Lung cancer
Also known as: bronchial carcinoma
A malignant tumour arising from the lining of the airways or alveoli, divided into non-small-cell (about 85%) and small-cell types.
Overview
Lung cancer is the leading cause of cancer death because it is usually found late: symptoms appear only when a tumour blocks an airway, invades the chest wall or spreads. Smoking causes about eight in ten cases. Low-dose CT screening of heavy smokers finds tumours early enough to cure.
Causes
- Tobacco smoke
- Radon gas
- Asbestos, diesel exhaust and other occupational carcinogens
- Air pollution
- Family history
Risk factors
- Smoking, including second-hand smoke
- COPD and pulmonary fibrosis
- Previous radiotherapy to the chest
- Age over 60
Symptoms
What a clinician may find
- Finger clubbing
- Hoarse voice
- Enlarged lymph nodes in the neck
- Signs of a pleural effusion or collapsed lobe
- Weight loss
Complications
- Spread to lymph nodes, liver, bones, brain and adrenals
- Airway obstruction and pneumonia
- Superior vena cava obstruction
- Paraneoplastic syndromes
Diagnosis
Chest X-ray then CT of the chest and abdomen; tissue by bronchoscopy or CT-guided biopsy; PET-CT for staging; molecular tests on the tumour to guide targeted therapy.
Treatment
Depends on type and stage: surgery or radical radiotherapy for early non-small-cell cancer; chemotherapy, immunotherapy and targeted drugs (for EGFR, ALK and other mutations) for advanced disease; chemotherapy and radiotherapy for small-cell cancer; palliative care for symptoms throughout.
Prevention
Not smoking is the single most effective measure; radon testing of homes; workplace protection; CT screening for eligible heavy smokers.
When to seek care
See a doctor within days for a cough lasting three weeks, coughing blood, unexplained breathlessness, weight loss or a new hoarse voice, especially if you smoke or have smoked.