Lung Cancer

Lung cancer is the most common cause of cancer-related death worldwide, characterized by uncontrolled growth of cells in the lungs that can form tumors and spread to other body parts. It predominantly affects men more than women and is strongly linked to smoking, which accounts for 80–90% of cases, although non-smokers can also develop the disease. The two main types are non-small cell lung cancer (NSCLC), including adenocarcinoma, squamous cell carcinoma, and large cell carcinoma, and small cell lung cancer (SCLC), which tends to grow and spread rapidly. Risk factors include exposure to tobacco smoke, radon gas, asbestos, and other carcinogens. Early-stage lung cancer often presents no symptoms, but later signs may include persistent cough, coughing up blood, shortness of breath, chest pain, and unexplained weight loss. Diagnosis relies on imaging techniques such as X-rays, CT scans, and PET scans, along with biopsy confirmation. Treatment options vary by stage and type and typically involve surgery, chemotherapy, radiation therapy, or targeted therapies. Prognosis remains poor overall, especially for advanced or late-diagnosed cases, underscoring the importance of early detection through screening. Genetic factors such as mutations in the BRAF gene and involvement of pathways like innate immunity and infectious disease contribute to its pathogenesis. Lung cancer has significant geographical variation in mortality, largely reflecting differences in smoking prevalence, and continues to be a major focus of research, clinical trials, and public health efforts.
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