Mégraud, F.

pylori cancer patient study helicobacter eradication gastriti metaplasia infection h pylori infection helicobacter pylori infection lesion dysplasia recommendation treatment evidence level serum gastroenterol pepsinogen h pylori h pylori eradication pylori eradication helicobacter pylori grade population atrophy diagnosis aliment pharmacol helicobacter pylori eradication endoscopy biopsy follow-up endoscopic group precancerou factor management gastroenterology result condition porto ulcer trial portugal review development progression strain statement screening carcinoma surveillance therapy system resistance antibody effect society department disease european country premalignant virchow precancerous lesions di mario f classification epithelial dysplasia dinis-ribeiro pathology kuiper testing mucosa cohort choice treatment university /lesion pathol assessment