Cancer represents an escalating global public health challenge, with low- and middle-income countries (LMICs) bearing a disproportionate burden of cancer incidence and mortality. According to the GLOBOCAN 2020 report [1], more than 70% of cancer-related deaths now occur in LMICs, largely due to late-stage diagnosis, limited access to diagnostic and treatment services, and weak cancer surveillance systems. Sub-Saharan Africa is among the most affected regions, with cancer incidence projected to double by 2040, driven by population growth, aging, epidemiological transition, persistent infectious diseases, and changing lifestyle and environmental exposures [1][2].

A defining feature of cancer epidemiology in sub-Saharan Africa is the high proportion of infection-related cancers. Oncogenic infections such as human papillomavirus (HPV), hepatitis B and C viruses (HBV/HCV), Epstein-Barr virus (EBV), and human immunodeficiency virus (HIV) contribute substantially to cancers of the cervix, liver, nasopharynx, stomach, and Kaposi sarcoma [3][4]. In Burundi, these infections remain endemic, while preventive interventions—such as HPV vaccination, hepatitis B vaccination, and systematic screening—are still limited. As a result, infection-related cancers are likely to play a major role in the national cancer burden, although precise local data remain scarce.

Beyond infections, lifestyle and environmental risk factors are increasingly relevant in the region. Tobacco use, alcohol consumption, dietary changes toward processed and low-fiber foods, physical inactivity, and exposure to environmental pollutants associated with urbanization have been linked to rising incidences of colorectal, liver, breast, and stomach cancers [2][5]. However, the impact of these factors in Burundi has not been well characterized, underscoring the need for locally generated epidemiological evidence.

Despite the growing cancer burden, Burundi lacks a population-based cancer registry. Available national estimates rely largely on modeled data from international sources such as GLOBOCAN [1], which suggest that breast, cervical, prostate, and colorectal cancers are among the most prevalent. The absence of comprehensive local data limits effective planning for cancer prevention, early detection, staging, and treatment services.

In this context, histopathology services at referral institutions—namely the University Hospital Centre of Kamenge (CHUK) and the Bujumbura Pathology Centre (BujaPath)—play a central role in cancer diagnosis. Hematoxylin and Eosin (H&E) staining remains the cornerstone of histopathological diagnosis in resource-limited settings, offering reliable morphological classification of tumors at relatively low cost [6][7]. While H&E alone does not provide detailed molecular characterization or staging information, it remains indispensable for confirming malignancy and guiding initial clinical decision-making.

This study aims to address the national data gap by providing a descriptive analysis of 1708 histologically confirmed cancer cases diagnosed using H&E staining in Burundi between January 2021 and December 2023. The study focuses on age and sex distribution, organ involvement, and histological cancer types, with comparisons to global and regional patterns reported in GLOBOCAN 2020 [1]. Although cancer staging and treatment data were not systematically available, the findings provide critical baseline evidence to inform future cancer control strategies, including prevention of infection-related cancers, lifestyle interventions, and strengthening diagnostic and treatment pathways.

Cancer remains a leading cause of morbidity and mortality worldwide. In 2020 alone, approximately 19.3 million new cancer cases and 10 million cancer-related deaths were reported globally [1]. Breast, lung, colorectal, prostate, and stomach cancers account for the majority of cases, with carcinomas and adenocarcinomas representing the dominant histological subtypes [1].

In contrast to high-income countries—where cancer predominantly affects older populations (median age ≥ 65 years)—LMICs experience earlier onset, often affecting individuals in their economically productive years [2][3]. This pattern has significant socioeconomic implications, particularly in sub-Saharan Africa.

Infection-associated malignancies are disproportionately common in sub-Saharan Africa, accounting for up to one-third of cancers in some countries [3][4]. Cervical cancer (HPV), hepatocellular carcinoma (HBV/HCV), and Kaposi sarcoma (HIV) are particularly prevalent due to limited vaccination coverage, inadequate screening programs, and delayed diagnosis. Evidence shows that HPV vaccination, hepatitis B vaccination, early antiviral treatment, and cervical cancer screening can significantly reduce cancer incidence [3][5]. However, implementation of these preventive strategies remains suboptimal in Burundi, highlighting an urgent public health gap.

Alongside infectious causes, lifestyle-related and environmental factors are increasingly shaping cancer epidemiology in Africa. Tobacco smoking and alcohol consumption contribute to cancers of the lung, liver, esophagus, and head and neck, while dietary patterns low in fruits and fiber and high in processed foods are linked to colorectal and stomach cancers [2][5]. Environmental pollution and occupational exposures further compound cancer risk, particularly in rapidly urbanizing settings. These factors may partially explain the rising incidence of non-infection-related cancers observed in recent African studies [2].

Sub-Saharan Africa exhibits a distinct cancer profile characterized by high burdens of breast, cervical, prostate, liver, and colorectal cancers, alongside notable pediatric malignancies such as retinoblastoma, Burkitt lymphoma, and osteosarcoma [4][5]. Studies by Bray et al. and others confirm that aggressive cancers frequently present at younger ages and advanced stages, largely due to delayed health-seeking behavior and limited diagnostic capacity [2][4].

Hematoxylin and Eosin staining remains the foundation of cancer diagnosis worldwide and is particularly vital in resource-constrained settings [6][7]. H&E allows reliable differentiation of major tumor categories, including carcinoma, sarcoma, lymphoma, and melanoma, and supports organ-specific cancer classification. Studies from Uganda, Rwanda, and Tanzania demonstrate that H&E-based diagnoses accurately reflect regional cancer patterns and can support cancer surveillance efforts in the absence of advanced molecular tools [8][9].

