Esophageal cancer Quiz: Ace Your Exams

A 63-year-old woman presents to the clinic with a 6-month history of progressive difficulty swallowing, initially with solid foods but now also with liquids. She describes a sensation of food 'sticking' in her throat and pain with swallowing. She has also experienced occasional regurgitation of undigested food, unintentional weight loss (baseline BMI of 20.7), and a persistent dry cough, especially at night. She has a history of H. pylori infection that was treated one year ago and resolved. She has a 30-pack year smoking history and currently smokes a pack a day. She drinks one alcoholic drink every few months when she meets up with friends. Temperature is 36.8°C (98.2°F), heart rate is 76/min, blood pressure is 132/78 mm Hg, and respiratory rate is 14/min. BMI is 19. Oral examination is unremarkable. Neck examination shows no lymphadenopathy. Abdominal examination is significant for mild epigastric tenderness. Endoscopy reveals an esophageal lesion. Which of the following most likely contributed to the development of this patient’s underlying condition?