CT 15 Lung Cancer Flashcards
Common driver mutations in non smokers in adenocarcinomas of the lungs
EGFR
ALK
RET
ROS1
common driver mutations more common in smokers in adenocarcinomas
KRAS
BRAF
mutations common in Squamous cell carcinoma
- Tp53
mutations associated with small cell carcinoma
- TP53
- RB1
examples of causes of lung cancer
- smoking (90% of cases)
- carcinogenic metals
- carcinogenic chemicals like acetaldehyde
- occupational exposure to radon etc
- environmental radon accounts for 10% of cases
Symptoms of lung cancer
- SOB
- persistent cough
- weight loss
- chest pain
- hoarseness
- haemoptysis
-paraneoplastic syndromes
classification of lung cancer
- non small cell lung cancer (85%)
includes adenocarcinoma, Squamous cell and large cell - small cell lung cancer (accounts for 10 -15% of cancer cases)
carcinoid syn drome
Carcinoid tumors produce hormones like:
Serotonin (causes diarrhea and flushing)
Histamine (contributes to skin reactions)
Bradykinins (cause low blood pressure)
over time causes RHF and valvular disease
- investigated with urinary 5HIAA or blood test chromogranin A
treated with surgery and ocreotide (somatostatin analogue)
histology of the lungs
- pseudostratified columnar epithelium
the progression of squamous cell cancer
- starts off as squamous cell metaplasia (replacement of normal bronchial histology to squamous epithelium triggered by chronic irritation)
next is squamous dysplasia
- last step is malignancy
what type of lung cancer are non smokers likely to get
adenocarcinoma of the lung
what are some complications of lung cancer
- pneumonia, pleural effusion, abscess (caused by tumour obstruction of the airway)
- hoarseness(indicates invasion of recurrent laryngeal nerve)
-diaphragm paralysis (indicates invasion of phrenic nerve)
- dysphagia (indicates oesophageal invasion)
- SVC syndrome (SVC is compressed by tumour)
- Horner’s syndrome (sympathetic ganglia is invaded by tumour)
-pericarditis, tamponade
how does SVC syndrome present
- positive pemberton’s sign
rising arms above head causes facial congestion, cyanosis, neck swelling and respiratory distress
how does horner’s syndrome present
-ptosis (partial, drooping)
- anhidrosis
- miosis (pupil constriction)
how else may a pancoast tumour present
- shoulder pain
- upper limb neurological signs
- horner’s syndrome
PNS associated with small CC
- SIADH (ADH secretion)
- ACTH secretion
- Lambert eaton syndrome
- PNS cerebellar degeneration (autoimmune) leads to ataxia
- encephalomyelitis
what is lambert eaton syndrome
reduction in Ach release from presynaptic nerve terminals, which arises from autoimmune antibodies targeting VGCCs within the presynaptic neuronal cell membrane. (influx of ca causes release of ACh)
- muscle weakness
- dry eyes and mouth
- constipation
which PNS are associated with squamous CC
- PTH secretion: hypercalcaemia
(bones, groans, stones and psychiatric overtones) - Ectopic TSH leading to hyperthyroid
- hypertrophic pulmonary osteoarthropathy (Swollen joints and pain) + clubbing
what is HPOA
The tumor secretes growth factors (VEGF, PDGF, and PGE2), leading to:
Increased blood vessel growth (vascular proliferation).
New bone formation in the periosteum (bone lining).
Fibrosis and swelling of connective tissue.
These changes cause pain, clubbing, and joint symptoms.
PNS associated with adenocarcinoma of the lung
- HPOA
- trosseaus sign of malignancy
Adenocarcinoma increases blood clotting factor production.
Symptoms:
Deep vein thrombosis (DVT) – Leg pain, swelling.
Pulmonary embolism (PE) – Chest pain, difficulty breathing.
Migratory thrombophlebitis – Recurrent blood clots in different locations.
- gynaecomastia
treatment for small CC
early stage disease is treated with radical chemo and RT
extensive disease: palliative chemo and RT
treatment for NSCC
surgery or radical RT
tyrosine kinase inhibitors like erlotinib or gefitinb for EGFR mutations
ALK inhibitors like crizotinib
PDL1 inhibitors atexolizumab
PD1 inhibitors permbrolizumab
Mesothelioma is associated with what
asbestos exposure
no current cure
what are the central cancers
squamous and small cell
