Early diagnosis of lung cancer.
D003581:Cytodiagnosis; D006801:Humans; D008175:Lung Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D010349:Patient Compliance; D011859:Radiography; D012306:Risk; D013183:Sputum / Q000166:cytology