Incidence of male breast cancer in Scotland over a twenty-five-year period (1992-2017)

Global, regional, and national burden of male breast cancer in 204 countries and territories: a systematic analysis from the global burden of disease study, 1990-2021

Background

Male breast cancer (MBC) is a rare malignancy that has been under-investigated, with limited global epidemiological research dedicated to it. A comprehensive estimate of the global, regional, and national burden of MBC is valuable for policy planning. This study aims to evaluate the burden of MBC across 204 countries and territories.

Methods

MBC data were collected from the 2021 Global Burden of Diseases, Injuries, and Risk Factors (GBD) Study estimates spanning from 1990 to 2021. The global incidence, prevalence, deaths, and disability-adjusted life-years (DALYs) attributed to MBC, as well as corresponding age-standardized rates, were calculated. Temporal trends, projections of incidence and mortality to 2050, lifetime risk, and risk factors of MBC were also estimated according to regions and countries.

Findings

In 2021, there were 38,827 (95% uncertainty interval [UI], 24,650-47,846) new cases, 320,459 (95% UI, 220,533-384,317) prevalent cases, 13,274 (95% UI, 9074-16,240) deaths, and 380,917 (95% UI, 252,922-476,417) DALYs attributed to MBC worldwide, with the highest disease burden observed in the Eastern Sub-Saharan Africa region. From 1990 to 2021, the age-standardized incidence and mortality rates of MBC significantly increased, but they are projected to decrease over the next 30 years. High-middle Socio-demographic Index (SDI) quintile had the highest lifetime risk of developing MBC, while the low SDI quintile had the highest lifetime risk of dying from MBC. Dietary risk and alcohol use were identified as important risk factors for MBC deaths and DALYs globally.

Interpretation

The global burden of MBC significantly increased from 1990 to 2021, with notable geographic disparities. Efforts aimed at MBC prevention and control strategies should take into account the inequities in its global distribution.

Funding

This study was supported by the National Natural Science Foundation of China (grant numbers 82372996 and 82202913) and the Chongqing Natural Science Foundation (grant number CSTB2023NSCQ-MSX0480).

Conditional survival of male breast cancer

BACKGROUND

The incidence of male breast cancer has been increasing in recent years; however, the long-term survival outcomes of diagnosed patients remain uncertain. This study was designed to evaluate the conditional survival of male breast cancer patients and to predict the future survival of patients through the conditional nomogram, to provide important suggestions for clinical decision-making.

METHODS

Retrospective data from the SEER database included 3600 male breast cancer patients, divided into training and validation groups (7 : 3 ratio). Overall survival rates were calculated using Kaplan-Meier analysis. Conditional survival analysis described survival at specific years. Time-dependent multivariate Cox analysis identified prognostic factors' impact. The conditional survival nomogram model predicted real-time survival rates.

RESULTS

Over time, the 5-year real-time survival rate of patients gradually improved, increasing from 70.5 to 74.8, 79.4, 85.8, and 92.9% (respectively, representing 5-year survival rates of 1-4 years after diagnosis). In addition, the improvement in conditional survival rate CS5 showed a nonlinear trend. After 5 years of diagnosis, age, tumor size, and tumor stage had a sustained impact on patient prognosis. Finally, a conditional survival nomogram was constructed to predict the 10-year survival rate in real time.

CONCLUSION

Five years after diagnosis, the conditional survival rate of male patients with breast cancer has improved, but it is not nonlinear. In the first 5 years after diagnosis, patients with older age, larger tumor size, poorer tumor stage, and distant metastasis should be actively followed up and treated to improve their long-term survival.

Cost-effectiveness of adjuvant endocrine treatment with tamoxifen for male breast cancer

BACKGROUND

Tamoxifen (TAM) is recommended as the first-line strategy for men with estrogen receptor (ER)-positive early breast cancer who are candidates for adjuvant endocrine therapy in ASCO guideline. Our study aims to analyze the cost-effectiveness of receiving adjuvant endocrine therapy with TAM compared to no TAM, and to assess the cost-effectiveness of using TAM with high adherence over low adherence for ER-positive early male breast cancer in the USA.

METHODS

Two Markov models comprising three mutually exclusive health states were constructed: (1) the first Markov model compared the cost-effectiveness of adding TAM with not using TAM (TAM versus Not-TAM); (2) the second model compared the cost-effectiveness of receiving TAM with high adherence and low adherence (High-adherence-TAM versus Low-adherence-TAM). The simulation time horizon for both models was the lifetime of patients. The efficacy and safety data of two models were elicited from the real-world studies. Model inputs were derived from the US website and published literature. The main outcomes of two models both included the total cost, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios (ICERs).

RESULTS

In the first model, TAM yielded an ICER of $5707.29 per QALY compared to Not-TAM, which was substantially below the WTP threshold of $50,000.00 per QALY in the USA. Probabilistic sensitivity analysis results demonstrated a 100.00% probability of cost-effectiveness for this strategy. In the second model, High-adherence-TAM was dominated absolutely compared to Low-adherence-TAM. The High-adherence-TAM was cost-effective with a 99.70% probability over Low-adherence-TAM when WTP was set as $50,000.00/QALY. All of these parameters within their plausible ranges did not reversely change the results of our models.

