Lung cancer

Question 1

Classification of lung cancer

Answer 1

Two main categories: small cell and non-small cell

Small cell - originate from neuroendocrine cells

• generally develop centrally near a main bronchus
• strong association with smoking
• grow quickly and metastasise rapidly in comparison to non-small cell lung cancers

Non-small cell carcinomas - squamous cell, adenocarcinoma, carcinoid tumours, large cell

• scc - develop centrally, strong association with smoking
• adenocarcinomas - develop peripherally in a bronchial/alveolar wall, associated with smoking & more common in women
• large cell - found throughout the lung

Question 2

Lung cancer risk factors

Answer 2

Smoking

Asbestos exposure

Air pollution

Exposure to radon gas

Exposure to ionising radiation

Question 3

Lung cancer clinical features

Answer 3

Cough

Haemoptysis

SoB

Constitutional symptoms - unintentional weight loss, malaise & fatigue

Distant mets - brain, liver, bone or adrenal glands

Question 4

Lung cancer clinical features from local invasion

Answer 4

Apical tumours (pancoast tumours)

• compression on brachial plexus, producing upper limb paraesthesia or weakness
• compression on the cervical sympathetic chain, resulting in Horner’s syndrome: ptosis, meiosis and/or facial anhidrosis
• compression on the phrenic nerve - paralysis of the ipsilateral hemidiaphragm can cause further respiratory compromise
• compression of the recurrent laryngeal nerve - hoarse voice
• compression of the SVC - can cause facial plethora, prominence of facial and/or upper limb veins & respiratory compromise (Pemberton’s sign)

Question 5

Lung cancer clinical features from paraneoplastic syndromes

Answer 5

Squamous cell - PTHrP which can mimic the function of PTH, leading to clinical features of hypercalcaemia

Adenocarcinoma - cause hypertrophic osteoarthropathy → clubbing, joint pain & bone pain

Small cell

• ADH which can lead to SIADH → hyponatraemia
• ACTH - Cushing’s syndrome
• Lambert-Eaton syndrome - antibodies against the presynaptic calcium channel of the neuromuscular junction; can present with proximal muscle weakness

Question 6

Lung cancer investigations

Answer 6

Blood tests - FBC, CRP, U&Es, bone profile

CXR

Contrast CT chest

Staging Ix - PET-CT or CT C/AP +/- CT head

Biopsy options

• centrally: transbronchial biopsy or ultrasound-guided endoscopic biopsy
• peripherally: transthoracic approach
• pleural effusion - diagnostic thoracocentesis

Question 7

Lung cancer general management

Answer 7

MDT discussion

Chemotherapy +/- radiotherapy will form the mainstay of management for metastatic lung cancer

Prophylactic radiotherapy to the brain can be performed, especially for small cell lung cancer

Newer immunotherapy agents can be of benefit, especially in non-small cell lung cancer

Question 7

Lung cancer surgical management

Answer 7

Surgical resection is the only definitive curative treatment options

• lobectomy - the standard approach for most NSCLC
• pneumonectomy - removal of the whole lung
• wedge resection - removal of a small part of one of the lobes
• sleeve resection - removing one lobe & part of the bronchi

LFT should be performed in all patients prior to resection → guide type of resection performed

Video-assisted thoracoscopic surgery lobectomy - standard approach for resection of early stage lung cancer

• reduces post-operative pain, length of stay, fewer in-hospital complications, shorter hospital stay, preserved pulmonary function & improved cosmetic result