Hot beverages and oesophageal cancer risk in western Kenya:Findings from the ESCCAPE case–control study

Abstract

Oesophageal squamous cell carcinoma (ESCC) has markedly high incidence rates in Kenya and much of East Africa, with a dire prognosis and poorly understood aetiology. Consumption of hot beverages—a probable carcinogen to humans—is associated with increased ESCC risk in other settings and is habitually practiced in Kenya. We conducted a case–control study in Eldoret, western Kenya between August 2013 and March2018. Cases were patients with endoscopically confirmed oesophageal cancer whose histology did not rule out ESCC. Age and sex-matched controls were hospital visitors and hospital out and in-patients excluding those with digestive diseases. Odds ratios (ORs) and95% confidence intervals (CIs) were estimated for self-reported drinking temperatures; consumption frequency; mouth burning frequency and hot porridge consumption using logistic regression models adjusted for potential confounders. Drinking temperature association with tumour sub-location was also investigated. The study included430cases and440controls. Drinkers of‘very hot’and‘hot’beverages (>95% tea) had a3.7(95% CI:2.1–6.5) and1.4-fold (1.0–2.0) ESCC risk, respectively compared to‘warm’ drinkers. This trend was consistent in males, females, never and ever alcohol/tobacco and was stronger over than under age50years. The tumour sub-location distribution (upper/middle/lower oesophagus) did not differ by reported drinking temperature. Our study is the first comprehensive investigation in this setting to-date to observe a link between hot beverage consumption and ESCC in East Africa. These findings provide further evidence for the role of this potentially modifiable risk factor in ESCC aetiology.