title: [Clinical studies on preoperative irradiation therapy in primary thoracic esophageal cancer].
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D004938:Esophageal Neoplasms / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D004947:Esophagus / Q000473:pathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis