A 64-year-old man complains of cough with expectoration consisting of blood-streaked mucus, dyspnea, low grade fever and general fatigue. He has been presenting with these symptoms for 3 months. He has been smoking since early adolescence. Objectively to is 37.4°C, respirations are 26/min., pulse is 82/min., rhythmic, blood pressure is 130/85 mm Hg. The right side of the thorax lags behind in the respiratory process, dull percussion sound and acute decrease of breathing activity are observed there. X-ray shows homogeneous shadow of the lung field on the right with mediastinum displacement towards the affected side. What is the most likely diagnosis?