Lung Ca Flashcards
Primary lung toumours: the majority are…
95% are bronchial carcinomas
common sites for lung Ca to metastasise
kidney, prostate, breast, bone, gastrointestinal tract, cervix and ovary
Lung cancer subtypes and frequency
non-small cell 85%
3 main subtypes of non-small cell lung cancer (NSCL) :
- 1. Squamous cell cancer 42%
- 2. Adenocarcinoma 39%
- Large cell lung carcinoma 8%
- Carcinoid 7%
- Alveolar cell carcinoma: not related to smoking, ++sputum
Small Cell 15%
features of squamous cell lung ca
typically central
associated with ectopic PTH secretion –> hypercalcaemia
strongly associated with finger clubbing
hypertrophic pulmonary osteoarthropathy (HPOA)
features of adenocarcinoma
- most common type in non-smokers, although the majority of patients who develop lung adenocarcinoma are smokers
- typically located on the lung periphery
NSCLCa management
- only 20% suitable for surgery
- mediastinoscopy performed prior to surgery as CT does not always show mediastinal lymph node involvement
- curative or palliative radiotherap
- y
poor response to chemotherapy
paraneoplastic features of small cell
- ADH
- ACTH - not typical Cushingoid, hypertension, hyperglycaemia, hypokalaemia, alkalosis and muscle weakness are more common than buffalo hump etc
- Lambert-Eaton syndrome
paraneoplastic features of squamous cell Ca
- PTH-rp>> HyperCa
- clubbing
- hypertrophic pulmonary osteoarthropathy (HPOA)
- hyperthyroidism due to ectopic TS
paraneoplastic features of adenocarcinom
gynaecomastia
Lung Ca risk factors
- Smoking: increases risk of lung ca by a factor of 10
- asbestos - increases risk of lung ca by a factor of 5.
- Smoking and asbestos are synergistic= 50 times increased risk
- arsenic
- radon
- nickel
- chromate
- aromatic hydrocarbon
- cryptogenic fibrosing alveolitis
is coal dust a risk factor for lung Ca?
No
feautres of Small Cell Lung Ca
Features
- usually central
- arise from APUD cells
- Amine - high amine content
- Precursor Uptake - high uptake of amine precursors
- Decarboxylase - high content of the enzyme decarboxylase
- associated with ectopic ADH, ACTH secretion
- ADH –> hyponatraemia
- ACTH –> Cushing’s syndrome
- ACTH secretion can cause bilateral adrenal hyperplasia, the high levels of cortisol can lead to hypokalaemic alkalosis
- Lambert-Eaton syndrome: antibodies to voltage gated calcium channels causing myasthenic like syndrome
Mx for small cell lung ca
- usually metastatic disease by time of diagnosis
- surgery: only for debulking
- most with limited disease now receive a combination of chemotherapy and radiotherapy
patients with more extensive disease are offered palliative chemotherapy
Local tumour effects
- Persistent cough, or change in usual cough
- Haemoptysis
- Chest pain (suggests chest wall or pleural involvement)
- Unresolving pneumonia or lobar collapse
- Unexplained dyspnoea (bronchial narrowing or obstruction)
- Wheeze or stridor
- Shoulder pain (diaphragm involvement)
- Pleural effusion (direct tumour extension or pleural metastases)
- Hoarse voice (tumour invasion of the left recurrent laryngeal nerve)
- Dysphagia
- Raised hemi-diaphragm (phrenic nerve paralysis)
- SVCO
- Horner’s syndrome (meiosis, ptosis, enopthalmos, anhidrosis) due to apical or Pancoast’s tumour
- P
ancoast’s tumours can directly invade the sympathetic chain, brachial plexus, and rib→weakness of small muscles of the hand—C5/6, T1 motor loss, and shoulder pain
Paraneoplastic syndromes
- Cachexia and wasting
- Clubbing (up to 29% of pts; any cell type, more common in squamous and adenocarcinoma)
- Gynaecomastia
- SIADH (mainly SCLC) in up to 15% of pts
- Ectopic ACTH (Cushing’s syndrome, but due to rapid development biochemical changes predominate, mainly SCLC) in 2–5% of pts
- Hypertrophic pulmonary osteo-arthropathy (HPOA, often in association with clubbing, any cell type; more common in squamous and adenocarcinoma)
- Lambert–Eaton myasthenic syndrome (or LEMS)—with SCLC. Affects proximal limbs and trunk, with autonomic involvement (dry mouth, constipation, erectile failure) and hyporeflexia (although reflexes return on exercising the affected muscle group), and only a slight response to edrophonium. Symptoms may predate lung cancer by up to 4 years
- Cerebellar syndrome (usually SCLC)
- Limbic encephalitis (SCLC, also breast, testicular, other cancers. Occurs within 4 years of dx of cancer. Personality change, seizures, depression, sub-acute onset confusion and short-term memory loss. Dxd by pathological or radiological involvement of limbic system. Anti-Hu antibodies positive in 50% if associated with lung cancer.)
- Glomerulonephritis
