Many patients are asking whether it is not better to have annual screening for the whole population, given that the country is so affluent and the superiority of socialist universal health care insurance must guarantee annual screening for the whole population. In fact, lung cancer screening also has certain hazards, mainly in the following aspects: the false positive rate is extremely high: the detection rate of NLST lung nodules is 24.2%, of which the false positive rate (the proportion of those eventually proved not to be lung cancer) is as high as 96.4%. Suspected patients require follow-up ranging from 2 to 3 years, causing great fear for patients and families and a serious waste of medical resources. According to American economists, the cost of screening a lung cancer patient is as high as $240,000, mainly because of the extremely high cost of the decadent capitalist doctors to see the films and issue reports. The company’s main goal is to provide the best possible service to the public. It is estimated that the associated costs can be reduced to 1%, but it is not known how many years it will last. Overdiagnosis, overtreatment: This is a new concept that is difficult to be accepted by patients and even by some doctors. Simply put, this screening is for lung cancer, but with such low malignancy that its probability of eventual death from the tumor is extremely low, even if no treatment is given. The concept of tumor multiplication time needs to be mentioned here. First of all, we should remember that even the largest tumor develops from a single cell. One tumor cell becomes two, two becomes four, and four becomes eight is three times multiplication. According to statistics, it takes about 22 times for lung cancer to develop from a single cell to a shadow of 1.5mm on CT, 28 times to reach a shadow of 6mm, and about 40 times to develop to a life-threatening tumor of 10cm or more. For example, a 55-year-old patient with a shadow of 5mm has been observed continuously for 3 years without any change, which means that even if the tumor has been multiplying for more than 3 years, the tumor is currently in the 28th multiplication stage and it takes 36 years to develop to the final 40th multiplication stage, and the patient is 91 years old. Currently the average life expectancy of the people in China is about 80 years, which means that the patient is likely to die from other causes. There is no need for aggressive surgical treatment of this tumor; NLST data show an overdiagnosis rate of about 12%, with other reports of up to 80% overdiagnosis in hairy glass lesions. However, there are exceptions to everything. Tumors do not grow at a uniform rate and there is a possibility of explosive growth in a short period of time, and the physician needs to make a judgment based on the actual condition of the patient. Radiation damage of CT: The unit of radiation dose is Sv, and its damage to human body has cumulative effect, it does not mean that if I do CT once, I will be fine if I take a few years off and do it again. A normal person receives 3mSv of basic environmental radiation each year, and 4mSV of radiation from a single low-dose spiral CT, which increases the probability of developing tumors by 0.08%. In other words, for every 1000 residents screened for lung cancer, 1 in 1000 may develop a tumor as a result of this screening. In summary, there is no evidence to encourage or discourage lung cancer screening in non-high risk groups.