What are the six major causes of lung cancer?

Lung cancer is a disease that seriously threatens people's health and life. Due to its high mortality rate, some people have asked, is lung cancer contagious? No, to be precise, cancer is not contagious. So what causes lung cancer in the body? The relevant information explains it this way.

1. Smoking

At present, smoking is considered to be the most important high-risk factor for lung cancer. There are more than 3,000 chemical substances in tobacco, among which polycyclic aromatic hydrocarbons (such as benzopyrene) and nitrosamines have strong carcinogenic activity. Polycyclic aromatic hydrocarbons and nitrosamines can cause DNA damage in bronchial epithelial cells through various mechanisms, activating oncogenes (such as Ras genes) and inactivating tumor suppressor genes (such as p53, FHIT genes, etc.), thereby causing cell transformation and eventually canceration.

2. Occupational and environmental exposure

Lung cancer is the most important type of occupational cancer. It is estimated that about 10% of lung cancer patients have a history of environmental and occupational exposure. It has been proven that the following 9 occupational environmental carcinogens increase the incidence of lung cancer: byproducts of aluminum products, arsenic, asbestos, bis-chloromethylether, chromium compounds, coke ovens, mustard gas, nickel-containing impurities, and vinyl chloride. Long-term exposure to substances such as beryllium, cadmium, silicon, and formalin will also increase the incidence of lung cancer. Air pollution, especially industrial waste gas, can cause lung cancer.

3. Ionizing radiation

The lungs are organs that are relatively sensitive to radiation. The initial evidence that ionizing radiation causes lung cancer came from the data of the Schneeberg-Joakimov mine, where the concentration of radon and its progeny in the air was high, and most of the cases induced were small cell carcinomas of the bronchus. It has been reported in the United States that 70% to 80% of miners who mined radioactive ores died of occupational lung cancer caused by radiation, mainly squamous cell carcinoma. The time from the beginning of exposure to the onset of the disease was 10 to 45 years, with an average time of 25 years and an average age of onset of 38 years. The incidence rate began to increase when the accumulated dose of radon and its progeny exceeded 120 working level days (WLM), and it increased significantly by 20 to 30 times when it exceeded 1800 WLM. Exposing mice to the gas and dust from these mines can induce lung tumors. The number of lung cancer survivors in the atomic bomb explosion in Japan increased significantly. Beebe found in the lifelong follow-up of the survivors of the Hiroshima atomic bomb explosion that the survivors who were less than 1400m from the explosion center had a significantly higher rate of death from lung cancer than the survivors who were 1400-1900m or more than 2000m away from the explosion center.

4. Previous chronic lung infection

In patients with pulmonary tuberculosis, bronchiectasis, etc., the bronchial epithelium may metaplasia into squamous epithelium and cause cancer during chronic infection, but this is relatively rare.

5. Genetic factors

Familial aggregation, genetic susceptibility, reduced immune function, metabolic and endocrine dysfunction may also be involved.

Many studies have shown that genetic factors may play an important role in the occurrence of lung cancer.

6. Air pollution

The high incidence of lung cancer in developed countries is mainly due to the pollution of the atmosphere by harmful substances such as benzopyrene carcinogenic hydrocarbons produced by the combustion of oil, coal and internal combustion engines and asphalt road dust in industrial and transportation-developed areas. Air pollution and smoking may promote each other and play a synergistic role in the incidence of lung cancer.

The ever-changing technology makes each of us inseparable from electronic products. For example, computers, mobile phones, game consoles, etc. will bring radiation, and even some household appliances. We should use these products appropriately. Especially for children who are addicted to games, they should enhance their awareness in this regard. Staying away from radiation is also a way of prevention.