A 50-year-old woman presents to the clinic with reports of nausea and vomiting for 3 weeks. She states she received treatment with metoclopramide at another clinic 2 weeks ago, but her symptoms have become progressively worse. The patient also reports abdominal pain and early satiety. Her records indicate a 10-pound weight loss since her last visit to the clinic 1 month ago. Physical examination reveals abdominal distention and a succussion splash on abdominal auscultation. Which of the following is a potential underlying cause of the suspected diagnosis? Appendicitis Gastroesophageal reflux disease Pancreatic cancer Ulcerative colitis