Lung cancer, also called primary bronchogenic carcinoma, is a malignant pulmonary tumor primarily originating from bronchial mucosa and glands, manifested mainly by irritable cough, blood-stained sputum or hemoptysis, chest pain and oppression, shortness of breath, fever, etc. Its incidence is the highest of all tumors in males and takes the second place in females. With an ominous prognosis, it has a very high mortality. Its average survival rate of five years is about 10% after various treatments.

The etiology and mechanism of lung cancer is not completely clear. It is believed that the disease is related to some inherent factors of the body and some environmental factors; and in particular, the lung is the organ exposed to the environment, so environmental factors should not be ignored. It is already known that all the carcinogenic factors can cause lung cancer, for instance, cigarette smoking, air pollution, occupational carcinogenic factors, ionizing radiation, etc. Other factors related to it, to some degree, are immunologic hypofunction, metabolic disorder, endocrine dysfunction and heredity.