A 62-year-old obese white man presents with progressive dysphagia to solids over 8 months and weight loss of 6 kg. Upper endoscopy reveals a fungating, ulcerated mass within salmon-pink columnar mucosa in the distal esophagus extending from the gastroesophageal junction, as marked **A** in the diagram. Biopsies confirm adenocarcinoma with intestinal metaplasia and goblet cells in the surrounding mucosa. Which of the following best describes the pathogenic sequence that led to the lesion marked **A**?