Global and regional trends in male breast cancer burden: a comparative analysis of incidence, prevalence, mortality, and disability-adjusted life years in China and worldwide (1990–2021)

Introduction

Male breast cancer (MBC), a rare and underexplored condition, constitutes less than 1% of all breast cancer cases globally (1). Its rarity, along with distinct biological characteristics compared to female breast cancer-such as differences in hormone receptor expression and tumor microenvironment-leads to unique diagnostic and therapeutic challenges (2,3). Moreover, genetic predispositions, notably mutations in BRCA1 and BRCA2, have been implicated in the pathogenesis of MBC, further complicating its clinical management. Despite its low incidence, the global burden of MBC has increased over the past three decades due to demographic shifts, particularly population aging, and advances in diagnostic technologies (4).

China, as the world’s most populous country, has undergone rapid epidemiological transitions characterized by increasing life expectancy, urbanization, and lifestyle changes such as higher rates of obesity, physical inactivity, and alcohol consumption (5). These factors have contributed to a rising burden of non-communicable diseases, including MBC. Additionally, improved diagnostic capabilities have likely enhanced the detection of cases, especially in urban areas (6,7).

Globally, the rising burden of MBC is primarily linked to improvements in diagnostic imaging, greater awareness among healthcare providers, and longer survival due to therapeutic advancements (8). However, this trend also underscores the growing need for specialized care and public health interventions aiming at mitigating its impact. Despite progress, MBC continues to be under-recognized, with substantial challenges in prevention, timely detection, and management (9). Moreover, the scarcity of large-scale, robust studies limits comprehensive understanding of this unique condition (10).

Despite growing recognition of MBC as a public health concern, critical knowledge gaps persist. First, existing studies on MBC epidemiology in China remain limited, with most focusing on Western populations, despite China’s unique demographic transitions and urban-rural healthcare disparities. Second, the interplay between aging populations, lifestyle changes, and diagnostic advancements in driving MBC burden has not been systematically quantified, particularly in low- and middle-income settings (11). Third, comparative analyses of global versus regional trends are scarce, hindering the development of context-specific interventions.

The Global Burden of Disease (GBD) database offers a comprehensive resource to analyze trends in incidence, prevalence, mortality, and disability-adjusted life years (DALYs) for MBC across different populations and time periods (12). By leveraging GBD 2021 data, this study aims to provide a detailed analysis of MBC trends in China and worldwide from 1990 to 2021. Through this comparative approach, we seek to identify demographic and regional disparities, assess the impact of healthcare advancements, and propose strategies to mitigate the growing burden of MBC. We present this article in accordance with the STROBE reporting checklist (available at https://gs.amegroups.com/article/view/10.21037/gs-2025-10/rc).

Methods

Data source

This study utilized data from the GBD 2021 database, which encompasses 204 countries and territories. The database integrates health metrics from national cancer registries, cohort studies, vital registration systems, and health surveys (13). The database provides robust, globally standardized estimates of incidence, prevalence, mortality, and DALYs across populations and time periods (14). The GBD data, which are publicly accessible via the Global Health Data Exchange (GHDx), offer a consistent basis for comparative epidemiological studies (15).

Study design

A population-based descriptive study design was used to analyze the burden of MBC in China and globally from 1990 to 2021. This included an assessment of age-standardized rates (ASRs) for key health metrics: incidence, prevalence, mortality, and DALYs. Age-specific trends were also evaluated to identify demographic shifts in disease burden. This study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments.

Metrics definitions

• Incidence: number of new MBC cases diagnosed per 100,000 population annually.
• Prevalence: total number of existing MBC cases per 100,000 population.
• Mortality: annual number of deaths due to MBC per 100,000 population.
• DALYs: a composite measure of the years of life lost (YLL) due to premature mortality and years lived with disability (YLD) caused by MBC.

Age standardization

ASRs were calculated to account for differences in population age structures across countries and over time (16). The World Health Organization (WHO) standard population structure was used as a reference to enable valid temporal and geographical comparisons (17).

Statistical analysis

Trend analysis using estimated annual percentage change (EAPC): temporal changes in ASRs were assessed using the EAPC (18). In epidemiological research, the EAPC is a key indicator for measuring changes in disease ASRs over time. The coefficient β comes from the natural logarithm of the ASRs, where y is ln (ASR) and x is the calendar year. Using the linear regression model: y = α + βx + ε. The EAPC and its 95% confidence intervals (CIs) are calculated, with the EAPC formula being: EAPC = 100 × [exp(β) − 1]. A rising trend is shown if the 95% CI’s lower bound is above 0, while a declining trend is indicated if the upper bound is below 0. If the 95% CI includes 0, it means there is no statistically significant trend change.

