approaches.

Characterizing steroid hormone receptor chromatin binding landscapes in male and female breast cancer

Male breast cancer (MBC) is rare and poorly characterized. Like the female counterpart, most MBCs are hormonally driven, but relapse after hormonal treatment is also noted. The pan-hormonal action of steroid hormonal receptors, including estrogen receptor alpha (ERα), androgen receptor (AR), progesterone receptor (PR), and glucocorticoid receptor (GR) in this understudied tumor type remains wholly unexamined. This study reveals genomic cross-talk of steroid hormone receptor action and interplay in human tumors, here in the context of MBC, in relation to the female disease and patient outcome. Here we report the characterization of human breast tumors of both genders for cistromic make-up of hormonal regulation in human tumors, revealing genome-wide chromatin binding landscapes of ERα, AR, PR, GR, FOXA1, and GATA3 and enhancer-enriched histone mark H3K4me1. We integrate these data with transcriptomics to reveal gender-selective and genomic location-specific hormone receptor actions, which associate with survival in MBC patients.

Increased risk of arterial thromboembolism in older men with breast cancer

PURPOSE

Male breast cancer is a rare and understudied disease predominantly affecting men over age 60. Risk of arterial thromboembolic events (ATE) in men increases with age. We examined ATE risk following primary breast cancer diagnosis in elderly men.

METHODS

Men with primary breast cancer diagnoses from 2002 to 2011 were identified using the Surveillance, Epidemiology, and End Results (SEER)-Medicare-linked database. Cases were individually matched by age, sex, race, registry, and comorbidities with controls without cancer using SEER-Medicare's 5% noncancer sample. Medicare claims were used to identify ATE, defined as myocardial infarction or ischemic stroke. Cumulative incidence of ATE was calculated using competing risk methodology, with death considered a competing event. Cox proportional hazards analysis was used to compare rates of ATE among cases and controls.

RESULTS

Three months following primary breast cancer diagnosis, ATE risk in the cohort of 881 men was 80% higher than matched controls (hazard ratio 1.8; 95% confidence interval 1.0-3.2). Six months post-cancer diagnosis, 5.7% of cases had experienced ATE, whereas only 3.5% of controls had (HR 1.6; 95% CI 1.0-2.6). ATE risk remained elevated 12 months post-cancer diagnosis. Among cases, risk of death was threefold higher in men who developed ATE.

CONCLUSIONS

We provide population-based evidence that male breast cancer patients have a substantially elevated risk of ATE in the first year following a cancer diagnosis compared with matched controls. Care providers should consider this heightened risk when evaluating cardiovascular health in men with a recent breast cancer diagnosis.

Prediction of Breast and Prostate Cancer Risks in Male BRCA1 and BRCA2 Mutation Carriers Using Polygenic Risk Scores

Purpose BRCA1/2 mutations increase the risk of breast and prostate cancer in men. Common genetic variants modify cancer risks for female carriers of BRCA1/2 mutations. We investigated-for the first time to our knowledge-associations of common genetic variants with breast and prostate cancer risks for male carriers of BRCA1/ 2 mutations and implications for cancer risk prediction. Materials and Methods We genotyped 1,802 male carriers of BRCA1/2 mutations from the Consortium of Investigators of Modifiers of BRCA1/2 by using the custom Illumina OncoArray. We investigated the combined effects of established breast and prostate cancer susceptibility variants on cancer risks for male carriers of BRCA1/2 mutations by constructing weighted polygenic risk scores (PRSs) using published effect estimates as weights. Results In male carriers of BRCA1/2 mutations, PRS that was based on 88 female breast cancer susceptibility variants was associated with breast cancer risk (odds ratio per standard deviation of PRS, 1.36; 95% CI, 1.19 to 1.56; P = 8.6 × 10-6). Similarly, PRS that was based on 103 prostate cancer susceptibility variants was associated with prostate cancer risk (odds ratio per SD of PRS, 1.56; 95% CI, 1.35 to 1.81; P = 3.2 × 10-9). Large differences in absolute cancer risks were observed at the extremes of the PRS distribution. For example, prostate cancer risk by age 80 years at the 5th and 95th percentiles of the PRS varies from 7% to 26% for carriers of BRCA1 mutations and from 19% to 61% for carriers of BRCA2 mutations, respectively. Conclusion PRSs may provide informative cancer risk stratification for male carriers of BRCA1/2 mutations that might enable these men and their physicians to make informed decisions on the type and timing of breast and prostate cancer risk management.

Metastatic Breast Carcinoma to the Superior Oblique in a Male

We describe a case of breast cancer metastatic to the superior oblique, in a male. The patient was a 66-year-old Caucasian male with a history of stage IIIB rectal adenocarcinoma and stage IIA left breast carcinoma diagnosed 12 years and 5 years prior, respectively, who presented with headaches and intermittent diplopia. He underwent left total mastectomy with sentinel lymph node biopsy 6 years prior, which showed ER/PR+, HER2/neu-, moderately-differentiated, infiltrating ductal carcinoma with 3/14 positive nodes. He completed adjuvant doxorubicin/cyclophosphamide and oral tamoxifen, and prior routine surveillance imaging had found no evidence of recurrent disease. MRI of the orbit revealed a 0.7 × 1.4 × 1.9 cm mass in the superomedial right orbit in the region of the superior oblique. Transcaruncular orbitotomy with biopsy of the superior oblique revealed metastatic breast carcinoma. Unfortunately, he developed new metastases. Post-operatively, he continues to have good vision with minimal diplopia.

Clinicopathological characteristics and survival outcomes of male breast cancer according to race: A SEER population-based study

To investigate the clinicopathological characteristics and survival outcomes of breast cancer in the male population, 8,607 cases of patients were identified in the Surveillance, Epidemiology, and End Results (SEER) database, including white males (n = 7122), black males (n = 1111), and other males (American Indian/AK Native, Asian/Pacific Islander) (n = 374). Black male breast cancer patients were more likely to be in stages II–IV and have more advanced tumors. The rate of lymph node (LN) involvement at diagnosis was higher in black men than in whites and others. The ER- and PR-positive rates were lower in black men than in whites and others. The distant metastasis rate was higher in blacks than in whites and others. Furthermore, the overall survival (OR) rates and breast cancer-specific survival rates were significantly poorer in blacks than in whites and others (χ² = 29.974, P < 0.001; χ² = 7.285, P = 0.026, respectively). In a multivariate analysis, the results showed that race could also be a prognostic indicator (P < 0.001). Moreover, significant differences were also observed in OS among 1:1:1 matched white, black, and other groups (P < 0.001). Differences in outcomes may be partially explained by differences in tumor grades, LN status, and ER and PR status between the 3 groups. This study might provide insights into a better understanding of male breast cancer.