Lung Cancer

There are 2 main types of lung cancer:

• Non-small cell lung cancer (85%) - Adenocarcinoma most common, followed by Squamous cell

• Small cell lung cancer

  • This releases neuroendocrine hormones to lead to many paraneoplastic syndromes.

Risk factors for it include:

• Smoking (active/passive)

• Occupational exposure e.g. asbestos, silica, arsenic

• Environmental exposure e.g. radon gas

• Genetics

N.B. Adenocarinomas are much more common in non-smokers.

Lung cancer commonly metastasises to BBBA - Breast, Brain, Bone, Adrenals.

Presentation

Patients typically present with:

• Persistent cough

• SOB

• Haemoptysis (rust-coloured)

• Chest pain

• Recurrent infection

• Weight loss

• Clubbing

• Supraclavicular and axillary lymphadenopathy

• Paraneoplastic syndromes

Some of its non-metastatic manifestations include:

• Pleural effusion - cancer causes inflammatory reactions, leading to fluid accumulation in the pleural space

• SVC obstruction - cancer compresses the SVC, leading to dyspnoea and facial plethora due to venous congestion

  • Managed with immediate IV dexamethasone, followed by balloon venoplasty

• Atelectasis - tumour invasion, leading to total airway obstruction and lung collapse

Paraneoplastic syndromes

• Carcinoid syndrome - presents with hepatomegaly, flushing and diarrhoea

• SIADH – leads to hyponatraemia

• Ectopic ACTH secretion – causes Cushing’s syndrome

• Hypercalcemia – due to the secretion of parathyroid hormone related peptides (PTHrP)

Investigations

1st line investigation to do is a CXR, which will show a visible lesion, hilar enlargement, unilateral pleural effusion, or lung collapse.

Other investigations to do include:

• CT Chest

• Sputum cytology

• Endo-bronchial US (EBUS)

Management

NSCLC - 1st line is Lobectomy. 2nd line is chemo/radiotherapy to control the disease and improve quality of life.

SCLC - Palliative chemotherapy as tumours are disseminated on presentation.