Pathology of lung cancer Flashcards
which type of cancer is the most common cause of death worldwide (out of all other cancers)
lung cancer
main cause of lung cancer
tobacco smoke HOWEVER not everyone that smokes get lung cancer and just because they do it doesn’t mean that smoking is the cause
true or false: there is a gradual decline in lung cancer incidences
TRUE due to decrease in men having lung cancer. Pretty much the same for women though
Cure rate for lung cancer
under 10%
Causes of lung cancer (6)
tobacco asbestos environmental radon other occupational exposure air pollution and urban environment pulmonary fibrosis passive smoking
what is environmental radon
radon is naturally occuring
comes about from radioactive decay of other radioactive isotopes in naturally occurring rock like granite
what happens if you stop smoking?
your risk decreases but VERY slowly… >15 years and even still may not be enough
N-nitrosamines give rise to which type of cancer
adenocarcinomas
occupational exposure to polycyclic aromatic hydrocarbons (PAH) give rise to which type of cancer?
squamous SCC
N-nitrosamines modern day cigarettes
more common in modern cigarettes
and these modern cigarettes have caused a shift in the types of cancers present now compared to in the past
in order to develop lung cancer from smoking you most likely need to have had at least one of which 3 things?
epithelial effects
multi-hit ie a number of genetic alterations - in a sequence
inherited genetic polymorphisms that increase chance of lung cancer
what are the two main pathways of carcinogenesis in the lungs
in the lung periphery - bronchioloalveolar epithelial stem cells transform - adenocarcinoma
in the central lung airways - bronchial epithelial stem cells transform - squamous cell carcinoma
what are the 4 main cell type in lung cancers
most common are:-
Squamous Cell
Adenocarcinoma
less common:-
Small Cell Carcinoma
Large Cell Carcinoma
primary lung cancer and detection of symptoms
presents LATE in its natural history
as can grow ‘clinically silent’ for many years
symptomatic lung cancer is fatal- by the time it shows symptoms, cannot be cured
how can tumours be undetected in CT or scan?
sometimes they can grow behind the heart
why might you get haemoptysis or internal bleeding in tumours that grow into central bronchi
may be bleeding as it ulcerates into the airway
local effects of lung cancer (7)
Bronchial Obstruction : Collapse Endogenous Lipoid Pneumonia Infection / Abscess Bronchiectasis Direct invasion - chest wall pleural - inflammatory or malignant (if in periphery)
what is bronchiectasis?
a long-term condition where the airways of the lungs become abnormally widened, leading to a build-up of excess mucus that can make the lungs more vulnerable to infection.
what local neural effects can lung cancer have if it spreads further into the mediastinum (4)
- Phrenic – diaphragmatic paralysis
- L Recurrent laryngeal (Hoarse, Bovine cough)
- Brachial plexus- neurological conditions in hands
- Cervical Sympathetic (in neck) - Horner’s syndrome - damage to the sympathetic nerves of the face
signs of Horner’s syndrome
unresponsive pupil
drooping of upper eyelids
absence of facial sweating
lymph node metastases
spreads into mediastinum and can then spread elsewhere
most common place in the body that lung cancer lymph node metastases spreads to
neck
other distant metastases of lung cancer
Liver adrenals bone brain skin
what signs do you look for in the hands for lung cancer
finger clubbing
what is TNM staging
the staging mechanism in place to stage tumour growth
how many stages are there in TNM
stages 1-4
treatment depends on which stage
when is PET scan used
patients who are in stage`1 or 2 (localised cancer of the lung- only spread to 1 side of the lymph glands) are offered surgery to remove tumour
but before they go for surgery they have a PET scan done
what happens in PET scan
Inject glucose tag with radioactive element in PET scan
tumour- very metabolically active, glucose dye shows up
management/ treatment options
Performance status Patient wishes Histological type and stage Multidisciplinary team meeting Aims of treatment e.g. radical or palliative
radical radiotherapy means?
treatment with the intention to cure
radiotherapy, surgery
main types of lung cancer names
carcinoma of the bronchus (most common) cigarette smoke biggest cause also asbestos, radiation etc
bronchial adenoma - rare, mainly carcinoid tumours (slow growing)
malignant mesothelioma - rare, cancer in the lining of the lung (pleura). Associated with asbestos exposure
if you have never smoked and get lung cancer then it is extremely likely that it will be what type of lung cancer?
adenocarcinoma
What are the 2 main types of lung cancer?
non-small cell carcinoma
small cell carcinoma
non-small cell carcinoma covers which cell types?
adenocarcinomas
squamous cell carcinoma
large cell carcinoma
what is oncogene addiction?
growth of cancer at molecular level is driven by an abnormality in one particular gene. Not to say there aren’t others. Growth is driven by intercellular signaling of one gene
If you can identify this gene and you can target the protein that is making that then you can have a better treatment
these abnormalities are independent of tobacco carcinogens
Oncogene targets for adenocarcinoma therapy
EGFR mutation
ALK rearrangement
ROS1 rearrangement
BRAF mutation
oncogene addiction is virtually never present in which type of lung cancer
squamous cell carcinomas
Very few suitable targets – very few addictive oncogenes
Bronchioloalveolar cell carcinoma can also be called what?
adenocarcinoma in situ
