Basic types and causes of lung cancer

Lung cancer is the most common primary lung malignancy. Most lung cancers originate from the bronchial mucosal epithelium, so it is also called bronchial lung cancer. In the past 50 years, the incidence and mortality of lung cancer have increased rapidly in countries around the world, especially in industrialized countries. Lung cancer has ranked first among male patients who died of cancer.

More than 40 years ago, among patients in China who underwent surgical treatment for lung diseases, the vast majority suffered from tuberculosis, followed by pulmonary suppurative infections such as bronchiectasis and lung abscess, and there were only a few cases of lung cancer.

Basic types of lung cancer

1. Small cell lung cancer: Small cell lung cancer (SCLC) or oat cell carcinoma, nearly 20% of lung cancer patients belong to this type; small cell lung cancer (SCLC) tumor cells have a short doubling time and progress quickly, often accompanied by endocrine abnormalities or carcinoid syndrome; because patients have hematogenous metastasis in the early stage and are sensitive to radiotherapy and chemotherapy, the treatment of small cell lung cancer should be based on systemic chemotherapy, combined with radiotherapy and surgery as the main treatment methods. Comprehensive treatment is the key to the successful treatment of small cell lung cancer.

2. Non-small cell lung cancer: About 80% of lung cancer patients belong to this type. This distinction is quite important because the treatment options for these two types of lung cancer are completely different. Patients with small cell lung cancer are mainly treated with chemotherapy, and surgical treatment does not play a major role in patients with this type of lung cancer. On the other hand, surgical treatment is mainly suitable for patients with non-small cell lung cancer.

The cause of lung cancer is still not completely clear. A large amount of medical data shows that the risk factors of lung cancer include smoking (including second-hand smoke), asbestos, radon, arsenic, ionizing radiation, halogenated olefins, polycyclic aromatic compounds, nickel, etc. The details are as follows:

Causes of lung cancer

1. Smoking: Long-term smoking can cause proliferation of bronchial mucosal epithelial cells, induce squamous cell carcinoma or undifferentiated small cell carcinoma. Although non-smokers can also develop lung cancer, adenocarcinoma is more common. Cigarettes release carcinogens when they burn.

2. Air pollution

3. Occupational factors: Long-term exposure to radioactive substances such as uranium and radium and their derivatives, carcinogenic hydrocarbons, arsenic, chromium, nickel, copper, tin, iron, coal tar, pitch, petroleum, asbestos, mustard gas and other substances can induce lung cancer, mainly squamous cell carcinoma and undifferentiated small cell carcinoma.

4. Chronic lung diseases: such as tuberculosis, silicosis, pneumoconiosis, etc., can coexist with lung cancer. The incidence of cancer in these cases is higher than that of normal people. In addition, chronic inflammation of the lung bronchi and pulmonary fibrosis and scar lesions may cause squamous metaplasia or hyperplasia during the healing process. On this basis, some cases may develop into cancer.

5. Internal factors of the human body: such as family heredity, reduced immune function, metabolic activity, endocrine dysfunction, etc.