Traditional and Commercial Alcohols as Risk Factors for Esophageal Cancer in Tanzania

PURPOSE Esophageal cancer (EC) is one of the most common cancers in East Africa; however, risk factors that underly the high incidence in this region are not well understood. We aimed to investigate the association between exposure to specific alcohol subtypes and EC in Tanzania. METHODS We performed a secondary analysis of data from a hospital-based, case-control study conducted at Muhimbili National Hospital and Ocean Road Cancer Institute in Dar es Salaam, Tanzania. Cases of EC were identified between 2014 and 2016. Hospital controls were identified from patients with nonmalignant conditions and matched 1:1 for gender and age (± 10 years). Interviews were conducted using a survey with culturally relevant and context-specific questions on alcohol and smoking exposure. Conditional logistic regression analyses were applied to evaluate specific associations of potential exposures and EC. RESULTS A total of 473 EC cases and 473 controls were enrolled. Alcohol consumption was reported in 61% and 64% of cases and controls, respectively. Neither ‘current use of alcohol (any type)’, nor ‘ever use’ were associated with EC; however, local brew consumption was associated with increased EC risk (odds ratio [OR], 2.01; 95% CI, 1.53 to 2.66; P < .01). Increased risk was observed with consumption of gongo (OR, 2.91), komoni (OR, 2.41), wanzuki (OR, 2.40), kindi (OR, 3.13), and kangara (OR, 2.86). Smoking increased EC risk; however, it did not significantly modify the association between EC and alcohol subtypes. CONCLUSION This is the first case-control study to report a detailed analysis of alcohol exposures as a potential risk factor for EC in Tanzania. Although combined measures of alcohol use were not found to be associated with EC, several types of locally brewed alcohols emerged as risk factors. Additional research is needed to investigate these findings and examine the carcinogenic role of ingredients and/or contaminants, as well as any interactions with other putative risk factors in this region.