Lung cancer is the most common malignant tumor in the world, and it is also the most common cancer in China, and the most common cancer among Chinese people is lung cancer. 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 to become a “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 (WHO) in 2008, cancer has become the first direct cause of death of human beings. Among them, lung cancer tops the incidence rate of all cancers, which is about 21.96 per 100,000 people. The situation in China is particularly serious. The results of the data 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 risen significantly by 465%, which has replaced liver cancer as the first cause of death of malignant tumors in China, and the incidence and mortality rates 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 one 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 deaths due to lung cancer in China will be as high as 18 million, which means that one person will die of lung cancer every minute Not only that, but in recent years, lung cancer has also shown a trend of rejuvenation and feminization. In the past, we locked the high-risk group of lung cancer at the age of 65-70 years old or above, and considered it as a kind of “old people’s disease”. But now, some data show that the incidence and death age of lung cancer in China starts to rise rapidly from 40 years old and reaches the peak at 70 years old, among which patients aged 45-65 years old account for 75%, and the age of incidence decreases by one year every five years on average. From clinical observation, lung cancer patients in their forties and fifties nowadays are significantly more common than in the past. Lung cancer patients under 40 years old were rare in the past, but now they are common, and there are more and more non-smoking female lung cancer patients. The reasons leading to the incidence and mortality of lung cancer are mainly related to the changes of people’s living environment and lifestyle, among which the expansion of smoking population and the serious harm of second-hand smoke are the most prominent, and there are also the risk factors such as the aggravation of atmospheric pollution, kitchen pollution and pollution of house decoration materials, etc. Long-term psychological pressure, lack of exercise and other bad lifestyles are also related to it to a certain extent. What are the high-risk cancer-causing factors in life? Smoking has been recognized as the first cancer-causing factor of lung cancer. Currently, the number of smokers in China has exceeded 300 million, and the number of people exposed to second-hand smoke is as high as 740 million. Every year, more than 1 million people die of lung cancer and other smoking-related diseases, of which 80% of male lung cancer and 19.3% of female lung cancer are attributed to smoking. Some data show that the incidence of lung cancer is more than 10 times higher among smokers than non-smokers, and that non-smokers who inhale second-hand smoke (passive smoking) also have an increased risk of developing lung cancer. So how does tobacco attack our lungs? Tobacco produces more than 4,000 new chemicals during the combustion process, which contain a variety of carcinogens, such as polycyclic aromatic hydrocarbons (PAHs) and nitrosamines (Nitrosamines), and phenolic carcinogens. Not only that, but tobacco gradually destroys 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 and prevents them from doing their job properly, leading to a buildup of carcinogens in the lungs that can cause lung cancer. Generally speaking, the more you smoke and the deeper you inhale into your lungs, the greater the 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, as long as they fulfill one of these criteria, they are at high risk of developing lung cancer. The second factor leading to lung cancer is indoor air pollution, including decoration, furniture pollution and cooking fume pollution. Among them, indoor radon pollution is known as 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 building materials and indoor decoration materials. Some building materials such as slag bricks and slag bricks usually contain radium to different degrees, and some indoor decoration materials such as granite, ceramic tiles and sanitary wares contain high levels of uranium, and radon gas will be produced by radon after the decay of radium and uranium. In addition, some patients with chronic lung diseases, such as chronic bronchitis, tuberculosis and pneumonia, have a higher risk of lung cancer than healthy people. There are also people who are often exposed to soot or oil smoke, such as gas, asphalt and coking workers, who have a higher risk of lung cancer than the general population. And the increasingly serious 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 rate of lung cancer are both high, in fact, as Prof. 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 thing to do 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 smoking before the age of 30 can reduce the risk of lung cancer by 90%. For those who quit smoking within 5 years, the chance of dying from lung cancer will be reduced to half of those who smoke 1 pack of cigarettes a day; after quitting smoking for more than 10 years, the chance of dying from lung cancer will be reduced to that of non-smokers. Secondly, use environmentally friendly decoration materials to avoid indoor air pollution; ventilate often at home and wear a mask when going out. Third, minimize exposure to kitchen fumes. Experts found that kitchen fumes have become a threat to our lives and health of the invisible killer. Cooking produced by the high temperature fumes, will produce toxic fumes, resulting in the deterioration of the indoor environment, toxic fumes long-term stimulation of the eyes and throat, will damage the respiratory system cells and tissues, if not protected, the long-term accumulation may lead to lung cancer. Therefore, when frying food must open the hood, keep the kitchen well ventilated, reduce deep-fried, fried food cooking, try to low oil temperature cooking. In addition, scientific and reasonable diet, eating more fresh fruits and vegetables, adhering to appropriate exercise, maintaining a good mood, positive and optimistic attitude towards life, ensuring a regular life, and avoiding overwork can all help us keep lung cancer away. And patients with chronic lung diseases should be diagnosed and treated in time, so as to avoid minor illnesses dragging into major ones. How to detect lung cancer as early as possible? According to some data, if cancer can be detected in early stage in time, the cure rate can reach 65%. 