Lung Cancer

Question 1

What type of lung cancer does smoking have the strongest link to?

Answer 1

• squamous
• small cell
  (Central tumours around hilum)

Question 2

What are the risk factors for lung cancer?

Answer 2

• smoking
• environmental tobacco smoke
• ionising radiation - radon, uranium
• air pollution
• asbestos
• other eg. Fibrosing conditions of the lung, HPV, hereditary conditions

Question 3

What are the signs and symptoms of lung cancer?

Answer 3

• cough
• haemoptysis
• SOB
• chest pain
• weight loss/anorexia
• general malaise

Question 4

What are the symptoms of a central lung tumour?

Answer 4

• haemoptysis
• bronchial obstruction: SOB, retention pneumonia

Question 5

What are the symptoms of a peripheral lung tumour?

Answer 5

• few symptoms
• chest pain possible is pleura/chest wall is involved

Question 6

What are the possible locations for local spread of a lung cancer?

Answer 6

• 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)

Question 7

What are the signs and symptoms of SVC obstruction?

Answer 7

• headache
• oedema
• raised JVP

Question 8

What symptom/sign does recurrent laryngeal nerve paralysis lead to?

Answer 8

Hoarseness

Question 9

What are the signs/symptoms of Horner’s syndrome?

Answer 9

• anhydrosis
• eye sunken in
• ptosis
• dilation of pupil

Question 10

Describe the locations of distant spread of a lung tumour?

Answer 10

• haematogenous spread (commonly to pulmonary veins, or the liver, bone, brain, adrenal)
• lymphatic spread (commonly to cervical lymph nodes)

Question 11

What are the non-metastatic effects of lung cancer?

Answer 11

• 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

Question 12

What are the signs/symptoms of Cushing’s Syndrome?

Answer 12

• obesity
• moon facies
• osteoporosis
• muscle weakness
• abdominal striae

Question 13

Why is histological classification important in lung cancer?

Answer 13

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

Question 14

Why is adenocarcinoma becoming a more common type of lung cancer?

Answer 14

• 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)

Question 15

Describe the features of squamous cell carcinoma

Answer 15

• 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

Question 16

Describe the appearance of squamous cell carcinoma

Answer 16

• malignant epithelial tumour showing keratinisation and/or intercellular bridges
• possible in-situ squamous cell carcinoma in adjacent mucosa

Question 17

Describe the features of adenocarcinoma

Answer 17

• more common in females
• most arise in periphery sometimes in relation to scarring

Question 18

Describe the appearance of adenocarcinomas

Answer 18

• glandular, solid, papillary or lepidic (along alveolar walls)
• mucin production

Question 19

Describe the features of small cell carcinoma

Answer 19

• most aggressive
• metastasises early and widely
• good initial response to chemo but high rate of relapse

Question 20

Describe the appearance of small cell carcinoma

Answer 20

• oval to spindle shaped cells
• inconspicuous nucleoli
• scant cytoplasm
• nuclear moulding

Question 21

Describe the features of large cell carcinoma

Answer 21

• diagnosis of exclusion
• arises centrally
• undifferentiated malignant epithelial tumour that lacks cytological features of SCLC and glandular or squamous differentiation

Question 22

Describe the features of the carcinoid tumour

Answer 22

• tumour of neuroendocrine cells
• central or peripheral
• typical or atypical
• can metastasise but good prognosis

Question 23

Describe the pathogenesis of lung cancer

Answer 23

• 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)

Question 24

Describe the features of mesothelioma

Answer 24

• 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)