Week 3/4 - A - Lung cancer - Risk factors/Presentation/DIagnosis/Staging/Treatment (NSCLC and SCLC), targeted therapies Flashcards
What are the most common cancers in the UK?
The most common cancers in the UK are prostate, breast, lung and colorectal cancers
Is there a difference between the incidence and prevalence of lung cancer?
The incidence of lung cancer is very high as many new cases arrive daily (roughly 100 new cases daily in UK) The prevalence of lung cancer is actually quite low due to most cases presenting quite late and majority of lung cancers are incurable (90%)
What are the risk factors for lung cancer?
Cigarette smoking or passive smoking Family history Radon gas Asbestos exposure
What is a paraneoplastic syndrome?
A paraneoplastic syndrome is a set of signs and symptoms that are consequence of cancer in the body but not due to the local or distant spread of the tumour cells. It is specifically due to the production of chemical signalling molecules (hormones or cytokines) by the tumour cells or an immune response to the tumour.
What are the common presenting symptoms in patients with lung cancer? (try and list the most common symptoms first)
* Persistent cough for longer than three weeks * Haemoptysis * Dyspnoea * Chest pain * Weight losss * Recurrent or slowly resolving pneumonia * Unexplained tiredness or lack of energy * A hoarse voice
Explain the two images Image on the right- man who presented to his GP with a three week history of haemoptysis
Left image - bronchoscope at lower trachea looking directly at the carina - healthy pale pink mucosa and underlying cartilage rings Right image - mucosa is very red, shrowing fresh blood from the tumour which is ulcerating throug the surface of the bronchii. Cytology brush positioned just above the tumour
What happens to the lung volume in the affected lung with cancer?
In lung cancer, the larger the tumour gets, the smaller the lung volume appears to be - visible on CXR - this is because the tumour obstructs the proximal branches of the bronchial tree therefore air cannot reach the part of the lung beyond this to expand Right lung smaller than left (image)
We have discussed the presentation of the primary tumour (cough, haemoptysis, dyspnoea, chest pain, weight loss, recurrent/slowly resolving pneumonia. lethargy, hoarse voice) Lets discuss the local invasion, metastes and non-metastatic (paraneoplastic) presentations What are the neighboring structures that are locally invaded by lung cancers?
LOCAL INVASION * Recurrent laryngeal nerve * Pericardium * Oeosphagus * Brachial plexus * Pleural cavity * Superior vena cava
LOCAL INVASION * Recurrent laryngeal nerve * Pericardium * Oeosphagus * Brachial plexus * Pleural cavity * Superior vena cava What is the course of the recurrent laryngeal nerves? What symptom does it result in?
RRLN - branches off the vagus nerve & hooks under the right subclavian artery LRLN - branches off the vagus nerve & hooks under the arch of the aorta They both travel upwards to supply the intrinsic muscles of the larynx Invasion of the nerve results in nerve palsy causing hoarseness (due to reduced mobility of the vocal cords)
What are the symptoms caused by local invasion of the pericardium and oesophagus?
Pericardium invasion - breathlessness, atrial fibrillation and pericardial effusion Oesophageal invasion can present as dysphagia (difficulty swallowing)
In patient’s who present with a lung tumour in the apex, what can this cause? What is the term for a apex tumour of the lung known as?
Apex tumour of the lung is also known as a pancoast tumour * Can invade the brachial plexus causing weakness and/or atrophy of the intrinsic muscles of the hand, and paraesthesias and/or pain in C8/T1 distribution. * Can causes ipsilateral Horner’s syndrome by invading the sympathetic chain (miosis, ptosis, anhidrosis and appraent enopthalmos) * Can also cause recurrent laryngeal nerve palsy
What is the cough that may be seen in patients with a recurrent laryngeal nerve palsy known as?
This is a bovine cough - a non-explosive cough caused by somebody unable to close their glottis (vocal cords cannot fully adduct due to nerve palsy) during coughing
What happens when a lung tumour locally invades the pleural cavity?
Invasion of the pleural cavity can cause pleural fluid to accumulate - cause symptoms of breathlessness Requires draining usually
What are the symptoms/signs of suprerior vena cava obstruction in local lung cancer invasion?
Obstruction of the SVC is an oncological emergency Local invasion of the SVC obstructs drainage of blood from the arms and head. The patient may describe puffy eyelids and a headache. There is also superficial distension of the veins - JVP, abdomen and thorax
How would you treat the SVCO if cause by extrinsic malignant compression?
Give O2 if needed Give dexamethasone to reduce inflammation Stenting provides the most rapid relief of symptoms but the underlying tumour must be treated Treat underlying cancer with radiotherapy or chemotherapy depending on sensitivities
Why can you also get rib erosion in lung cancer?
The cancer can locally invade into the chest wall and therefore through the ribs destorying part of it and causing pain (bone pain often worse at night)
What are common sites for lung cancer metastases? (most common come under the acronym BLAB)
Brain Liver Adrenals Bone Also skin and lung
Metastases from the lung most commonly are brain, liver, adrenal or bone How do patients with brain mets present?
