Lung cancer

Question 1

What causes lung cancer?

Answer 1

Tobacco
Radon
Asbestos

Question 2

What are the clinical features of lung cancer?

Answer 2

- Haemoptysis
	• Unexplained or persistent (i.e. > 3 weeks)
- Cough
- Chest/shoulder pain
- Chest signs
- Dyspnoea (shortness of breath)
- Hoarseness
- Finger clubbing
- Urgent referral for chest x-ray+

Question 3

What is the choice of lung cancer treatment based on?

Answer 3

• Histological cell type
  
  • Small cell cancer
  • Non small cell cancer (75%)
• The stage of the lung cancer
• Performance status of the patient

Question 4

What are types of non small cell cancer?

Answer 4

squamous cell carcinoma 
large cell carcinoma
anaplastic carcinoma
Adenocarcinoma
bronchiolo-alveolar cell carcinoma

Question 5

What is the pathogenesis of lung cancer?

Answer 5

arise as a consequence of accumulation of mutations of genes which regulate cell proliferation, invasion, angiogenesis and senescence
- polymorphisms in certain genes affect the risk of developing lung cancer

Question 6

What are types of precursor lesions of squamous cell carincoma and adenocarcinoma?

Answer 6

• Epithelium–>hyperplasia–>squamous metaplsia–>dysplasia–>carcinoma in situ–>invasive carinoma
• Different genes mutated at different points
• Atypical adenomatous hyperplasia (lesions with atypical cells along alveolar wall) –> adenocarcinoma

Question 7

What are 3 main types of lung cancer, their prevalance and cause?

Answer 7

Squamous cell carcinoma:

• Epithelial lining skin and oesophagus
• 25-40% of lung cancer
• strong association with smoking
• Commonest
• mainly central, distant spread is later than seen in adenocarcinoma

Adenocarcinoma:

• 25-40% of lung cancer
• incidence increasing,
• most common type in non-smokers,
• often peripheral and multicentric

Large cell carcinoma:

• Poorly differentiated tumours composed of large cells
• No histological evidence of flandular or squamous epithelium
• Poorer prognosis

see notes for histology

Question 8

What are charactersitics of small cell carcinome?

Answer 8

• 20-25% of lung cancer
• 80% present with advanced
• Often central near bronchi
• very strong association with smoking
• very aggressive behavior.
• Small cells, essentially ags of chromatin that outgrow their blood supply os oftn necrotic
• Chemoradiotherapy because chemosensative

see notes for histology

Question 9

What is a common molecular pathways for cancer pathogenesis?

Answer 9

Mutation ins in membrane receptor tyrosine kinase

- EGFR pathway

Question 10

What are local complications of lung cancer?

Answer 10

• Local – airway obstruction, local invasion

- May cause collapse of lung or impaired bronchus drainage causing chest infecton

Question 11

What are systemic complications of lung cancer?

Answer 11

- Metastases
		○ Hemoptysis or cough if invade local airways 
                   or vessel 
		○ Dysphagia if esophagus 
		○ Pain if chest wall 
		○ Nerves if hornor's syndrome 
		○ Inflammation of pericardium 
- Paraneoplastic syndromes
		○ Endocrine 
		○ Non endocrine e.g hematologic or 
                   coagulation defect

Question 12

What is paraneoplastic syndrome?

Answer 12

systemic effects of tumour secondary to abnormal expression by tumour cells of substances (e.g. hormones) not normally expressed by the tissue from which the tumour arose.E.g ADH secretion

Question 13

How is lung cancer diagnosed?

Answer 13

• Cytology – Study of cells: Look for malignant cells shed in sputum, or washed/brushed off airways at bronchoscopy.
  
  • Cell type
  • Subgroup
  • Molecular phenotype
• Histology – study of tissues: Biopsy tumour at bronchoscopy or via CT guidance.
• Staging
• Fitness

Question 14

How are cytological samples aquired?

Answer 14

• Sputum
• Bronchial washings and brushings
• Pleural fluid
• Endoscopic fine needle aspiration of tumour/enlarged lymph nodes

Question 15

How are histological samples aquired?

Answer 15

• Biopsy e.g bronchoscopy

- Surgical biopsy :

Question 16

What are the advantages of CT biopsy?

Answer 16

• Real time

- Sensitivity 70-100%

Question 17

What are the disadvantages of CT biopsy?

Answer 17

• Risk of pneumothorax (25-30%)
• Small sample size
• In case of bleeding no immediate intrabronchial treatment possible

Question 18

How is lung cancer staged?

Answer 18

Most accurate is pathological (can be clinical or radiologica)

T 1-4
- Size, Invasion pleura, invasion other structures e.g. pericardium

N 0-3

• N0 – lymph node not involved by tumour
• N1 or N2 or N3 - lymph nodes involved by tumour

M 0-1
- M1 – tumour has spread to distant sites

Question 19

What are clinicial objectives for cancer treatment?

Answer 19

• Establish diagnosis, staging, treatment plan with mutidisciplinary team

Question 20

How are small cell lung cancers treated?

Answer 20

chemotherapy and radiotherapy.

combination chemotherapy including cisplatinand etoposide

Question 21

How is non small cell lung cancer treated?

Answer 21

• Mostly surgery because slow growing - may have adjuvant chemo or radiotherapy
• offered at least three cycles of chemotherapy with sequential or concomitant radiotherapy.
• If advanced have combination of radiotherapy and chemotherapy

Question 22

What are the risk factors for mesothelioma?

Answer 22

Asbestos

Question 23

What is the pathology of mesothelioma?

Answer 23

Symptoms. Dry coughing, Shortness of breath, Respiratory complications, Pain in the chest or abdomen, Fever or night sweats, Pleural effusion (fluid around the lungs), Fatigue, Weakness in the muscles

Pathology:

• cancer of pleural mesothelium (soft tissue covering lungs)
• asbestos fibers cause irritation, chronic inflammation and genetic changes that turn cells cancerous
• malignant tumor can develop on either layer and quickly spread to the other layer