Lung Cancer Flashcards
What different ways can lung cancers present?
Primary tumour
Local invasion symptoms
Metastases
Paraneoplastic syndrome (e.g. hormones)
What symptoms should prompt you to think of making a lung cancer referral?
- Cough >3 weeks
- Breathless for no reason
- Chest infection that doesn’t clear up
- Coughing up blood
- Unexplained weight loss
- Chest/shoulder pain
- Unexplained tiredness
- Hoarse voice
When you look at any chest X-ray, the smaller of the two lungs is usually the diseased one. TRUE/FALSE?
TRUE
- enlarging tumour obstructs proximal divisions of the bronchial tree
- air beyond obstruction is absorbed
- lung tissue shrinks
Describe the appearance of the lung mucosa when a tumour lies underneath it
red (prone to haemoptysis) and ulcerated
Why do lung cancers often cause stridor (inspiratory noise) rather than an expiratory wheeze?
- tumour causes bronchi narrowing and pools of secretions
=> difficulty breathing in - asthma and COPD have expiratory wheeze as the air can enter the lungs but has difficulty getting out
What structures can be locally invaded by a lung cancer?
Recurrent laryngeal nerve Pericardium Oesophagus Brachial plexus Pleural cavity Superior vena cava
What symptom does the patient experience if a lung cancer invades the recurrent laryngeal nerve?
Hoarse voice
What symptoms can the patient experience if a lung cancer invades the pericardium?
AF
pericardial effusion
What symptom would indicate that a lung tumour has spread to the oesophagus?
Dysphagia to solids
A pancoast tumour can invade what structure and cause what symptoms?
Invades brachial plexus
=> causes neuropathy in hand/arm
Why do lung cancers cause pleural effusions?
- tumour invades the pleural space
- generates large volume of pleural fluid (can be litres!!)
- presenting symptom = breathlessness
What symptoms are caused by local invasion and obstruction of the SVC?
- obstructs drainage of blood from the arms and head
- superficial veins on abdomen distend to avoid SVC
Bone pain due to lung cancer invasion is often worse at what time of the day?
Night
Where do lung cancers commonly metastasise to?
Adrenal Skin Liver Brain Bone Other Lung
What sign in the hands may point towards a lung cancer diagnosis?
Finger clubbing
What hormones can be secreted from lung tumours and what effects do these cause?
PTH Mimic => causes Hypercalcaemia (Bones, groans, moans, stones etc)
ADH released => SIADH => hyponatraemia and confusion
What acute neuropathy is caused by a primary lung tumour and resolves upon tumour resection?
Lambert Eaton syndrome
causes weakness similar to mysathenia gravis
What is Hypertrophic pulmonary osteoarthropathy?
- association of lung cancers
- causes bone pain/tenderness near joints
- periosteum of bone lifts away from bone surface
- it is NOT a sign of metastasis to the bone
How is hypercalcaemia due to a lung tumour treated?
- Bisphosphonates may need to be used to prevent bone disease
- initial Tx = rehydration
What type of lung cancer is more likely to release a mimic of PTH and cause hypercalcaemia?
Squamous Cell
What type of lung cancer usually secretes ADH?
Small cell
How is SIADH due to lung cancer treated?
Fluid restriction – 1.5L/day
What other differential diagnoses exist for patients who smoke, have experienced haemoptysis and have an abnormal CXR?
Tuberculosis Vasculitis Pulmonary embolism Secondary cancer Lymphoma Bronchiectasis
What chemicals are found in tobacco smoke that are responsible for lung cancer?
polycyclic hydrocarbons aromatic amines phenols nickel cyanates
Other than the lung, smokers are also known to suffer from what types of cancer?
- Laryngeal
- Cervical
- Bladder
- Oral
- Oesophageal
- Colon cancer
Why do patients with lung cancer struggle to clear pneumonia and lung infections?
Tumour causes obstruction
=> area of pneumonia is often stuck distal to this site and cant be cleared/ reached by antibiotics
Why do larger airways have cartilage rings for support?
- to help conduct the movement of air in and out of the lungs
- smaller airways (e.g. terminal bronchioles) take place in gas exchange instead
What type of epithelium covers the respiratory system in order to produce mucous and secretions?
Pseudostratified Ciliated Columnar Epithelium with Goblet cells (these secrete mucous)
- this is also known as Respiratory Epithelium
If the bronchioles of the lung contain no cartilage, how are they held open?
elastic “tug” of surrounding alveoli
What parts of the respiratory tract make up the functional unit of the lung?
