Pathology of Lung cancers Flashcards
(37 cards)
What is the most common cause of death by cancer ?
Lung Cancer
What is the aetiology of lung cancer ?
Tobacco Asbestos Environmental radon Occupational exposures: - chromates - hydrocarbons - nickel Air pollution and urban environment Other radiation Pulmonary fibrosis
How much of lung cancer is attributable to tobacco ?
> 85%
What percentage of smokers get lung cancer ?
10%
What gender is more susceptible to cancer ?
Females
What percentage of non-smoking lung cancers are caused by passive smoking ?
At least 25%
Why does tobacco smoke cause lung cancer ?
Epithelial effects Multi-hit theory in carcinogenesis Host activation of pro-carcinogens - Inherited polymorphisms predispose (metabolism of pro-carcinogens, nicotine addiction)
How does adenocarcinoma arise in the lung ?
Bronchoalveolar epithelial stem cells transform
How does squamous cell carcinoma arise from ?
Bronchial epithelial stem cells transform
Where about do you see adenocarcinoma ?
In the lung periphery
Where about do you see squamous cell carcinoma?
In the central lung airways
Which oncogene is activated by smoking ?
KRAS
What are the other important oncogenes that give rise to lung cancer ?
EGFR BRAF HER2 ALK rearrangements
What are the common tumours of the lung ?
Carcinoid tumours: - <5% of lung neoplasms - low grade malignancy Tumours of bronchial glands: - very rare - adenoid cystic carcinoma - mucoepidermoid carcinoma - benign adenomas Lymphoma Sarcoma Metastases
What are the 4 main types of lung cancer ?
Squamous cell carcinoma
Adenocarcinoma
Small cell carcinoma
Large cell carcinoma
What is an adenocarcinoma in situ ?
Bronchioalveolar cell carcinoma (subtype of adenocarcinoma)
When does primary lung cancer present itself ?
Late in its natural history, grows clinically silent for many years
What does symptomatic lung cancer indicate ?
Fatal
What are the local effects of bronchial obstruction caused by lung cancer ?
Bronchial obstruction:
- collapse - endogenous lipoid pneumonia - infection/ abscess - bronchiectasis
What is endogenous lipoid pneumonia ?
When lipids enter the bronchial tree (the result of localised accumulation of lipid laden macrophages within alveolar spaces distal to an obstructed airway)
What are the local pleural effects caused by lung cancer ?
Inflammation
Malignancy
What are the direct invasions caused by lung cancer ?
Into the chest wall
Nerves
Mediastinum (superior vena cava and pericardium)
Lymph nodes
What are the local effects of cancer on the nerves ?
Phrenic- diaphragmatic paralysis
L recurrent laryngeal- hoarse, Bovine cough
Brachial plexus- Pancoast T1 damage
Cervical sympathetic- Horner’s syndrome
What is the outcome from lymph node metastasis ?
Lymphangitis carcinomatosa