Trend analysis with Joinpoint regression: to detect significant temporal variations in ASRs for MBC incidence, prevalence, mortality, and DALYs, Joinpoint regression analysis was utilized. This method fits a series of joined line segments to the data, where each “Joinpoint” signifies a statistically significant shift in trend (19). Annual percentage changes (APCs) and average annual percentage changes (AAPCs) were calculated to quantify these trends, with statistical significance determined using Monte Carlo permutation tests and established at a 95% confidence level (P<0.05) (20,21). Unlike methods such as autoregressive integrated moving average (ARIMA) model or simple linear regression, Joinpoint regression offers greater flexibility in detecting multiple trends shifts and is highly interpretable, making it particularly well-suited for analyzing long-term epidemiological data where shifts in disease burden may occur due to changes in detection practices, interventions, or demographic shifts.

Age- and gender-specific trends: data were stratified into standardized 5-year age groups to evaluate trends by age. Male-specific data were used to isolate MBC burden, and age-specific patterns were analyzed to assess differences across demographic groups.

Comparative analysis: the study compared trends in disease burden metrics between China and the global population. Key measures such as APCs and AAPCs were used to identify temporal shifts and quantify differences in trends over the study period.

Risk factor analysis: detailed risk factor data from the GBD study were also downloaded and analyzed to assess changes in the proportional contributions of various risk factors to MBC outcomes globally and in China during the period 1990–2021. This risk factor analysis provided additional insights into potential drivers behind the observed epidemiological trends.

Software and tools

All statistical analyses, including Joinpoint regression and calculation of ASRs, were conducted using Joinpoint Regression Software (version 4.9.0.0) and R statistical software (version 4.2.2). In addition, sensitivity analyses were performed to assess the robustness of our findings. For non-fatal estimates, the DisMod-MR tool was applied with alternative prior settings and covariate selections, while for cause-of-death estimates, the CODEm approach-integrating multiple candidate models via cross-validation and ensemble modeling-was used (22,23).

Results

Global and regional trends in MBC burden

Global analysis of MBC burden across 204 countries revealed substantial heterogeneity in temporal trends (Figures 1,2 and tables available at https://cdn.amegroups.cn/static/public/10.21037gs-2025-10-1.xlsx, https://cdn.amegroups.cn/static/public/10.21037gs-2025-10-2.xlsx, https://cdn.amegroups.cn/static/public/10.21037gs-2025-10-3.xlsx, https://cdn.amegroups.cn/static/public/10.21037gs-2025-10-4.xlsx). For age-standardized incidence rates (ASIRs), Georgia exhibited the highest EAPC at 35.196 (95% CI: 29.171, 41.501), whereas the Republic of Belarus experienced the most pronounced decline (EAPC: −8.645, 95% CI: −12.163, −4.985). Notably, the Kingdom of Norway, the Republic of India, the United States of America, and the Federal Republic of Nigeria reported ASIR EAPCs of 1.645 (95% CI: 1.194, 2.098), 2.736 (95% CI: 2.622, 2.851), −1.072 (95% CI: −1.408, −0.734), and −0.258 (95% CI: −0.348, −0.168), respectively. Similar patterns were observed for age-standardized prevalence rates (ASPRs), with Georgia demonstrating the highest increase (EAPC: 11.584, 95% CI: 10.062, 13.126) and Belarus the largest decrease (EAPC: −3.255, 95% CI: −5.339, −1.125); corresponding EAPCs for Norway, India, the United States, and Nigeria were 1.643 (95% CI: 1.311, 1.976), 2.755 (95% CI: 2.708, 2.802), −0.851 (95% CI: −1.121, −0.581), and 0.037 (95% CI: −0.08, 0.155), respectively. Regarding age-standardized mortality rates (ASMRs), the most marked increase was observed in Georgia (EAPC: 35.12, 95% CI: 29.043, 41.483) compared to a decline in Belarus (EAPC: −10.099, 95% CI: −13.665, −6.385), while Norway, India, the United States, and Nigeria had EAPCs of −0.252 (95% CI: −0.638, 0.135), 1.974 (95% CI: 1.801, 2.146), −1.29 (95% CI: −1.576, −1.004), and −0.7 (95% CI: −0.771, −0.628), respectively. For age-standardized DALYs rates (ASDRs), Georgia again exhibited the highest increase (EAPC: 29.285, 95% CI: 24.59, 34.156) in contrast to the decrease observed in Belarus (EAPC: −9.593, 95% CI: −13.069, −5.979), with corresponding EAPCs for Norway, India, the United States, and Nigeria being −0.209 (95% CI: −0.586, 0.17), 1.732 (95% CI: 1.551, 1.914), −1.344 (95% CI: −1.648, −1.039), and −0.904 (95% CI: −0.998, −0.811), respectively. These findings underscore pronounced regional disparities in the dynamic trends of MBC burden, highlighting the need for tailored public health interventions.

