<prompt> Answer this question truthfullyWhat is the confirmatory diagnostic method for esophageal cancer following a barium swallow?  <response>: <reason> The confirmatory diagnostic method for esophageal cancer following a barium swallow is an esophagogastroduodenoscopy EGD with biopsy. This procedure involves passing a flexible tube with a camera through the mouth and into the esophagus to obtain a tissue sample for biopsy. 