31st December 2024

Presentation of lung cancer

Symptoms include cough, haemoptysis, dyspnoea, recurrent chest infection, chest pain, hoarse voice, and symptoms of metastatic disease. Presentation may be delayed, in part as symptoms may be dismissed as side effects or benign complications of smoking.

Two-week-wait referral criteria are outlined in the table below.

The various classical and/or emergency presentations of lung cancer depend on histological type, site within the lung, and disease stage at presentation:

• SCC classically causes hypercalcaemia secondary to parathyroid hormone-related protein (PTHrP) release. Hypercalcemia has a range of clinical manifestations (e.g. constipation, confusion, thirst, depression, renal stones). The typical ECG finding is a shortened QTc (corrected QT interval).
• Both adenocarcinoma and SCC are classically associated with hypertrophic pulmonary osteoarthropathy (HPOA), which manifests as digital clubbing and painful inflammation of the interphalangeal, metacarpophalangeal and metatarsophalangeal joints.
• SCLC may feature ectopic secretion of antidiuretic hormone (ADH) or adrenocorticotropic hormone (ACTH), giving rise to an SIADH (syndrome of inappropriate antidiuretic hormone secretion) or Cushing’s syndrome, respectively. Cushing’s syndrome can be differentiated from other causes of raised cortisol with several investigations. ACTH is raised, and cortisol levels remain high (i.e. are not suppressed) with both the low- and high-dose dexamethasone tests.
• SCLC may be associated with paraneoplastic Lambert Eaton myasthenic syndrome (LEMS), a progressive disease of the neuromuscular junction. It results in muscle weakness that improves with exercise (with proximal lower limb muscles affected first), cranial nerve palsies, autonomic dysfunction (e.g. constipation and dry mouth) and areflexia.  In 60% of patients, there is underlying SCLC, so screening for this is essential. Other less common underlying malignancies include NSCLC, lymphoproliferative disease and prostate cancer.
• Pancoast tumours (of the lung apex) may present with upper limb pain and weakness resulting from invasion of the brachial plexus and with an ipsilateral Horner’s syndrome resulting from compression of the thoracic sympathetic chain.
• Emergency presentations of lung cancer include superior vena cava obstruction (SVCO), of which lung cancer is the commonest cause, and metastatic spinal cord compression, which, if suspected, requires MRI of the whole spine to be performed.