2. AETIOLOGY
Tobacco:
Latent period of 10-30 years
The primary determinants are:
Number of cigarettes consumed
Age of onset of smoking (those under 16 years of age at start
have irreversible damage to their bronchial genetic
makeup
Length of time of smoking
Type of tobacco (cigarettes or pipe, filter or non-filter)
Passive exposure to tobacco smoke
Asbestos exposure
Irradiation
Toxic metals
Certain chemicals
4. Squamous cell carcinoma:
60% of all lung tumors
Associated with smoking and is rare in non-smokers
Squamous metaplasia -> carcinoma in situ -> invasive
carcinoma
5. Adenocarcinoma:
15% of lung tumours
Has a tendency to be more peripheral, arising in the
small bronchial glands
Most common in women
Is the type seen in non-smokers
6. Small cell (oat cell) carcinoma:
20% of lung tumours
Arises from the chromaffin cells
Highly malignant
Hormone production by the tumour is common
A benign form of a small cell carcinoma is a carcinoid
tumour
7. Alveolar cell carcinoma:
5% of lung tumours
Arises in the distal airways
Often diffuse, multifocal and bilateral
Resistant to radio-/chemotherapy
Very poor prognosis
8.
9.
10. TNM STAGING
(T)
T1 - tumor
Diameter of 3 cm or smaller and surrounded by lung
or visceral pleura or
endobronchial tumor distal to the lobar bronchus
11.
12.
13. T2 - tumor
Greater than 3 and smaller than 7 cm
Invasion of the visceral pleura
Atelectasis or obstructive pneumopathy involving less
than the whole lung
Tumor involving the main bronchus 2 cm or more
distal to the carina.
14.
15.
16. T3 - tumor
Tumor with atelectasis or obstructive pneumonitis of the
entire lung
Tumor in the main bronchus within 2 cm of the carina but
not invading it
Tumor of any size with invasion of non-vital structures
such as the chest wall, mediastinal pleura, diaphragm,
pericardium.
Separate tumour nodules in the same lobe as the primary
tumor.
17.
18.
19. T4 - tumor
Invasion of vital mediastinal structures: fat, heart, trachea,
esophagus, great vessels, recurrent laryngeal nerve, carina.
Invasion of vertebral body.
Malignant pleural or pericardial effusion (cytologically
proven).
Separate tumour nodule(s) in a different ipsilateral lobe to
that of the primary tumor.
28. N3 - Nodes
N3-nodes are clearly unresectable.
These are contralateral mediastinal or contralateral
hilar nodes or any scalene or supraclavicular nodes.