Lung cancer Flashcards
RF for bronchial carcinoma
- Cigarettes inc passive exposure, esp large no pack years (cig per day*no years smoked divided by 20)
- Toxins like radon, asbestos, polycyclic aromatic hydrocarbons, arsenic
- Pre-existing lung disease like pulmonary fibrosis
- Immunosuppression
- Age
Small cell lung cancer
12% of bronchial carcinomas
Mostly caused by smoking
Often a/w paraneoplastic syndromes due to hormone secretions
Metastasise early
Non-small cell lung cancer
- Adenocarcinoma: commonest type in UK, a/w smoking (but is also the commonest type in non-smokers), typically a peripheral lesion
- Squamous cell carcinoma: also a/w smoking, typically central lesions, metastasises fairly late compared to others, a/w hypercalcaemia from PTHrp release + finger clubbing + hypertrophic pulmonary osteoarthropahty
- Large cell carcinoma: large round cells, poorly-differentiated, early mets, typically peripheral, may secrete beta-hCG
Local effects of lung cancer
- Persistent cough
- Breathlessness
- Haemoptysis
- Chest pain from chest wall/pleura (sharp pain) or mediastinal nodes (dull central ache)
- Wheeze from partial obstruction
- Hoarseness - compression of LRLN
- Brachial plexus invasion in Pancoast tumours causing C8/T1 palsy (wasting + pain of small muscles in hand)
- Horner syndrome in Pancoast tumours if invades sympathetic chain (ptosis, miosis and anhidrosis)
- Recurrent infection
- Invasion of phrenic nerve causing hemidiaphragm paralysis
- SVCO
- Tracheal tumours-dyspnoea, stridor
- Atelectasis
Metastasis of lung cancer
- Liver: anorexia, nausea, WL, RUQ pain
- Bone: pain, #, SC compression
- Adrenals: asymptoamtic
- Brain: RICP, carcinomatous meningitis, N+V, focal signs, headache, vision
- Malignant pleural effusion
Extra-pulmonary non-metastatic manifestations
- Metabolic: WL, anorexia, anaemia
- Endocrine (mostly SCLC): ectopic ACTH, SIADH, hypercalcaemia (squamous cell usually), hypoglycaemia, hyperthyroidism, gynaecomastia
- Neuro: encephalopathies, myelopathies, neuropathies
- Vascular (uncommon): thrombophlebitis migrans, thrombotic endocarditis, DIC, TTP
- Skeletal: clubbing, hypertrophic osteoarthropathy (causing wrist pain)
- Cutaneous (uncommon): acanthosis nigricans, dermatomyositis
Signs on CXR
Mass lesion, large u/l pleural effusion, mediastinal widening, slow-resolving consolidation, collapse, reticular shadowing
or
normal!
Staging of lung cancer
TNM
- T1 not in main bronchus, T2 in bronchus/pleura, T3 big, T4 mediastinal invasion
- N: N0 none, N1 + N2 ipsilateral, N3 C/L or supraclavicular or mediastinal
- M: M- none, M1a in c/l lung, M1b distant
Management of lung cancer
- NSCLC: small number are suitable for resection which can cure in early stages, radiotherapy can help (but poor lung function is a common CI), usually some chemo to improve QoL
- SCLC: stage 1 or neuroendocrine tumours may benefit from surgery but usually is a palliative scenario with chemo or radio if deemed appropriate; may do prophylactic brain radiation to prevent cerebral mets
- Majority advanced disease so symptomatic v important esp for breathless + pain. E.g. radiotherapy for some bone pains or SVCO
Where do mets in the lungs often originate from?
Kidney, prostate, breast, bone, GIT, cervix or ovary
Present as parenchymal round shadows and are asymptomatic unless in the bronchi
Lymphangitis carcinomatosis
When spread occurs along lymphatics of the lungs
Usually from stomach, pancreas or breast
Causes progressive dyspnoea, CXR shows b/l lymphadenopathy + streaky basal shadowing
What are cannonball mets?
A solitary round shadow
Due to renal cell carcinoma
Mesothelioma
Asbestos-related
Presents late with pleural effusion or chest wall pain
Poor prognosis
CF
- Symptoms do not predict diagnosis as often asymptomatic but may have the typical things like sob, persisting cough, dysphagia, hoarse voice
- Possible signs include clubbing, Horner’s, swelling of face/arms/engorged veins, anaemia, hypercalcaemia, SIADH, Lambert-Eaton myasthenic syndrome
Imaging
- staging CT from neck to lower abdomen (continuous scan so doesn’t miss stuff)
- HRCT + CT thorax take slices every 1cm so not good for cancer as miss areas
- use to work out TNM stage
- May do PET scan if intended surgery to see mets not detected on CT - uses radio labelled glucose, look at uptake, higher areas of uptake in rapidly dividing cells