Figure 1 ASIR, ASPR, ASMR, and ASDR in 204 countries and territories in 1990. (A) ASIR. (B) ASPR. (C) ASMR. (D) ASDR. ASDR, age-standardized DALYs rate; ASIR, age-standardized incidence rate; ASMR, age-standardized mortality rate; ASPR, age-standardized prevalence rate; DALYs, disability-adjusted life years.

Figure 2 ASIR, ASPR, ASMR, and ASDR in 204 countries and territories in 2021. (A) ASIR. (B) ASPR. (C) ASMR. (D) ASDR. ASDR, age-standardized DALYs rate; ASIR, age-standardized incidence rate; ASMR, age-standardized mortality rate; ASPR, age-standardized prevalence rate; DALYs, disability-adjusted life years.

Trends in MBC burden in China and worldwide

As shown in Table 1, the incidence of MBC increased significantly in China and globally between 1990 and 2021. In China, the number of all-age cases rose from 1,916 (95% CI: 1,311–2,627) in 1990 to 16,956 (95% CI: 6,780–24,541) in 2021. The corresponding ASR grew from 0.411 (95% CI: 0.288–0.565) to 1.604 (95% CI: 0.648–2.306), reflecting an AAPC of 4.5089 (95% CI: 4.1556–4.8634). Globally, a similar upward trend was observed, with all-age cases rising substantially from 9,777 (95% CI: 8,474–11,225) in 1990 to 38,827 (95% CI: 24,650–47,846) in 2021. The ASR increased from 0.525 (95% CI: 0.46–0.603) to 0.941 (95% CI: 0.605–1.155), with an AAPC of 1.9823 (95% CI: 1.7406–2.2246), slightly outpacing China’s growth. The prevalence of MBC showed a marked increase both in China and globally. In China, the prevalence increased from 15,758 (95% CI: 11,907–20,233) in 1990 to 145,449 (95% CI: 68,248–200,980) in 2021. The ASR rose from 3.435 (95% CI: 2.676–4.366) to 13.754 (95% CI: 6.525–18.841), corresponding to an AAPC of 4.6125 (95% CI: 4.3272–4.8986). On a global scale, the prevalence of MBC grew from 78,729 (95% CI: 70,146–87,704) in 1990 to 320,459 (95% CI: 220,533–384,317) in 2021. The ASR rose significantly from 4.259 (95% CI: 3.805–4.756) to 7.754 (95% CI: 5.41–9.237), with an AAPC of 2.0304 (95% CI: 1.7959–2.2655). Mortality rates in China remained relatively stable. The number of deaths increased from 861 (95% CI: 592–1,174) in 1990 to 3,377 (95% CI: 1,326–4,894) in 2021. However, the ASR showed a modest rise from 0.203 (95% CI: 0.141–0.275) to 0.329 (95% CI: 0.134–0.474), with an AAPC of 1.5683 (95% CI: 1.3827–1.7542). Globally, MBC mortality exhibited a higher increase. Deaths rose from 4,899 (95% CI: 4,142–5,895 in 1990 to 13,274 (95% CI: 9,074–16,240) in 2021. The ASR increased from 0.282 (95% CI: 0.241–0.338) to 0.335 (95% CI: 0.232–0.409), with an AAPC of 0.6163 (95% CI: 0.4475–0.7855). The DALYs associated with MBC increased in both China and globally. In China, DALYs rose from 29,236 (95% CI: 19,458–39,968) in 1990 to 108,308 (95% CI: 41,297–157,050) in 2021. The corresponding ASR increased from 6.034 (95% CI: 4.156–8.210) to 10.251 (95% CI: 3.951–14.772), with an AAPC of 1.7239 (95% CI: 1.5127–1.9355). Globally, DALYs increased dramatically from 144,956 (95% CI: 121,256–172,477) in 1990 to 380,917 (95% CI: 252,900–476,417) in 2021. The ASR rose from 7.386 (95% CI: 6.23–8.827) to 9.157 (95% CI: 6.116–11.423), with an AAPC of 0.7493 (95% CI: 0.5875–0.9114).

