We will conduct a pilot for a case-control study of ESCC at Tenwek Hospital, recruiting people that live within 50 km of the hospital. Initial pilot testing showed that neither hospital-visitor controls nor general-population controls were practical control sources. We now plan to test the feasibility of collecting 50 hospital-based non-cancer patient controls. We will then enroll 50 cases and 50 additional hospital-based non-cancer patient controls to test all aspects of our protocol. We will ship the biological samples collected from these individuals to the US and test their suitability for our intended assays. All subjects will be interviewed using a structured questionnaire and will be asked to provide biological samples including blood and urine. Environmental risk factors (including lifestyle, habits, and diet) will be assessed through questionnaires.