Types of lung cancer
The type of tumor is determined only by examining the tissue under a microscope, and treatment tactics depend on it. There are two large groups. Non-small cell cancer is more common and grows relatively slower; it includes adenocarcinoma, squamous cell and large cell carcinoma. Small cell cancer is almost always associated with smoking, grows quickly and metastasizes early. In non-small cell cancer, molecular research is important: in some patients, mutations are found against which targeted drugs exist. The stage is determined by the size of the tumor, damage to the lymph nodes and the presence of distant metastases.
- Adenocarcinoma is the most common type, including in non-smokers
- Squamous cell carcinoma - most often central, in smokers
- Large cell carcinoma
- Small cell carcinoma—rapid growth and early spread
- Central cancer - in large bronchi, peripheral - in lung tissue
Causes and risk factors
Most cases of lung cancer are associated with tobacco smoke: carcinogens damage the DNA of bronchial cells, and mutations accumulate over the years. The risk increases with the number of cigarettes smoked and smoking experience, but gradually decreases after quitting. Other types of smoking, including hookah, are also dangerous; The safety of e-cigarettes has not been proven. Lung cancer also occurs in non-smokers: the causes may be passive smoking, indoor radon, polluted air, occupational hazards and heredity. Chronic lung disease with scarring also increases the risk.
- Smoking, including hookah, and a long history of smoking in the past
- Passive smoking
- Radon, asbestos, arsenic, chromium, nickel in production
- Polluted air and smoke from burning fuel indoors
- Radiation therapy to the chest in the past
- Lung cancer in close relatives
- COPD and pulmonary fibrosis
Symptoms
Early lung cancer usually has no symptoms and is discovered by chance on a CT scan. Symptoms appear when the tumor narrows the bronchus, grows into neighboring tissues, or metastasizes. A new cough or a change in the habitual cough of a smoker, streaks of blood in the sputum, repeated pneumonia in the same area of the lung should alert you. A tumor of the apex of the lung may cause pain in the shoulder and arm, drooping of the eyelid, and constriction of the pupil on one side. When it spreads, bone pain, headache, weakness and weight loss occur.
- Persistent cough or change in its character
- Hemoptysis
- Shortness of breath and wheezing
- Chest pain
- Hoarseness of voice
- Repeated pneumonia
- Weakness, weight loss, loss of appetite
Diagnostics and screening
Plain X-rays may not show a small tumor, so the main method is a chest CT scan, often with contrast. Low-dose CT is used for screening in people without symptoms: it is discussed with a doctor by smokers and former smokers aged 50–80 years with a long smoking history. If a suspicious lesion is detected, a biopsy is performed - through a bronchoscope, with a needle under CT control, or during surgery. The resulting tissue is examined histologically and for molecular markers. The prevalence of the process is assessed using PET-CT, MRI of the brain and other studies.
- CT scan of the chest, including with contrast
- Low-dose CT - for screening
- Bronchoscopy with biopsy
- CT-guided transthoracic biopsy
- Histological, immunohistochemical and molecular examination
- PET-CT and MRI of the brain for staging
- Spirometry before surgery
Treatment and prevention
Treatment is planned by a team of specialists: oncologist, thoracic surgeon, radiotherapist. In the early stages of non-small cell cancer, the main treatment is to remove part of the lung, sometimes followed by chemotherapy. If surgery is not possible, stereotactic radiation therapy is used. For locally advanced forms, chemotherapy and radiation are combined, for metastatic forms, targeted drugs, immunotherapy and chemotherapy are taken into account, taking into account the molecular profile of the tumor. Small cell cancer is treated primarily with chemotherapy and radiation. The best prevention is quitting smoking at any age and protecting yourself from passive smoking.
- Surgical removal of a lobe or segment of the lung
- Stereotactic and conformal radiotherapy
- Chemotherapy
- Targeted therapy for identified mutations
- Immunotherapy
- Supportive and palliative care
- Smoking cessation and protection from secondhand smoke