Socioeconomic Determinants of Esophageal Cancer Incidence in the East African Corridor: A Systematic Review with Meta-Analysis

Background and aim of the work: In the East African corridor, environmental exposures such as alcohol and tobacco are comparatively lower than in many other regions globally. Despite this, more than 40% of global esophageal cancer cases are concentrated in this area. This raises the hypothesis that individual factors, specifically socioeconomic status [SES] indicators such as income, occupation, and education, may contribute to the high incidence of esophageal cancer in this region. Given the limited existing information and lack of meta-analyses on this subject, our study aimed to establish the relationship between SES and the rising prevalence of esophageal cancer in the East African Corridor.
Materials and Methods: We conducted a comprehensive search for observational studies reporting SES in individuals with esophageal cancer, published up to December 2023, using databases including PubMed/Medline, Web of Science, Scopus, Cochrane Library, and African Journal Online. The data extraction and analysis were performed following the PRISMA guidelines. Quality assessment and evaluation of publication bias were conducted using standard tools. To estimate summary effects, meta-analyses were performed with RevMan and Stata software, utilizing random-effects models.
Results: Our study encompassed 18,602 participants from 19 selected studies. The results strongly indicate a significant correlation between education level and esophageal cancer incidence. Individuals with no formal education exhibited a notably higher risk [OR=2.32 [95% CI, 1.89-2.85]], followed by those with only primary education [OR=1.68 [95% CI, 1.48-1.91]], compared to individuals with secondary and higher education. Furthermore, our findings revealed that the risk of esophageal cancer is highest among individuals employed in farming [OR=1.53 [95% CI, 1.24-1.90]] compared to office workers. Additionally, individuals with low family income faced a significantly higher risk [OR=2.82 [95% CI, 1.93-4.12]] compared to those with high family income.
Conclusion:  Our study strongly supports the assertion that socioeconomic status is closely correlated with the escalating incidence of esophageal cancer in the East African Corridor.