4. Lung Cancer Flashcards
Does it help to stop smoking once diagnosed with lung cancer?
Aside from smoking, what are some other causes of lung cancer?
What genetics/molecular mechanisms may lead to lung cancer?
Stopping smoking does not lower risk back down to non-smoking levels, but it increases life expectancy.
Asbestos, radiation (environmental radon), arsenic, chromium, coal tar and oils, iron oxides, pollution.
- Activation of oncognes e.g. KRAS, myc family. EGFR and ALK mutations
- Inactivation of tumour supressor genes e.g. p53
- Autocrine growth factors e.g. derivatives of nicotine found in smoke
- Inherited predisposition
Lung cancer is the most common malignant tumour in the West. What are the 4 different types of lung cancer?
What are the main features of the different types?
- Small cell (oat cell) lung cancer (SCLC) 10%
- Non small cell lung cancer (NSCLC)
- Squamous cell carcinoma 20-30%
- Adenocardinoma 40-50%
- Large cell carcinoma 10-15%
SCLC: agressive, early spread, usually inoperable. Cells divide rapidly. May respond to chemo. Endocrine cells: hormones produced.
Squamous cell: often cavitates (10%), typically in smokers.
Bronchoalveolar cell (adenocarcinoma in situ): may radiologically resemble pneumonia
Large cell: undifferentiated, early metastasis
NB. cavitates: center of the tumor dies, gets absorbed by body, so scans show hollowed out shell of tumour
What are the indications for an urgent CXR RE. lung cancer?
What chest signs would indicate investigation for LC?
Haemoptysis and any of the following for >3 weeks, unexplained: cough, chest/shoulder pain, dyspnoea, wt loss, chest signs, hoarseness, clubbing, features of metastasis (kidneys, brain, liver, skin etc.), supraclavicular/cervical lymphadenopathy.
- Visible swelling. 2. Facial swelling. 3. Distended veins (pic). 1, 2 and 3 = poss SVC obstruction e.g. tumour pressing on SVC so blood uses collateral vessels (skin BV) -> to diaphragm -> IVC.
Reduced expansion of chest e.g. tumour blocks bonchus. Dullness, decreased TVF and VR = poss pleural effusion. Wheeze - esp. unilateral. Reduced breath sounds - tumour squeezing large bronchi?
What are some paraneoplastic syndromes that arise as consequence of LC? List some.
When would a patient be given a “2 week wait” referral?
When should a patient be reffered whilst awaiting CXR (urgent referral)?
A syndrome that is the consequence of cancer in the body but is not due to the local presence of cancer cells. In contrast, these phenomena are mediated by humoral factors (such as hormones or cytokines) excreted by tumor cells or by an immune response against the tumor.
- SCLC: Cushing’s syndrome (ectopic ACTH), SIADH (Syndrome of inappropriate antidiuretic hormone secretion - H2O retention so decreased electrolytes e.g. Na+), Lambert Eaton myasthenic syndrome, Limbic encephalitis, cerebellar syndrome
- Any but more common in SCLC: dermatomyositis
- Squamous cell carcinoma: hypercalcaemia
If CXR or CT scan suggests LC including PE, or slowly resolving consolidation (b/c bronchoalveolar cell carcinoma looks like pneumonia -> consolidation onCXR so give abx and come back in 6w for repeat CXR). If the CXT/CT is normal but there is high clinical suspicion of LC e.g. severe cough/rapid wt loss, the pt should be referred.
Persistent haemoptysis in smokers/ex-smokers > 40 yrs. Signs of superior vena caval obstruction (swelling of face/neck with fixed elevation of JVP. Stridor.
What investigations are done for LC?
What is TNM staging?
“Staging” CT of chest - including upper abdo to cover liver, adrenals and kidneys (common areas for mets), + blood test B4 CT! Bronchoscopy. CT guided biopsy. PET scan. MRI scan for Pancoast tumours (at apex). Other staging investigations include bone scan, brain CT/MRI, mediastinoscopy, EUS/EBUS guided FNA (take samples), transbronchial “blind” FNA.
- *T:** based on size and location of tumour. T1 = small peripheral tumour which may be removed surgically (stage 1 or 2). T4 = advanced large tumour invading e.g. heart (stage 3).
- *N:** depends on which lymph nodes are involved. N1 = hilar (stage 2), N2 = mediastinal, N3 = contralateral (stage 3).
- *M:** if metastases are present, M1 (stage 4). Common sites: liver, lungs, adrenals, brain, bones.
How is LC treated? (6 types of treatment)
1) Surgical: for localised tumours - no signs of spread, only chance of “cure”. 5-10% suitable. 70% 5-yr survival.
