Lung Cancer Flashcards
How to classify lung cancers?
- non-small cell carcinoma (85%)
- small cell carcinoma (15%).
This distinction is based on the size of the malignant cells seen on microscopy.
How is non-small cell carcinoma further classified?
- adenocarcinoma (40% of all lung cancer)
- squamous cell carcinoma (30%)
- large cell carcinoma (10%)
Non small cell: Adenocarcinoma
- location
- histology findings ?
- clinical features?
Located peripherally (in the smaller airways)
Histology: glandular differentiation
Clinical features:
* More common in non-smokers and Asian females
* Metastasise early
* Responds well to immunotherapy
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Squamous cell carcinoma:
* location?
* histology findings ?
* clinical features?
CF: assoicated with / more common in
Located centrally (in the bronchi)
Histology: squamous differentiation (keratinisation)
Clinical features:
* More common in smokers
* Secrete PTHrP, causing hypercalcaemia
* Metastasise late (via lymph nodes)
Large cell carcinoma:
* location?
* histology findings ?
* clinical features?
CF: more common in
Located peripherally and centrally
Histology: large and poorly-differentiated
Clinical features:
* More common in smokers
* Metastasise early
Small cell carcinoma:
* location?
* histology findings ?
* clinical features?
CF: assoicated with / more common in
Located centrally
Histology: poorly-differentiated
Clinical features:
* More common in older smokers
* Metastasise early
* Secrete ACTH (Cushing’s syndrome) and ADH (SIADH)
* Associated with Lambert-Eaton syndrome
Risk factors for lung cancer
- TOBACCO SMOKING - 80% lung cancer cases
other:
* Air pollution (indoor and outdoor)
* Family history of cancer, especially lung cancer
* Male sex
* Radon gas (typically affects miners)
History: what are typical symptoms of lung cancer?
- Unexplained cough for at least 3 weeks (with or without haemoptysis)
- Unintended weight loss (>5% in 6 months)
- New-onset dyspnoea
- Pleuritic chest pain (due to the tumour invading the pleura or the chest wall)
- Bone pain (due to metastases – commonly the spine, pelvis and long bones)
- Fatigue (due to anaemia of chronic disease)
- Note that up to 20% of patients present with non-respiratory symptoms (such as fatigue).
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What are other areas important to cover in history if you suspect lung cancer ?
- Family history: lung cancer in a first-degree relative increases risk
- Smoking history: (remember passive smoking) quantify smoking in pack-years (1 pack-year = smoking 20 cigarettes a day for a year).
- Occupation: indoor air pollution or radon gas (e.g. miners)
What are some physical findings on clinical examination of a patient with lung cancer?
- Cachexia: cancer can cause increased resting energy expenditure and lipolysis.
- Finger clubbing
- Dullness to percussion: due to the tumour (solids are less resonant than gases).
- Cervical lymphadenopathy: mets to the lymphatic system.
- Wheeze on auscultation: due to the tumour obstructing an airway.
When to refer urgently: NICE RED FLAG symptoms for 2 WW?
- Chest X-ray findings suggestive of lung cancer
or - Over 40 years old and unexplained haemoptysis
Note: pt also needs a CXR in 2 weeks
Lung cancer: When to refer urgently for a CXR (within 2 weeks)…..?
urgent CXR (w/in 2 weeks) before a decision to refer on a 2-WW is made
Patient >40 yrs
AND have 2 of the following unexplained symptoms ( 1 if never smoked):
* Cough
* Weight loss
* Appetite loss
* Dyspnoea
* Chest pain
* Fatigue
Patient >40 yrs and ANY of the below :
* Clubbing
* Lymphadenopathy (supraclavicular or persistent abnormal cervical nodes)
* Recurrent or persistent chest infections
* Raised platelet count (thrombocytosis)
* Chest signs of lung cancer
What are some differencial diagnosis for Lung cancer?
Will expand later on differenciating features
- TB
- Mets to the lung from other sites
- Sarcoidosis
- Granulomatoiss with polyangitis
- Non-Hodgkins lymphoma
Features differenciating TB from lung cancer
- Drenching night sweats
- Positive sputum culture and microscopy
- Chest X-ray: cavitating lesion/hilar lymphadenopathy
Features differenciating cancer that has metastaised TO THE lungs FROM (primary) Lung cancer
i.e. its not lung cancer
Symptoms relevant to the primary tumour (e.g. haematuria due to renal cell carcinoma)
CT head-abdomen-pelvis: shows primary tumour
FDG-PET: increased uptake at the primary tumour site
fluorodeoxyglucose (FDG) (PET) detects metabolically active malignant le
features differenciating sarcoidosis from lung cancer ?
Enlarged parotids
Skin signs: erythema nodosum and lupus pernio
Tissue biopsy: non-caseating granulomas
Features differenciating Non-hodgkins lymphoma from lung cancer?
Drenching night sweats
Hepatosplenomegaly
Positive lymph node biopsy (anti-CD20 stain)
Dr Tom loves which 2 physical findings which would suggest lung cancer and need urgent CXR?
Finger clubbing
supraclavicular lymphadenopathy