Lung Cancer Flashcards
How common is lung cancer?
Third most common cancer in the UK behind breast and prostate
What is the biggest cause of lung cancer?
Cigarette smoking is the biggest cause and around 80% of lung cancers are thought to be preventable.
What are the two types of lung cancers?
Non-small cell lung cancer
(80%)
Small cell lung cancer (20%)
What are the four types of non-small cell lung cancers?
Adenocarcinoma (around 40%)
Squamous cell carcinoma (around 20%)
Large-cell carcinoma (around 10%)
Other types (around 10%)
What do small cell lung cancer (SCLC) cells contain?
Neurosecretory granules that can release neuroendocrine hormones.
This makes SCLC responsible for multiple paraneoplastic syndromes.
Signs
Cachexia
Finger Clubbing
Hypertrophic pulmonary osteoarthropathy
Anaemia
Horner’s syndrome (if the tumour is apical)
Enlargement of supraclavicular and axillary lymph nodes
Signs on examination
Consolidation (pneumonia)
Collapse (absent breath sounds, ipsilateral tracheal deviation)
Pleural effusion (Stony dull percussion, decreased vocal resonance and breath sounds)
Paraneoplasmic syndromes
Cushing’s syndrome, SIADH, and Lambert-Eaton syndrome (suggest small-cell), hyperparathyroidism (suggests squamous cell)
What are the features of adenocarcinoma?
Located peripherally (in the smaller airways)
Histology: glandular differentiation
More common in non-smokers and Asian females
Metastasise early
Responds well to immunotherapy
What are the features of squamous cell carcinoma?
Located centrally (in the bronchi)
Histology: squamous differentiation (keratinisation)
More common in smokers
Secrete PTHrP, causing hypercalcaemia
Metastasise late (via lymph nodes)
What are the features of large carcinoma?
Located peripherally and centrally
Histology: large and poorly-differentiated
More common in smokers
Metastasise early
What are the features of small cell?
Located centrally
Histology: poorly-differentiated
More common in older smokers
Metastasise early
Secrete ACTH (Cushing’s syndrome) and ADH (SIADH)
Associated with Lambert-Eaton syndrome
What are the risk factors for lung cancer?
Main: smoking
Air pollution (indoor and outdoor)
Family history of cancer, especially lung cancer
Male sex
Radon gas (typically affects miners)
Clinical features of lung cancer
Unexplained cough for at least 3 weeks (with or without haemoptysis)
Unintended weight loss (>5% in 6 months)
New-onset dyspnoea
Pleuritic chest pain (due to the tumour invading the pleura or the chest wall)
Bone pain (due to metastases – commonly the spine, pelvis and long bones)
Fatigue (due to anaemia of chronic disease)
What is the first line investigation for suspected lung cancer?
CXR
Findings suggesting cancer:
Hilar enlargement
“Peripheral opacity” – a visible lesion in the lung field
Pleural effusion – usually unilateral in cancer
Collapse
After a CXR, what investigations are used?
Staging CT scan
PET-CT
Bronchoscopy with endobronchial ultrasound
Histological diagnosis
Why would a staging CT scan be used for lung cancer?
To establish the stage and check for lymph node involvement and metastasis.
Should be contrast enduced.
Why would a PET-CT scan be used?
To identify areas that the cancer has spread to by showing areas of increased metabolic activity suggestive of cancer
What do PET-CT scans include?
Injecting a radioactive tracer (usually attached to glucose molecules) and taking images using a combination of a CT scanner and a gamma ray detector to visualise how metabolically active various tissues are.
What does a bronchoscopy involve?
Endoscopy of the airways (bronchi) with ultrasound on the end of the scope.
This allows for detailed assessment of the tumour and ultrasound guided biopsy.
What is a histological diagnosis used for and how can it be carried out?
Check the type of cells in the cancer requires a biopsy.
This can be either by bronchoscopy or percutaneously (through the skin).
How is lung cancer staged?
