Lung cancer is a type of cancer that begins in the lungs, the two organs in the chest responsible for taking in oxygen and expelling carbon dioxide. It is one of the leading causes of cancer-related deaths worldwide. There are two main types of lung cancer: non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC), with NSCLC being more common.

Types of Lung Cancer

• Non-Small Cell Lung Cancer (NSCLC): This is the most common type, accounting for about 85% of cases. It includes subtypes such as adenocarcinoma, squamous cell carcinoma, and large cell carcinoma.
• Small Cell Lung Cancer (SCLC): This type is less common but more aggressive, often spreading quickly to other parts of the body.

Causes and Risk Factors
Several factors increase the risk of developing lung cancer, including:

• Smoking: The leading cause, responsible for the majority of lung cancer cases. The risk increases with the number of cigarettes smoked and the length of time spent smoking.
• Secondhand Smoke: Exposure to secondhand smoke also increases the risk of lung cancer.
• Exposure to Radon Gas: Radon is a naturally occurring radioactive gas that can accumulate in homes and increase lung cancer risk.
• Exposure to Asbestos and Other Carcinogens: Occupations involving exposure to asbestos, arsenic, and other chemicals can elevate the risk.
• Family History: A family history of lung cancer can increase risk.
• Personal History of Lung Disease: Conditions like chronic obstructive pulmonary disease (COPD) can raise the risk of lung cancer.
• Air Pollution: Long-term exposure to high levels of air pollution can contribute to lung cancer risk.

Symptoms
Symptoms of lung cancer vary depending on the type and stage of the disease but often include:

• Persistent cough
• Coughing up blood or rust-colored sputum
• Shortness of breath
• Chest pain that worsens with deep breathing, coughing, or laughing
• Hoarseness
• Unexplained weight loss
• Loss of appetite
• Fatigue
• Recurrent infections such as bronchitis or pneumonia
• New onset of wheezing

Diagnosis
Diagnosing lung cancer involves several tests and procedures, including:

• Imaging Tests: Chest X-rays, CT scans, PET scans, and MRI can detect abnormalities in the lungs and assess the spread of cancer.
• Sputum Cytology: Examining sputum under a microscope to check for cancer cells.
• Biopsy: Removing a sample of lung tissue for laboratory analysis to confirm the presence of cancer cells. Methods include bronchoscopy, needle biopsy, or surgical biopsy.
• Molecular Testing: Analyzing cancer cells for specific mutations or markers to guide targeted therapy.

Treatment Options
Treatment for lung cancer depends on the type, stage, and individual patient factors. Options include:

• Surgery: Removing the tumor and surrounding tissue, often used in early-stage NSCLC. Procedures include lobectomy, pneumonectomy, and segmentectomy.
• Radiation Therapy: High-energy rays target and kill cancer cells, used alone or in combination with other treatments.
• Chemotherapy: Drugs that kill cancer cells, often used before surgery to shrink tumors or after to kill remaining cancer cells.
• Targeted Therapy: Drugs that specifically target genetic mutations or proteins in cancer cells, effective in some cases of NSCLC.
• Immunotherapy: Treatments that boost the body’s immune system to recognize and attack cancer cells, particularly effective in advanced lung cancer.
• Radiofrequency Ablation (RFA): Using heat to destroy cancer cells, an option for small tumors.
• Palliative Care: Focuses on relieving symptoms and improving quality of life for patients with advanced cancer.

Prevention and Monitoring
Preventing lung cancer involves reducing risk factors:

• Avoid Smoking: The most effective way to reduce lung cancer risk. Quitting smoking at any age can significantly lower risk.
• Avoid Secondhand Smoke: Limiting exposure to secondhand smoke.
• Test for Radon: Testing homes for radon and taking steps to reduce levels if necessary.
• Protective Measures: Using protective equipment if exposed to hazardous substances at work.
• Healthy Diet and Exercise: Maintaining a healthy lifestyle can help reduce cancer risk.