lung cancer Flashcards
types
Lung cancer is initially classified histologically as being either small cell lung cancer (SCLC) or non-small cell lung cancer (NSCLC) due to the different features, management and prognosis see in the two groups.
🥨 SCLC accounts for around 15% of cases and generally carries a worse prognosis.
🥨 NSCLC can be broken down into (percentages refer to total lung cancer cases, not just NSCLC:
- squamous: c. 35%
- adenocarcinoma: c. 30%
- large cell: c. 10%
- alveolar cell carcinoma: not related to smoking, ++sputum
- bronchial adenoma: mostly carcinoid
Differentiating between NSCLC is now important than before due to the different drugs available treat the subtypes.
Small cell cancer aka ‘oat cell carcinoma’
epidemiology
20%
smokers
Small cell cancer aka ‘oat cell carcinoma’
pathology
central location
near bronchi
HISTO: small, poorly differential cells
Small cell cancer aka ‘oat cell carcinoma’
behaviour
80% present w/ advanced disease
v chemosensitive but v poor prognosis
ectopic hormone secretion:
- 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
Small cell cancer aka. oat cell carcinoma
mx
Management
- usually metastatic disease by time of diagnosis
- patients with very early stage disease (T1-2a, N0, M0) are now considered for surgery. NICE support this approach in their 2011 guidelines
- however, most patients with limited disease receive a combination of chemotherapy and radiotherapy
- patients with more extensive disease are offered palliative chemotherapy
NSCC: squamous cell carcinoma
epidemiology
35%
M>F
smoking
radon gas
NSCC: squamous cell carcinoma
pathology
centrally located
histo: evidence of squamous differentiation, keratinisation
NSCC: squamous cell carcinoma
behaviour
locally invasive
metastasize late [via LN]
cancer cells release parathyroid related protein= cause hypercalcemia
NSCC: adenocarcinoma
epidemiology
25%
females
non smokers
far-east
NSCC: adenocarcinoma
pathology
peripherally located
histo: glandular differentiation [gland/mucin formation]
NSCC: adenocarcinoma
behaviour
extrathoraic mets common and early
80% present with mets
NSCC: large cell
epidemiology
10%
NSCC: large cell
pathology
peripheral/central
histo: large, poorly differentiated cells
lung cancer symptoms
cough and hemoptysis
dyspnoea
chest pain
recurrent/slow resolving pneumonia
anorexia/wt loss
hoarseness
lung cancer: chest signs
consolidation
collapse
pleural effusion
lung cancer: general signs
cachexia
anemia
clubbing + HPOA [hypertrophic pulmonary osteoarthropathy]
supraclavicular +/ axillary LNs
lung cancer: metastatic signs
bone tenderness
hepatomegaly
confusion, fits, focal neuro
addisons
lung cancer RFs
smoking
asbestos
occupational exposures [chromium, aresnic, iron oxide,]
radiation [radon gas]
local complications of lung ca
[RRASH]
Recurrent larnygneal n palsy
phrenic n palsy
svc obstruction
horner’s syndrome: ptosis, miosis, anhydrosis, enopthalmos [pancoast tumour]
AF
lung ca: paraneoplastic features
Small cell
- ADH
- ACTH - not typical, hypertension, hyperglycaemia, hypokalaemia, alkalosis and muscle weakness are more common than buffalo hump etc
- Lambert-Eaton syndrome
Squamous cell
- parathyroid hormone-related protein (PTH-rp) secretion causing hypercalcaemia
- clubbing
- hypertrophic pulmonary osteoarthropathy (HPOA)
- hyperthyroidism due to ectopic TSH
Adenocarcinoma
- gynaecomastia
- hypertrophic pulmonary osteoarthropathy (HPOA)
Lung cancer: investigation
Chest x-ray
- this is often the first investigation done in patients with suspected lung cancer
- in around 10% of patients subsequently diagnosed with lung cancer the chest x-ray was reported as normal
CT
- is the investigation of choice to investigate suspected lung cancer
Bronchoscopy
- this allows a biopsy to be taken to obtain a histological diagnosis sometimes aided by endobronchial ultrasound
PET scanning
- is typically done in non-small cell lung cancer to establish eligibility for curative treatment
- uses 18-fluorodeoxygenase which is preferentially taken up by neoplastic tissue
- has been shown to improve diagnostic sensitivity of both local and distant metastasis spread in non-small cell lung cancer
Curative treatment for localised non-small cell carcinoma (NSCLC) i.e. squamous, adenocarcinoma or large cell carcinoma,
🍜 is surgical excision - lobectomy or pneumonectomy.🍜
1. surgery with curative intent for non-small-cell lung cancer
- open or thoracoscopic lobectomy as the treatment of first choice
- if it is not possible to do a complete resection, consider segmentectomy or wedge resection for patients with smaller tumours and borderline fitness
- more extensive surgery (bronchoangioplastic surgery, bilobectomy, pneumonectomy) is only required when needed to obtain clear margins
- hilar and mediastinal lymph node sampling or en bloc resection should be undertaken for all patients undergoing surgery with curative intent
2. radiotherapy with curative intent for non-small-cell lung cancer
lung function should be assessed before offering radiotherapy with curative intent
3. combination treatment for non-small-cell lung cancer
consider chemoradiotherapy for patients with stage II or III NSCLC who are not suitable for surgery
4. chemotherapy for non-small-cell lung cancer
chemotherapy should be offered to patients with stage III or IV NSCLC and good performance status
small cell cancer mx
Management
- usually metastatic disease by time of diagnosis
- patients with very early stage disease (T1-2a, N0, M0) are now considered for surgery. NICE support this approach in their 2011 guidelines
- however, most patients with limited disease receive a combination of chemotherapy and radiotherapy
- patients with more extensive disease are offered palliative chemotherapy
?Asbestos and the lung- what pathology would you see
Asbestos can cause a variety of lung disease from benign pleural plaques to mesothelioma.
Pleural plaques
Pleural plaques are benign and do not undergo malignant change. They are the most common form of asbestos related lung disease and generally occur after a latent period of 20-40 years.
Pleural thickening
Asbestos exposure may cause diffuse pleural thickening in a similar pattern to that seen following an empyema or haemothorax. The underlying pathophysiology is not fully understood.
Asbestosis
The severity of asbestosis is related to the length of exposure. This is in contrast to mesothelioma where even very limited exposure can cause disease. The latent period is typically 15-30 years. Asbestosis typically causes lower lobe fibrosis. As with other forms of lung fibrosis the most common symptoms are shortness-of-breath and reduced exercise tolerance.
Mesothelioma
Mesothelioma is a malignant disease of the pleura. Crocidolite (blue) asbestos is the most dangerous form.
Possible features
- progressive shortness-of-breath
- chest pain
- pleural effusion
Patients are usually offered palliative chemotherapy and there is also a limited role for surgery and radiotherapy. Unfortunately the prognosis is very poor, with a median survival from diagnosis of 8-14 months.
Lung cancer
Asbestos exposure is a risk factor for lung cancer and also has a synergistic effect with cigarette smoke.
