AKT-2480

A 72-year-old man presents to his General Practice Surgery, as he has developed difficulty swallowing. He has a long history of ‘heartburn’, which he manages with over-the-counter antacids. He is a smoker with a 50-pack-year history and drinks around 15 units of alcohol per week. He thinks he has lost 4 kg of weight in the last few months.
Endoscopy reveals a lesion in the lower third of the oesophagus.
What is the most likely diagnosis?