Lung Cancer

Question 1

Describe the incidence of lung cancer

Answer 1

• 35000 deaths per year in UK - most common cancer death in UK
  
  • Low 5-year survival rate
• Lower social economic groups have higher incidence
• Incidence increases with age - 60-90

Question 2

Give an account of the aetiological factors involved in lung cancer

Answer 2

• Smoking
• Asbestos or radon exposure
• Occupational carcinogens - chromium, nickel, arsenic
• Genetic factors

Question 3

Describe the symptoms reported by patients with lung cancer

Answer 3

• Asymptomatic
• Persistent, productive cough
• Dyspnoea
• Wheezing
• Haemoptysis
• Chest tightness/pain - parietal pleura involvement
• Weight loss
• Fatigue
• Lung infection - sputum cannot drain
• Breathlessness - compression of phrenic nerve, lobar/lung collapse, compression of airways
• Hoarseness - compression of recurrent laryngeal nerve

Question 4

Describe the clinical signs associated with lung cancer

Answer 4

• No signs
• Finger clubbing
• Cachexia
• Pale conjunctiva
• Superior vena cava obstruction - oedema in face, dilated veins on chest
• Horner’s syndrome - compression of sympathetic input to face
• Hand wasting and weakness - compression of brachial plexus, specifically C8+T1 common

Question 5

Understand the imaging techniques used in the diagnosis and staging of the disease

Answer 5

• White mass on CXR
• Imaging techniques include CXR, staging chest CT scan (from shoulders to top of pelvis), PET scan (increase uptake of glucose seen in lung cancer), MRI, ultrasound, bone scan
  
  • PET scan - cancer cells have increased uptake of glucose and can be found using a biologically active molecule similar to glucose
    
    • Can detect metastases to lymph nodes and other organs
    • Full body scan
• Lung function test
• Staging shows tumour size, location, number of tumours and extent of invasion
  
  • Any staging beyond N1 is not operable (N1 = lymph node involvement at ipsilateral mediastinum)

Question 6

State where lung cancer commonly spreads to

Answer 6

Lung cancer commonly spreads to lymph node, adrenal gland, liver, bone and brain

Question 7

Describe the common methods used to obtain material for histological diagnosis

Answer 7

• Needle biopsy of the lung or pleura
  
  • Confirm diagnosis and find which type of cell cancer
  • Cancer cells may be present in pleural effusion or pulmonary oedema
• Bronchoscopy
• Cervical fine needle biopsy of lymph nodes
• CT guided lung/pleural biopsy
• Thorocoscopy
• Surgical
• Biopsy of areas associated with metastases - confirm lung cancer diagnosis and define its staging
• Biopsy not done for patients with end-term lung cancer

Question 8

State the main histological types of lung cancer

Answer 8

• Small cell carcinoma
• Squamous cell carcinoma
• Adenocarcinoma - common for patients who do not smoke

Question 9

Describe the difference in treatment between small cell and non-small cell carcinoma

Answer 9

• Small cell carcinoma normally involve radiotherapy and chemotherapy
  
  • Potentially cured through chemotherapy
  • Can also increase ACTH or ADH levels resulting in Cushing’s syndrome and SIADH
• Non-small cell carcinoma (adenocarcinoma, squamous cell) mostly surgical treatment
  
  • Squamous cell carcinoma can produce PTHrP which causes hypercalcaemia

Question 10

Describe the types of treatment for lung cancer

Answer 10

• Only 20% of lung cancer patients are operable and treatable
  
  • Patients with many lymph metastases are not operated on
• Surgery - mostly for non-small cell carcinoma, best chance for cure
• Radiotherapy - radical can cure but mostly symptom control
• Combination chemotherapy - controls tumour
• Combination therapy - combination of radio and chemotherapy
• Biological therapy
• Palliative care - eg.
  - Airway stents, treat tobacco addiction, analgesia