[3] Lung Cancer Flashcards
What is lung cancer?
A malignant lung tumour characterised by uncontrolled cell growth in tissues of the lung
Of what type are most primary lung cancers?
Carcinomas
What is a carcinoma?
A malignancy that arises from epithelial cells
What are the two main types of primary lung cancer?
- Small cell lung cancer
- Non-small cell lung cancer
Where is the histological type important in lung cancer?
In determining the management and predicting outcomes in lung cancer
What are the 3 main subtypes of non-small-cell lung cancer?
- Adenocarcinoma
- Squamous-cell carcinoma
- Large cell carcinoma
What % of lung cancers are adenocarcinomas?
40%
Where do adenocarcinomas usually arise from?
Peripheral lung tissue
What are most cases of adenocarcinoma associated with?
Smoking
What % of lung cancer cases are squamous cell carcinomas?
30%
Where do squamous cell carcinomas typically occur close to?
Large airways
What is commonly found at the centre of a squamous cell carcinoma?
Hollow cavity and associated cell death
What % of lung cancers are large cell carcinomas?
9%
Describe the cells in large-cell carcinomas
Large (obviously), with excess cytoplasm, large nuclei, and conspicuous nucleoli
Where do most cases of small-cell lung cancer arise from?
Larger airways (primary and secondary bronchi
What do the cells contain in small-cell carcinoma?
Dense neurosecretory granules
What results from the presence of dense neuro-secretory granules in small-cell carcinoma?
An endocrine/paraneoplastic syndrome association
What % of patients with small-cell lung cancer have extensive disease at presentation?
60-70%
Can cancers contain a combination of different subtypes?
Yes, for example adenosquamous carcinoma
What are the rare subtypes of lung cancer?
- Carcinoid tumours
- Bronchial gland tumours
- Sarcomatoid carcinomas
What are the risk factors for lung cancer?
- Smoking, including passive smoking
- Asbestos
- Previous radiotherapy to chest
- Inhalation of gas, polycyclic aromatic hydrocarbons, nickel, chromate, or inorganic arsenical
- Genetic predisposition
What % of cases of lung cancer are due to smoking?
80-90%
What does the risk of lung cancer relate to, in terms of smoking?
- Number of cigarettes smoked
- Number of years smoking
- Early age of starting smoking
- Type of cigarette (filtered or unfiltered)
What % of lung cancer cases occur in never-smokers?
<10%
Is lung cancer in never-smokers more common in men or women?
Women
What % of the UK adult population smokes?
30%
How has tobacco use been changing recently?
It has been reducing in men, perhaps due to health education, but increasing in women and adolescents
What options do the NHS provide to people wanting to stop smoking?
Provides free stop smoking services, inclduing medications, one-on-one group stop smoking sessions, and preventing relapse
What medications can be given to help stop smoking?
- Varenicline
- Bupropion
- Nicotine replacement therapy
When did the UK ban smoking in public and work-places?
2007
How may the smoking ban impact health?
It may in the long run decrease cancer rates from passive smoking
By how much does family history of lung cancer increase the risk?
2.5%, even when smoking is taken into account
What are the likely mechanisms through which family history contributes to increased risk of lung cancer?
- Genetic variation in the enzymes responsible for carcinogen metabolism and detoxification and DNA repair
- Germline mutation of Rb or p53 (rare)
What are the signs and symptoms of primary lung cancer?
- Cough
- Dyspnoea
- Wheezing
- Haemoptysis
- Chest pain
- Post-obstructive pneumonia
- Weight loss
- Lethargy
- Malaise
What are the signs and symptoms of regional metastases of lung cancer?
- Superior vena cava obstruction
- Hoarseness
- Dysphagia