I - One small tumour (<4cm) – localised to one lung
II - Larger tumour (>4cm) – may have spread to nearby lymph nodes
III - Tumour that has spread to contralateral lymph nodes, or grown into nearby structures (e.g. trachea)
IV - Tumour that has spread to lymph nodes outside the chest, or other organs (e.g. liver)
Management:
Non-small cell lung cancer
Stage I-III
Surgery: options include lobectomy/pneumonectomy in patients with intact lung function, or wedge resection in patients with reduced lung function (e.g. elderly, underlying respiratory conditions).
Pre-operative chemotherapy
Post-operative chemotherapy and radiotherapy: may not be needed in some cases of stage I lung cancer.
What can be given to patients with non-small cell lung cancer who cannot have surgery?
Stages I-III
Stereotactic ablative radiotherapy (SABR).
Directing a more intense and focused beam of radiation at the tumour
Reduces the number of radiotherapy sessions needed and minimises damage to surrounding tissue.
Management:
Non-small cell lung cancer
Stage IV
Targeted therapy
Immunotherapy
Chemotherapy
Palliative care
What is targeted therapy?
These drugs target mutations which drive the pathogenesis of lung cancer
What is immunotherapy?
These drugs target immune checkpoints, which prevent the patient’s immune cells from killing tumour cells.
What is the treatment in small cell lung cancer?
Chemotherapy & radiotherapy
Surgery: rare in small cell lung cancer, as most patients present with advanced disease.
Prophylactic cranial irradiation: since small cell lung cancer is associated with a high risk of brain metastases, radiotherapy is directed at the brain to prevent brain metastases.
How does cancer lead to a hoarse voice?
Recurrent laryngeal nerve palsy
-
cancer pressing on or affecting the recurrent laryngeal nerve as it passes through the mediastinum
How can cancer lead to phrenic nerve palsy?
Due to nerve compression causes diaphragm weakness and presents as shortness of breath
What is superior vena cava obstruction?
Direct compression of the tumour on the superior vena cava.
It presents with facial swelling, difficulty breathing and distended veins in the neck and upper chest.
“Pemberton’s sign” is where raising the hands over the head causes facial congestion and cyanosis.
This is a medical emergency.
What is Horner’s syndrome?
A triad of partial ptosis, anhidrosis and miosis.
It is caused by a Pancoast’s tumour (tumour in the pulmonary apex) pressing on the sympathetic ganglion.
Ptosis is when the upper eyelid droops over the eye
Anhidrosis is a condition in which you can’t sweat (perspire) normally in one or more areas of your body
Miosis means excessive constriction (shrinking) of your pupil
What happens in Horner’s syndrome?
Affects the face and eye on one side of the body.
It is caused by the disruption of a nerve pathway from the brain to the head and neck.
Typically, signs and symptoms of Horner syndrome include decreased pupil size, a drooping eyelid and decreased sweating on the affected side of the face.
What causes syndrome of inappropriate ADH (SIADH)?
Ectopic ADH secretion by a small cell lung cancer and presents with hyponatraemia
How can cushing’s syndrome be caused?
Ectopic ACTH secretion by a small cell lung cancer.
What is cushing’s syndrome?
Condition caused by having too much of a hormone called cortisol in your body.
What are the symptoms of cushing’s syndrome?
Increased fat on your chest and tummy, but slim arms and legs
a build-up of fat on the back of your neck and shoulders, known as a “buffalo hump”
A red, puffy, rounded face
Skin that bruises easily
Large purple stretch marks
Weakness in your upper arms and thighs
Reduced sex drive (low libido) and fertility problems
Depression and mood swings
What is the most common type of lung cancer?
Squamous cell cancer followed by adenocarcinoma
Where does lung cancer commonly spread to?
Brain
Breast
Adrenals
Bone
How does lung cancer spread?
Via lymph nodes
What should be given for superior vena cava obstruction?
Intravenous dexamethasone
Dexamethasone can be administered to reduce swelling and therefore the pressure on the SVC
What does SIADH cause?
Hyponatraemia
What lung cancer is most likely to show cavitating lesions in a CXR?
Squamous cell carcinoma
Hypercalcaemia treatment
Intravenous 0.9% sodium chloride infusion