CONCLUSIONS

Our study will offer valuable guidance for physicians or patients when making treatment decisions and provide an effective reference for decision-making to consider the appropriate allocation of funds to this special group.

Imaging the Male Breast: Gynecomastia, Male Breast Cancer, and Beyond

The number of men undergoing breast imaging has increased in recent years, according to some reports. Most male breast concerns are related to benign causes, most commonly gynecomastia. The range of abnormalities typically encountered in the male breast is less broad than that encountered in women, given that lobule formation rarely occurs in men. Other benign causes of male breast palpable abnormalities with characteristic imaging findings include lipomas, sebaceous or epidermal inclusion cysts, and intramammary lymph nodes. Male breast cancer (MBC) is rare, representing up to 1% of breast cancer cases, but some data indicate that its incidence is increasing. MBC demonstrates some clinical features that overlap with those of gynecomastia, including a propensity for the subareolar breast. Men with breast cancer tend to present at a later stage than do women. MBC typically has similar imaging features to those of female breast cancer, often characterized by an irregular mass that may have associated calcifications. Occasionally, however, MBC has a benign-appearing imaging phenotype, with an oval shape and circumscribed margins, and therefore most solid breast masses in men require tissue diagnosis. Histopathologic evaluation may alternatively reveal other benign breast masses found in men, including papillomas, myofibroblastomas, and hemangiomas. Radiologists must be familiar with the breadth of male breast abnormalities to meet the rising challenge of caring for these patients. ©RSNA, 2024 Supplemental material is available for this article.

Exploring the One Health Paradigm in Male Breast Cancer

How cancer patterns in humans compare to those of other species remains largely unknown and there is an even bigger knowledge gap for rare cancers like male breast cancer. One Health is a convergence of human and animal healthcare that encourages cross-pollination of medical research uniting human and veterinary medicine. Recognising that breast cancer occurs spontaneously in other male species (e.g. primates, canines, felines), and knowing that no laboratory models exist for male breast cancer, which limits our ability to perform functional studies, we explored the feasibility of applying One Health to breast cancer in men by conducting a narrative review of the topic. Spontaneous development of breast cancer was reported in captive male primates and in companion canines and felines. Some parallels in tumour biology of human male breast cancer with canines and primates were found. The age distribution, pattern of biomarker expression and metastasis were similar, with mammary tumours typically detected after two-thirds of average lifespan. However, instances of triple negative and inflammatory breast cancer, which are rarely observed in human male breast cancer, were found in canines and histological classification was inconsistent between species. These disparities need redressing to enable full exploration of the One Health paradigm in rare cancers.

Establishment of Prognostic Nomogram for Male Breast Cancer Patients: A Surveillance, Epidemiology and End Results Database Analysis

BACKGROUND

Male breast cancer (MBC) represents a rare subtype of breast cancer, with limited prognostic factor studies available. The purpose of this research was to develop a unique nomogram for predicting MBC patient overall survival (OS) and breast cancer-specific survival (BCSS).

METHODS

From 2010 to 2020, clinical characteristics of male breast cancer patients were obtained from the Surveillance, Epidemiology and End Results (SEER) database. Following univariate and multivariate analyses, nomograms for OS and BCSS were created. Kaplan-Meier plots were further generated to illustrate the relationship between independent risk variables and survival. The nomogram's ability to discriminate was measured by employing the area under a time-dependent receiver operating characteristic curve (AUC) and calibration curves. Additionally, when the nomogram was used to direct clinical practice, we also used decision curve analysis (DCA) to evaluate the clinical usefulness and net clinical benefits.

RESULTS

A total of 2143 patients were included in this research. Univariate and multivariate analysis showed that age, grade, surgery, chemotherapy status, brain metastasis status, subtype, marital status, race, and AJCC-T, AJCC-N, and AJCC-M stages were significantly correlated with OS. Lung metastasis, age, marital status, grade, surgery, and AJCC-T, AJCC-N, and AJCC-M stages were significantly correlated with BCSS. By comprising these variables, a predictive nomogram was constructed in the SEER cohort. Then, it could be validated well in the validation cohort by receiver operating characteristics (ROCs) curve and calibration plot. Furthermore, the nomogram demonstrated better decision curve analysis (DCA) results, indicating the ability to forecast survival probability with greater accuracy.

CONCLUSION

We created and validated a unique nomogram that can assist clinicians in identifying MBC patients at high risk and forecasting their OS/BCSS.

Peptide-Based Vaccine against Breast Cancer: Recent Advances and Prospects

Breast cancer is considered the second-leading cancer after lung cancer and is the most prevalent cancer among women globally. Currently, cancer immunotherapy via vaccine has gained great attention due to specific and targeted immune cell activity that creates a potent immune response, thus providing long-lasting protection against the disease. Despite peptides being very susceptible to enzymatic degradation and poor immunogenicity, they can be easily customized with selected epitopes to induce a specific immune response and particulate with carriers to improve their delivery and thus overcome their weaknesses. With advances in nanotechnology, the peptide-based vaccine could incorporate other components, thereby modulating the immune system response against breast cancer. Considering that peptide-based vaccines seem to show remarkably promising outcomes against cancer, this review focuses on and provides a specific view of peptide-based vaccines used against breast cancer. Here, we discuss the benefits associated with a peptide-based vaccine, which can be a mainstay in the prevention and recurrence of breast cancer. Additionally, we also report the results of recent trials as well as plausible prospects for nanotechnology against breast cancer.