- *2) Radical radiotherapy:** may be useful in squamous cell carcinoma if surgery not possible (LN involved, pt declines or not fit. Complications include post radiation pneumonitis (early) and fibrosis (late).
- *Palliative radiotherapy:** Relieve pain, haemoptysis, neurological problems (brain/spinal metastases)
3) Chemotherapy: small survival advantage, pemetrexed and carboplatin often used for SCLC. Newer agents incl EGFR antagonists like erlotininb.
- *4) Adjuvent chemo:** after surgery to reduce recurrence (usually if disease found in hilar LN)
- *Neo-adjuvent chemo:** before surgery to make sure cancer as well controlled as poss
5) Other palliative: endobronchial laser relieves obstruction, breathlessness, haemoptysis. Stenting. Endobronchial radiotherapy. General: painkillers, antitussives, O2, steroids
6) Cancer nurse specialist: psychosocial support, councelling. Ethical issues discussed with pt and family Re: timing of investigations and tx. DNAR and advanced directives.
What is the ideal pathway from pt with LC presenting to A and E/GP?
Pt presents to AandE/GP -> CXR -> CXR abnormal -> referral to chest physician -> chest physcian requests CT -> CT report -> OPA (oropharyngeal airway) and PET request -> Bronchoscopy/CT bx/EUS -> histology available -> PET available, decide on chemo/RT/surgery.
Case 1
75 yo male, heavy pain in R side of chest for 1 month, gradually progressive dyspnoea, mild cough. What is your next step:
- Bronchoscopy
- US of chest
- CT of chest and abdo
- Lung function tests
- Srick a needle into chest
What investigations could you do?
- US of chest -> fluid sample
* NB: ‘heavy pain’ - fluid! In CXR can see massive pleural effusion - so big that get upwards convexity rather than the usual.*
Pleural tap: preferably under US, exudate needs further Ix
CT chest
Pleural biopsy
If diagnosis not obtained - VATS
May need drainage +/- pleurodesis (stick lung to chest wall so fluid has no space to go)
If mesothelioma - radiotherapy to biopsy/drain site
Case 2
53 yo female Caribbean Health Support Worker, recurrent pneumonia for 3 months, better with abx each time, blood tests show low Na+ level. SIADH (excessive unsuppressible release of ADH either from posterior pituitary gland, or an abnormal non-pituitary source).
The CXR is below - is it normal?
No - consolidation in R lower zone - pneumonia? Bronchoalveolar cell carcinoma? Therefore CT (below). Can see R main bronchus squeezed by tumour.
Bronchoscopy showed small cell carcinoma of lung.
Low Na+ indicates SIADH.
Case 3
70 yo female ex-smoker, previous TB in 1950s, ECOG performance score 1, FEV1 0.89 litres (56%), chronic breathlessness and wt loss, previous RLL shadowing - resolved then reappeared.
What can you say about the XRay and CT?
Rather low lung function.
CXR: faint shadowing in R lung -> thoracoplasty (lung deliberately collapsed).
CT guided biopsy showed adenocarcinoma. Would have been operable if not for previous thoracoplasty. Referred for chemo.
Case 4
Presented to A and E with facial swelling, through to be allergy (angio-oedema) and referred to allergy clinic approx 6w later. Found to have high Ca level on blood tests. CXR done.
What does it show?
a) cancer
b) PE
c) TB
d) pulmonary oedema
e) pneumonia
Facial swelling maybe due to SVC obstruction? High Ca maybe sign of cancer?
CXR: R upper lobe collapsed down, probably tumour inside, compressing SVC.
Outcome: bronchoscopy showed non-small cell carcinoma. Referred to radiologist at RLH for SVC stent. Chemo followed.
Case 5
72 yo ex-smoker, mild anaemia, pharyngeal pouch, performance score 1. What can you see in the following Ixs?
Shadow in CXR. CT = bilateral lesions.
Outcome: PET scan showed FDG uptake in large lesion in RLL as well as in LLL. Referred for chemo.
Case 7
38 yo Pakistani female, cough and haemoptysis for 4 weeks, CXR “bulky L hilum”, further history: never smoked, recent trip to Pakistan. What would you do next?
a) CT
b) blood tests
c) bronchoscopy
d) sputum test
e) lung biopsy
D. Sputum test.
Outcome: sputum smear +ve for AAFB. Started anti-TB meds.
Case 8
49 yo female smoker, cough and rusty brown sputum for 4 days prior to consulting GP. CXR shows dense shadowing RLL. What would you do next?
a) CT
b) repeat CXR
c) bronchoscopy
d) sputum test
e) lung biopsy
B. Repeat CXR
Further history: 15 pack year smoking, no chest pain or wt loss, by time pt seen in clinic symptoms had improved with abx from GP. Given another appt in 4 weeks time. Repeat CXR showed pneumonia had resolved.
