Medically Fit For Exams
Medically Fit For Exams

Lung Cancer


  • Malignant tumour/growth of the lung


Risk factors

  • Smoking and second-hand smoke exposure
  • Occupational exposure – eg asbestos, particulates
  • Family history
  • Exposure to radon
  • Poor diet


Differential diagnoses

  • Asthma
  • COPD
  • Chest infection
  • TB



  • Is the leading cause of cancer deaths in men and women – 1 in 4 cancer deaths are from lung cancer
  • Mortality rates reflect smoking rates – has more than halved since the 70s
  • 10% 5-year survival
  • 5% 10-year survival
  • 1/3 1-year survival
  • 89% of cases are preventable
  • Affects men more than women, although rates in women are increasing relative to men (reflects trends in smoking)
  • Almost half of lung cancer deaths are in the over 75s



  • Damage caused by cigarette smoke and other irritating/toxic particles causes dysplasia and then cancerous changes
  • 86% cases as a result of smoking


Clinical features

  • Cough
  • Haemoptysis
  • Weight loss
  • Fatigue/lethargy
  • Pleural chest pain (worse on laughing or coughing) – if tumour has invaded pleura
  • SOB – if tumour is occluding airway
  • Arm and hand weakness – if tumour has invaded the brachial plexus
  • Horner syndrome – tumour in lung apex, invading/impinging on brachial plexus
    • Shoulder pain
    • Drooping/weakness of one eyelid
    • Smaller pupil
    • Absence of sweating on one side of the face



  • Lung cancer can be split into small cell and non-small cell cancer (which includes large cell cancer)
    • Small cell is so called because cells look small under microscope, and filled with nucleus. Spreads early, poor prognosis. Almost entirely due to smoking.
    • Non small cell is most common (87%) – 3 mains types
      • Adenocarcinoma is most common – cancer of mucus-making cells
      • Squamous cell cancer – in areas with squamous cells – often in bronchii. Almost entirely due to smoking
      • Large cell cancer – large cells under microscope – grows quickly
  • Normal pseudo-stratified cells undergo metaplasia to squamous epithelia
    • Squamous cells are more resistant to irritation caused by smoke, so this is a physiological change
    • Normal metaplasia is reversible, but with sufficient insult can progress to non-reversible dysplasia
    • Histologically abnormal dysplasia is referred to as ‘carcinoma in situ’ (often Stage 0 cancer)
    • Inflammatory mediators are involved in this progression from normal to cancerous cells
  • Spread of lung cancer – all cancer spreads through 2 main mechanisms
    • Lymphatic spread
      • More likely in carcinomas (epithelial cell cancer) such as lung cancer
      • Cancer cells likely to lodge in first node – the sentinel node
      • Can be used to map spread
    • Haematogenous spread
      • More common in sarcomas (connective tissue)
      • Cancer cells secrete enzymes to digest and move through extracellular matrix
      • Intravasation – secrete enzymes to break into capillaries and venules
      • Transport – likely to get stuck in capillary beds
      • Extravasation – cells must be able to exit the blood vessel and return to extracellular matrix
    • Cells must be able to establish themselves at new site
      • Angiogenesis
      • Evade apoptosis
      • Most cells remain dormant or die



  • CXR – after 3 week cough
  • Sputum sample to rule out infective cause
  • CT scan
  • Bronchoscopy
  • Biopsy



  • Radical therapy aims to cure – and is usually surgery
    • Few patients are eligible
      • Must have small cancer, with clear margins
      • Must be fit enough to cope with surgery and resection/loss of lung
      • Especially small cell cancer must be very early stage to consider surgery
    • Chemotherapy and radiotherapy are also used as first line treatments, but are unlikely to be truly radical
  • Palliative treatment can also include surgery, chemotherapy and radiotherapy, but the aim is to reduce symptoms and maybe extend life rather than cure the cancer
    • Small cell carcinoma – may be given prophylactic brain irradiation to prevent brain mets



  • Generally poor – 33% 1 year survival, 10% 5 year survival, 5% 10 year survival
  • Depends on stage and eligibility for surgery
    • Stage 0 and 1A – no spread of cancer
    • Stage 1B – spread to (or origin in) areas such as hilar, pleura, main bronchi
    • Stage 2 – Spread to lymph nodes
    • Stage 3 – Lymph node involvement and spread to surrounding areas
    • Stage 4 – distant metastases
  • Even stage 1 lung cancer only has about 35% 5-year survival
Lung cancer.docx
Microsoft Word document [15.9 KB]

Get social with us.

Print Print | Sitemap