- Primary lung cancer represents the leading cause of cancer deaths in both males and females, and is the commonest cancer in males.
- Strong association with smoking, exposure to industrial chemicals (e.g. asbestos).
- Age of onset usually>40, but beware aggressive forms in a younger age group.
- Three main subtypes
- Small cell (most aggressive) (SCLC).
- Non-small cell (squamous, large cell and adenocarcinoma) (NSCLC).
- Bronchoalveolar cell carcinoma (BAC).
- Clinical management depends on disease extent (staging) and importantly tumour type.
- May be asymptomatic – identified on routine CXR.
- Any of the following symptoms, cough, SOB, wheeze and/or haemoptysis, raises the possibility of tumour presence.
- Chest pain, dysphagia or a hoarse voice from local extension of the tumour.
- Systemic upset – anorexia, cachexia, clubbing.
- Associated with metastatic spread – headaches, bone pain.
- Associated paraneoplastic syndromes with hormone release (Cushing’s, acromegaly, gynaecomastia).
- CXR – solitary peripheral mass. Central in 40%. The mass can be smooth or irregular in outline and can cavitate. Satellite nodules may be present. There may be hilar, paratracheal and/or mediastinal lymphadenopathy. Direct spread may result in rib destruction and extrathoracic extension. There may be distant rib metastases.
- Other CXR presentations include patchy consolidation that fails to respond to antibiotics (commonly BAC), pleural effusions, bronchoceles and lung collapse, which may be partial or complete (lobar/segmental).
- CT allows characterisation of the mass and full staging of the cancer
- Size and location of the tumour.
- Presence of lymphadenopathy.
- Presence of metastases (bone, adrenals and liver).
- PET/CT – increased uptake of FDG tracer in primary cancer and metastases. Sensitive tool for staging tumours and discriminating ambiguous mass lesions.
Differential diagnosis (solitary pulmonary nodule)
- Neoplasms – lymphoma, carcinoid, hamartoma and solitary metastasis.
- Infective – granuloma, pneumonia or abscess.
- Non-infective – rheumatoid arthritis, sarcoid, Wegener’s.
- Congenital – arteriovenous malformation, pulmonary sequestration.
- Miscellaneous – pulmonary infarct, rounded atelectasis.
- Compare with old films – beware slow-growing squamous cell carcinomas.
- Tissue diagnosis is important – either with bronchoscopy or percutaneous biopsy (>90% sensitivity) of the primary tumour or metastatic deposit.
- Full tumour staging.
- Consideration for surgical resection (potentially curative) and/or chemoradiotherapy.
- Palliative treatment of symptoms (pain and hypercalcaemia).
- Screening has not shown any benefit in the early detection and treatment of lung cancer.