Lung Cancer (pathology) Flashcards
What is a primary carcinoma of the lung?
Cancer of epithelial cells
What is the multi hit theory of carcinogenesis?
- Host activation of pro carcinogens by liver enzymes
- Inherited polymorphisms
What is the periphery pathway for primary carcinoma?
Periphery—> atypical adenomatous hyperplasia—> adenocarcinoma in situ—> invasive adenocarcinoma
What is the central pathway for primary carcinoma?
Central lung airways—> bronchial cell hyperplasia—> squamous dysplasia & carcinoma in situ—> invasive squamous cell carcinoma
What % of lung cancers are caused by small cell carcinoma vs non-small cell carcinoma?
Small cell carcinoma ~15%
Non-small cell carcinoma ~85%
What are the risk factors for lung cancer (9)?
- Tobacco smoking
- passive smoking
- Asbestos
- environmental radon
- other occupational exposure
- air pollution
- Radiation
- Diesel exhaust
- pulmonary fibrosis
How does tobacco smoking cause cancer?
Tobacco smoking – 400 chemical compounds ~ 60 recognised carcinogens
• polycyclic aromatic hydrocarbons= unfiltered products- Central tumour- squamous cell or small cell
• N-nitrosamines = adenocarcinomas (F>M)
Symptoms of lung cancer (9)
- Chronic cough (> 3 weeks)
- Wheeze
- Haemoptysis
- Chest/bone pain (hypertrophic pulmonary osteoarthropathy)
- Difficulty swallowing
- Hoarseness
- SOB
- Unexplained weight loss
- Nail clubbing
Signs of lung cancer (6)
- Clubbing
- Supraclavicular lymphadenopathy
- Horner’s syndrome
- SVC obstruction
- Hepatomegaly
- Skin nodules
What are the local effects of lung cancer?
- Bronchial obstruction (lung collapse, endogenous lipoid pneumonia, infection/abscess, bronchiectasis)
- Pleural
• Inflammation (fibrosis, irritation, effusion)
• Malignant invasion - Chest wall invasion
- lymph node metastasis, distant metastasis
What are the effects on nerves following chest wall invasion of lung cancer
- Phrenic n. (C3-C5)-> diaphragm paralysis
- L recurrent laryngeal n. in left central lung cancer – hoarseness
- Brachial plexus (C5-T1) in Pancoast tumour- apices- hand symptoms
- Cervical sympathetic ganglia – Horner’s syndrome (anhidrosis, ptosis, miosis)
What are the effects on the mediastinum following chest wall invasion of lung cancer
- SVC obstruction- veins in upper limb engorged when raised above heart height- risk of cerebral oedema
- Pericardium
What are the investigations for lung cancer?
ANYONE WITH > 3 WEEKS COUGH: - CXR - cavitation, - effusion, - opacity in hilar LN - Mediastinal shift (away for effusion, towards white for collapse or pneumectomy) - FBC - Renal, liver & Ca2+ - Anaemia - ↑alkaline phosphatase liver/bone mets - Clotting screen - Spirometry - CT - Tissue biopsy - Bronchoscopy/mediastinoscopy - EBUS - CT guided lung/liver biopsy - Fine needle aspirate neck LN/skin - MRI - Vascular/neurological inv. In Pancoast tumour PET (18 FDG)-> upstages 15% Bone scan-> bone mets + chest wall invasion ECHO - Pericardial effusion - Patient fitness
How is a tumour staged?
T= tumour size
N= number of LN involved
M= distant metastasis
Requires CT/PET
Where in the lung is small cell carcinoma located?
Central
