Question category: Gastroenterology
A 57 year old man presents with epigastric pain radiating through to his back. This has been associated with nausea and vomiting and he has had significant weight loss in the past few months. He is known to be a heavy drinker and smoker. On examination there is evidence of epigastric tenderness. An upper GI endoscopy is performed and reveals oesophagitis. What investigation would you organise next?