Non-small cell lung cancer (NSCLC)

Overview Lung cancer is one of the most common malignant tumors in the world and has become the number one cause of death in malignant tumors in urban population in China. Non-small cell lung cancer includes squamous cell carcinoma (squamous cell carcinoma), adenocarcinoma, and large cell carcinoma. Compared with small cell carcinoma, its cancer cells grow slowly and have a relatively slow diffusion and metastasis. Non-small cell lung cancer accounts for about 80% of all lung cancers, and about 75% of patients are already in the advanced stage, and the 5-year survival rate is very low. Causes 1. Smoking is currently considered to be the most important risk factor for lung cancer. There are more than 3,000 chemicals in tobacco, among which multi-chain aromatic hydrocarbons (such as benzopyrene) and nitrosamines have strong carcinogenic activity. . Multi-chain aromatic hydrocarbons and nitrosamines can cause DNA damage in bronchial epithelial cells through various mechanisms, which inactivates oncogenes (such as Ras gene) and tumor suppressor genes (such as p53, FHIT genes, etc.), thereby causing cells. Transform and eventually become cancerous. 2. Occupational and environmental exposure Lung cancer is the most important type of occupational cancer. It is estimated that about 10% of lung cancer patients have a history of environmental and occupational exposure. The following nine occupational environmental carcinogens have been shown to increase the incidence of lung cancer: by-products of aluminum products, arsenic, asbestos, bis-chloromethylether, chromium compounds, coke ovens, mustard gas, nickel-containing impurities, vinyl chloride. Long-term exposure to sputum, cadmium, silicon, formalin and other substances will also increase the incidence of lung cancer, air pollution, especially industrial waste gas can cause lung cancer. 3. Ionizing radiation The lungs are organs that are more sensitive to radiation. The number of people suffering from lung cancer among Japanese atomic bomb survivors has increased significantly. 4. In patients with chronic lung infections such as tuberculosis and bronchiectasis, the bronchial epithelium may become squamous and cause cancer in the process of chronic infection, but it is rare. 5. Genetic factors such as family aggregation, genetic susceptibility and decreased immune function, metabolism, endocrine dysfunction, etc. may also play an important role in the occurrence of lung cancer. Many studies have shown that genetic factors may play an important role in people and/or individuals susceptible to environmental carcinogens. 6. Air pollution The incidence of lung cancer in developed countries is high, mainly due to the pollution of pollutants such as benzopyrene carcinogenic hydrocarbons produced by burning oil and coal and internal combustion engines in the industrial and transportation developed areas. Air pollution and smoking may promote each other's incidence of lung cancer and play a synergistic role. Clinical manifestations 1. Early symptoms (1) Chest pain The symptoms of early chest pain in lung cancer are mild, mainly manifested as dull pain, stuffy pain, not necessarily in the site, and the relationship with breathing is also uncertain. If the pain persists, it means that the cancer has the possibility of involving the pleura. (2) Blood stasis Tumor inflammation caused necrosis, capillary blood vessels will have a small amount of bleeding, often mixed with sputum, intermittent or intermittent appearance. Many lung cancer patients see a doctor because of blood stasis. (3) Low fever After obstructing the bronchus, the obstructive lobes often have different degrees. The mild ones have only low fever, while the severe ones have high fever. After medication, they can temporarily improve, but they will relapse soon. (4) Cough Lung cancer is caused by respiratory irritation and irritating cough due to the growth of bronchopulmonary tissue. 2. Late symptoms Non-small cell lung cancer patients with fatigue, weight loss, loss of appetite, etc., have local symptoms such as difficulty breathing, cough, hemoptysis. Examination 1. X-ray examination X-ray examination can understand the location and size of lung cancer, and may see local emphysema, atelectasis or invasive lesions in the vicinity of the lesion or inflammation of the lungs due to bronchial obstruction. 