Globally, breast and cervical cancers dominate among females, while prostate and liver cancers are most common among males [1]. Similar gender-specific trends have been reported across African studies [8][10]. Organ-specific patterns—such as the predominance of adenocarcinoma in the breast, stomach, and colorectum—are consistent with global observations [11]. Pediatric cancers, although less frequent, remain clinically significant due to their aggressive nature and diagnostic challenges [5][12].

While histological diagnosis is essential, cancer staging and treatment information are crucial for understanding disease severity, prognosis, and management strategies. Many studies in LMICs, including Burundi, lack comprehensive staging and treatment data due to fragmented clinical records and limited oncology services [13]. This gap underscores the need to integrate pathology data with clinical oncology services and cancer registries.

Recent literature emphasizes that strengthening basic pathology services—including systematic use of H&E staining—is a critical first step toward effective cancer control in LMICs [7][8][13]. The experience from BujaPath and CHUK demonstrates that even in the absence of advanced diagnostics, H&E-based data can generate valuable epidemiological insights, inform prevention strategies for infection-related cancers, and support the development of national cancer surveillance systems.

The present analysis shows that cancer in this cohort predominantly affected middle-aged and older adults, with a mean age of 52.5 years and a median of 56 years. This age profile is consistent with GLOBOCAN 2020 estimates for Burundi, which indicate that the majority of cancer cases occur after the age of 40, with incidence rising steadily with advancing age [1]. Similar age patterns have been reported across sub-Saharan Africa, reflecting cumulative carcinogenic exposure and biological aging processes [14]. However, the mean age observed in this study remains lower than that reported in high-income countries, where cancer diagnoses typically peak after 60 - 65 years, a difference attributed to lower life expectancy and a higher burden of infection-related cancers in African populations [15].

The concentration of cases within the 25-64-year age group mirrors GLOBOCAN data for Burundi, which show that a substantial proportion of cancer cases occur among economically productive adults [1]. This pattern has been consistently reported in recent African studies and highlights the significant socioeconomic impact of cancer in low-resource settings [16]. The presence of pediatric cases, including retinoblastoma and bone tumors, aligns with global and regional evidence indicating a relatively higher proportional burden of childhood cancers in low- and middle-income countries [17].

Gender distribution in this cohort was nearly equal, contrasting with the global male predominance reported by GLOBOCAN, but closely aligning with estimates for Burundi, where female cancers—particularly breast and cervical cancer—contribute substantially to overall incidence [1]. This balance may also reflect higher healthcare utilization among women, facilitating earlier diagnosis [18].

Organ-specific analysis revealed that breast, skin, prostate, and colorectal cancers accounted for more than 65% of cases. This distribution is broadly consistent with GLOBOCAN Burundi profiles, where breast cancer is the leading cancer overall and prostate cancer is the most common among men [1]. The notable contribution of colorectal cancer supports evidence of an epidemiological transition associated with urbanization and lifestyle changes [19].

Histologically, the predominance of carcinoma and adenocarcinoma (~80%) reflects global patterns where epithelial malignancies dominate cancer diagnoses [14]. The presence of Kaposi sarcoma and hepatocellular carcinoma is consistent with Burundi’s burden of HIV- and hepatitis-related cancers, which remain significant contributors to cancer incidence in sub-Saharan Africa [10][15].

Overall, these findings (Table 4, Table 5) show strong concordance with GLOBOCAN estimates for Burundi, while providing institution-level evidence to guide targeted prevention, screening, and cancer control strategies [20].

Table 4. Comparison of study findings with GLOBOCAN 2020 data.

Table 5. Comparison of local cancer findings with GLOBOCAN 2022 burundi incidence rankings.

This study demonstrates that the cancer burden in the analyzed cohort is concentrated mainly among middle-aged and older adults, with patterns that closely mirror GLOBOCAN estimates for Burundi. The predominance of cancers in the 25 - 64-year age group highlights a substantial impact on the economically productive population.

The near-equal gender distribution reflects the high contribution of female cancers—particularly breast and cervical cancer—alongside male-dominant cancers such as prostate cancer. Organ-specific and histological patterns, dominated by epithelial malignancies (carcinoma and adenocarcinoma), are consistent with regional and global epidemiological profiles. The presence of infection-related cancers, including Kaposi sarcoma and hepatocellular carcinoma, underscores the persistent role of HIV and viral hepatitis in shaping the cancer landscape in Burundi. Overall, the findings confirm strong concordance with GLOBOCAN data while providing valuable institution-level evidence to support national cancer control efforts.

Several limitations should be considered when interpreting these results. First, the study is based on data from two institutions Bujapath-Chuk and may not fully represent the national cancer burden, particularly for rural or underserved populations. Second, the absence of age-standardized incidence rates limits direct quantitative comparison with GLOBOCAN estimates. Third, potential underdiagnosis and referral bias may have influenced the observed cancer distribution, especially for cancers requiring advanced diagnostic capacity. Finally, limited information on staging, treatment outcomes, and survival restricts broader interpretation of disease severity and prognosis.

To strengthen cancer control in Burundi, the following actions are recommended:

Enhance population-based cancer registration to improve national representativeness and enable accurate incidence and survival analyses.Expand early detection and screening programs, particularly for breast, cervical, and colorectal cancers, targeting adults in the 25 - 64-year age group.Strengthen diagnostic and pathology services to reduce underdiagnosis and improve histological confirmation.

Promote future multicenter and longitudinal studies incorporating staging and outcome data to better inform evidence-based cancer policy and resource allocation.