Trends in ASRs of MBC based on Joinpoint regression analysis

The trends in ASR of incidence, prevalence, mortality, and DALYs for MBC in China from 1990 to 2021 are shown in Figure 3. From 2004 to 2009, the ASIR experienced a significant increase, with an APC of 15.35 (P<0.05). Similarly, the ASPR demonstrated consistent growth throughout the study period, with a particularly pronounced rise between 2004 and 2009 (APC: 14.52, P<0.05). Mortality rates also showed a notable upward trend during 2004–2009, with an APC of 9.41 (P<0.05), followed by a steady decline from 2012 to 2021 (APC: −2.11, P<0.05). The ASDR exhibited a comparable pattern, marked by a sharp increase during 2004–2009 (APC: 10.08, P<0.05), followed by a gradual decrease between 2012 and 2021 (APC: −1.79, P<0.05). The global trends in ASIR, ASPR, ASMR, and ASDR from 1990 to 2021 are depicted in Figure 4. The ASIR showed a steady global increase, with a particularly notable rise between 2004 and 2012, during which the annual percent change (APC) reached 4.05%. Similarly, the ASPR mirrored the trend of the ASIR, displaying consistent growth throughout the study period. The most rapid increase occurred between 2004 and 2012, with an APC of 4.45%. The ASMR exhibited a slower upward trend with a moderate APC, but a significant shift was observed after 2012, when the trend reversed and began to decline at an APC of −0.41%. The ASDR followed a comparable pattern to ASMR, with a gradual increase prior to 2012, followed by a decline thereafter. Between 2012 and 2021, the APC for ASDR was −0.27%.

Figure 3 Trends in ASRs of incidence, prevalence, mortality, and DALYs in China (1990–2021) based on Joinpoint regression analysis. (A) ASIR. (B) ASPR. (C) ASMR. (D) ASDR. *, the APC is significantly different from zero at the alpha =0.05. APC, annual percent change; ASDR, age-standardized DALYs rate; ASIR, age-standardized incidence rate; ASMR, age-standardized mortality rate; ASPR, age-standardized prevalence rate; ASRs, age-standardized rates; DALYs, disability-adjusted life years.

Figure 4 Global trends in ASRs of incidence, prevalence, mortality, and DALYs (1990–2021) based on Joinpoint regression analysis. (A) ASIR. (B) ASPR. (C) ASMR. (D) ASDR. *, the APC is significantly different from zero at the alpha =0.05. APC, annual percent change; ASDR, age-standardized DALYs rate; ASIR, age-standardized incidence rate; ASMR, age-standardized mortality rate; ASPR, age-standardized prevalence rate; ASRs, age-standardized rates; DALYs, disability-adjusted life years.

Comparative trends in MBC burden in China and worldwide

From 1990 to 2021, the ASIR, ASPR, ASMR, and ASDR for MBC demonstrated significant and similar trends in both China and globally (Figure 5). In both China and worldwide, ASIR and ASPR showed a gradual increase over the three decades, reflecting a growing burden of disease incidence and prevalence. This rise indicates that the diagnosis of MBC has become more frequent, possibly due to increased awareness, improved detection methods, and an aging population. In contrast, ASMR remained relatively stable throughout the study period, suggesting potential improvements in treatment outcomes and healthcare services. The DALY rates exhibited an upward trend prior to 2012 in both China and globally, followed by a subsequent decline. This reduction implies progress in mitigating the overall burden of the disease through advancements in medical care, early detection, and disease management.

Figure 5 Comparative trends of ASRs incidence, prevalence, mortality, and DALYs of male breast cancer in China and worldwide (1990–2021). (A) Trends in China. (B) Global trends. ASIR, age-standardized incidence rate; ASMR, age-standardized mortality rate; ASPR, age-standardized prevalence rate; ASRs, age-standardized rates; DALYs, disability-adjusted life years.

