Biomarkers of Barrett's esophagus

Table 1 Phases of biomarker production

Phases of biomarker validation and development

Phase 1: Biomarkers of promise are identified based on application in other cancers and elucidation of novel pathways

Phase 2: Cross-sectional studies validate the biomarker of interest to be sufficiently discriminatory and biomarker assays are standardized

Phase 3: Case-control studies with a retrospective but longitudinal design confirm the biomarker is expressed before the development of cancer

Phase 4: Prospective longitudinal studies avoid biases associated with case-control studies

Phase 5: Population-based studies show the impact of biomarker detection on disease burden and cancer control