Cerebral mets usually have an insidious onset * Headaches worse in the morning * Weakness * Visual disturbance * Ataxia * Nausea and vomiting * Fits can occur
Liver mets can cause an obstructive jaundive type picture if obstructing the biliary drainage State what is scene on the CT
Can see the irregular outline of liver mets Also incidental finding of a smooth growth in the right kidney - benign cyst
Pic just showing adrenal metastases from lung cancer What are the presenting symptoms of bone cancer metastes from the lung? What is increased in the blood?
Pain or pathological fractures can result from bone metastases. The axial skeleton and proximal long bones are most frequently involved May cause hypercalcaemia
What investigation would you do in new bone pain in someone with suspected bone metastasis?
Investigation - CXR and radionuclide bone scan (Tc-99m)
We have discussed risk factors, symptoms of primary tumour/local invasion/metastases Now we discuss the non-metastatic presentation - paraneoplastic syndorme What are other causes of finger clubbing?
* Cyanotic heart disease * Lung disease (hypoxia, cancer, CF, IPF) * UC/Crohns * Biliary cirrhosis * Birth defect * Infective endocarditis * Neoplasm * GI malabsorption
What is hypertrophic pulmonary oesteoarthropathy characterised by?
HPOA is characterised by a triad of finger clubbing, symmetrical arthtitis and periosteal bone formation causing periostitis Symptoms of pain and tenderness of the long bones near the adjacent joints are due to elevation of the periosteum away from the bone surface. This bone scan shows increased activity, particularly in the distal part of the tibia and fibula.
As previously stated, the greatest risk factor for lung cancer is cigarette smoking followed by passive smoking (biggest risk factor for all patients) What type of lung cancer is associated with non smoking? What lung cancers are central and which are peripheral usually?
If a non-smoker presents with lung cancer - think adenocarcinoma - usually located peripherally in the lung (large cell also found peripherally) Small cell and squamous cell carcinomas are usually found centrally
Making the diagnosis of lung cancer - lots of possible tests Why would sputum cytology be carried out?
Sputum cytology isn’t normally carried out because whether it is positive or negative the patient will still recieve a bronchoscopy Only use sputum cytology for investigation in people with suspected lung cancer who have centrally placed nodules or masses and who decline or cannot tolerate bronchoscopy or other invasive tests.
The history, examination, imaging and blood tests are all important BUT we need tissue to make the diagnosis with certainty. This slide lists the common ways to make the diagnosis. What investigation is used in people with central or peripheral tumours on CT?
Tissue is sampled from bronchoscopy where possible - only useful in central lesions - cannot pass bronchscope into dividisons smaller than the scope in the peripheries.. Transthoracic needle aspiration biopsy, typically using CT guidance, is used to biopsy suspicious peripheral pulmonary lesions that are not accessible with bronchoscopy.
When wanting to assess the intrathoracic lymph nodes, what imaging and diagnosis technique is used to accurately diagnosis the tumour? (same imaging as used for patients potentially receiving curative intent treatment)
Assessing intrathoracic nodes PET-CT is carried out followed by Endobranchial ultrasound guided transbronchial needle aspiration (EBUS-TBNA) - ultrasound guides scope to target and lymph nodes and allow needle aspiration of the nodes
Bronchoscopy - central tumours CT guided transbronchial needle aspiration - peripheral tumours Lymph node aspirate - EBUS-TBNA What is carried out if the patient has a pleural effusion? (1st and 2nd line)
Many patients present with a pleural effusion, and US guided thoracentesis is indicated, followed by thoracoscopy, if fluid is negative. Direct visualisation of the pleura using thoracoscopy has a very high degree of specificity for the diagnosis of pleural effusion.
The surgeon will need to be certain that the cancer can be completely removed by an operation so the pre-operative staging amounts to a thorough search for evidence of metastases or local invasion. E.g, if a pneumectomy is being carried out, how much disease free bronchus is required and why?
If a pneumectomy is being carried out, there must be at least 2cm disease free bronchus to close off the hole. If the tumour encroaches within 2cm of the carina, it will be impossible to remove it without leaving a hole in the side of the trachea. In pic - inoperable (carina invaded)
The TNM staging is used to classify the tumour into 4 stages Try and describe the 4 stages
Stage I: The cancer is located only in one lung and has not spread to any lymph nodes. (T1/2, NO, MO) Stage II: The cancer is in one lung and nearby lymph nodes. (T1/2, N1, MO) Stage III: Cancer is found in the lung and in the lymph nodes in the middle of the chest, aka locally advanced disease. * If only to ipsilateral lymph nodes - stage IIIA. * If to contralateral lymph nodes or above collar bone - stage IIIB Stage IV: Advanced disease. Cancer has spread to both lungs, to fluid in the area around the lungs, or to another part of the body, such as the liver or other organs.
How does immunohistochemistry help to differentiate between cancers in small biopsies?
Immunohistochemistry involves using antibodies that target specific antigens present in different types of cancers to allow you to see which type of cancer it is Ie squamous and adenocarcinomas will have different proteins expressed on their surfaces
Specific genetic mutations increasing tumour activity are being tested for in lung cancer and treatments are becoming available Eg mutations in EGFR, ALK1 and ROS1 What type of lung cancer do these mutations usually occur in ? Where in the lung are these cancers often found?
EGFR, ALK1 and ROS1 mutations (if occurring) usually occur in adenocarcinomas promoting cancer growth Adenocarcinomas are usually found in the periphery of the lung