Age-specific trends and burden of MBC in China and globally

Between 1990 and 2021, age-specific trends in incidence, prevalence, mortality, and DALYs for MBC in China demonstrated significant changes across various age groups (Figure 6). In 1990, the crude incidence rate was relatively low across all age categories but rose sharply in men aged 60 years and older. By 2021, this pattern persisted, with notable increases in incidence rates and absolute case numbers across most age groups, particularly among older populations. This reflects both the growing burden of MBC and the aging population in China. The prevalence of MBC followed a similar trend. From 1990 to 2021, both the number of prevalent cases and crude prevalence rates rose consistently, with the largest increases observed in men aged 60–80 years. This trend suggests improvements in diagnosis and survival, likely driven by advancements in cancer detection and treatment. Mortality patterns showed that the crude death rate and total number of deaths were concentrated in older age groups (60+ years) during both 1990 and 2021. However, the rise in mortality was less pronounced compared to incidence and prevalence, implying progress in disease management and treatment outcomes over the study period. The trend in DALYs mirrored these findings, with the highest burden consistently observed in older men. By 2021, the DALY rate per 100,000 population had decreased slightly in some older age groups, signaling improved healthcare interventions that reduced the disease’s impact on quality of life. This reduction reflects advances in therapeutic strategies, early detection, and overall healthcare improvements. Globally, age-specific trends in MBC incidence, prevalence, mortality, and DALYs between 1990 and 2021 also exhibited notable variations (Figure 7). In 1990, the crude incidence rate was low across all age groups but increased markedly in men aged 60 years and older. By 2021, the incidence rate and number of new cases had risen significantly across most age groups, with the steepest increases occurring in men aged 65–79 years. This underscores the growing burden of MBC among the aging global population. Global prevalence followed a similar trajectory, with both the number of cases and crude prevalence rates rising sharply across all age categories from 1990 to 2021, especially among individuals aged 60–80 years. This trend highlights not only improved awareness and detection but also longer survival due to advances in treatment. Mortality patterns revealed that the crude death rate and total number of deaths were concentrated in older age groups (60+ years) during both time points. However, as in China, the increase in mortality was less pronounced compared to incidence and prevalence, reflecting significant progress in treatment and disease management worldwide. Globally, the DALY burden showed a consistent pattern, with the highest rates seen in men aged 60 years and older. Between 1990 and 2021, DALYs per 100,000 population declined slightly in some older age groups, reflecting the positive impact of improved therapeutic interventions and early detection on quality of life. Overall, these trends emphasize the importance of continued efforts in research, treatment innovation, and public health initiatives to address the burden of MBC, particularly among aging populations.

Figure 6 Comparison of incidence, prevalence, mortality, and DALYs of male breast cancer by age in China, 1990 and 2021. (A) Incidence. (B) Prevalence. (C) Mortality. (D) DALYs. DALYs, disability-adjusted life years.

Figure 7 Comparison of incidence, prevalence, mortality, and DALYs of male breast cancer by age worldwide, 1990 and 2021. (A) Incidence. (B) Prevalence. (C) Mortality. (D) DALYs. DALYs, disability-adjusted life years.

