Lung cancer is the most often diagnosed and deadly cancer in the world (2.2M cases, 1.8M deaths in 2020).
Histologic Classifications
• NSCLC (85% of cases): Adenocarcinoma (alveoli mucus cells), Squamous Cell Carcinoma (epidermoid bronchial lining), Adenosquamous, Sarcomatoid.
• SCLC (15% of cases): Small cell carcinoma (oat cell) and combined small cell carcinoma; fast-growing, strongly linked to tobacco.
Detailed Stage Groupings (Stage 0 to IVB)
• Stage 0: Carcinoma in situ (TisN0M0).
• Stage IA1-IA3 & IB: Tumors 1-4 cm without nodal spread.
• Stage IIA-IIB: Tumors 4-7 cm or ipsilateral hilar nodes (N1).
• Stage IIIA-IIIC: Mediastinal nodes (N2/N3) or chest wall/diaphragm invasion.
• Stage IVA-IVB: Malignant pleural effusion or distant metastasis to brain, bones, liver.
Symptoms & Advanced Therapies
Symptoms: Chronic worsening cough, hemoptysis (coughing blood), dyspnea, wheezing, hoarseness, pleural effusion.
Treatment: Surgical Lobectomy, SBRT radiation, Chemotherapy, Targeted therapy (EGFR/ALK), Immunotherapy (pembrolizumab).
Prevention: No smoking, avoid secondhand smoke, test home for radon, wear workplace protection masks.