Lung cancer is the most common malignant tumor in the world and the number one cancer in China, and the most common cancer among Chinese people. Lung cancer not only tops the list of malignant tumors in terms of incidence rate, but also ranks first in terms of mortality rate, and has surpassed liver cancer as the “super killer” among cancers, threatening people’s health invasively. What is the incidence of lung cancer in China? According to the statistics of World Health Organization in 2008, cancer has become the first direct cause of human death. Among them, lung cancer tops the incidence rate of all cancers, which is about 21.96/100,000. The situation in China is particularly serious. The data results provided by the Ministry of Health show that compared with 30 years ago, the incidence rate of lung cancer in China has increased by 26.9% per year and the mortality rate has increased significantly by 465%, which has replaced liver cancer as the first cause of death from malignant tumors in China, and the incidence rate and mortality rate are still continuing to rise rapidly. If effective control measures are not taken in time, it is expected that by 2025, the number of lung cancer patients in China will reach 1 million, becoming the world’s number one lung cancer country. The Harvard School of Public Health even analyzed that in the next 30 years, the number of people dying from lung cancer in China will be as high as 18 million, which means that one person will die from lung cancer every minute. Not only that, in recent years, lung cancer has also shown a trend of being younger and feminized. Previously, the age of people at risk for lung cancer was 65-70 years old or above, and we considered it as an “old people’s disease”. But now, some data show that the age of lung cancer incidence and death in China starts to rise rapidly from 40 years old and reaches a peak at 70 years old, among which patients aged 45-65 years old account for 75%, and the incidence age decreases by one year every five years on average. From clinical observation, there are significantly more lung cancer patients in their 40s and 50s than in the past, and lung cancer patients under 40 years old were rare in the past, but now they are common, and there are more and more female lung cancer patients who do not smoke. The reasons for the increasing incidence and mortality of lung cancer and the trend of youthfulness are mainly related to the changes in people’s living environment and lifestyle, among which the expansion of the smoking population and the serious harm of second-hand smoke are the most prominent, as well as risk factors such as the increase of atmospheric pollution, kitchen pollution and house decoration material pollution, and the poor lifestyle such as long-term psychological stress and lack of exercise are also related to it. What are the high-risk cancer-causing factors in life? Smoking is recognized as the first cancer-causing factor for lung cancer. Currently, the number of smokers in China has exceeded 300 million, and the number of people exposed to secondhand smoke is 740 million. More than 1 million people die each year from smoking-related diseases such as lung cancer, of which 80% of lung cancers in men and 19.3% of lung cancers in women are attributed to smoking. Some data show that the incidence of lung cancer is more than 10 times higher in smokers than in nonsmokers, and that inhaling secondhand smoke (passive smoking) in nonsmokers also increases the risk of lung cancer. So, how does tobacco attack our lungs? Tobacco produces more than 4,000 new chemicals during combustion, including many carcinogens, such as polycyclic aromatic hydrocarbons and nitrosamines, and phenolic carcinogenic substances. Not only that, tobacco will gradually destroy the natural defense system of the lungs. The airways are lined with tiny hairs called cilia, which protect the lungs by blocking toxins, bacteria and viruses. Tobacco smoke paralyzes the cilia, preventing them from “working” properly, which can lead to a buildup of carcinogens in the lungs, causing lung cancer. Generally speaking, the more you smoke, the deeper you inhale into your lungs, the greater your risk of lung cancer. Those who have smoked for more than 20 years, those who started smoking under the age of 20, and those who smoke more than 20 cigarettes a day are at high risk of developing lung cancer if they meet one of these criteria. The second factor that causes lung cancer is indoor air pollution, including decoration, furniture pollution and cooking fumes pollution. Among them, indoor radon pollution is called the “second killer” of lung cancer. Radon gas is listed as the most dangerous indoor carcinogen by the International Agency for Research on Cancer, and its main sources are construction materials and interior decoration materials. Some slag bricks, slag bricks and other construction materials usually contain radium in different degrees, and some granite, tiles, sanitary ware and other interior decoration materials contain high uranium. In addition, some patients with chronic lung diseases, such as chronic bronchitis, tuberculosis and pneumonia, have a higher risk of developing lung cancer than healthy people. There are also people who are often exposed to soot or oil smoke, such as gas, asphalt and coke workers, who also have a higher risk of lung cancer than the general population. The increasing air pollution in cities is also an important factor in inducing lung cancer, which is now receiving more and more attention. How can healthy people prevent lung cancer? Although the mortality rate and incidence of lung cancer are both high, in fact, as Professor Zhi Xiuyi, a famous expert in tobacco control and lung cancer surgery in China, said, lung cancer is one of the most preventable cancers. To stay away from lung cancer, the first step is to stay away from tobacco, not to smoke, and also to avoid second-hand smoke. Quitting smoking as early as possible can greatly reduce the risk of lung cancer. Data show that quitting before the age of 30 can reduce the risk of lung cancer by 90%, and those who quit within 5 years will have half the chance of dying from lung cancer as those who smoke 1 pack of cigarettes a day; after quitting for more than 10 years, the chance of dying from lung cancer drops to the level of non-smokers. Secondly, use environmentally friendly decoration materials to avoid indoor air pollution; ventilate often at home and wear a mask when you go out. Third, to minimize exposure to kitchen fumes. Expert surveys have found that kitchen fumes have become a threat to our lives and health of the invisible killer. High-temperature fumes generated when