People with the following high-risk factors need to be alert for the development of central lung cancer and should be screened regularly for early lung cancer
Men aged 55 to 80 years.
Smoking index ≥ 400 annual cigarettes (or 20 pack years).
A history of occupational exposure at high risk of lung cancer.
History of malignancy or family history of lung cancer.
History of chronic obstructive pulmonary disease, diffuse pulmonary fibrosis and tuberculosis.