Lung Cancer: Symptoms, Diagnosis, Treatment, and More

10 min read Posted on 8 Jul 2024

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Lung cancer is one of the most common and severe types of cancer. It involves the uncontrolled growth of abnormal cells in one or both lungs. These abnormal cells do not function like normal lung cells and do not develop into healthy lung tissue. Instead, they form tumors that interfere with the functioning of the lungs, making it difficult to breathe.

This article provides a comprehensive overview of lung cancer, including its types, causes, symptoms, diagnosis, treatment, and prevention strategies.

Types of Lung Cancer

Lung cancer is broadly classified into two main types based on the appearance of the cancer cells under a microscope:

Non-Small Cell Lung Cancer (NSCLC): This is the most common type, accounting for about 85% of cases. NSCLC can be further divided into several subtypes:
1. Adenocarcinoma: Often found in the outer regions of the lungs, this type is most common among non-smokers.
2. Squamous Cell Carcinoma: Typically located in the central part of the lungs near a bronchus.
3. Large Cell Carcinoma: Can appear in any part of the lung and tends to grow and spread quickly.
Small Cell Lung Cancer (SCLC): This type accounts for about 15% of lung cancers and is more aggressive, spreading more quickly than NSCLC. It is strongly associated with smoking.

Causes and Risk Factors

Causes

The primary cause of lung cancer is smoking, which is responsible for about 85% of cases. However, lung cancer can also occur in non-smokers due to other factors such as exposure to secondhand smoke, radon gas, asbestos, and other carcinogens. Genetic predisposition also plays a role.

Risk Factors

Smoking: The most significant risk factors include both active smoking and exposure to secondhand smoke.
Radon Exposure: A naturally occurring radioactive gas that can accumulate in homes.
Asbestos Exposure: Often found in older buildings and specific work environments.
Air Pollution: Long-term exposure to polluted air can increase the risk.
Family History: Having a close relative with lung cancer increases the risk.
Previous Lung Disease: Conditions like chronic obstructive pulmonary disease (COPD) and pulmonary fibrosis can increase the risk.

Symptoms of Lung Cancer

Lung cancer symptoms often do not appear until the disease is advanced, but they can include:

Persistent Cough: A cough that does not go away or worsens over time.
Chest Pain: Pain that is often worse with deep breathing, coughing, or laughing.
Shortness of Breath: Difficulty breathing or wheezing.
Coughing Up Blood: Even a small amount of blood in the sputum can be a sign.
Hoarseness: Changes in the voice or a hoarse voice.
Weight Loss and Loss of Appetite: Unintentional weight loss and reduced appetite.
Fatigue: Persistent tiredness or weakness.
Infections: Frequent lung infections such as bronchitis or pneumonia.

Diagnosis of Lung Cancer

Diagnosing lung cancer involves several steps and tests:

Medical History and Physical Examination: Initial assessment by a healthcare provider.
Imaging Tests:
- Chest X-ray: Often the first imaging test to identify lung abnormalities.
- CT Scan: Provides more detailed images of the lung and surrounding structures.
- PET Scan: Helps determine if cancer has spread.
Sputum Cytology: Examination of mucus coughed up from the lungs.
Biopsy: Removing a small sample of lung tissue for examination. This can be done through:
- Bronchoscopy: A thin tube is passed through the throat into the lungs.
- Needle Biopsy: A needle is inserted through the chest wall to remove tissue.
- Surgical Biopsy: Involves removing a larger piece of tissue through surgery.

Staging of Lung Cancer

Staging describes how much cancer has spread and helps guide treatment options. The stages range from I (localized cancer) to IV (cancer that has spread to other parts of the body).

Stage I: Cancer is confined to the lung.
Stage II: Cancer has spread to nearby lymph nodes.
Stage III: Cancer has spread to further lymph nodes and other parts of the chest.
Stage IV: Cancer has spread to other organs.

Treatment of Lung Cancer

Treatment options for lung cancer depend on the type, stage, and overall health of the patient. Common treatments include:

Surgery: Removing the tumour and some surrounding healthy tissue. Types of surgery include:
- Lobectomy: Removal of an entire lobe of the lung.
- Pneumonectomy: Removal of an entire lung.
- Segmentectomy or Wedge Resection: Removal of part of a lobe.
Radiation Therapy: Using high-energy rays to kill cancer cells. It can be used alone or in combination with other treatments.
Chemotherapy: Using drugs to kill cancer cells. It can be administered orally or intravenously and is often combined with other treatments.
Targeted Therapy: Drugs that specifically target cancer cells with specific genetic mutations. These therapies are less likely to harm normal cells.
Immunotherapy: Using the body’s immune system to fight cancer. It can be used for advanced lung cancer and includes drugs like checkpoint inhibitors.
Palliative Care: Focuses on relieving symptoms and improving the quality of life for patients with advanced cancer.

Prevention of Lung Cancer

While not all cases of lung cancer can be prevented, certain measures can significantly reduce the risk:

Quit Smoking: The most effective way to reduce the risk. Resources and support are available to help quit smoking.
Avoid Secondhand Smoke: Stay away from environments where people smoke.
Test for Radon: Especially in homes where radon is known to be an issue.
Protect Against Occupational Hazards: Follow safety guidelines to avoid exposure to harmful substances.
Healthy Diet and Exercise: A balanced diet and regular physical activity can improve overall health and reduce cancer risk.
Regular Screening: For high-risk individuals, such as smokers and those with a family history of lung cancer, regular screening with low-dose CT scans can help detect cancer early.

Conclusion

Lung cancer is a severe disease with significant health implications, but understanding its types, causes, symptoms, and treatment options can help manage and potentially prevent the condition. Early detection through screening and a healthy lifestyle can improve outcomes. Advances in treatment are offering new hope and improved quality of life for those diagnosed with lung cancer. If you are at risk or experiencing symptoms, consult a healthcare provider for appropriate evaluation and management.