A 65 year old male, heavy smoker, complains of dysphagia to solids for 2 months duration. At present he can only take fluids. He has quite severe cough when he tries to swallow any food or fluids. He feels this is different to his ‘smokers cough’whichch he has suffered for many years. He has lost about 10kg in weight since the onset of these symptoms. What is the most likely here?