Lung Cancer

Lung Cancer

Lung cancer originates in the lungs, which are situated in the chest. Air travels through the nose, down the windpipe (trachea), and into the lungs, spreading through tubes called bronchi. The majority of lung cancer initiates in the cells lining these tubes.

There are two primary types of lung cancer:

• Non-small cell lung cancer (NSCLC), the most prevalent form.
• Small cell lung cancer, constituting around 20% of all lung cancer cases.

If the cancer comprises both types, it's termed mixed small cell/large cell cancer. When cancer originates elsewhere in the body and spreads to the lungs, it's known as metastatic cancer to the lung.

Causes, Incidence, and Risk Factors

Lung cancer ranks as the most fatal cancer for both men and women, claiming more lives annually than breast, colon, and prostate cancers combined. It's more prevalent among older adults and rare in individuals under 45.

Cigarette smoking stands as the primary cause of lung cancer. The risk increases with the number of cigarettes smoked per day and early initiation of smoking. Smoking low-tar cigarettes doesn't mitigate the risk. However, lung cancer can occur in nonsmokers too.

Secondhand smoke exposure heightens the risk. Around 3,000 nonsmoking adults die yearly from lung cancer attributed to secondhand smoke inhalation, as per the American Cancer Society.

Other risk factors include:

• Exposure to asbestos and cancer-causing chemicals.
• Family history of lung cancer.
• Elevated air pollution levels.
• Arsenic in drinking water.
• Lung radiation therapy.
• Radon gas exposure.

Symptoms

Early lung cancer may be asymptomatic. Symptoms vary based on cancer type and may include:

• Persistent cough.
• Coughing up blood.
• Chest pain.
• Unexplained weight loss.
• Fatigue.
• Loss of appetite.
• Shortness of breath.
• Wheezing.

Late-stage lung cancer may also present with:

• Bone pain.
• Facial swelling or paralysis.
• Hoarseness.
• Joint pain.
• Difficulty swallowing.
• Weakness.

These symptoms could signify other conditions, hence consulting a healthcare provider is vital.

For more information, refer to:

• Non-small cell lung cancer.
• Small cell lung cancer.

Signs and Tests

Lung cancer is often incidentally discovered during X-rays or CT scans. Diagnostic procedures are detailed in the sections on non-small cell and small cell lung cancer.

Treatment

Treatment modalities are elaborated in the sections on non-small cell and small cell lung cancer.