Lung Cancer Flashcards
(36 cards)
Identify smoking-related lung diseases.
1) COPD
- Emphysema
- Chronic bronchitis
What is the common link between genetics and smoking in the development of lung disease ?
In cigarette smoking, there are different genetic predispositions to respond to cigarette smoke. Some patients, may activate more quickly leading to more reactive oxygen species, while others may be slow at detoxification (at removing toxic metabolites). Otherwise might be in the middle, better for them.
That’s why not every smoker gets lung disease, also if they do not at the same age
Identify the main kinds of emphysema, from an anatomical POV. Identify their main anatomical features.
Centrilobular Emphysema
Panacinar Emphysema
1) Centrolobular emphysema: If particle is of a big size (i.e. cigarette smoke), tends to get deposited in branching point of bronchioles. Damage therefore typically happens at center of acinus, resulting in enlargement of airspaces because of damage tissue. Area for gas exchange reduced, so less gas exchange so hypoxia.
2) Panacinar emphysema: Permanent destruction of the airspaces (alveoli) distal to the respiratory bronchioles (whole of acinus is damaged). The pathogenesis relates to an intrinsic imbalance in the activity of protease/elastase released and an inhibitor of protease - alpha-1 antitrypsin.
E.g. smoking, get inflammation because smoking, neutrophils release proteases which damage tissue which causes holes (emphysema).
alpha-1 antitrypsin deficinency results in more protease activation so results may be more diffuse.
Explain the delay in seeking medical advice in emphysema patients.
For symptoms to show at rest, requires 60% of lost lung tissue.
Before then, patient tend to adapt their lifestyles (e.g. stop sports or activities which cause symptoms).
As a result, patients tend to only present when symptoms are felt at rest or become a significant obstacle in daily life.
Identify the main clinical features of chronic bronchitis.
- Cough
- Productive sputum (due to increased mucus production, since more mucus glands in bronchi, not due to infection)
- Possible reversible wheeze (hypersensitive muscle, may go into spasm if allergy or infection)
- Irreversible wheeze (due to thicker bronchi)
- Increased susceptibility to infection
- Edema
-Can still expand lungs fully, but takes time (more tissue, more mucus, possible edema)
What are causes of chronic bronchitis ?
- Cigarette smoking mainly
- Industrial exposure and passive cigarette smoking
- E-cigarettes and vaping
Define interstitial lung disease.
Pulmonary disorders characterized by interstitial inflammatory infiltrates, decreased lung volume and decreased oxygen-diffusing capacity on pulmonary function studies.
Identify the main interstitial lung diseases.
- Hypersensitivity pneumonitis (extrinsic allergic alveolitis)
- Sarcoidosis
- Idiopathic Pulmonary Fibrosis
Describe the main features of hypersensitivity pneumonitis (extrinsic allergic alveolitis).
♠ Inhaling antigen, and getting hypersensitivity reaction (type III and type IV)
♠ Extrinsic because antigens come from outside
♠ Acute or chronic interstitial inflammation in the lung
♠ In time, fibrosis and scarring occur, causing restriction to lungs
♠ Common types:
-Bird fancier (allergic to pigeons)
-Farmer’s lung (allergic to dust from moldy hay)
Describe the main features of sarcoidosis. )
- Cell-mediated
- Granulomas are scattered in the interstitium of the lung
- The granulomatous phase of sarcoidosis can progress to a fibrotic phase (hence restriction)
- Hilar lymphadenopathy also occurs
- Raised angiotensin converting enzyme
Is sarcoidosis specific to lungs ?
No, sarcoidosis is a systemic disease but typically presents in lungs
Identify treatment for hypersensitivity pneumonitis and sarcoidosis.
1) Hypersensitivity pneumonitis: get away from allergen
2) Sarcoidosis: Steroids or immunosupressants
Describe the main features of idiopathic pulmonary fibrosis.
- Etiology unknown (possibly partly post-viral)
- Scarring typically in lower lobes (hence restriction)
- Fibrosis is often patchy, with areas of dense scarring and honeycomb cystic change
Is idiopathic pulmonary fibrosis specific to lungs ?
No, systemic disease
What are the main types of tumors clinically ?
Benign
Malignant (primary and secondary)
What are the characteristics of a benign lung tumor which could help you distinguish it from a malignant tumour ? What treatment would be required in such a situation ?
Lack of invasiveness
Clearly defined borders.
Slow growth from old CXR
In that situation, surgical excision
Where can a primary malignant tumour grow in the lung ?
- Epithelium (most common)
- Vessels
- Muscle
- Cartilage
- Lymphoid
- Pleura
What are the characteristics of a malignant lung tumor which could help you distinguish it from a benign tumour ? What treatment would be required in such a situation ?
Not well defined
Invasion pushing and invading lymph nodes
Define metaplasia. How is it relevant in the lung ?
the change in the type of adult cells in a tissue to a form abnormal for that tissue. It is NOT pre-malignant.
In the lung, irritation (e.g. due to smoking) can result in metaplasia, from glandular columnar epithelium into squamous epithelium.
Define dysplasia. How is it relevant in the lung ?
an abnormality of development. It IS pre-malignant.
If metaplasia occurred due to cigarette smoking, and continue to expose epithelium it to carcinogens, squamous epithelium will become dysplasic. Either dysplasia superimposes original glandular (giving you adenocarcinoma) or superimposes squamous (giving you squamous carcinoma, which is likely to be central because airways larger so more likely to get direct trauma).
Identify the main tumours which cause secondary malignant tumours in the lung. How does it reach the lungs ?
- Renal carcinoma: via lymph nodes, and along renal veins
- Osteosarcoma: by blood (not lymph nodes)
What are the main types of primary epithelial malignant tumours ?
- Squamous cell carcinoma (=NSCLC)
- Adenocarcinoma
- Small cell undifferentiated carcinoma
- Carcinoid tumours
Describe the main causes, and features of small cell undifferentiated carcinoma of the lung.
-Causes: smoking, asbestos, air pollution.
From neuro-endocrine stem cells, primitive. May have Paraneoplasticeffects: can produce bioactive amines or peptide such as parathromone (so may present with hyperparathryoidiism, increased Calcium). Can produce ADH, so patient does not pass urine (presenting as high sodium, edema, confusion).
Patients can also present with demyelination due to immune mediated reaction to tumor .
What are different ways of diagnosing a lung cancer ?
- Radiology – size change
- Cytology
- EBUS
- Biopsy
- Circulating DNA (find evidence of particular mutation, typically in EGFR, and non-invasive way to monitor if disease is responding to treatment)
