Endoscopic screening for esophageal squamous-cell carcinoma in high-risk patients: a prospective study conducted in 62 french endoscopy centers - Dubuc, J; Legoux, J -L; Winnock, M; Seyrig, J -A; Barbier, J -P; Barrioz, T; Laugier, R; Boulay, G; Grasset, D; Sautereau, D; Grigoresco, D; Butel, J; Scoazec, J -Y; Ponchon, T; null (Endoscopy, 2006)