“Respiratory acinus”
AKA respiratory bronchioles + alveolar ducts + alveoli
What lung tumours are mostly associated with smoking?
adenocarcinoma (35%)
squamous carcinoma (30%)
small cell carcinoma (25%)
large cell carcinoma (10%)
Adenocarcinomas are the most common type of lung tumour and therefore a large percentage of these can also occur in non-smokers. TRUE/FALSE?
TRUE
- whereas virtually ALL small cell cancers are caused by smoking
How can a histological sample of a lung cancer be obtained?
Bronchoscopy
- biopsy tumour if seen during this (wont see it if at lung periphery)
Biopsy/ needle aspiration of mets
- mediastinal/supraclavicular lymph nodes
Endobronchial ultrasound guided specimens (EBUS)
What feature on histology would indicate a squamous carcinoma?
Keratinising lesion
=> producing keratin layers similar to that of skin
=> dark pink on H+E stain
What histological feature indicates an adenocarcinoma of the lung?
Formation of glands
- can be stained for mucin (turns blue)
What histological feature indicates a small cell carcinoma?
Lots of small cells packed tightly into space
- high nuclear:cytoplasm ratio
- i.e. very dark purple
How are small cell and non-small cell lung cancers treated differently?
Small cell - chemosensitive
Non-small cell - surgery is treatment of choice (radical radiotherapy may also be an option)
Chemotherapy and radiotherapy can also be used in Non-small cell lung cancer. TRUE/FALSE?
TRUE
beware many lung cancers get Pemetrexed chemo but this is CONTRAINDICATED in squamous Ca.)
EGFR mutations are commonly present in what type of lung cancer? And what can be used to treat this?
Adenocarcinoma
Tyrosine Kinase Inhibitors used to target EGFR signalling pathway
Tumours can express PD-L1 and avoid cytotoxic killing by the immune system. How do they do this?
PD-L1 binds to PD (programmed death) receptor on T lymphocytes
=> inactivating the cytotoxic immune response
What type of tumours usually occur in the bronchi and larger airways?
Squamous cell carcinomas
- epithelium undergoes metaplasia (often related to smoking)
- becomes dysplastic and forms carcinoma in situ before becoming invasive
Adenocarcinomas are normally found at the periphery of the lung. Why is this?
Spread of neoplastic cells along alveolar walls (bronchioloalveolar carcinoma)
- this means these are often difficult to reach on bronchoscopy
What is meant by a carcinoid tumour in the lungs?
neuroendocrine tumour of low grade malignancy
What needs to be considered before commencing surgery on a primary lung cancer?
- can it be excised?
- is disease localised?
- will patient survive?
- what will their lung function be afterwards?
Before surgery, clinicians stage the tumour and have a thorough look for metastases. How do they do this?
Bronchoscopy (to check for:)
- Vocal cord palsy
- Proximity to carina
- Cell type
Mediastinoscopy/EBUS
- Lymph nodes
CT Head (mets) CT Thorax PET Scan (mets)
Surgery cannot be attempted if the tumour is within how many cm of the carina?
2cm
What types of surgery can be used to operate on a lung cancer?
- Pneumonectomy or lobectomy
This can be done via:
Thoracotomy - large incision (length of 6th rib), takes weeks to recover
Minimal access VATS
- video assisted throacic surgery, keyhole technique
- multiple smaller scars and quicker recovery time
What happens to the hemi-diaphragm after a loss of lung volume on the affected side (usually after surgery)
Hemi diaphragm shifts up to compensate for loss of volume
What side effects can occur due to cytotoxic chemotherapy?
- N+V
- Tiredness
- Bone marrow suppression (rapidly dividing cells targeted by chemo)
- Infection (due to neutropenia)
- Anaemia
- Hair loss
- Pulmonary fibrosis
What is the difference between radical and palliative radiotherapy?
Radical has curative intent
Palliative = for symptom relief e.g. bone mets pain
What are the disadvantages of radiotherapy?
- There is a maximum cumulative dose
- Can cause collateral damage (Spinal cord, Oesophagus, Adjacent lung tissue)
- may cause lung fibrosis in patients who already have poor lung function (i.e. COPD)
- causes temporary oesophagitis
What is Stereotactic ablative radiotherapy?
- more beams (but each is less powerful)
=> Less collateral damage - Total dose delivered to tumour is higher
=> more effective
HOWEVER - 4D scanning required
What palliative endobronchial therapies are available for patients symptom control?
Stent insertion for stridor
Photodynamic therapy
Other laser therapy
