About This Page
This is a clinician-written, evidence-based summary aligned to the 2026 MLA Content Map. It is intended for medical students and junior doctors preparing for the UKMLA. Always cross-reference with NICE guidance, local protocols, and clinical judgement.
The Bottom Line
- Leading cause of cancer death in the UK — ~48,000 new cases/year; 5-year survival ~15%
- NSCLC (85%): squamous, adenocarcinoma, large cell. SCLC (15%): aggressive, rapid doubling, often metastatic at presentation
- 2-week-wait referral: unexplained haemoptysis, or CXR suggestive of lung cancer
- NICE NG122: contrast-enhanced CT chest (including liver, adrenals, lower neck) → PET-CT if curative intent → tissue biopsy
- Treatment: surgery for early NSCLC (lobectomy), radical radiotherapy, chemotherapy, immunotherapy (pembrolizumab), targeted therapy (EGFR/ALK)
Overview
Lung cancer is classified into non-small-cell lung cancer (NSCLC, ~85%) and small-cell lung cancer (SCLC, ~15%). NSCLC subtypes include adenocarcinoma (most common overall, often peripheral, may occur in non-smokers), squamous cell carcinoma (central, associated with smoking, may cavitate), and large cell carcinoma. SCLC arises from neuroendocrine cells, is strongly associated with smoking, has a rapid doubling time, and is usually disseminated at diagnosis. Paraneoplastic syndromes are common with both types.
Epidemiology
Lung cancer is the third most common cancer and the leading cause of cancer death in the UK, accounting for approximately 21% of all cancer deaths. Around 48,000 new cases are diagnosed annually. Smoking causes approximately 72% of cases. Incidence is declining in men but increasing in women. Other risk factors include occupational carcinogens (asbestos, radon, arsenic), air pollution, and family history. Survival remains poor: overall 5-year survival is approximately 15%, though early-stage disease has much better outcomes (stage I: ~60–80%).
Clinical Features
Symptoms
Persistent cough (>3 weeks) or change in character of chronic cough
Haemoptysis — even a single episode warrants investigation in a smoker
Unexplained weight loss and appetite loss
Breathlessness — may indicate pleural effusion, airway obstruction, or lymphangitis
Chest or shoulder pain — may indicate chest wall invasion or Pancoast tumour
Hoarseness (recurrent laryngeal nerve palsy)
Dysphagia (oesophageal compression)
Bone pain (metastatic disease)
Signs
Finger clubbing — especially with NSCLC
Fixed monophonic wheeze (endobronchial obstruction)
Signs of pleural effusion (stony dull percussion, reduced breath sounds)
SVC obstruction: facial swelling, plethora, distended neck/chest veins, stridor
Horner syndrome (miosis, ptosis, anhidrosis) — Pancoast tumour invading sympathetic chain
Supraclavicular or axillary lymphadenopathy
Hepatomegaly, bony tenderness (metastatic disease)
Investigations
First-line
Chest X-rayOften the first investigation — may show mass, hilar enlargement, pleural effusion, collapse, mediastinal widening
Urgent 2-week-wait referralNICE NG12: unexplained haemoptysis (age ≥40), or CXR findings suggestive of lung cancer
Second-line
Contrast-enhanced CT chest (including liver, adrenals, lower neck)NICE NG122: for all patients with suspected lung cancer — diagnosis and staging
PET-CTFor all patients being considered for treatment with curative intent — assesses mediastinal nodes and distant metastases
Tissue biopsyCT-guided percutaneous biopsy (peripheral lesions), bronchoscopy + biopsy (central lesions), EBUS-TBNA (mediastinal nodes)
Specialist
Molecular testingEGFR, ALK, ROS1, PD-L1 expression — guides targeted therapy and immunotherapy decisions for advanced NSCLC
MRI brainStaging for metastatic disease, especially before curative treatment
Lung function testsAssess fitness for surgery — FEV1 and TLCO predict postoperative risk
1
NSCLC — early stage (I–II)
- Surgical resection: lobectomy is preferred (better oncological outcome than wedge/segmentectomy)
- Adjuvant chemotherapy for stage II and above (cisplatin-based doublet)
- Stereotactic ablative radiotherapy (SABR) for patients unfit for surgery
2
NSCLC — locally advanced (III)
- Concurrent chemoradiotherapy for inoperable stage III
- Durvalumab consolidation after chemoradiation for unresectable stage III (NICE TA578)
- Consider surgery + adjuvant chemo for selected stage IIIA-N2
3
NSCLC — advanced (IV)
- Molecular profiling: EGFR mutation → TKI (osimertinib); ALK rearrangement → TKI (alectinib)
- PD-L1 ≥50%: first-line pembrolizumab monotherapy
- PD-L1 <50%: pembrolizumab + chemotherapy
- Best supportive care for poor performance status (WHO PS ≥3)
4
SCLC
- Limited-stage: concurrent chemoradiotherapy (cisplatin + etoposide) with prophylactic cranial irradiation (PCI)
- Extensive-stage: chemotherapy (cisplatin or carboplatin + etoposide) ± immunotherapy (atezolizumab)
- Very chemosensitive but almost always relapses
5
Palliative care
- Early integration of palliative care for all patients with advanced disease
- Symptom management: breathlessness, pain, cough, SVC obstruction (stenting/radiotherapy)
- Smoking cessation at all stages
Complications
- SVC obstruction: Facial swelling, plethora, distended veins — oncological emergency, treat with stenting/radiotherapy
- Spinal cord compression: Back pain, limb weakness, bladder dysfunction — emergency dexamethasone + urgent MRI
- Paraneoplastic syndromes: SIADH and Lambert-Eaton (SCLC); hypercalcaemia from PTHrP (squamous); HPOA and clubbing (NSCLC)
- Recurrent laryngeal nerve palsy: Hoarse voice from left-sided tumour or mediastinal nodes
- Phrenic nerve palsy: Raised hemidiaphragm
UKMLA Exam Tips
- 1Haemoptysis in a smoker >40 = 2-week-wait referral and urgent CXR
- 2Pancoast tumour = apex of lung + Horner syndrome (miosis, ptosis, anhidrosis) + T1 wasting + shoulder/arm pain
- 3Squamous cell = central, cavitates, PTHrP (hypercalcaemia). Adenocarcinoma = peripheral, non-smokers. SCLC = central, paraneoplastic (SIADH, Lambert-Eaton, Cushing)
- 4SCLC is staged as limited (fits in one radiotherapy field) vs extensive (not limited)
- 5Finger clubbing + hypertrophic pulmonary osteoarthropathy (HPOA) = think lung cancer
- 6PD-L1 expression guides immunotherapy choice in advanced NSCLC
- 7SVC obstruction: pemberton sign = raising arms above head causes facial plethora and JVD
practicetest your knowledge on lung cancerApply what you've learnt with UKMLA-style questions from the iatroX Q-Bank — respiratory and beyond.
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