Lung Cancer - Pathology Flashcards
What is the most common category of lung cancers?
Carcinomas
Name the most common 4 lung carcinomas and their porportion:
Squamous Cell Carcinoma (40%)
Adenocarcinoma (41%)
Small Cell Carcinoma (15%) (SCLC)
Large Cell Carcinoma (4%) (LCLC)
What is NSCLC?
Non-Small Cell Lung Cancer.
It is used to catergoize the other 3 types of lung carcinoma.
However its an outdated term as they are vastly different cancers.
It should only be use it is in diagnosis when they only thing we can tell about the cancer is that its definetely not small cell.
What other types of cancer can appear in the lung beyond the carcinomas?
- Carcinoid Tumours
- Bronchial Tumours
- Lymphoma
- Sarcoma
- Metastases from elsewhere
How is important is lung cancer specifically?
IT is the 3rd most prevalent cancer in the world.
It also has the alrgest mortality of all cancers.
How many deaths does ,ung cancer cause in the UK?
~6% of all UK deaths
What are the possible causes of Lung Cancer?
- Smoking
- Asbestos
- Enviromental Radon
- Occupational Exposure
- Air pollution
- Radiation
- Pulmonary Fibrosis
Which cause is the most important in lung cancer aetiology?
Smoking accounts for >85% of lung cancers.
What kind of materials are people exposed to at work that can cause lung cancer?
Chromates
Hydrocarbons
Nickel
Etc.
How do we meausre someones tobacco consumption?
In pack years
Which packs per day per year
How does passive smoking affect cancer risk?
Passive smoking doubles your risk of cancer.
It accounts for 1/4 of non-smoking lung cancers
Does the cancer risk from smoking stop when you do?
No genomic damage persists but it does very slow improve over years
How many recognised carcinogens are there in tobacco smoke?
~60
What do inherited polymorphisms predispose some people to regarding smoking?
Some people are predisposed to nicotine addiction
Others metabolise pro-carcinogens into carcinogens.
What divides the 2 main carcinogenisis pathways in the lung?
Location.
One is peripheral and one central
Describe the peripheral pathway for lung carcinogensis?
Bronchioalveolar epithelial cells transform
-> Adenocarcinoma
Describe the central pathway of carcinogenenisis?
Bronchial epithelial stem cells transform
-> Squamous Cell Carcinoma
Define oncogene addiction?
Despite containing many genetic abnormalities, a cancer is often reliant upon a sinle oncogene mutation known as the key driver.
How is oncogene addiction useful to us?
It provides the basis for targeted molecular therapy. Targeting the key driver oncogene can disable the whole cancer
What is the most common oncogene addiction?
KRAS.
~35% of oncogene addictions are to KRAS/
This mutation is smoking induced.
Name some non-tobacco related oncogene addictions:
EGFR (15%)
BRAF/HER2 (2%)
ALK rearragements (2%)
Where can lung cancers spread to by local invasion?
The pleura
The thoracic Wall
Tissues in the mediastinum
Where can lung cancers metastases to locally?
Thoracic Lymoh Nodes
Where can lung cancers metastasis to outiwht the thorax?
- Liver
- Adrenal Glands
- Bone
- Brain
- Skin
Name some prognostic factors for lung cancer?
- Stage & classification
- Markers
- Oncogenes
What would we use pronostic markers for in the future?
Selecting patients for pre-emptive adjuvant therapy
What kind of investigations do we use when diagnosing lung canceR?
- Imaging (CXR, CT, MRI, PET)
- Bronchoscopy
• Trans-thoracic Fine Needle Aspiration
• Trans-thoracic Core Biopsy
• Pleural effusion
How many operable lung cancers have a 5 year survival rate?
Stage 1 operable lung cancers have >60% 5YS
Stage 2 operable lung cancers have 35% 5YS
Whats the overall 5YS of lung cancer in scotland?
<7%
How many scottish patietns recieve surgical treatment for lung cacner?
~10%
What is the 5YS for NSCLC?
Between 10-25%
What is the 5YS for SCLC?
4%, median survival is 9 months
How does immunotherapy work?
Cancers hide from or deactivate parts of the immune system to survive (E.g. The PD-1/PDL-1 relationship).
Drugs are being developed to counter and reactivate the immune system so it attacks the cancers itself.
Also Immune checkpoint inhibitors are being developed to stop tumour cell growth at certain checkpoints.
How do we select patients for specific tareted treatments?
By predictive biomarkers
What predictive biomarkers are present in adenocarcinoma?
- EGFR mut.
- KRAS mut.
- HER2 mut.
- BRAF mut.
- ALK translocations
What predictive biomarkers are present in squamous cell carcinoma?
- FGFR1 gene copy
- DDR2 mut.
- FGFR2 mut.
Why dont we spot lung cancers early?
They tend to grow ‘clinically silent’ until very advanced
Generally by the time its symptomatic its fatal
Why is haemoptysis importnat?
ITs an early(ish) sign of lung cancer that can help you catch it before its fatal. Sadly lots of patients think its “stoic” to not mention they bleeding into a vital organ.
What local effects of lung cancer relate to bronchial obstruction?
- Cancer can cause the bronchi to collapse
- Endogenous lipid pneumonia can occur if the tumour blocks the path of the muco-ciliary escalator
- Infection/Abcess
- Bronchiectasis
What local effects do lung cancers have on the pleura?
Inflammatory or malignant.
Its important to distinguish as if its invasive we have to remove that seciton of pleura.
What happens if the cancer invades the chest wall?
IT can still be surgically removed but its much more dangerous
Can we surgically treat once the cancer has invaded the mediastinum?
eh-NO!
What is lymphangitis carcinomatosa?
Inflammation of lymph tissue due to a malignancy
Where does lung cacner commonly metastasise to?
Liver Adrenal Glands Bone Brain Skin
What happens if cancer invades the cervical sympathetic ganglion (mediastinum)?
Horners syndrome removes the sympathetic innervation to one side of the face:
- Can lose control of one eye & side of face
- Lose ability to sweat in one side of face
What happens if cancer invades the Left recurrent Laryngeal Nerve?
Hoarseness & Bovine Cough:
- One vocal cord is paralysed
- > Cant oppose vocal cords
- > Cough like a cow
What happens if cancer invades the brachial plexus?
Loss of function & sensation in parts of the apporpriate limb
What happens if cancer invades the phrenic nerve?
Diaphragmatic Paralysis
What are paraneoplastic syndromes?
An altered immune response that damages our own tissue
What are some paraneoplastic syndromes of small cell carcinoma?
SCLC are neuroendocrine so produce hormones:
- ACTH can cause cushings
- ADH can lead to diabetes-like conditions
What are some paraneoplastic syndromes of squamous cell carcinoma?
Parathyroid hormone (PTH) production:
- > Hyperthyroidism
- > Hypocalcaemia
What are some non-metastatic effects of lung cancer on the skeletal system?
- Finger Clubbing
- Hypertrophic Pulmonary Osteoarthropathy (HPOA)
