18 - Lung Cancer

Question 1

Lung cancer

Answer 1

A malignant tumour derived from the epithelium of the lung

Question 2

How common is lung cancer

Answer 2

Fifth most common in aus, leading cause of cancer related death

Question 3

Aetiology of most common types of lung cancer

Answer 3

Stepwise accumulation of genetic abnormalities that transform benign bronchial epithelium to neoplastic tissue

Question 4

Passive smoking during childhood

Answer 4

associated with higher
chance of developing nasal cancer

Question 5

Mechanisms of action of smoking causing cancer

Answer 5

carcinogenic components e.g. aromatic hydrocarbons, nitrosamine resulting in DNA damage

Question 6

Risk factors

Answer 6

• Industrial hazards (ionising radiation, asbestos)
• Air pollution
• Radon gas
• Infections (HPV 6 and 11, EBV)
• Lung injury
• Genetic predisposition

Question 7

Symptoms and signs

Answer 7

• Cough
• Weight loss
• Chest pain
• Dyspnoea (difficulty breathing)
• Haemoptysis (coughing up blood)

Question 8

Precursor (Preinvasive) lesions

Answer 8

• Squamous dysplasia and carcinoma in situ
• Atypical adenomatous hyperplasia
• Adenocarcinoma in situ
  -Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia

Question 9

Adenocarcinoma

Answer 9

• Malignant epithelial tumour with glandular differentiation
  or mucin production by the tumour cells
• Occurs in smokers & non-smokers
• Often display gain-of-function mutations of growth factor receptors or their pathway components

Question 10

Squamous cell carcinoma

Answer 10

• Arise from metaplastic squamous epithelium of the
  bronchi that develop secondary to irritants
• Strong association with smoking
• Characterised by squamous differentiation on histology
• Often preceded by intraepithelial dysplasia
• Diverse genetic aberrations

Question 11

Small cell carcinoma

Answer 11

• arise from neuroendocrine progenitor cells of the lining bronchial epithelium
• Strong relationship to smoking
• Usually arise in major bronchi
• Very aggressive malignancy

Question 12

Carcinoid tumours

Answer 12

• Low-grade malignant epithelial neoplasms
• Often circumscribed, polypoid masses that project into the lumen of a bronchus
• Relatively monomorphous cells with round to oval nuclei, arranged in nests
• neuroendocrine tumours, some have secretory ability leading to the “carcinoid syndrome”

Question 13

Mesothelioma

Answer 13

• Tumour that arises from the mesothelial cells lining the pleura
• Strong association with asbestos
• Most patients present with pleural effusion or pain
• Present at an advanced stage

Question 14

EGFR (epidermal growth factor receptor)

Answer 14

Certain mutations in the EGFR gene predict response to tyrosine kinase inhibitors

Question 15

ALK (anaplastic lymphoma kinase)

Answer 15

• Inversion of ALK results in formation of EML4-ALK fusion gene and oncogenic activation of ALK
• Predicts response to a novel ALK inhibitor

Question 16

K-RAS (Kirsten ras sarcoma)

Answer 16

• Mutation associated with poorer prognosis
• Used to predict response to agents targeting EGFR and ALK