Lung cancer Flashcards
What are the three types of non-small cell lung cancer?
Squamous cell cancer
Adenocarcinoma
Lung cell carcinoma
In what type of lung cancer are caveating lesions more common in?
Squamous cell cancer
Typical location of squamous cell lung cancer?
Central
What peripheral clinical sign is lung SCC strongly associated with?
Finger clubbing
What electrolyte disturbance is SCC lung cancer associated with?
HYPERCALCEMIA
Associated with parathyroid hormone-related protein (PTHrP) secretion → hypercalcaemia
What type of lung cancer is associated with hypercalcemia and why?
SCC
Associated with parathyroid hormone-related protein (PTHrP) secretion → hypercalcaemia
What lung cancer is associated with hypertrophic pulmonary osteoarthropathy (HPOA)?
SCC
What type of lung cancer is most common in non-smokers?
Adenocarcinoma
(although the majority of patients who develop lung adenocarcinoma are smokers)
Typical location of adenocarcinoma type lung cancer?
Peripheral
Typical location of large cell lung carcinoma?
Peripheral
What type of lung cancer may secrete β-hCG?
Large cell lung cancer
What might large cell lung cancer secrete?
B-hCG
Characteristics of large cell lung cancer tumours?
anaplastic, poorly differentiated tumours with a poor prognosis
What type of cancer is most commonly associated with superior vena cava obstruction?
Lung cancer
Small vs non-small cell lung cancer - which is more common?
Non small cell, adenocarinoma most common subtype
What is the most common subtype of non-small cell cancer
Adenocarcinoma
Lung cancer - general risk factor
Smoking (tobacco and cannabis)
Passive smoking
Occupation exposure (asbestos, silica, welding fumes, coal)
HIV
Organ transplantation
Radiation exposure (X-ray, gamma rays).
Beta-carotene supplements in smokers (convert to vit A in body)
Lung cancer - general SYMPTOMS
Cough
Haemoptysis
Dyspnoea
Chest Pain
Weight loss
Nausea and Vomiting
Anorexia
Lung cancer - general SIGNS
Cachexia
Finger Clubbing
Hypertrophic pulmonary osteoarthropathy
Anaemia
Horner’s syndrome (if the tumour is apical)
Examination of the chest: consolidation (pneumonia); collapse (absent breath sounds, ipsilateral tracheal deviation); pleural effusion (Stony dull percussion, decreased vocal resonance and breath sounds)
Enlargement of supraclavicular and axillary lymph nodes
Paraneoplastic syndromes: Cushing’s syndrome, SIADH, and Lambert-Eaton syndrome (suggest small-cell), hyperparathyroidism (suggests squamous cell)
Lung cancer: O/E - auscultation
Absent breath sounds - lung collapse
Decreased vocal resonance and bronchial breath sounds - pleural effusion
Pleural firction rub (Nonmusical, explosive, usually biphasic sounds; typically heard over basal regions) - pleural tumour or pleural inflamation
Corase crackle (indicates intermittent airway opening, may be related to secretions) - pneumonia
Lung cancer: O/E - percussion
Stony dull percussion - pleural effucsion
Dull percussion - consolidation
If lymphadenopathy is present in lung cancer, which lymph nodes may be elarged?
Supraclavicular
Axillary
What paraneoplastic syndromes may be present in small cell lung cancer?
Cushing’s syndrome (ectopic ACTH)
SIADH (ectopic ADH)
Lambert-Eaton syndrome
What non-metastatic complications of bronchial carcinoma, which can arise due to local invasion, may be present and why?
DYSPONEA
People with lung cancer can experience shortness of breath if the cancer invades major airways.
HAEMOPTYSIS
The invasion of cancer into the airways which is friable tissue may lead to bleeding.
PAIN
Advanced lung cancer may cause local invasion affecting the lining of pleural cavity or bone causing pain.
PLEURAL EFFUSION
Lung cancer can cause inflammatory reactions which lead to the accumulation of fluid in the pleural space.
SUPERIOR VENA CAVA OBSTRUCTION
The cancer may invade into surrounding tissues leading to compression of the drainage of the superior vena cava leading to dyspnea and facial plethora due to venous congestion.
PNEUMOTHORAX
Invasion of the tumour may lead to a communication between the lung parenchyma and the pleural cavity resulting in the collapse of the lung.