2. Bronchoscopy can directly observe the lesions of the endobronchial and luminal lumens through bronchoscopy. Tumor tissue can be taken for pathological examination, or bronchial secretions can be taken for cytological examination to confirm the diagnosis and determine the histological type. 3. Cytological examination 痰 cytology is a simple and effective method for the screening and diagnosis of lung cancer. Most patients with primary lung cancer can find shed cancer cells in sputum. The positive rate of sputum cytology in central lung cancer can reach 70% to 90%, and the positive rate of peripheral lung cancer sputum detection is only about 50%. 4. The thoracoscopic exploration of the lung mass after a variety of examinations and short-term diagnostic treatment still failed to determine the nature of the disease, the possibility of lung cancer can not be excluded, should be used for thoracotomy. This avoids delays in the disease and causes lung cancer patients to lose the opportunity for early treatment. 5. ECT examination of ECT bone imaging can be found early in bone metastases. X-ray films and bone imaging have positive findings. For example, if the osteogenesis reaction in the lesion is static and the metabolism is inactive, the bone imaging is negative and the X-ray film is positive. The two complement each other, which can improve the diagnosis rate. It should be noted that the false positive rate of ECT bone imaging for the diagnosis of bone metastasis of lung cancer can reach 20% to 30%. Therefore, the positive ECT bone imaging needs to be the MRI scan of the bone in the positive area. 6. Mediastinoscopy Mediastinoscopy is mainly used in patients with mediastinal lymph node metastasis, not suitable for surgical treatment, and other methods can not obtain pathological diagnosis. Mediastinoscopy should be performed under general anesthesia. A transverse incision was made in the concave part of the sternum, and the soft tissue before the neck was bluntly separated to reach the anterior space of the trachea. The anterior channel of the trachea was bluntly released, and the observation mirror was slowly passed through the innominate artery to observe the paratracheal, tracheobronchial horn and the bulge. The enlarged lymph nodes in the site were dissected by special biopsy forceps to obtain lymph node tissue for pathological examination. Diagnosis of early diagnosis of lung cancer is of great significance. For adults over 40 years old, X-ray examinations are conducted regularly every six months. If you have a long-term cough or blood stasis in middle-aged, you should be vigilant and do a thorough examination. If the chest X-ray shows a shadow of the lungs, you should first consider the possibility of lung cancer. Differential diagnosis of typical lung cancer is easy to identify, but in some cases, lung cancer is easily confused with the following diseases: 1. Tuberculosis Tuberculosis, especially tuberculoma (ball) should be differentiated from peripheral lung cancer. Tuberculoma (ball) is more common in young patients, with a longer course of disease, less blood in the sputum, and tuberculosis in the sputum. The imaging is mostly round, found in the tip or the back of the upper leaf, the volume is small, not more than 5cm in diameter, the boundary is smooth, and the density is uneven and calcification is visible. There are often scattered tuberculosis lesions around the tuberculoma (ball) called satellite foci. Peripheral lung cancer is more common in patients over 40 years old, and blood stasis is more common, and 40% to 50% of cancer cells in the sputum are positive. X-ray chest radiographs are often lobulated, with irregular edges, small burr and pleural shrinkage, and rapid growth. In some cases of chronic tuberculosis, lung cancer can occur on the basis of tuberculosis, and further sputum cytology and bronchoscopy must be performed, and if necessary, thoracotomy should be performed. 2. Pulmonary infection Pulmonary infection is sometimes difficult to distinguish from obstructive pneumonia caused by lung cancer obstruction of the bronchi. However, if pneumonia has multiple episodes in the same site, it should be vigilant. It should be highly suspected to be caused by tumor blockage. Patients should be taken for cytological examination and fiber light-guided vascular examination. In some cases, pulmonary inflammation Absorption, when the remaining inflammation is wrapped by fibrous tissue to form nodules or inflammatory pseudotumors, it is difficult to distinguish from peripheral lung cancer, and thoracoscopic exploration should be performed for suspicious cases. 3. Benign tumors of the lungs Read more...