Barrett's esophagus GIST Lauren histotype MALT lymphoma Public health & preventive medicine adjuvant therapy cancer dormancy chemo-radiotherapy clinical pathways complications conversion surgery definitive chemoradiotherapy early adenocarcinoma of esophagus endoscopic mucosal resection endoscopic submucosal dissection esophageal anastomosis esophageal cancer esophageal squamous cell carcinoma esophagectomy failure to rescue gastrectomy gastric cancer gastric surgery gastric/gastroesophageal cancer gastro-esophageal reflux disease gastrointestinal stromal tumor gastrointestinal tract genetic diagnosis genetics imatinib