The availability, quality, and extent of the epidemiological evidence base for oesophageal cancer in Africa vary greatly; thus, parallel approaches are being pursued:
Descriptive studies: Several studies are being undertaken, including a review of the gender variation in oesophageal cancer incidence rates across Africa, and an update of oesophageal cancer mortality rates in different racial groups of South Africa.
Cross-sectional studies: Population-based community surveys to examine the prevalence and exposure patterns to multiple risk factors, including measurements of hot beverage drinking, alcohol consumption, tobacco use, exposure to polycyclic aromatic hydrocarbons (PAHs), and urinary-based estimates of micronutrient levels and N-nitrosamines.
Case-control studies: In study sites where a case–control study can be undertaken, at minimum a “core” study protocol is being followed, which includes the recruitment of newly diagnosed oesophageal cancer patients and other hospital patients as controls. Controls are frequency-matched on age and sex to the distribution in cases. All consenting cases and controls are asked to complete a face-to-face interview on risk factors using a structured questionnaire. No biospecimens are taken in this core-only protocol. In the full study protocol, i.e. where endoscopy and freezers are available, a blood sample and tumour tissue are also being collected.
Where possible, all data collection is being implemented using real-time mobile-phone-based tailored applications, or on tablets. This serves to ensure efficient and higher-quality data collection through immediate quality-control implementation.