Lung Cancer (AAG) Flashcards
How common is lung cancer worldwide, compared to other cases?
Most common cancer worldwide
How common is lung cancer in the UK compared to other cancers?
Second most common cancer
What % of cases of lung cancer are in people over 65?
87%
At what age is the highest incidence of lung cancer?
Between 80 and 84 years
What demographic shift has occurred with lung cancer?
The incidence and mortality rates are falling in males and rising in females
How does mortality from lung cancer compare to other cancers?
It is the biggest cause of cancer deaths in the UK and USA
What is the most significant risk factor for lung cancer?
Smoking, including passive smoking
What % of cases of lung cancer are associated with smoking?
80-90%
What is the risk of lung cancer from smoking proportional to?
- The person’s pack years
- Age they started smoking
- Type of cigarettes smoked
How is pack years calculated?
Packs smoked per day x years smoked
What are the other risk factors for lung cancer?
- Previous radiotherapy to the chest
- Occupational exposure to chemicals
Exposure to which chemicals increases the risk of lung cancer?
- Asbestos
- Acetaldehyde
- Beryllium
- Cadmium
- Chromium
- Formaldehyde
- Polycyclic aromatic hydrocarbons
- Nickel
- Inorganic arsenic compounds
By how much does a significant family history increase the risk of lung cancer?
2.5x
What genetic mutation can increase the risk of lung cancer?
Germline mutations in genes such as Rb TP53
What are the main categories of lung cancer?
- Small cell lung cancer
- Non-small cell lung cancer
What % of lung cancers are small cell lung cancers?
20%
Where does SCLC arise?
In the larger airways - tends to be a more central tumour
How do most patients with SCLC present?
Systemic disease
Does SCLC frequently metastasise?
Yes
How does SCLC metastasise?
Via haematogenous spread
Where does SCLC metastasise to?
- Liver
- Skeleton
- Bone marrow
- Brain
- Adrenal glands
What do the small cells in SCLC contain?
Dense neurosecretory granules
What can the dense neurosecretory granules in SCLC produce?
Ectopic biological substances such as ACTH and ADH
What can ectopic production of ACTH by SCLC cause?
Cushing’s syndrome
What can ectopic production of ADH by SCLC cause?
SIAD
What genetic abnormalities are common in SCLC?
- Mutations in RB1 and TP53
- Abnormal DNA methylation of the cyclin D2 gene
What % of cases of SCLC have mutations in RB1 and TP53?
80%
What % of lung cancers are non-small cell lung cancers?
80%
Where do NSCLC arise from?
The epithelial cells of the lung, from the central bronchi to the terminal alveoli
What types can NSCLC be divided into?
- Squamous cell carcinoma
- Adenocarcinoma
- Large cell carcinoma
What % of lung cancers are squamous cell carcinomas?
50%
How do lung squamous cell carcinomas often present?
As an obstructive lesion of the bronchus, causing infection
How might lung squamous cell carcinomas appear on the CXR?
Cavitation
Describe the course of lung squamous cell carcinomas?
They tend to grow slowly, spread locally, and disseminate late
What % of lung cancers are adenocarcinomas?
15%
Where do lung adenocarcinomas arise from?
The bronchial mucosal glands - tend to arise in the periphery
What is the result of lung adenocarcinomas tending to occur at the periphery?
The presentation can represent a metastasis from a distant site, so careful patient assessment is required
How do the risk factors for lung adenocarcinomas differ from other lung tumours?
There is less of an association with smoking with adneocarcinomas
What can lung adenocarcinomas arise in?
Scar tissue
Do lung adenocarcinomas metastasise?
Yes, they have a high risk of metastatic spread
Where do lung adenocarcinomas often metastasise to?
- Mediastinal lymph nodes
- Pleura
What does lung adenocarcinoma metastasising to the pleural produce?
Effusion