Problem: Which one of the following signs would indicate gastrointestinal bleeding above the ligament of Treitz? An older adult patient with a long history of tobacco and alcohol use presents with progressive dysphagia, unintentional weight loss, and a history of heartburn. A barium swallow shows irregular narrowing and mucosal irregularities in the lower esophagus. What is the most likely cause of the patient's progressive dysphagia? An older adult patient with a long history of tobacco and alcohol use presents with progressive dysphagia, unintentional weight loss, and a history of heartburn. A barium swallow shows irregular narrowing and mucosal irregularities in the lower esophagus. What is the most likely cause of the patient's progressive dysphagia?