Published: 18 Jun 2025

ICD9: 162.9      ICD10: C34.90      ICD11: 2C25

Lung cancer is a type of cancer that begins in the lungs.
It's the leading cause of cancer death worldwide, for both men and women.

Here's a more detailed breakdown:

What it is:

Uncontrolled Cell Growth: Lung cancer is characterized by the uncontrolled growth of abnormal cells in one or both lungs. These cells can form tumors that interfere with lung function.
Spreading (Metastasis): If left untreated, lung cancer can spread (metastasize) to other parts of the body, making it more difficult to treat. Common sites of metastasis include lymph nodes, bones, brain, liver, and adrenal glands.

Types of Lung Cancer:

The two main types are classified based on how the cells look under a microscope:

Non-Small Cell Lung Cancer (NSCLC): This is the most common type, accounting for about 80-85% of all lung cancers. Subtypes of NSCLC include adenocarcinoma, squamous cell carcinoma, and large cell carcinoma.
Small Cell Lung Cancer (SCLC): This type grows and spreads more quickly than NSCLC. It is strongly associated with smoking.

Causes and Risk Factors:

Smoking: By far the leading cause of lung cancer. Both current and former smokers are at risk. The more you smoke and the longer you smoke, the greater your risk. Exposure to secondhand smoke also increases risk.
Radon Gas: A naturally occurring radioactive gas that can seep into homes from the ground. It's the second leading cause of lung cancer.
Asbestos: Exposure to asbestos fibers, often in occupational settings (e.g., construction, shipbuilding), increases risk.
Other Carcinogens: Exposure to certain chemicals and substances, such as arsenic, chromium, nickel, and vinyl chloride, can increase the risk.
Air Pollution: Long-term exposure to high levels of air pollution can contribute to lung cancer risk.
Family History: Having a close relative (parent, sibling, or child) who had lung cancer slightly increases your risk.
Previous Lung Diseases: Conditions like pulmonary fibrosis or chronic obstructive pulmonary disease (COPD) may increase risk.
Previous Radiation Therapy: Radiation therapy to the chest for other cancers can increase the risk later in life.
Age: The risk of lung cancer increases with age.

Symptoms:

Lung cancer often doesn't cause symptoms in its early stages. When symptoms do appear, they can vary but may include:

A persistent cough that worsens or doesn't go away
Coughing up blood (hemoptysis)
Chest pain
Hoarseness
Weight loss without trying
Loss of appetite
Shortness of breath
Wheezing
Frequent lung infections, such as pneumonia or bronchitis
New onset of wheezing

Diagnosis:

Diagnosis typically involves:

Imaging Tests: Chest X-rays and CT scans are often used to detect lung abnormalities. MRI and PET scans may be used to determine if the cancer has spread.
Sputum Cytology: Examining sputum (mucus coughed up from the lungs) under a microscope to look for cancer cells.
Biopsy: Removing a sample of tissue for examination under a microscope. This can be done through bronchoscopy, needle biopsy, or surgery.

Treatment:

Treatment options depend on the type of lung cancer, its stage, and the person's overall health. Common treatments include:

Surgery: Removing the tumor and surrounding tissue.
Radiation Therapy: Using high-energy rays to kill cancer cells.
Chemotherapy: Using drugs to kill cancer cells throughout the body.
Targeted Therapy: Using drugs that specifically target cancer cells with certain genetic mutations.
Immunotherapy: Using drugs to help the body's immune system fight cancer.
Palliative Care: Focusing on relieving symptoms and improving quality of life.

Prevention:

Don't Smoke: The best way to prevent lung cancer.
Avoid Secondhand Smoke: Stay away from places where people smoke.
Test Your Home for Radon: Radon testing is relatively inexpensive. If levels are high, mitigation systems can be installed.
Avoid Exposure to Carcinogens: If you work in an industry with exposure to carcinogens, follow safety guidelines and use protective equipment.
Eat a Healthy Diet: A diet rich in fruits and vegetables may help reduce the risk of lung cancer.
Exercise Regularly: Physical activity may also help reduce the risk.

Prognosis:

The prognosis (outlook) for lung cancer varies widely depending on the stage of the cancer at diagnosis, the type of cancer, and the person's overall health. Early detection and treatment are crucial for improving outcomes.

Important Note: This information is for general knowledge and does not constitute medical advice. If you have concerns about lung cancer, please consult a doctor or other qualified healthcare professional. They can provide personalized advice based on your individual circumstances.