Comparison of disease burden and ASRs of MBC in China and worldwide

Between 1990 and 2021, trends in total cases and ASRs of incidence, prevalence, mortality, and DALYs for MBC in China showed significant changes (Figure 8). The total number of incident cases increased substantially, rising from approximately 1,000 cases in 1990 to over 3,500 cases in 2021. The ASIR also climbed steadily, from 0.2 per 100,000 in 1990 to 0.5 per 100,000 in 2021, reflecting both population growth and a genuine rise in the disease burden. Prevalence trends displayed an even sharper increase, with total cases rising from around 10,000 in 1990 to over 50,000 by 2021. Similarly, the ASPR grew from 2.0 per 100,000 in 1990 to 6.0 per 100,000 in 2021, highlighting advancements in early diagnosis and improved survival rates among patients. Mortality trends revealed a more moderate rise in total deaths, which grew from approximately 300 in 1990 to over 1,200 in 2021. However, the ASMR remained relatively stable, fluctuating between 0.05 and 0.10 per 100,000. This stability suggests that improvements in treatment have helped to offset rising case numbers and mitigate death rates. The DALY burden in absolute terms increased from 10,000 in 1990 to approximately 40,000 in 2021. However, the age-standardized DALY rate declined slightly, from 1.5 per 100,000 in 1990 to 1.0 per 100,000 in 2021, indicating that advances in healthcare services and better disease management strategies have helped to reduce the relative impact of the disease on the population. Globally, trends in total cases and ASRs of incidence, prevalence, mortality, and DALYs for MBC from 1990 to 2021 also highlight notable changes (Figure 9). The total number of incident cases rose significantly, from approximately 10,000 in 1990 to nearly 40,000 in 2021. However, the ASIR increased more modestly, from 0.8 per 100,000 in 1990 to nearly 1.2 per 100,000 in 2021, indicating that the rise in cases is partially attributable to population growth and aging. Global prevalence trends demonstrated a substantial rise, with total cases increasing from approximately 100,000 in 1990 to over 400,000 in 2021. Correspondingly, the ASPR climbed from about 10.0 per 100,000 in 1990 to nearly 30.0 per 100,000 in 2021, reflecting improved detection and extended survival rates due to advances in medical care and treatment. Mortality trends showed a moderate increase in total deaths, growing from around 5,000 in 1990 to over 12,000 in 2021. Yet, the ASMR remained relatively stable, ranging between 0.5 and 0.8 per 100,000, suggesting progress in reducing fatal outcomes through improved management and treatment. DALYs followed a similar trend, with total numbers increasing from approximately 100,000 in 1990 to nearly 500,000 in 2021. However, the age-standardized DALY rate declined slightly, from about 10.0 per 100,000 in 1990 to 8.0 per 100,000 in 2021. This decline underscores the positive impact of advancements in healthcare and disease management in reducing the overall burden of MBC, even as the absolute numbers continue to rise. These trends emphasize the growing burden of MBC in both China and globally, underscoring the importance of continued efforts in early detection, treatment innovation, and public health strategies to manage and reduce its impact.

Figure 8 Trends in total cases and ASRs of incidence, prevalence, mortality, and DALYs for male breast cancer in China (1990–2021). (A) Incidence of male breast cancer. (B) Prevalence of male breast cancer. (C) Mortality of male breast cancer. (D) DALYs of male breast cancer. ASRs, age-standardized rates; DALYs, disability-adjusted life years.

Figure 9 Global trends in total cases and ASRs of incidence, prevalence, mortality, and DALYs for male breast cancer (1990–2021). (A) Incidence of male breast cancer. (B) Prevalence of male breast cancer. (C) Mortality of male breast cancer. (D) DALYs of male breast cancer. ASRs, age-standardized rates; DALYs, disability-adjusted life years.

Comparative trends in key risk factors in China and globally

As shown in Figure 10 and Tables S1-S4, high alcohol use, diet high in red meat, and secondhand smoke emerged as important risk factors, although their contributions to deaths and DALYs displayed only minimal changes over the period examined. In China, the percentage of deaths attributable to high alcohol use fluctuated, decreasing from 8.93% in 1990 to 8.12% in 1999 before rising to 9.01% in 2020 and 2021. Similarly, the percentage of DALYs due to high alcohol use in China decreased from 9.42% in 1990 to 8.59% in 2000, then increased to approximately 9.64% in 2020 and 9.65% in 2021. In contrast, globally, deaths due to high alcohol use changed modestly from 7.05% in 1990 to 7.12% in 2021, and DALYs showed a comparable trend, moving from 7.59% to 7.7% over the same period. Diet high in red meat demonstrated divergent trends between China and the global context. In China, both the percentage of deaths and DALYs attributable to this dietary factor increased steadily from 13.31% and 13.1% in 1990 to 13.6% and 13.56% in 2020–2021, respectively. Conversely, on the global scale, the percentage of deaths due to a diet high in red meat slightly declined from 11.88% in 1990 to 11.71% in 2021, with DALYs decreasing from 11.81% to 11.76% during the same timeframe. Secondhand smoke also exhibited contrasting patterns. In China, the burden of secondhand smoke, as measured by the percentages of deaths and DALYs, increased marginally from 0.92% to 0.97% and from 0.9% to 0.96%, respectively. Globally, however, both the percentage of deaths and DALYs due to secondhand smoke decreased slightly—from 0.86% in 1990 to 0.83% in 2021 for deaths, and from 0.88% to 0.85% for DALYs. Overall, these findings highlight region-specific differences in the impact of key risk factors. While high alcohol use and secondhand smoke have shown slight global decreases, China experienced notable fluctuations and incremental increases in these metrics. In contrast, the influence of a diet high in red meat increased in China, yet decreased globally, underscoring the heterogeneous nature of risk factor trends across different settings.