ATELECTASIS
The invasion of a tumour may lead to total obstruction of the airway leading to collapse of that lobe
What is the most common presentation of lung squamous cell carcinoma and why?
Infection, due to obstructive lesions of the bronchus
Differentiating between a lung abscess or SCC on imaging
Hard to differentiate on CXR as the border’s definition cannot easily be seen
Jagged border in SCC is obvious on CT
Spread pattern of lung SCC?
Local spread common
Mets frequent, but normally LATE
By what two mechanisms can lung SCC cause hypercalcemia?
by bone destruction or
production of PTH analogues (PTHrp)
What paraneoplastic syndromes are lung SCCs associated with?
HPOA (Hyper trophic pulmonary osteoarthropathy)
Hypercalcemia - PTHrP-producing
From which cells does lung adenocarcinoma arise?
Mucous cells in the bronchial epithelium
From which cells does the most common type of lung cancer arise?
Adenocarcinoma -
Mucous cells in the bronchial epithelium
Where does adenocarcinoma of the lung tend to invade?
Invades the mediastinal lymph nodes and the pleura
Spreads to the brain and bones
Which types of lung cancer are most likely to cause pleural effusion
Adenocarcinoma and mesotheliomas
Which type of lung cancer is least likely to be related to smoking?
Adenocarcinoma
What type of lung cancer is proportionally more common in women?
Adenocarcinoma
What type of lung cancer is proportionally more common in the Far East?
Adenocarcinoma
From what cells does small cell carcinoma of the lung arise, and what is the signficance of this?
Arise from endocrine cells (Kulchitsky cells).
These are APUD cells, and as a result, these tumours will secrete many poly-peptides mainly ACTH.
What endocrine presentations might small cell carcinoma of the lung cause?
CUshing’s disease
Addison’s disease
Why is the prognosis of lung small cell carcinoma generally poor?
Small cell carcinoma spreads very early and is almost always inoperable at presentation
.
These tumours do respond to chemotherapy, but the prognosis is generally poor.
What management do small cell carcinoma lung tumour tend to respond well to?
Chemotherapy
Neurological paraneoplastic syndromes in lung cancer?
Polyneuropathy (Antibodies against the myelin sheath)
Cerebellar degeneration
Lambert-Eaton Syndrome
Vascular and haematological paraneoplastic syndromes in lung cancer?
Anaemia
Thrombophlebitis migrans
Features of Hypertrophic pulmonary osteoarthropathy?
Joint stiffness
Join pain: severe in wrist and ankles
Sometimes, gynaecomastia
XR: proliferative periostitis at the ends of the long bones, which have an ‘onion skin’ appearance
Finger clubbing (if cancer the cause)
What are 30% of finger clubbing cases caused by?
Non-small cell carinoma of the lung
What is though to cause HPOA in lung cancer and why?
It is thought to be caused by a blood borne factor released by the tumour – when patients have the primary tumour removed, the pain goes away
Which features does carcinoid syndrome present with?
hepatomegaly
flushing
diarrhoea
Why might lung cancer cause hyponatremia?
Paraneoplastic syndrome of SIADH (inappropriate ADH secretion)
Particularly associated with SMALL CELL lung cancer
Why might lung cancer be associated with Cushing’s syndrome?
Secretion of ectopic ACTH.
Small cell lung cancer is the most common cause.
Ectopic ACTH stimulates excessive cortisol release from the adrenal glands.
Cushingoid features on inspection of patient
Features on inspection (round in the middle with thin limbs):
Round face (known as a “moon face”)
Central obesity
Abdominal striae (stretch marks)
Enlarged fat pad on the upper back (known as a “buffalo hump”)
Proximal limb muscle wasting (with difficulty standing from a sitting position without using their arms)
Male pattern facial hair in women (hirsutism)
Easy bruising and poor skin healing
Hyperpigmentation of the skin in patients with Cushing’s disease (due to high ACTH levels)
Where does lung cancer commonly metastesise to and how?
BRAIN
BREAST
ADRENALS
BONE
The most likely mechanism by which brain metastases spread is via the bloodstream.
What CXR abnormalities may be seen in lung cancer?
