Lung cancer is second in terms of cancer incidence and first in terms of cancer death. The study of its risk factors and epidemiologic patterns may aid in describing regional distribution and identifying high-risk demographic groupings. Lung cancer is the second most frequent cancer and the leading cause of cancer mortality worldwide. Lung cancer was responsible or 1.8 million new death cases in 2020,accounting for 18% of all cancer mortality. Lung cancer had a substantially poorer 5-year survival rate (7% -25%) than other major malignancies. Because of its high death rate, the distribution of mortality for lung cancer was extremely comparable to that of its incidence, resulting in a significant worldwide disease burden.