cooking, will produce toxic fumes, resulting in the deterioration of the indoor environment, toxic fumes long-term irritation of the eyes and throat, will damage the respiratory system cell tissue, if not protected, long-term accumulation may lead to lung cancer. Therefore, you must turn on the range hood when frying, keep the kitchen well ventilated, reduce the cooking of fried and pan-fried foods, and try to cook with low oil temperature. In addition, scientific and reasonable diet, eating more fresh fruits and vegetables, insisting on proper exercise, maintaining good emotion, positive and optimistic life attitude, ensuring a regular life and avoiding overwork can help us keep lung cancer away. Patients with chronic lung diseases should also be promptly diagnosed and treated to avoid small diseases from becoming big ones. How to detect lung cancer as early as possible? Some data show that if cancer can be detected in early stage, the cure rate can reach 65%. However, unfortunately, the 5-year survival rate of lung cancer patients in China is still less than 15%, and more than half of the lung cancer patients are already in the middle and late stages when they are diagnosed, losing the best time for radical treatment. The prognosis of lung cancer will be significantly improved if surgical resection can be performed in the early stage of the tumor. Early detection of lung cancer is particularly difficult because it basically has no special symptoms in the early stage, even if there is already a 1 to 2 cm tumor in the lobe of the lung, there are no obvious symptoms. Some patients will have symptoms such as prolonged cough, blood in sputum, low fever, chest pain, chest tightness, fever and wasting during the course of the disease, but they are often easy to be ignored. Some patients show joint pain, similar to arthritis, especially wrist and ankle joint pain. If the effect of treatment as arthritis does not improve, tumor should be considered. Some patients also have thickened fingers, medically known as pestle fingers, which should also be considered at risk of tumor. To detect lung cancer as early as possible, the most effective way is medical examination. The screening means for lung cancer mainly include: X-ray chest film + sputum cytology; low-dose spiral CT; blood and sputum biomarkers; exhaled gas monitoring and other diagnostic techniques. Among them, low-dose spiral CT examination has become the most commonly used clinical tool for lung cancer screening and early diagnosis, which can improve the detection rate and reduce the mortality rate of lung cancer patients compared with chest radiography. The American Cancer Society’s 2013 updated lung cancer screening guidelines recommend lung cancer screening for people aged 55 to 74 years with a smoking history greater than 30 pack-years (pack-years = number of packs smoked per day × number of years of continuous smoking) who are current smokers or have quit smoking within the past 15 years. Therefore, we suggest that healthy people should have a low-dose spiral CT at the age of 50 to promptly screen for lung cancer; high-risk people such as heavy smokers should have CT once a year; if early symptoms of lung cancer such as long-term incurable cough and blood in sputum occur, CT examination should be done as soon as possible for early detection and treatment than. How can lung cancer patients live a long and good life? Distinguished by the appearance of cancer cells under microscope, lung cancer can be divided into two major categories: one is small cell lung cancer, which arises from endocrine cells of the lung; the other is non-small cell lung cancer, which is all other types of lung cancer except small cell lung cancer. Of these, small cell lung cancer is more aggressive, can spread rapidly to other parts of the body in its early stages, and is closely associated with smoking, which is rare in nonsmokers. Non-small cell lung cancer grows more slowly and is more common, accounting for about 90 percent of lung cancers. Patients who have been diagnosed with lung cancer need not be too panic and nervous, as lung cancer is already a common disease and should be treated and controlled with the same mentality as treating chronic diseases such as diabetes and hypertension. As long as the treatment is timely and standardized, lung cancer patients can live longer and better. Surgery, radiotherapy, chemotherapy, together with the emerging targeted therapy, constitute the current mainstream quadruple carriage for cancer treatment in the world. They all work roughly by taking advantage of two basic characteristics of cancer cells, one is that most cancers are localized diseases before they spread, and the other is that tumor cells grow extremely fast and are stripped, shot or inhibited. In general, treatment is graded according to the severity of the patient’s cancer. For early stage lung cancer patients, surgery is advocated as soon as possible. Once a lump is found and the diagnosis of lung cancer is confirmed, it should not be delayed. For mid-stage lung cancer patients, comprehensive treatment with radiotherapy and chemotherapy done simultaneously is advocated, which can cure some patients. When lung cancer has reached an advanced stage and cannot be cured, treatment can still help patients prolong their lives and improve their quality of life. Radiotherapy and chemotherapy can help patients shrink tumors and control symptoms, such as bone pain and airway obstruction. It is important to point out about tumor markers. Patients are subjected to imaging and tumor markers during the course of treatment, as well as during regular review during the follow-up phase. Not all patients used have abnormal tumor markers. The presence of elevated tumor markers prior to treatment and their decline or return to normal after treatment can be used as an adjunctive indicator to detect tumors. Persistent elevation of tumor markers should be alert to the recurrence or progression of tumor. However, there is sometimes a longer time between the elevation of tumor markers and the clinical finding of imaging visible tumor recurrence. Moreover, the manner of tumor progression or recurrence can often vary widely. For example, there are times when patients present with isolated metastases, when they can be well controlled by local management. Therefore, in my clinical practice, when patients present with elevated tumor markers alone, tumor-specific treatment is mostly not recommended. Patients with lung cancer also need to maintain a positive and optimistic attitude, enhance confidence in curing the disease, and strengthen communication with doctors, all of which can help improve the treatment effect.