1st April 2022

A 58-year-old male postman, with a 30-pack-year history of smoking, presents to the GP

A 58-year-old male postman, with a 30-pack-year history of smoking, presents to the GP with a 5-week history of a productive cough, which produces bloodstained sputum. He also complains of a 4-month history of progressive difficulty in standing from a seated position and a persistent dry mouth.

On examination, he has proximal muscle weakness. 

Based on the patient history, what is the most likely form of cancer this patient has?