Traditional and commercial alcohols and esophageal cancer risk in Kenya

Kigen

et al. 2019

Intl Journal of Cancer

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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 March 2018. 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) and 95% 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 included 430 cases and 440 controls. Drinkers of ‘very hot’ and ‘hot’ beverages (>95% tea) had a 3.7 (95% CI: 2.1–6.5) and 1.4‐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 age 50 years. 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.

Section: Participant and Exposure Characteristicsmentioning

confidence: 96%

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

Middleton

Kigen

et al. 2019

Intl Journal of Cancer

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“…Residential location of participants by (a) case and control status, (b) moderate/severe dental fluorosis status, in cases; (c) moderate/severe dental fluorosis status, in controls. 3 Other tooth brushing implement = 7 cases and 2 controls used hand/handkerchief. 4 DMFT = sum of decayed + missing + filled teeth (range 0 = best to 21 = worst in this sample).…”

Section: Principle Findingsmentioning

confidence: 99%

“…The hypothesized etiological model for this African EC corridor involves the presence of an unknown but highly spatially‐patterned factor conveying substantial risk, on top of which lifestyle factors act . In Kenya alcohol contributes to ESCC but to a lesser extent than in western countries . Among other potential contributors, poor oral health has not been examined comprehensively in Africa, but beyond the continent studies have found that different aspects of poor oral health status are associated with increased ESCC risk.…”

Section: Introductionmentioning

confidence: 99%

“…2 In Kenya alcohol contributes to ESCC but to a lesser extent than in western countries. 3 Among other potential contributors, poor oral health has not been examined comprehensively in Africa, but beyond the continent studies have found that different aspects of poor oral health status are associated with increased ESCC risk. In Asia (6 studies [4][5][6][7][8][9] ), the US, 10 a European-Latin American study 11 and in a single small Kenyan study, 12 each study found that at least one of periodontal disease, poor oral hygiene and/or tooth loss and decay were positively associated with ESCC risk.…”

Section: Introductionmentioning

confidence: 99%

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Dental fluorosis and oral health in the African Esophageal Cancer Corridor: Findings from the Kenya ESCCAPE case–control study and a pan‐African perspective

Maina

Kibosia

et al. 2019

Intl Journal of Cancer

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There are no studies of oral health in relation to esophageal cancer in Africa, or of Eastern Africa's endemic dental fluorosis, an irreversible enamel hypo‐mineralization due to early‐life excessive fluoride intake. During 2014–18, we conducted a case–control study of squamous cell esophageal cancer in Eldoret, western Kenya. Odds ratios (AORs (95% confidence intervals)) were adjusted for design factors, tobacco, alcohol, ethnicity, education, oral hygiene and missing/decayed teeth. Esophageal cancer cases (N = 430) had poorer oral health and hygiene than controls (N = 440). Compared to no dental fluorosis, moderate/severe fluorosis, which affected 44% of cases, had a crude OR of 20.8 (11.6, 37.4) and on full adjustment was associated with 9.4‐fold (4.6, 19.1) increased risk, whilst mild fluorosis (43% of cases) had an AOR of 2.3 (1.3, 4.0). The prevalence of oral leukoplakia and tooth loss/decay increased with fluorosis severity, and increased cancer risks associated with moderate/severe fluorosis were particularly strong in individuals with more tooth loss/decay. Using a mswaki stick (AOR = 1.7 (1.0, 2.9)) rather than a commercial tooth brush and infrequent tooth brushing also independently increased risk. Geographic variations showed that areas of high esophageal cancer incidence and those of high groundwater fluoride levels have remarkably similar locations across Eastern Africa. In conclusion, poor oral health in combination with, or as a result of, high‐altitude susceptibility to hydro‐geologically influenced dental fluorosis may underlie the striking co‐location of Africa's esophageal cancer corridor with the Rift Valley. The findings call for heightened research into primary prevention opportunities of this highly fatal but common cancer.

“…We report on fieldwork experience in the pilot phase of an esophageal squamous cell carcinoma casecontrol study in Western Kenya. The study proceeded to the main study which has now recruited over 400 cases and 400 controls (cumulative) and its first results are emerging 10 . The pilot study called for protocol changes and considerations specific to this setting, which are discussed below and from which we make recommendations for fieldwork (R1-R9) in Box 1.…”

Section: Discussionmentioning

confidence: 99%

Cancer epidemiology fieldwork in a resource-limited setting: Experience from the western Kenya ESCCAPE esophageal cancer case-control pilot study

Oduor

Kigen

et al. 2018

Cancer Epidemiology

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Background: Case-control studies remain an important study design for aetiologic research on cancer, particularly when cohorts are not available. In addition to the potential biases inherent in this design, conducting fieldwork in settings with weak health care and information systems for cancer, such as in sub Saharan Africa, confer additional challenges which we present here with the aim to share experience to guide future studies. Methods: We undertook a hospital-based case-control study of squamous cell esophageal cancer at the Moi Teaching and Referral Hospital in Eldoret, West Kenya. Cases were recruited at endoscopy and controls from hospital wards, age and gender frequency-matched to cases. Urine, toenails, blood and tumour biopsy were collected and a questionnaire administered. Results: During this pilot phase, 143 cases and 155 controls were successfully recruited. Complete questionnaire data was obtained through e-data collection. Biospecimen collection was possible with support of an already existing equipped laboratory. We introduce changes made in the main study phase, including on expansion of the control groups to allow to consideration of selection bias. Conclusions: Extra attention and funding to train and monitor data quality and biospecimen collection and reimbursement of a large group held together by strong leadership are essential. We recommend studies based on regional treatment centres with their more defined catchment areas rather than in the capital cities as referral routes in multi-level health care systems are severely attrition prone.