Best practices to quantify the impact of reproductive toxicants on development, function, and diseases of the rodent mammary gland

Work from numerous fields of study suggests that exposures to hormonally active chemicals during sensitive windows of development can alter mammary gland development, function, and disease risk. Stronger links between many environmental pollutants and disruptions to breast health continue to be documented in human populations, and there remain concerns that the methods utilized to identify, characterize, and prioritize these chemicals for risk assessment and risk management purposes are insufficient. There are also concerns that effects on the mammary gland have been largely ignored by regulatory agencies. Here, we provide technical guidance that is intended to enhance collection and evaluation of the mammary gland in mice and rats. We review several features of studies that should be controlled to properly evaluate the mammary gland, and then describe methods to appropriately collect the mammary gland from rodents. Furthermore, we discuss methods for preparing whole mounted mammary glands and numerous approaches that are available for the analysis of these samples. Finally, we conclude with several examples where analysis of the mammary gland revealed effects of environmental toxicants at low doses. Our work argues that the rodent mammary gland should be considered in chemical safety, hazard and risk assessments. It also suggests that improved measures of mammary gland outcomes, such as those we present in this review, should be included in the standardized methods evaluated by regulatory agencies such as the test guidelines used for identifying reproductive and developmental toxicants.

Survival Analysis in Male Breast Cancer With Bone Metastasis Based on the SEER Database

Purpose

Breast cancer (BC) has been extensively and deeply studied as the number one malignant tumor in women, but its status in male patients, especially in male metastatic patients, is rarely reported. Thus, this study aimed to explore the prognosis and risk factors of male BC with bone metastasis.

Patients and Methods

We searched the Surveillance, Epidemiology, and End Results (SEER) database to identify all patients diagnosed with male BC with bone metastasis from 2010 to 2016. Risk factors of overall survival (OS) and cancer-specific survival (CSS) were analyzed by univariable and multivariable Cox analyses. We also drew Kaplan–Meier plots to show the correlation between independent risk factors and survival.

Results

A total of 207 male BC patients with bone metastasis were included for analysis. Approximately one-third of patients also had lung metastasis. Luminal A subtype comprised 58.5% of the overall patient population. These patients had a poor prognosis, with 3-year OS and CSS rates, 36.7% and 39.5%, respectively. Further analysis revealed that age ≤60 years old, luminal A or B, and surgery were independent predictors of prolonged OS and CSS. On Cox multivariable analysis, brain metastasis was associated with OS and not CSS.

Conclusion

We identified four independent factors associated with prognosis in male BC patients with bone metastasis, namely age, tumor subtype, surgery, and brain metastasis. Knowing these risk factors will help clinicians make more appropriate treatment plans.

Management of Male Breast Cancer: The Journey so Far and Future Directions

Male breast cancer is now shown to be a unique entity and should be considered as a distinct disease. Given the relatively smaller number of cases, randomized controlled trials for treatment are extremely limited and majority of practices are derived from female breast cancer studies. This paper reviews available literature on surgical, radiation, and systemic therapies for male breast cancer, and discusses current practice recommendations.

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.

Cardiovascular and Other Competing Causes of Death in Male Breast Cancer Patients: A Population-Based Epidemiologic Study

Purpose

Male breast cancer (MBC) is a rare disease that tends to occur in elderly men. Little is known about the causes of death in MBC because of the small sample size of most studies. This study aimed to investigate the causes of death in MBC patients.

Patients and Methods

MBC patient data were obtained from the Surveillance, Epidemiology, and End Results database (1975-2016). Time trends of MBC mortality in the US population were analyzed using Joinpoint software. We calculated the proportion of each cause of death in the overall cohort and in different patient subgroups. Competing risk models were used to calculate cumulative mortality at different follow-up times. The risk of cardiovascular death (CVD) in MBC patients was compared to that of the age-matched general population by calculating standardized mortality ratio (SMR).

Results

In total, 6426 patients were included in the analysis. MBC mortality rate increased between 2004 and 2019 (annual percentage change=1.16, 95% confidence interval [CI]: 0.50, 1.80). There were 1757 patients (27.3%) who died of non-breast cancer causes. CVD was the leading cause of death in patients who were elderly or had localized disease. MBC patients had a 6.58-fold higher risk of CVD than the general population (SMR=6.58, 95% CI: 6.14, 7.05).

Conclusion

Non-breast cancer death accounts for the majority of deaths in MBC patients who are elderly or have localized cancer. Compared to the general population, MBC patients have an increased risk of CVD. These results highlight the importance of monitoring cardiovascular comorbidities in MBC patients.

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.