Nodules
Lung collapse
Pleural effusion
Consolidation
Bony metastases
(image A chest x-ray of an individual with a left sided lung cancer)
Lung cancer: investigations
Sputum cytology
CXR - first line
Contrast-enhanced CT scan: this is used to further confirm the diagnosis and stage The CT scan should also include both the adrenals and liver to look for sites of metastases.
PET-CT (positron emission tomography) scans involve 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. They are useful in identifying areas that the cancer has spread to by showing areas of increased metabolic activity suggestive of cancer.
Bronchoscopy with endobronchial ultrasound (EBUS) involves 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 - Endobronchial ultrasound transbronchial needle aspiration (EBUS-TBNA - allows biopsy of lymph nodes, paratracheal and bronchial lung lesions for histology
HISTOLOGY - to check the type of cells in the cancer requires a biopsy. This can be either by bronchoscopy or percutaneously (through the skin).
Cardiovascular review and lung function tests should also be performed to assess patient’s suitability for treatment options.
Roles of endobronchial transbronchial needle aspiration in investigating lung cancer (EBUS-TBNA)
Allows biopsy of the following for histology:
Lymph nodes
Paratracheal lung lesions
Bronchial lung lesions
What should be included in the contrast-enhanced CT scan performed when investigating pts with lung cancer?
Both adrenals and liver, to look for sites of mets
What is the first line management of non-small cell lung cancers (NSCLC) if pt is suitable?
Lobectomy
NSCLC management
First-line: lobectomy
Curative radiotherapy can also be offered to patients with stage I, II and III NSCLC.
Chemotherapy should be offered to patients with stage III and IV NSCLC to control the disease and improve quality of life.
Which stages of NSCLC can be offered curative radiotherapy?
Stages I-III
What stages of NSCLC should be offered chemotherapy to control the disease and improve quality of life?
Stages III and IV
How is small cell lung cancer managed (generally)
Generally palliative chemotherapy, as tumours are disseminated on presentation.
What is Pancoast’s syndrome?
Symptoms are caused by an apical malignant neoplasm of the lung.
These include ipsilateral invasion of the sympathetic cervical plexus leading to Horner’s syndrome with shoulder and arm pain due to Brachial Plexus invasion.
Association with smoking
What signs may be seen on CXR in lung cancer?
Hilar enlargement
“Peripheral opacity” – a visible lesion in the lung field
Pleural effusion – usually unilateral in cancer
Collapse
Extra-pulmonary manifestations of lung cancer?
Recurrent laryngeal nerve palsy
Superior vena cava obstruction
Horner’s syndrome (Pancoast’s tumour)
SIADH (small cell lung cancer)
Cushing’s syndrome (small cell lung cancer)
Hypercalcaemia (squamous cell carcinoma)
Limbic encephalitis (small cell lung cancer)
Lambert-Eaton myasthenic syndrome.
What might make a patient with lung cancer present with a hoarse voice and why?
Recurrent laryngeal nerve palsy
It is caused by the cancer pressing on or affecting the recurrent laryngeal nerve as it passes through the mediastinum.
What extrapulmonary manifestation of lung cancer might cause SOB and why?
Phrenic nerve palsy due to nerve compression causes diaphragm weakness and presents as shortness of breath.
What specific syndrome (inc symptoms) might you see in a patient with a Pancoast’s tumour, and why?
Horner’s syndrome
Triad of
PARTIAL PTOSIS
ANHIDROSIS
MIOSIS
It is caused by a Pancoast’s tumour (tumour in the pulmonary apex) pressing on the sympathetic ganglion (PRE-GANGLIONIC LESION)
Where is a Pancoast tumour situated?
Pulmonary apex
May press on the sympathetic ganglion and cause Horner’s syndrome
What is limbic encephalitis?
Limbic encephalitis. This is a paraneoplastic syndrome where the small cell lung cancer causes the immune system to make antibodies to tissues in the brain, specifically the limbic system, causing inflammation in these areas.
This causes symptoms such as short term memory impairment, hallucinations, confusion and seizures.
It is associated with anti-Hu antibodies.
What type of lung cancer is limbic encephalitis associated with?
Small cell
What antibodies is limbic encephalitis associated with?
Anti-Hu
What are the signs/symptoms of limbic encephalitis?
Short term memory impairment
Hallucinations
Confusion
Seizures
In what type of lung cancer does Lambert-Eton myasthenic syndrome occur and why?
