Esophageal Squamous Dysplasia is Common in Asymptomatic Kenyans: A Prospective, Community-Based, Cross-Sectional Study

Abstract

OBJECTIVE Esophageal squamous cell carcinoma (ESCC) is endemic in east Africa and is a leading cause of cancer death among Kenyans. The asymptomatic precursor lesion of ESCC is esophageal squamous dysplasia (ESD). We aimed to determine the prevalence of ESD in asymptomatic adult residents of southwestern Kenya. METHODS In this prospective, community-based, cross-sectional study, 305 asymptomatic adult residents completed questionnaires and underwent video endoscopy with Lugol’s iodine chromoendoscopy and mucosal biopsy for detection of ESD. RESULTS Study procedures were well tolerated, and there were no adverse events. The overall prevalence of ESD was 14.4% (95% CI: 10–19%), including 11.5% with low grade dysplasia and 2.9% with high grade dysplasia. The prevalence of ESD was >20% among men older than 50 years and women older than 60 years. Residence location was significantly associated with ESD (Zone A adjusted OR 2.37, 95% CI: 1.06–5.30, and Zone B adjusted OR 2.72, 95% CI: 1.12–6.57, compared to Zone C). Iodine chromoendoscopy with biopsy of unstained lesions was more sensitive than white light endoscopy or random mucosal biopsy for detection of ESD, and had 67% sensitivity and 70% specificity. DISCUSSION ESD is common among asymptomatic residents of southwestern Kenya, and is especially prevalent in persons over 50 years of age and those living in particular local regions. Lugol’s iodine chromoendoscopy is necessary for detection of most ESD but has only moderate sensitivity and specificity in this setting. Screening for ESD is warranted in this high-risk population, and endoscopic screening of Kenyans is feasible, safe, and acceptable, but more accurate and less invasive screening tests are needed.

Traditional and commercial alcohols and esophageal cancer risk in Kenya

“…With regards to alcohol, positive associations with ESCC were found in South Africa, acting synergistically with tobacco, but the latter habit was the larger contributor . Alcohol has also been associated with EC in Zimbabwe and in Kenya with both EC and ESCC's precursor high grade dysplasia . Ecological observations have also been made; notably, McGlashan's 1969 Gut publication drew attention to a specific home distillation of maize husks and sugar, known as kachasu in central Africa, akin to gongo in Tanzania and the aforementioned c hang'aa in Kenya .…”

“…13,[16][17][18][19][20][21] Alcohol has also been associated with EC in Zimbabwe 20 and in Kenya with both EC 4 and ESCC's precursor high grade dysplasia. 22 Ecological observations have also been made; notably, McGlashan's 1969 Gut publication drew attention to a specific home distillation of maize husks and sugar, known as kachasu in central Africa, akin to gongo in Tanzania and the aforementioned chang'aa in Kenya. 23 In this work, he noted that kachasu consumption in eastern Zambia coincided with that region's high EC incidence, whereas EC was apparently absent from northern Zambia where millet beer was consumed.…”

Clinical picture of patients with Barrett’s esophagus and different grades of dysplasia

“…21,22 Surveillance to populations with these risk factors have been widely discussed and the situation is more complicate because HGD can be present in patients with non-Barrett's esophagus, but peptic esophagitis, eosinophilic esophagitis and asymptomatic adult and they would have the same risk to progress to cancer. 23…”

Overexpression of Epidermal Growth Factor Receptor (EGFR) in Esophageal Squamous Cell Carcinoma and Its Correlation with Clinicopathological Characteristics in Central Uganda

“…ESCC develops through accumulation of somatic mutations and epigenetic changes in oncogenes, tumor suppressor genes and cell adhesion molecules [8]. Squamous dysplasia and carcinoma in situ of esophagus has been recognized with increased frequency in regions with high incidence of invasive EC [9].…”