Lung Flashcards
Epidemiology of lung cancer
Most common invasive malignancies in the United States
The male to female ratio has reached 1:1, compared to the 6:1 ratio in 1960
Lung cancer has surpassed breast cancer in the leading cause of cancer-related deaths in women.
Risk factors for lung cancer
Significant tobacco exposure is defined as more than one pack of cigarettes per day. Occupational exposures: - coal tar - nickel - chromium - arsenic - radon Asbestos has been shown to cause mesothelioma
Anatomy of the trachea
The trachea is the major airway.
The trachea begins at the lower end of the larynx and ends at T5 where it bifurcates (carina)
The wall is composed of rings of cartilage, smooth muscles and connective tissues.
Epithelial cells line the trachea.
Anatomy of primary bronchi
Divides into right and left bronchi at the level of T4/T5 where the trachea bifurcates.
Form branches of decreasing size until finally reaching the microscopic level where the gases are exchanged.
Hilum
Area of the lung where the blood vessels and lymphatics enter and exit the lung.
Two categories of lung cancer
Small cell
Non-small cell
* mesothelioma is distinct although less frequent cetergory
Pathology of non-small cell lung cancer
Non-small cell
- adenocarcinoma
- squamous cell carcinoma
- large cell adenocarcinoma
Most common signs and symptoms of lung cancer
Cough: the initial symptom of lung cancer. Noted in 30-75% of lung cancer.
Dyspnea (shortness of breath): occurs in 20-60% of patients
Chest pain: not a good prognosis due to the extent of the tumour
Hemoptysis: blood in sputum
Hoarseness: usually indicates the mediastinal extension
Weight loss: can be a sign of advanced disease
T1 stage non-small lung cancer
T1a: <2cm does not invade the main bronchus
T1b: >2cm but <3cm does not invade the main bronchus
T2 stage non-small lung cancer
T2a: >3cm but <5cm involves the main bronchus or invades visceral pleura >2cm from carina
T2b: >5cm but <7cm involves the main bronchus or invades visceral pleura >2cm from carina
T3 stage non-small lung cancer
> 3cm invades chest wall, diaphragm, mediastinal pleura or parietal pericardium or tumour in the main bronchus, <2cm from distal carina but without the involvement of carina
N1 stage non-small lung cancer
Positive ipsilateral peribronchial +/- hilar lymph nodes
N2 stage non-small lung cancer
Positive ipsilateral mediastinal +/- subcarinal nodes
N3 stage non-small lung cancer
Positive contralateral mediastinal or hilar nodes or ipsilateral +/- contralateral scalene or superclav nodes.
Small cell lung cancer staging
Limited: confined to hemithorax
Extensive: spread beyond the thorax, mets and pleural effusion