Lung Cancer – Causes, Symptoms, Diagnosis, & Treatment
What is lung cancer?
Cancer that starts in the lungs is lung cancer. There are two main types of lung cancers. One is non-small cell lung cancer (NSCLC) and the other is small cell lung cancer (SCLC). NSCLC is the most common type of lung cancer that makes up about 80% of all lung cancer cases. SCLC is the less common type of lung cancer, which makes up about 20% of all lung cancer cases. If the lung cancer is made up of both cell types, it is called mixed small cell/large cell cancer. If cancer started in other parts of the body and spreads to the lungs, it is called metastatic cancer to the lung.
Lung cancer is one of the most common and serious types of cancer in both men and women. More people die of lung cancer than of breast, colon, and prostate cancers combined. Lung cancer is more common in older adults. It is rare in people under age 45.
What causes lung cancer?
Cigarette smoking is the leading cause of lung cancer. The more cigarettes you smoke and the earlier you started smoking, the greater your risk of lung cancer.
Lung cancer can also affect people who have never smoked.
Secondhand smoke increases your risk of lung cancer. Secondhand smoke means breathing the smoke of others.
The following factors may also increase the risk of lung cancer:
- The family history of lung cancer.
- Exposure to asbestos.
- Exposure to radon gas.
- Radiation therapy to the lungs.
- Exposure to cancer-causing chemicals such as uranium, beryllium, vinyl chloride, nickel chromates, coal products, mustard gas, chloromethyl ethers, gasoline, and diesel exhaust.
- High air pollution levels in the air.
- High arsenic levels in drinking water.
What are the symptoms of lung cancer?
Early lung cancer may not cause any symptoms. When they occur, symptoms depend on the type and the stage of cancer.
The following are the common symptoms of lung cancer:
- A cough that does not go away
- Coughing up blood
- Shortness of breath
- Chest pain
- Unexplained weight loss
- Loss of appetite
Following are the other symptoms that may occur with advanced stages of lung cancer:
- Swallowing difficulty
- Hoarseness or changing voice
- Swelling of the face or arms
- Facial paralysis
- Eyelid drooping
- Bone pain or tenderness
- Joint pain
- Nail problems
- Shoulder pain
How is lung cancer diagnosed?
Lung cancer is often discovered when an x-ray or CT scan is done for another problem.
If lung cancer is suspected, the doctor will perform a physical exam and review your symptoms, medical history, and smoking history. The doctor will also ask about other things that may have put you at risk of lung cancer, such as exposure to certain chemicals.
If the doctor hears the sound of fluid around the lung during a stethoscope exam, the doctor may suspect lung cancer.
The doctor may order the following tests to diagnose lung cancer and see if it has spread:
- Chest x-ray
- CT scan of the chest
- MRI of the chest
- Bone scan
- Positron emission tomography (PET) scan
- Sputum test to look for cancer cells
- Complete blood count (CBC)
- Thoracentesis (sampling of fluid buildup around the lung)
Most often, a lung biopsy is done to confirm the diagnosis. This is done in one of the following methods:
- Open lung biopsy
- Pleural biopsy
- CT-scan-directed needle biopsy
- Bronchoscopy combined with biopsy
- Endoscopic esophageal ultrasound (EUS) with biopsy
- Mediastinoscopy with biopsy
If the biopsy confirms the diagnosis of cancer, more imaging tests will be done to find out the stage of the cancer. Staging helps to know the size of the tumor and how far it has spread. It also helps determine the mode of treatment.
How is lung cancer treated?
Treatment for lung cancer depends on the type of cancer, its stage, and the health condition of the patient.
Depending on the above factors, treatment may include:
- Surgery is done to remove the tumor if it has not spread beyond nearby lymph nodes.
- Chemotherapy is used to kill cancer cells and stop new cells from growing.
- Radiation therapy is given to destroy cancer cells.
The above treatments may be used alone or in combination depending on the type of lung cancer and its stage.
This feature is for informational purposes only and is not intended to substitute the expert guidance of a doctor. We advise seeing a doctor if you have any health concerns.