Lung cancer is a type of cancer that occurs when lung cells become abnormal and grow out of control.
There are different types of lung cancer:
- Non-small cell lung cancer is the most common type of lung cancer and accounts for 80% to 85% of cases
- Small cell lung cancer (also called oat cell cancer) accounts for 10% to 15% of cases
Other types of tumors that can form in the lungs include:
- Lung carcinoid tumors, which account for fewer than 5% of lung tumors
- Other lung tumors: adenoid cystic carcinomas, lymphomas, and sarcomas, and benign lung tumors such as hamartomas are rare
The Stages of Lung Cancer
Stage IIIB, IIIC, and all stage IV lung cancers (also called metastatic lung cancer) are advanced stages of lung cancer in which cancer has spread (metastasized) to sites beyond the primary lung cancer tumor.
- Stage IIIB lung cancer is lung cancer that has spread to the lymph nodes above the collarbone or to the lymph nodes on the side of the chest opposite from the primary lung cancer tumor.
- Stage IIIC lung cancer has spread throughout the chest.
- Stage IV lung cancers have spread (metastasized) to other parts of the body outside the lungs, such as the brain, bones, and liver.
Advanced lung cancers may be widespread, especially stage IV cancers, and can be difficult to treat and cure. Treatments may be used to help patients live longer, but they are unlikely to cure the disease at these advanced stages.
What Are Symptoms of Lung Cancer?
Lung cancer may not have symptoms early on. When the first signs and symptoms do occur, they may include:
- Persistent or worsening cough
- Coughing up blood or rust-colored sputum
- Chest pain that may be worse with deep breathing, coughing, or laughing
- Hoarseness
- Loss of appetite
- Unexplained weight loss
- Shortness of breath
- Breathing problems
- Fatigue/tiredness
- Weakness
- Wheezing
- Respiratory infections such as bronchitis and pneumonia that don’t go away or recur
Symptoms of metastatic lung cancer that has spread to other parts of the body may include:
- Bone pain, such as in the back or hips
- Nervous system effects from lung cancer that has metastasized to the brain
- Yellowing of the skin and eyes (jaundice) from cancer spread to the liver
- Swollen lymph nodes such as those in the neck or above the collarbone
What Causes Lung Cancer?
The main cause of all types of lung cancer is smoking, which is responsible for 80% of all lung cancer deaths, as well as a number of deaths from exposure to secondhand smoke. Smokers exposed to radon and asbestos are at higher risk.
In non-smokers, causes of lung cancer include:
- Secondhand smoke
- Exposure to radon
- Air pollution
- Workplace exposure to asbestos, diesel exhaust, or other chemicals
- Genetic changes
How is Lung Cancer Diagnosed?
Symptoms of lung cancer often do not appear until the cancer is advanced and has metastasized. For this reason, The American Cancer Society has lung cancer screening guidelines for people with a higher risk of getting lung cancer, such as smokers.
The American Cancer Society recommends people who are 55 to 74 years old, are in fairly good health, are current smokers or who have quit in the past 15 years, and have smoked a certain number of cigarettes per day should receive regular lung cancer screenings. A test called a low-dose CAT scan or CT scan (LDCT) is typically used.
If lung cancer is suspected, imaging tests may be used to diagnose it, such as:
- Chest X-ray
- Computed tomography (CT) scan
- Magnetic resonance imaging (MRI)
- Positron emission tomography (PET) scan
- Bone scan
Lab tests used to diagnose lung cancer include:
- Sputum cytology
- Thoracentesis
- Tissue biopsy
- Bronchoscopy masses
- Endobronchial ultrasound
- Endoscopic esophageal ultrasound
- Mediastinoscopy and mediastinotomy
- Thoracoscopy
- Lung function tests
- Molecular tests for gene changes
- Tests for certain proteins on tumor cells
- Blood tests
- Complete blood count (CBC)
- Blood chemistry
What Is the Treatment for Lung Cancer?
Advanced lung cancers may be widespread and can be difficult to treat and cure. Any of the treatments listed below may be used to help patients live longer, but they are unlikely to cure the disease at this stage.
Treatment for lung cancer depends on the stage, and may include:
- Surgery
- Removal of the tumor (stage 0)
- Removal of the lobe of the lung that has the tumor (lobectomy) or removal of a smaller piece of the lung (sleeve resection, segmentectomy, or wedge resection) (Stage 1)
- Lobectomy or sleeve resection or removal of the entire lung (pneumonectomy) (Stage 2 and later stages)
- Photodynamic therapy (PDT)
- Laser therapy
- Adjuvant chemotherapy
- Radiation therapy
- Radiofrequency ablation (RFA)
- Lymph node removal
- Chemotherapy
- Immunotherapy with pembrolizumab (Keytruda) or durvalumab (Imfinzi)
- Participation in clinical trials
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https://www.cancercenter.com/cancer-types/lung-cancer/stages