Tobacco and other risk factors for esophageal squamous cell carcinoma in Lilongwe Malawi: Results from the Lilongwe esophageal cancer case: Control study

Abstract

Objective Esophageal cancer is the second commonest cancer in Malawi, and 95% of all cases are esophageal squamous cell carcinoma (ESCC). Very little is known about the epidemiology of ESCC in Malawi including risk factors. The main objective of the study was to evaluate and describe risk factors of ESCC in Malawi. Methods We conducted a case-control study from 2017 to 2020 at two hospitals in Lilongwe, Malawi and consenting adults were eligible for inclusion. Endoscopy was conducted on all cases and biopsies were obtained for histological confirmation. Controls were selected from patients or their guardians in orthopedic, dental and ophthalmology wards and they were frequency matched by sex, age, and region of origin to cases. An electronic structured questionnaire was delivered by a trained interviewer. Multivariate conditional logistic regression models were used to assess the associations between subject characteristics, habits, and medical history and risk of ESCC. Results During the study period, 300 cases and 300 controls were enrolled into the study. Median age of cases and controls was 56 years and 62% of the cases were male. Among cases, 30% were ever cigarette smokers as were 22% of controls. Smoking cigarettes had an adjusted odds ratio of 2.4 (95% CI 1.4–4.2 p = 0.003). HIV+ status was present in 11% of cases and 4% controls, which resulted in an adjusted odds ratio was 4.0 (95% CI 1.8–9.0 p = 0.001). Drinking hot tea was associated with an adjusted odd ratio of 2.9 (95% CI 1.3–6.3 p = 0.007). Mold on stored grain has an adjusted odd ratio of 1.6 (95% CI 1.1–2.5 p = 0.021). Conclusion Reducing smoking cigarettes, consumption of scalding hot tea, and consumption of contaminated grain, could potentially help reduce the burden of ESCC in Malawi. Further investigation of the association between HIV status and ESCC are warranted.

The contribution of smoking and smokeless tobacco to oesophageal squamous cell carcinoma risk in the African oesophageal cancer corridor: Results from the ESCCAPE multicentre case‐control studies

“…Previous studies in Malawi found published in 2015 and 2022 an OR of 5.4 (95%CI 2.0‐15.2) and 2.4 (95%CI 1.4‐4.2) for cigarette smoking 21,22 . Two previous studies from Kenya, published in 2013 23 and 2015 24 both showed that tobacco smoking had an increased odds of ESCC risk of 2.5‐fold and 5%, respectively.…”

“…Previous studies in Malawi found published in 2015 and 2022 an OR of 5.4 (95%CI 2.0-15.2) and 2.4 (95%CI 1.4-4.2) for cigarette smoking. 21,22 Two previous studies from Kenya, published in 2013 23 and 2015 24 both showed that tobacco smoking had an increased odds of ESCC risk of 2.5-fold and 5%, respectively. In our study, data from Malawi and Kenya showed that smoking rolled cigarettes had a relatively stronger association to ESCC development, compared to never smokers (Table 3).…”

“…T A B L E 1 ESCCAPE case-control study participants: 1279 cases and 1345 controls. (24) 76 (24) 228 (42) 257 (43) 148 (34) 168 (38) Age (years) a 21 (7) 103 (19) 95 (16) 104 (24) 99 ( 23) Some primary 89 (29) 69 (22) 243 (45) 229 (39) 163 (38) 111 (25) Completed primary 118 (38) 162 ( 52) 67 (12) 82 (14) 85 (20) 91 (21) Secondary or higher 40 (13) 61 (19) 121 (22) 186 (31) 78 ( 18 7) 57 (11) 51 ( 9) 30 (7) 21 (5) Area of residence c Urban 33 (11) 45 (14) 207 (38) 252 ( 43 In Kenya, this variable was only collected in phase II of data collection.…”

Poor oral health and the risk of esophageal squamous cell carcinoma in Malawi

“…We used a structured questionnaire based on a mobile platform and delivered by trained research personnel to measure known or suspected ESCC risk factors, including history of tobacco smoking, alcohol consumption, household solid fuel use for heating, main source of cooking fuel, consumption of moldy grain, consumption of hot tea, socioeconomic status (SES), HIV status, geophagia (eating soil) and history of esophageal cancer among siblings, as described previously. 17 Tobacco smoking was defined as regular use of tobacco in any form at least once a week for a period of 6 months in one's lifetime. We further classified the type of tobacco regularly used as selfrolled cigarettes, shop-bought cigarettes, self-rolled and shop-bought cigarettes or other forms of tobacco.…”

“…14,15 The exact mechanisms of these associations between oral health and ESCC are not understood but are hypothesized to involve the oral microbiome. 16 We conducted a case-control study to examine the etiology of ESCC in Malawi, 17 and here we examined the relationship between poor oral health and ESCC risk in this study population. Oral health was assessed using multiple measures, including the sum of decayed, missing or filled teeth (DMFT score); dental fluorosis; oral mucosa status; lip depigmentation and toothbrushing method and frequency.…”