The high incidence of lung cancer is attributed to environmental factors, occupational exposure, smoking, home cooking, insufficient intake of green vegetables, chronic respiratory diseases and genetic factors, among which smoking remains the most dangerous cancer-causing factor. For the high incidence of lung cancer among non-smoking women in China, experts analyze that air pollution in the city and previous history of lung disease are the reasons why they are not spared. The relationship between lung cancer and smoking is well known: those who have smoked for more than 20 years, those who started smoking before the age of 20, and those who smoke more than 20 cigarettes a day (the so-called “320 group”) are all very vulnerable to lung cancer if they have one. Among the hundreds of millions of smokers in China, the number of female and underage smokers is increasing year by year, which leads to an increase in the incidence of lung cancer among women and young people. It is important to emphasize that heavy smokers are at high risk of lung cancer, with heavy smokers 5.7 times more likely to get lung cancer than non-smokers. Studies to date have concluded that there are 10 main facts about the relationship between smoking and cancer, as follows. (1) 30% of cancers can be attributed to smoking, especially lung, larynx, oral cavity and esophageal cancers, but also bladder, pancreatic and kidney cancers. The most deadly are lung and pancreatic cancers. (2) Long-term smokers have 10 to 20 times higher incidence of lung cancer, 6 to 10 times higher incidence of laryngeal cancer, 2 to 3 times higher incidence of pancreatic cancer, 3 times higher incidence of bladder cancer, 4 to 10 times higher incidence of esophageal cancer, and 1.78 times higher risk of blood cancer than non-smokers. (3) If you smoke more than 25 cigarettes a day, 12% of people will develop lung cancer. (4) Some women who live with smokers are 6 times more likely to develop lung cancer than normal people. (5) Among the 1000 cases of lung cancer patients admitted to Jiangsu Cancer Hospital, 80% were found to be long-term smokers. The risk is more serious for female smokers, and is 1.9 times more likely to have lung cancer than male smokers. (6) A smoking index (number of years smoking x average number of cigarettes smoked per day) over 400 is a red flag. If a man starts smoking at the age of 15 and smokes 1 pack per day, he may get lung cancer before he reaches 35 years old. (7) 90% of lung cancer in most countries around the world is caused by smoking, and 35 out of every 100,000 people in China have lung cancer. The earlier the age of smoking, the higher the incidence and mortality rate of lung cancer. If the mortality rate of lung cancer for nonsmokers is set at 1.00, the mortality rate for those who start smoking under 15 years old is 19.65, 10.08 for those aged 20 to 24 years old, and 4.08 for those aged 25 years or older. (8) The relative risk of cervical and ovarian cancer is higher for women who smoke. The former was 4.4 times higher than non-smokers and the latter was 2.8 times higher. The relative risk of cervical cancer among passive smokers in the family was 2.5 times higher than that of non-passive smokers. (9) Women who have smoked for more than 20 years have a 30% increased risk of breast cancer, and those who have smoked for more than 30 years have a 60% increased risk. Cancer develops 8 years earlier in smokers than in nonsmokers. (10) Smokers undergo beneficial changes after quitting, with lung cancer mortality decreasing or approximating that of nonsmokers over a 5-year period compared to the average smoker (one pack per day). The incidence of oral, respiratory, and esophageal cancers decreases to half the incidence of smokers. within 10 years, precancerous cells are replaced by healthy cells. The incidence of lung cancer drops to roughly the same as that of nonsmokers after 10 years of smoking cessation. The World Health Organization reports that 85-90 percent of all deaths from lung cancer can be attributed to smoking. Globally, nearly 6 million people die each year from smoking and secondhand smoke. There is currently a lack of public awareness of the health risks associated with secondhand smoke. Research has confirmed that living with a smoker for a long period of time increases the probability of developing lung cancer by 25%, and that being forced to smoke secondhand smoke for a long period of time also significantly increases the risk of developing lung cancer. Studies have also found that lung cancer caused by smoking is not sensitive to chemotherapy drugs, and the efficiency of chemotherapy is only 30% to 40%, while it is also not sensitive to molecularly targeted drugs.