What is lung cancer?
Lung cancer begins in the lungs, the spongy organs in your chest that exchange oxygen and carbon dioxide. It most often starts in the windpipe (trachea), major airways (bronchi), or lung tissue. Lung cancer is the leading cause of cancer deaths worldwide in both men and women.
Types of lung cancer
- Non-Small Cell Lung Cancer (NSCLC): the most common type (about 85%), including adenocarcinoma, squamous cell carcinoma, and large cell carcinoma.
- Small Cell Lung Cancer (SCLC): less common but more aggressive, strongly linked to heavy smoking.
Causes and risk factors
- Smoking: responsible for most cases; risk rises with duration and intensity of smoking.
- Secondhand smoke: non-smokers exposed to tobacco smoke have increased risk.
- Radon gas: a naturally occurring radioactive gas, second leading cause in the U.S.
- Occupational exposures: asbestos, arsenic, chromium, nickel, and other carcinogens.
- Air pollution: long-term exposure to vehicle exhaust and industrial pollutants.
- Genetics: family history of lung cancer increases your risk.
- Previous lung disease: COPD or pulmonary fibrosis raise risk.
- Chest radiation: prior radiation therapy to the chest area.
Symptoms of lung cancer
- A persistent or worsening cough
- Coughing up blood or rust-colored sputum
- Chest pain that worsens with deep breathing, coughing, or laughing
- Shortness of breath or wheezing
- Hoarseness
- Unexplained weight loss and appetite loss
- Fatigue or weakness
- Recurrent bronchitis or pneumonia
Advanced symptoms
- Bone pain (back or hips)
- Neurologic changes (headache, weakness, dizziness, seizures) if spread to brain
- Jaundice if spread to liver
- Swelling of face, neck, or arms
Diagnosis
- Medical history and physical exam, including smoking history and risk exposures
- Chest X-ray to detect masses or nodules
- CT scan for detailed imaging of lung lesions
- PET-CT scan to assess spread to other organs
- MRI for suspected brain or spinal involvement
- Sputum cytology to look for cancer cells in mucus
- Needle biopsy or bronchoscopy to obtain tissue samples
- Thoracentesis to analyze fluid around lungs
- Molecular testing of tumor tissue for genetic mutations
- Blood tests and lung function tests to assess overall health
Treatment options
- Surgery: lobectomy, pneumonectomy, or segmentectomy for early NSCLC
- Radiation therapy: external beam, brachytherapy, or proton therapy
- Chemotherapy: systemic or regional to kill cancer cells
- Targeted therapy: drugs that attack specific genetic mutations (EGFR, ALK, VEGF, etc.)
- Immunotherapy: checkpoint inhibitors to boost immune response (e.g., pembrolizumab, nivolumab)
- Combination therapy: pairing modalities for greater effectiveness
- Palliative care: symptom relief and quality-of-life support
- Clinical trials: access to experimental treatments
Sources
- National Cancer Institute. “Lung Cancer Treatment (PDQ).” Accessed May 28, 2024.
- American Cancer Society. “What Is Lung Cancer?” Accessed May 28, 2024.
- Abeloff’s Clinical Oncology, 6th ed. Elsevier; 2020.
- Burns DM. Cancer. 2000;89(11 Suppl):2506-9. PubMed 11147637.
- National Comprehensive Cancer Network. “Non-Small Cell Lung Cancer” and “Small Cell Lung Cancer.” Accessed May 28, 2024.
- World Health Organization. “Lung Cancer.” Accessed May 28, 2024.