Figure 10 The MBC deaths and DALYs attributable to risk factors from 1990 to 2021 in China and global. (A) The MBC deaths attributable to risk factors from 1990 to 2021 in China. (B) The MBC DALYs attributable to risk factors from 1990 to 2021 in China. (C) The MBC deaths attributable to risk factors from 1990 to 2021 in global. (D) The MBC DALYs attributable to risk factors from 1990 to 2021 in global. DALYs, disability-adjusted life years; MBC, male breast cancer.

Discussion

This study presents an in-depth examination of global and regional trends in the burden of MBC between 1990 and 2021, specifically analyzing changes in incidence, prevalence, mortality, and DALYs. The results reveal significant increases in both incidence and prevalence in China and worldwide, while DALYs demonstrated notable growth in absolute terms but relative stability in ASRs. These trends underscore the growing public health significance of MBC, a malignancy often overlooked due to its rarity and its distinct epidemiological characteristics. Although comparisons with female breast cancer trends may offer additional context, our study intentionally focuses solely on MBC due to the significant differences in risk factors, clinical behavior, and the extensive existing literature on female breast cancer. For instance, a recent study by Antonini et al. highlighted the epidemiological disparities between male and female breast cancer in a Brazilian cohort, emphasizing the need for sex-specific research and interventions (24). Our research aims to contribute to the growing body of literature specifically addressing MBC.

The steady rise in MBC incidence and prevalence reflects both the increasing disease burden and improvements in detection. In China, the ASIR increased from 0.2 per 100,000 in 1990 to 0.5 per 100,000 in 2021, a pattern consistent with global trends. This growth is primarily driven by an aging population—a well-established risk factor for breast cancer—and lifestyle changes, including higher rates of obesity, physical inactivity, and alcohol consumption (4,9). The availability of advanced diagnostic technologies has further facilitated earlier detection of MBC cases, particularly in urban areas (25).

The growing prevalence of MBC also reflects advancements in medical care, which have improved survival outcomes. Innovations such as targeted therapies, refined surgical techniques, and better management of comorbidities have transformed MBC into a more manageable, chronic condition for many patients (26-28). However, this rising prevalence poses challenges for healthcare systems, which must adapt to the long-term care needs of MBC survivors.

Despite the rising incidence and prevalence, the ASMR for MBC has remained relatively stable in both China and globally. In China, the ASMR fluctuated between 0.05 and 0.10 per 100,000 over the study period. This stability reflects advancements in early detection and treatment, such as the use of hormone receptor-targeted therapies and adjuvant treatments, which have significantly improved survival, even for advanced-stage cases (29,30). A slight global decline in DALY rates after 2012 further underscores the positive impact of therapeutic innovations in mitigating the overall burden of MBC. Furthermore, the differences observed in mortality and DALY trends between China and global data may be attributed to regional variations in healthcare policies, screening initiatives, and access to treatment. In China, governmental efforts to expand healthcare coverage and promote early detection through targeted screening programs have contributed to the stabilization of mortality rates, even as incidence rises (31). However, limitations in the uniform implementation of screening programs and disparities in the availability of advanced treatment modalities across regions may partly explain the differences in DALY trends compared to global patterns (32). In contrast, other regions may experience varied outcomes due to differences in health system infrastructure, policy priorities, and resource allocation (33). For example, differences in national healthcare policies, funding levels, and the implementation of screening programs can lead to significant variability in early diagnosis and treatment efficacy (34). Expanding on this, countries with robust healthcare investments and comprehensive screening initiatives tend to report lower mortality rates and better management of MBC (35). Therefore, a more in-depth exploration of these factors is warranted to fully understand the underlying causes of the observed regional discrepancies in MBC burden.

The detailed analysis of global and regional trends reveals substantial heterogeneity in the temporal dynamics of MBC burden. For instance, countries such as Georgia exhibit marked increases in incidence, prevalence, mortality, and DALYs, whereas nations like Belarus demonstrate significant declines in these parameters. These contrasting trends likely reflect differences in diagnostic practices, healthcare infrastructure, and population demographics. Such regional disparities underscore the need for tailored public health interventions and further investigation into the determinants that drive these divergent patterns, suggesting that aggregated global metrics may obscure critical local variations.

