Lung cancer

Question 1

What is lung cancer?

Answer 1

Primary malignant neoplasm of the lung 

Question 2

What are the different types of lung cancer you can have?

Answer 2

1. Small Cell Lung Cancer
2. Non-small Cell Lung Cancer:
   a. Squamous cell carcinoma
   b. adenocarcinoma

● Note: small cell has much worse prognosis with 3 month medial survival
● Small cell – made up of small cells that divide and spread rapidly
● Non-small cell: divide and spread slowly

Question 3

What are SCLC?

Answer 3

Small Cell Lung Cancer - 20%:
- Central tumours
- Treated with chemotherapy
- Associated with SIADH (causes hyponatraemia)
- Secreting ACTH can cause Cushing’s syndrome

Question 4

What are NSCLC?

Answer 4

Non-Small Cell Lung Cancer - 80% (adenocarcinoma, squamous cell carcinoma, carcinoid):
1. Squamous cell carcinoma:
- Treated with radiotherapy
- Associated with PTHrp release = hypercalcaemia
- Cavitating lesion CXR
2. Adenocarcinoma:
- Located peripherally
- More common than others in non-smokers
- Gynaecomastia
- Hypertrophic pulmonary osteoarthropathy (HPOA)

• Adenocarcinoma and squamous cell carcinoma can form Pancoast tumours - masses in the upper region of the lung that compresses the blood vessels and nerves. Can compress and damage the thoracic inlet, brachial plexus.

Question 5

What are the presenting symptoms of lung cancer?

Answer 5

May be ASYMPTOMATIC 
1. Symptoms due to primary:
Cough 
- Haemoptysis 
- Chest pain 
- Recurrent pneumonia 
2. Symptoms due to local invasion:
Brachial plexus invasion –> shoulder/arm pain:
- Left recurrent laryngeal nerve invasion –> hoarse voice and bovine cough  
- Dysphagia 
- Arrhythmias 
- Horner’s syndrome  
3. Symptoms due to metastatic disease or paraneoplastic phenomenon:
- Weight loss  
- Fatigue 
- Fractures  
- Bone pain  

Question 6

What are some non-metastatic manifestations of lung cancer?

Answer 6

PAPSS:
- Pneumothorax
- Atelectasis (the collapse of a lung or lobe)
- Pleural effusion
- Superior vena cava obstruction
- Shortness of breath

Question 7

What signs of lung cancer can be found on physical examination?

Answer 7

• May be NO SIGNS 
• Fixed monophonic wheeze (suggesting that there is a single obstruction) 
• Signs of lobar collapse or pleural effusion  
• Signs of metastases (e.g. supraclavicular lymphadenopathy or hepatomegaly) 
• Cachexia
• Anaemia
• Clubbing

Question 8

What investigations are used to diagnose/ manage lung cancer?

Answer 8

1. CXR → 1st line investigation for suspected lung cancer
2. PET-CT Scan → look for metastases and lymph node involvement
3. Bronchoscopy → allows biopsy for histological diagnosis and TNM staging
   - Image-guided (CT-guided) if peripheral lung lesion
   - (Bronchoscopy may be negative if adenocarcinoma as it is peripherally located)
4. Bloods → hypercalcaemia, raised ALP, thrombocytosis (raised platelets)
   - Hyponatraemia → small cell lung cancer
   - Hypercalcaemia/ALP/LFTs → bone mets or PTHrP (squamous cell)

Question 9

How is lung cancer managed?

Answer 9

1. NSCLC → lobectomy is first line
   - Curative radiotherapy can be offered to patients with stage I,II,III
   - Chemotherapy should be offered to stages III and IV to control disease and improve quality of life
   - Targeted Therapy (advanced NSCLCs) → EGFR inhibitors or ALK tyrosine kinase inhibitors
2. SCLC → generally palliative chemotherapy

Question 10

What are some risk factors for lung cancer?

Answer 10

● Smoking
● Asbestos exposure
● Other occupational exposure: polycyclic hydrocarbons, nickel, radon gas, chromium, arsenic, iron oxides
● Atmospheric pollution

Question 11

Summarise the epidemiology of lung cancer

Answer 11

● Most common FATAL cancer in the west (18% of cancer mortality worldwide)
● 3 x more common in MALES