Gastric cancer is one of the major causes of cancer mortality in Zambia, but factors leading to its development have not been fully investigated. The currently established risk factors influence gastric mucosal changes over several years and gastric cancer is therefore expected to manifest among the older age groups. In Zambia, however, it occurs at much younger ages than would be expected, suggesting that there are other unknown factors leading to its development in these young adults. In addition, clinical outcomes are very poor largely due to late presentation, diagnostic delays and limited treatment options. Early detection of gastric cancer requires endoscopic evaluation and biopsies of suspicious lesions. This is not only expensive but requires specialised personnel and it is therefore not feasible to screen whole populations using endoscopy. Identifying and offering endoscopy only to high-risk individuals is a more efficient and feasible strategy. This study will explore dietary, environmental and biological factors that could be used to identify individuals at an increased risk of developing gastric cancer and in need of diagnostic endoscopy. Patients with normal gastric mucosa, non-atrophic and atrophic gastritis, intestinal metaplasia and gastric cancer will be included in the study. Interviewer administered questionnaires and various laboratory techniques will be employed to study the probable risk factors. The study will also look at biomarkers in urine, blood and gastric juice that could be used in low-resource settings for identification of individuals at an increased risk of gastric cancer and/or its premalignant lesions.