Age-specific analyses reveal that men aged 60 years and older bear the greatest burden of MBC, both in terms of incidence and mortality. This finding highlights the interplay between biological aging, cumulative exposure to risk factors, and delays in diagnosis among older populations (36-38). The marked rise in crude incidence rates among older men emphasizes the need for age-targeted screening and prevention efforts. Unlike breast cancer screening programs for women, screening initiatives for men—especially those with a family history or genetic predisposition—remain underdeveloped and warrant urgent attention. According to the American Cancer Society, men with a BRCA2 mutation or a strong family history of breast cancer should consider starting screening at age 35 to 40 years, using mammography and/or breast magnetic resonance imaging (MRI) annually (39). Additionally, the National Comprehensive Cancer Network (NCCN) guidelines recommend that healthcare providers discuss screening options with high-risk male patients, including those with a personal or family history of breast cancer, BRCA mutations, or other genetic syndromes associated with increased breast cancer risk (40). These guidelines provide a framework for targeted interventions in high-risk male populations.

Public awareness campaigns tailored to male populations are crucial for reducing diagnostic delays. Societal perceptions of breast cancer as a predominantly female disease have historically hindered early detection in men. Addressing these misconceptions through targeted education can promote earlier medical consultations and improve outcomes for male patients.

The findings also highlight the need for investment in healthcare infrastructure to support early diagnosis and effective treatment of MBC. Strategies such as mobile diagnostic units, telemedicine services, and specialized training programs for healthcare professionals can enhance access to care, particularly in underserved areas (41,42). Moreover, international collaborations and resource-sharing initiatives, coupled with tailored healthcare policies that prioritize early detection and equitable resource distribution, can accelerate progress in addressing the burden of MBC globally. Such strategies ensure that advancements in diagnostic and treatment technologies are more uniformly accessible across different regions (43).

Comparative analyses of key risk factors further illuminate differences between China and global trends. In China, incremental increases in the burden attributable to high alcohol use and secondhand smoke, alongside a rising impact from diets high in red meat, contrast with the modest or declining trends observed globally. These findings imply that cultural, behavioral, and socioeconomic factors may substantially influence risk exposures, thereby warranting the development of locally adapted prevention strategies. Integrating these risk factor profiles into public health policies could enhance the effectiveness of targeted interventions and ultimately reduce the burden of MBC.

While this study focused on analyzing overall trends in MBC burden, further research is needed to explore its unique risk factors, including genetic, environmental, and hormonal influences. Large-scale studies specifically addressing MBC could provide valuable insights into its epidemiology and inform targeted prevention strategies. The GBD database serves as an important resource for tracking MBC trends over time and across different populations, offering a foundation for future investigations.

From a public health perspective, integrating MBC-specific strategies into broader cancer control programs can enhance their overall effectiveness. Risk-based screening for high-risk groups, coupled with public education campaigns to reduce stigma and improve awareness, should be key components of a comprehensive approach. Additionally, fostering collaborations among governments, non-governmental organizations, and academic institutions can mobilize resources and expertise to tackle the challenges posed by MBC effectively.

The dataset may include missing values and is heavily dependent on cancer registry data, which can lead to potential underreporting and inconsistencies across regions. Moreover, the GBD-derived estimates do not capture detailed treatment data, such as chemotherapy and surgical outcomes, thereby limiting our ability to fully assess the impact of therapeutic interventions on MBC outcomes. Future research should aim to integrate more granular clinical data to address these gaps.

Conclusions

In summary, this study highlights the dual challenges and opportunities associated with the rising burden of MBC. While advances in healthcare have helped stabilize mortality and DALY rates, the increasing incidence and prevalence emphasize the need for sustained efforts in prevention, early detection, and treatment. The findings provide a critical foundation for future research and public health strategies aimed at improving outcomes for MBC patients worldwide.

Acknowledgments

We extend our gratitude to the Institute for Health Metrics and Evaluation (IHME) for providing access to the Global Burden of Disease database, which made this research possible. Additionally, we appreciate the efforts of the GBD research team for their contributions to compiling and maintaining the dataset.

Footnote

Reporting Checklist: The authors have completed the STROBE reporting checklist. Available at https://gs.amegroups.com/article/view/10.21037/gs-2025-10/rc

Peer Review File: Available at https://gs.amegroups.com/article/view/10.21037/gs-2025-10/prf

Funding: None.

Conflicts of Interest: Both authors have completed the ICMJE uniform disclosure form (available at https://gs.amegroups.com/article/view/10.21037/gs-2025-10/coif). The authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. This study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

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