Universal concept dissection

Lung Cancer

Lung cancer happens when cells in the lungs start growing out of control, forming a lump called a tumor. These tumors can make it hard to breathe and can spread to other parts of the body. While smoking is the most common cause, it can also happen to people who have never smoked due to pollution or genetics. Lung cancer is a malignancy arising from the bronchial epithelium or glandular tissue of the lungs. It is broadly categorized into Small Cell Lung Cancer (SCLC), which is aggressive and highly associated with smoking, and Non-Small Cell Lung Cancer (NSCLC), which includes adenocarcinoma and squamous cell carcinoma. Diagnosis typically involves imaging (CT/PET) and histological confirmation via biopsy. Pathogenesis involves the accumulation of somatic mutations in driver genes (e.g., EGFR, KRAS, ALK) leading to dysregulated cell cycle control and evasion of apoptosis. NSCLC is characterized by heterogeneous genomic landscapes, often requiring molecular profiling to determine eligibility for tyrosine kinase inhibitors (TKIs) or immune checkpoint inhibitors (PD-1/PD-L1). SCLC is characterized by neuroendocrine differentiation and rapid doubling time, typically treated with platinum-based chemotherapy. Open questions: How can we overcome acquired resistance to third-generation EGFR inhibitors in NSCLC? | What are the precise epigenetic triggers for lung cancer in lifelong non-smokers? | Can liquid biopsies reliably detect minimal residual disease (MRD) before radiological recurrence? | How does the lung microbiome influence the efficacy of immunotherapy? Timeline: 1890 First documented case of lung cancer | 1950 Link between smoking and lung cancer established | 2004 Approval of first targeted therapy (Gefitinib) | 2015 FDA approval of Pembrolizumab