In recent years, the incidence and mortality rate of lung cancer in China have shown a significant upward trend, and in urban areas, its incidence and mortality rate has ranked first among all malignant tumors, and for youth lung cancer, its incidence rate is also increasing at a rate of 4.5% per year. Lung cancer mostly occurs in middle-aged and elderly people, and for people under 40 years old, although the incidence rate is low, with the increase of various high-risk factors, its incidence rate also shows a rising trend, and can account for 3.2% to 6.5% of the tumors in the same period. According to studies on young lung cancer patients, the incidence of lung cancer in young women showed a one-time upward trend. Lung cancer mainly occurs in older adults and its incidence increases with age, and is generally considered to be more prevalent in male smokers over 45 years of age. Therefore, the age limit of young lung cancer is tentatively set at below 40 years old. Young lung cancer patients have the following characteristics: high misdiagnosis rate, high morbidity and mortality rate, more female patients; pathological types are mostly adenocarcinoma, mainly progressive cases; low surgical resection rate and poor treatment effect. There are also significant differences in the histological types of lung cancer between the two groups, which is thought to be due to the longer carcinogenesis time of respiratory mucosa cells affected by environmental factors and autoimmune regulatory defects; and the higher susceptibility of small cell hypofractionated carcinoma to cellular carcinogenesis. For elderly patients, they are mostly accompanied by underlying lung diseases, up to 57.14%, and lung cancer in elderly patients is often secondary to various chronic obstructive pulmonary diseases (COPD), which may be related to the following factors: recurrent inflammation of the respiratory tract in COPD patients leads to proliferation and mutation of the bronchial mucosa, followed by carcinogenesis, and up to 83% of COPD patients have a history of smoking, which is currently All these factors contribute to the development of the disease. At the same time, because the early manifestations of lung cancer are easily confused and concealed by the underlying diseases, thus delaying the diagnosis or causing misdiagnosis, it is necessary to pay attention to the changes of the original symptoms of chronic lung diseases in elderly patients, such as blood in sputum, hemoptysis lasting for more than 1 week, hemoptysis that has failed to be treated for more than 1 week, and hemoptysis that has been treated for more than 1 week.
This requires attention to changes in pre-existing symptoms of chronic lung disease in elderly patients, such as blood in the sputum, hemoptysis that has not been treated for more than 1 week, and persistent irritating dry cough. When symptoms that are not consistent with pulmonary disease appear, bronchoscopy and CT should be performed as soon as possible to avoid missed diagnosis and misdiagnosis, delayed treatment, and impact on prognosis. For young patients, the lack of unique typical symptoms often leads to misdiagnosis, and the misdiagnosis rate is as high as 38.7% to 61.5%. The main reasons for misdiagnosis of lung cancer in young people are as follows: 1) lack of awareness and attention to lung cancer; 2) many patients have underlying diseases pneumonia or tuberculosis masking the characteristics of tumor; 3) long-term anti-inflammatory or anti-tuberculosis treatment is found to be ineffective or even the disease progresses and the shadow increases and the best opportunity of diagnosis and treatment is lost. Therefore, it is requested that for young patients, sufficient attention should be paid to the following conditions: unexplained irritating dry cough or change in the nature of cough, repeated persistent chest pain, sputum blood, asymptomatic intractable pleural effusion, poor anti-infective effect of repeated pneumonia at the same site, lung expansion insufficiency, especially isolated lung mass shadow with lobar and burr signs, or extra-pulmonary symptoms such as bone pain and decreased muscle strength. This requires more communication and communication with the clinician or visiting the hospital, where the doctor will combine the patient’s symptoms, signs and auxiliary examination results to make a correct diagnosis and differential diagnosis in order to improve the positive rate of diagnosis. To sum up, compared with young people’s lung cancer, the former has a higher proportion of smoking men and squamous carcinoma, accompanied by a variety of chronic lung complications; while young people have mainly adenocarcinoma, half of which are accompanied by chest pain, with late clinical stage and poor prognosis. For all lung cancer patients, early diagnosis and early treatment is a better way to improve the outcome.