Lung cancer Flashcards
Who gets lung cancer?
Age, peak 75-90 Sex, M>F Lower socioeconomic status Smoking history duration, intensity, when stopped
What are some causes of lung cancer other than smoking?
10-15% patients with lung cancer never smoked
Passive smoking (~15% of these)
Other aetiological factors
Asbestos – exposure (plumbers, ship-builders, carriage workers, carpenters, etc) – risk up to x2
Radon – e.g. silver miners in Germany late 19th century; 1950s uranium mining in Colorado
Indoor cooking fumes – wood smoke, frying fats
Chronic lung diseases (COPD, fibrosis)
Immunodeficiency
Familial/ genetic – several loci identified
What are the 4 main groups of lung cancer?
Squamous cell carcinoma (~30% of cases).
– previously the most common
– originating from bronchial epithelium; centrally located
Adenocarcinoma (~40%)
– most common from 1980s onwards – low tar cigarettes, inhaled more deeply / retained longer
– originating from mucus-producing glandular tissue; more peripherally-locate
Large cell lung cancer (~15%)
heterogenous group, undifferentiated
Small cell lung cancer (~15%)
originate from pulmonary neuroendocrine cells
highly malignant
Can be grouped into small cell and non small cell lung cancer
Define Metaplasia:
reversible change in which one adult cell type replaced by another adult cell type; adaptive
Define Dysplasia:
abnormal pattern of growth in which some of the cellular and architectural features of malignancy are present; pre-invasive stage with intact basement membrane
What are some of the important oncogenes associated with lung cancer?
epidermal growth factor receptor (EGFR) tyrosine kinase
15-30% of adenocarcinoma
more so in women, Asian ethnicity, never-smokers
anaplastic lymphoma kinase (ALK) tyrosine kinase
2-7% of non-small cell lung cancer
especially in younger patients and never smokers
c-ROS oncogene 1 (ROS1) receptor tyrosine kinase
1-2% of non-small cell lung cancer
especially in younger patients and never smokers
BRAF (downstream cell-cycle signalling mediator)
1-3% of non-small cell lung cancer
especially in smokers
DO NOT NEED TO MEMORISE
What are the key symptoms of lung cancer?
Cough Weight loss Breathlessness Fatigue Chest pain Haemoptysis Or frequently asymptomatic
What are the features of advanced disease?
Neurological features:
focal weakness, seizures, spinal cord compression
Bone pain
Paraneoplastic syndromes
clubbing, hypercalaemia, hyponatraemia, Cushing’s
What are the signs of lung cancer?
Clubbing
Cachexia
Horner’s syndrome ( apical lung tumour supresses sympathetic supply to the face)
Superior vena cava obstruction ( Pemberton’s sign)
What is the strategy for diagnosing lung cancer?
Establish most likely diagnosis
Establish fitness for investigation and treatment
Confirm diagnosis
specific type of cancer if considering systemic treatment
Confirm staging
What are the 3 features of Horners syndrome?
ptosis
myosis
hydrosis
What is the most useful scan to exclude occult metastases?
PET Scan
When would you use a bronchoscopy?
for tumours of central airway
where tissue staging not important
When would you use Endobronchial ultrasound?
Endobronchial ultrasound and transbronchial-needle aspiration of mediastinal lymph nodes (EBUS [TBNA])
To stage mediastinum +/- achieve tissue diagnosis
Why would you use a CT-guided lung biopsy?
To access peripheral lung tumours
What are the criteria for staging lung cancer?
T1-4: tumour size and location
N0-3: lymph node involvement – mediastinum + beyond
M0-1c: metastases + number
The bigger the number the worse the prognosis
What are the determinants of treatment?
Patient fitness Cancer histology Cancer stage Patient preference Health service factors
What are the criteria for the WHO patient fitness performance status?
0 – Asymptomatic (Fully active, able to carry on all predisease activities without restriction)
1 – Symptomatic but completely ambulatory (Restricted in physically strenuous activity but ambulatory and able to carry out work of a light or sedentary nature. For example, light housework, office work)
2 – Symptomatic, <50% in bed during the day (Ambulatory and capable of all self care but unable to carry out any work activities. Up and about more than 50% of waking hours)
3 – Symptomatic, >50% in bed, but not bedbound (Capable of only limited self-care, confined to bed or chair 50% or more of waking hours)
4 – Bedbound (Completely disabled. Cannot carry on any self-care. Totally confined to bed or chair)
5 – Death
Radical treatment usually restricted to PS 0-2
Comorbidity + lung function also very important
What surgeries can be used to treat lung cancer?
Surgical resection is standard of care for early stage disease
Lobectomy + lymphadenectomy usual approach
Sublobar resection if stage 1 (≤3 𝑐𝑚)
How is radiotherapy used in lung cancer treatment?
Alternative to surgery for early stage disease
Particularly if comorbidity
Stereotactic ablative body radiotherapy (SABR)
Technique of choice
High-precision targeting, multiple convergent beams
