Unmasking Early-Onset Gastric Cancer in a Low-Incidence Setting: Insights from Eritrea National Health Laboratory 11-year study

Introduction Gastric cancer (GC) remains a major global health concern, ranking among the leading causes of cancer-related morbidity and mortality, with over one million new cases and hundreds of thousands of deaths annually. While incidence and mortality are declining in high-income countries, the burden has shifted toward low- and middle-income countries, which now account for the majority of GC-related deaths. Sub-Saharan Africa is traditionally considered a low-incidence region, yet the paradox of a high prevalence of Helicobacter pylori alongside comparatively low GC rates, the so-called “African Enigma”, remains poorly understood, partly due to limitations in cancer data collection. In Eritrea, where robust data are scarce, the epidemiology of GC has not been systematically studied, highlighting the need for population-based evidence to clarify incidence, trends, and associated risk factors. Method We conducted a retrospective audit of gastric biopsy cases processed at the National Health Laboratory (NHL), the only diagnostic pathology center in Eritrea, between January 2011 and December 2021. All Eritrean patients who underwent endoscopic-guided gastric biopsy during this period were included, while non-Eritrean patients and records with missing outcome data were excluded. Demographic and clinical information was extracted from laboratory records, including age, sex, residence, and histopathological subtype. Data were analyzed using SPSS and R, with descriptive statistics, chi-square tests, Fisher’s exact test, and non-parametric comparisons as appropriate. Crude incidence rates (CIR), age-standardized incidence rates (ASIR), and estimated annual percentage change (EAPC) were calculated. Trends were assessed using Joinpoint regression, and logistic regression was applied to evaluate associations between risk factors and gastric cancer. Results Among 6,496 gastric biopsy samples processed from 2011 to 2021, 226 (3.6%) were gastroduodenoscopy specimens, of which 101 (44.6%) were malignant. Median age was higher for malignant cases (57 years) compared to non-malignant cases (47 years), while gender distribution was similar. Late-onset gastric cancer (> 50 years) accounted for 63% of malignant cases. Adenocarcinoma was the predominant histological subtype, peaking in older age groups, whereas lymphoma and squamous cell carcinoma showed distinct age and gender patterns. Crude incidence rates (CIR) and age-standardized rates (ASR) demonstrated temporal variability, with peak ASR in 2021 (1.535 per 100,000) and a male-to-female ratio of 1.27:1 overall. Regional analysis indicated higher case clustering in the Maekel zone, particularly around Asmara. Multivariate regression identified age as an independent risk factor for malignancy (OR = 1.04 per year), while sex and geographic region were not significantly associated. Conclusion Gastric cancer in Eritrea reflects global age and sex patterns but shows a relatively high proportion of early-onset cases and distinctive histological trends in women. Combined with high H. pylori prevalence, an aging population, and limited diagnostic capacity, these findings indicate a likely increase in gastric cancer burden. Strengthening surveillance, prevention, and equitable diagnostic access is essential to address this emerging challenge. Clinical trial number : not applicable.