SMALL CELL LUNG CANCER
Lambert-Eaton myasthenic syndrome is a result of antibodies produced by the immune system against small cell lung cancer cells.
Basic pathophysiology of Lambert-Eaton myasthenic syndrome?
Antibodies produced by the immune system against small cell lung cancer cells.
These antibodies also target and damage voltage-gated calcium channels sited on the presynaptic terminals in motor neurones
This leads to weakness, particularly in the proximal muscles but can also affect intraocular muscles causing diplopia (double vision), levator muscles in the eyelid causing ptosis and pharyngeal muscles causing slurred speech and dysphagia (difficulty swallowing).
Patients may also experience dry mouth, blurred vision, impotence and dizziness due to autonomic dysfunction.
Signs/symptoms of Lambert-Eaton Myasthenic Syndrome?
Proximal muscle weakness
Diplopia (intraocular muscle weakness)
Ptosis (levator muscles in the eyelids)
Slurred speech (pharyngeal muscle weakness)
Dysphagia (pharyngeal muscle weakness)
Post-tetanic potentiation - reduced tendon reflexes that become temporarily normal for a short period following a period of strong muscle contraction.
What is mesothelioma?
Mesothelioma is a lung malignancy affecting the mesothelial cells of the pleura.
What is mesothelioma highly linked to and what is notable about this association?
Asbestos inhalation.
There is a huge latent period between exposure to asbestos and the development of mesothelioma of up to 45 years.
Management/prognosis of mesothelioma?
The prognosis is very poor.
Chemotherapy can improve survival but it is essentially palliative.
What is a pleural effusion?
A pleural effusion is a collection of fluid in the pleural cavity.
This can be exudative meaning there is a high protein count (>3g/dL) or transudative meaning there is a relatively lower protein count (<3g/dL).
Whether it is exudative or transudative helps determine the cause.
What protein count would you expect in a pleural effusion due to lung malignancy?
Exudative pleural effusion -
meaning there is a HIGH protein count
(>3g/dL)
Is pleural effusion due to lung cancer exudative or transudative?
EXUDATIVE
When might a TRANSUDATIVE pleural effusion be seen in a patient with cancer?
Meig’s syndrome - (right sided pleural effusion with ovarian malignancy)
Lung cancer would cause an EXUDATIVE pleural effusion
Why does lung cancer cause pleural effusion?
The cancer itself or and opportunistic pneumonia causes inflamation.
The inflammation results in protein leaking out of the tissues in to the pleural space
Fluid collects in the pleural cavity - the potential space between the visceral and parietal pleura (which normally contains a small amount of lubricating serous fluid)
What are the signs/symptoms of pleural effusion?
Shortness of breath
Dullness to percussion over the effusion
Reduced breath sounds
Tracheal deviation away from the effusion if it is massive
CXR signs in pleural effusion?
Blunting of the costophrenic angle
Fluid in the lung fissures
Larger effusions will have a meniscus. This is a curving upwards where it meets the chest wall and mediastinum.
Tracheal and mediastinal deviation if it is a massive effusion
Taking a sample of the pleural fluid by aspiration or chest drain is required to analyse it for protein count, cell count, pH, glucose, LDH and microbiology testing.
Potential complications of pleural effusion
Complications vary depending on the cause of the pleural effusion.
Larger pleural effusions may cause increasing respiratory compromise. In parapneumonic effusions, complications may include empyema and sepsis.
Complications, such as pneumothoraces, may relate to pleural procedures carried out during the diagnosis and treatment of a pleural effusion.
Patients with malignancy or pneumonia have a poorer prognosis if a pleural effusion develops.
Management of pleural effusion?
Conservative management may be appropriate as small effusions will resolve with treatment of the underlying cause. Larger effusions often need aspiration or drainage.
Pleural aspiration involves sticking a needle in and aspirating the fluid. This can temporarily relieve the pressure but the effusion may recur and repeated aspiration may be required.
Chest drain can be used to drain the effusion and prevent it recurring.
Empyema
Empyema is where there is an infected pleural effusion.
Suspect an empyema in a patient who has an improving pneumonia but new or ongoing fever.
Pleural aspiration shows pus, acidic pH (pH < 7.2), low glucose and high LDH. Empyema is treated by chest drain to remove the pus and antibiotics.
