stage 4 oesophagus canceresophageal tumor stagingadenocarcinoma esophagus stage 4esophageal stageesophageal adenocarcinoma stagingesophageal carcinoma stagingesophagus cancer stage 4 prognosisesophagus esophagitisesophagus dysmotilityesophagus specialist near meesophagus inflammation treatmentirritated esophagus