Lung Cancer Flashcards
What type of lung cancer does smoking have the strongest link to?
- squamous
- small cell
(Central tumours around hilum)
What are the risk factors for lung cancer?
- smoking
- environmental tobacco smoke
- ionising radiation - radon, uranium
- air pollution
- asbestos
- other eg. Fibrosing conditions of the lung, HPV, hereditary conditions
What are the signs and symptoms of lung cancer?
- cough
- haemoptysis
- SOB
- chest pain
- weight loss/anorexia
- general malaise
What are the symptoms of a central lung tumour?
- haemoptysis
- bronchial obstruction: SOB, retention pneumonia
What are the symptoms of a peripheral lung tumour?
- few symptoms
- chest pain possible is pleura/chest wall is involved
What are the possible locations for local spread of a lung cancer?
- pleura (haemorrhagic effusion)
- hilar lymph nodes
- adjacent lung tissue (can involve large blood vessels causing haemoptysis)
- pericardium (pericardial effusion with subsequent involvement of pericardium)
- mediastinum (SVC obstruction, involvement of recurrent laryngeal and phrenic n.)
- pancoast tumour (involvement of brachial plexus, Horner’s)
What are the signs and symptoms of SVC obstruction?
- headache
- oedema
- raised JVP
What symptom/sign does recurrent laryngeal nerve paralysis lead to?
Hoarseness
What are the signs/symptoms of Horner’s syndrome?
- anhydrosis
- eye sunken in
- ptosis
- dilation of pupil
Describe the locations of distant spread of a lung tumour?
- haematogenous spread (commonly to pulmonary veins, or the liver, bone, brain, adrenal)
- lymphatic spread (commonly to cervical lymph nodes)
What are the non-metastatic effects of lung cancer?
- ACTH secretion (adrenal hyperplasia resulting in raised blood cortisol = Cushing’s syndrome)
- ADH secretion (water retention, dilutional hyponatraemia SIADH)
- parathyroid hormone related peptide secretion (osteoclastic activity = hypercalcaemia)
- encephalopathy and cerebellar degeneration
- neuropathy
- myopathy
What are the signs/symptoms of Cushing’s Syndrome?
- obesity
- moon facies
- osteoporosis
- muscle weakness
- abdominal striae
Why is histological classification important in lung cancer?
It can affect treatment:
- small cell cancer (is usually advanced at diagnosis) = responds to chemotherapy
- non-small cell cancer (usually localised at diagnosis) = responds to radiotherapy/surgery
Why is adenocarcinoma becoming a more common type of lung cancer?
- change in smoking demographics (more women)
- use of filter tips, lower tar and nicotine levels
- deeper inhalation when smoking which exposes the more peripheral airways to carcinogens (peripheral = predominantly adenocarinomas)
Describe the features of squamous cell carcinoma
- tend to arise centrally from major bronchi
- within dysplastic epithelium following squamous metaplasia
- slow growing and metastasise late (can be good candidate for surgery)
- can undergo cavitation and block bronchi leading to retention pneumonia/collapse
Describe the appearance of squamous cell carcinoma
- malignant epithelial tumour showing keratinisation and/or intercellular bridges
- possible in-situ squamous cell carcinoma in adjacent mucosa
Describe the features of adenocarcinoma
- more common in females
- most arise in periphery sometimes in relation to scarring
Describe the appearance of adenocarcinomas
- glandular, solid, papillary or lepidic (along alveolar walls)
- mucin production
Describe the features of small cell carcinoma
- most aggressive
- metastasises early and widely
- good initial response to chemo but high rate of relapse
Describe the appearance of small cell carcinoma
- oval to spindle shaped cells
- inconspicuous nucleoli
- scant cytoplasm
- nuclear moulding
Describe the features of large cell carcinoma
- diagnosis of exclusion
- arises centrally
- undifferentiated malignant epithelial tumour that lacks cytological features of SCLC and glandular or squamous differentiation
Describe the features of the carcinoid tumour
- tumour of neuroendocrine cells
- central or peripheral
- typical or atypical
- can metastasise but good prognosis
Describe the pathogenesis of lung cancer
- chronic irritation/stimulation of cells by carcinogens
- increased cell turnover
- progressive accumulation of genetic abnormalities in molecules involved in cell cycle signalling and angiogenesis pathways
- hyperplasia > metaplasia > dysplasia > carcinoma in situ (can then become invasive and metastasise)
Describe the features of mesothelioma
- primary pleural tumour (encases the lung - thickening of pleura)
- almost always due to asbestos exposure
- long lag period before disease develops
- tumour either epithelial or sarcomatoid appearance or mixture (biphasic)
