Bronchogenic carcinoma — types and management

Definition and epidemiology. Primary malignancy arising from the bronchial epithelium; the commonest cause of cancer death worldwide. The median age at diagnosis is about 70, making it essentially a disease of older adults. Tobacco smoking is the dominant risk factor; in India also important are biomass fuel smoke and indoor air pollution (notably in women who have never smoked), asbestos, radon, arsenic, chromium and scarring from prior pulmonary tuberculosis.

Classification.

Clinical features. Cough, haemoptysis, breathlessness, chest pain, weight loss and recurrent or non-resolving pneumonia. Older adults present late and atypically — with fatigue, anorexia, delirium, falls or functional decline rather than respiratory symptoms, and smoker's cough is often dismissed. Local invasion: hoarseness (recurrent laryngeal nerve), superior vena cava obstruction, Pancoast tumour with Horner's syndrome and T1 root pain, phrenic nerve palsy, dysphagia, pericardial effusion.

Diagnosis and staging. Chest radiograph → contrast CT chest and upper abdomen → tissue diagnosis. Central lesions: bronchoscopy with EBUS-guided transbronchial needle aspiration; peripheral lesions: CT-guided percutaneous biopsy. Stage with PET-CT and MRI brain, using the TNM 9th edition (2024). In NSCLC always test for EGFR, ALK, ROS1, BRAF, KRAS G12C, RET, MET alterations and PD-L1 expression, since these determine treatment. Assess lung function and performance status before any radical treatment.

Management of NSCLC. Stage I–II: surgical resection (lobectomy with lymph node dissection); sublobar resection or stereotactic body radiotherapy (SBRT) for the frail or those with poor lung function — SBRT is a major advance for older patients. Adjuvant chemotherapy for stage II–III; adjuvant osimertinib for resected EGFR-mutant disease. Stage III (unresectable): concurrent chemoradiotherapy followed by consolidation durvalumab. Stage IV: targeted therapy if a driver mutation is present (osimertinib for EGFR, alectinib for ALK), otherwise immunotherapy (pembrolizumab) alone if PD-L1 ≥ 50%, or combined with a platinum doublet.

Management of SCLC and geriatric principles. Limited stage: platinum plus etoposide with concurrent thoracic radiotherapy, and prophylactic cranial irradiation in responders. Extensive stage: platinum–etoposide plus atezolizumab or durvalumab. Treatment decisions must be based on comprehensive geriatric assessment and performance status, not chronological age — but frailty, renal function, hearing (cisplatin ototoxicity), neuropathy and social support guide dose reduction, use of carboplatin instead of cisplatin, or single-agent therapy. Early integrated palliative care improves quality of life and survival. Symptom control: SVC stenting, palliative radiotherapy for haemoptysis and bone pain, opioids for breathlessness, and smoking cessation at any age.

Two 2024 practice-changing trials: ADRIATIC (NEJM 2024) — consolidation durvalumab after concurrent chemoradiotherapy significantly improved overall survival in limited-stage small cell lung cancer, the first major advance in this setting for decades; and LAURA (NEJM 2024) — osimertinib after chemoradiotherapy markedly prolonged progression-free survival in unresectable stage III EGFR-mutant NSCLC. In relapsed SCLC, tarlatamab, a DLL3-targeted bispecific T-cell engager (DeLLphi-301/304), has been approved and improved survival over chemotherapy in the second line.