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 have been diagnosed in the middle or late stage, losing the best time for radical treatment. If surgical resection can be performed at the early stage of tumor, the prognosis of lung cancer will be significantly improved. 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 1-2 cm tumor in the lung lobe. Some patients may have symptoms such as prolonged cough, blood in sputum, low-grade fever, chest pain, chest tightness, fever and emaciation during the course of the disease, but they are often easily overlooked. Some patients show joint pain, similar to arthritis, especially wrist and ankle joint pain. If the treatment effect is not improved according to arthritis, the tumor should be considered. Some patients have thickened fingers, which are called pestle fingers, and should also be considered to be at risk of tumors. The most effective way to detect lung cancer as early as possible is physical examination. Screening tools for lung cancer mainly include: X-ray chest radiograph + 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 X-ray. The American Cancer Society’s 2013 updated lung cancer screening guidelines recommend lung cancer screening for people aged 55-74 years, with a smoking history greater than 30 pack-years (pack-years = number of packs smoked per day x number of consecutive years of smoking), and who are current smokers or who 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 detect lung cancer in time; high-risk groups, such as heavy smokers, should have a CT once a year; and if there are early symptoms of lung cancer such as long term incurable cough and blood in sputum, a CT should be done as soon as possible to detect and treat the disease earlier than it would otherwise be. How can lung cancer patients live long and well? Distinguished by the appearance of cancer cells under the microscope, lung cancer can be divided into two major categories: one is small cell lung cancer, which arises from the endocrine cells of the lungs; and the other is non-small cell lung cancer, i.e., 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 strongly associated with smoking, being rare in non-smokers. Non-small cell lung cancer grows more slowly and is much more common, accounting for about 90 percent of lung cancers. Lung cancer patients who have already been diagnosed do not need to be too panic and nervous. Lung cancer is already a common disease and should be treated and controlled with the same mentality as chronic diseases such as diabetes and high blood pressure. With timely and standardized treatment, lung cancer patients can live longer and better. Surgery, radiotherapy, chemotherapy, together with the emerging targeted therapy, constitute the mainstay quartet of cancer treatment in the world at present, and all of them work roughly by taking advantage of the two basic characteristics of cancer cells, one is that most cancers are localized diseases before spreading, and the other is that the growth of the tumor cells is extremely fast, so that the cancer cells can be peeled off, 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, and once a lump is found and diagnosed as lung cancer, it should not be delayed. For middle stage lung cancer patients, comprehensive treatment with radiotherapy and chemotherapy done at the same time is advocated, which can cure some patients. When lung cancer has reached an advanced stage and cannot be cured, the treatment can still help patients prolong their lives and improve the quality of survival. Radiotherapy and chemotherapy can help patients shrink tumors and control symptoms, such as bone pain and airway obstruction. One thing to point out is about tumor markers. Patients undergo imaging and tumor markers during the course of treatment, as well as during regular reviews during the follow-up phase. Not all patients have abnormal tumor markers. The presence of elevated tumor markers prior to treatment, followed by a decrease or return to normal after treatment, can be used adjunctively as an indicator of tumor detection. Persistent elevation of tumor markers should alert to tumor recurrence or progression. However, there is sometimes a longer period of time between the elevation of tumor markers and the clinical finding of tumor recurrence visible on imaging. Moreover, the manner in which the tumor progresses or recurs often varies considerably. For example, there are times when patients present with isolated metastases, at which point they can be well controlled with local management. Therefore, in my clinical practice, when patients present with simple elevation of tumor markers, tumor-specific treatment is mostly not recommended. Lung cancer patients should also maintain a positive and optimistic mindset, enhance the confidence of curing the disease, and strengthen the communication with doctors, all of which can help to improve the therapeutic effect.