OncologyTier 1Approach to a presentation

Dyspnoea

Red flags

  • Sudden-onset dyspnoea + pleuritic pain/tachycardia -> PE - very high baseline risk in cancer
  • Stridor, facial/neck swelling, distended neck veins -> SVC obstruction
  • Muffled heart sounds, hypotension, raised JVP (Beck triad) -> cardiac tamponade from malignant effusion
  • Fever + dyspnoea in a neutropenic patient -> neutropenic sepsis pathway
  • Rapidly progressive dyspnoea post-thoracic radiotherapy (weeks-months later) -> radiation pneumonitis
  • New dyspnoea on an immune checkpoint inhibitor -> immune-related pneumonitis

Differential by mechanism

Direct tumour effect
  • Malignant pleural effusion, pericardial effusion/tamponade, airway obstruction (endobronchial tumour, extrinsic compression), lymphangitis carcinomatosa, SVC obstruction
Treatment-related
  • Chemotherapy-induced cardiotoxicity (anthracyclines, trastuzumab) -> heart failure
  • Radiation pneumonitis/fibrosis (weeks to months post-radiotherapy to the chest)
  • Immune checkpoint inhibitor pneumonitis - can occur at any point during treatment, even after cessation
  • Bleomycin, other cytotoxic pulmonary toxicity
Comorbid/incidental (still commoner than assumed in cancer patients)
  • Pulmonary embolism - markedly elevated baseline risk in malignancy
  • Infection (pneumonia, including atypical/opportunistic in immunosuppressed)
  • Anaemia (from marrow infiltration, chemotherapy, chronic disease)
  • Pre-existing COPD/heart failure decompensation, deconditioning/cachexia
  • Anxiety - a genuine contributor, but a diagnosis of exclusion

Focused history

  • Onset tempo (sudden = PE/pneumothorax; gradual = effusion, anaemia, disease progression)
  • Cancer type, stage, and treatment history (specific drugs and radiotherapy fields - localises treatment-related causes)
  • Current/recent immune checkpoint inhibitor use - even if stopped months ago
  • Chest pain, cough, haemoptysis, orthopnoea, leg swelling
  • Fever, neutropenia timing (chemotherapy nadir)
  • Functional impact, anxiety component

Focused examination

  • Vital signs including oxygen saturation, respiratory rate
  • Reduced breath sounds/stony dullness (effusion), raised JVP + muffled heart sounds + pulsus paradoxus (tamponade)
  • Facial/neck swelling, dilated chest wall veins (SVC obstruction)
  • Signs of DVT, pallor (anaemia), stridor/wheeze (airway obstruction)
  • Fine bibasal crackles (pneumonitis, cardiotoxicity)

Investigation strategy

  • Oxygen saturation, CXR as first-line for all
  • CTPA if PE suspected clinically (low threshold given elevated baseline risk) - D-dimer is of limited value in active malignancy (often elevated regardless)
  • Echocardiogram if tamponade or cardiotoxicity suspected
  • CT chest for effusion characterisation, lymphangitis pattern, or new lesion
  • FBE (anaemia, neutropenia), troponin/BNP if cardiotoxicity suspected
  • High-resolution CT if pneumonitis (radiation or immune-related) suspected - characteristic pattern often localises to radiotherapy field for radiation pneumonitis

Management

Sequence - treat the emergency first, then the mechanism

1. Exclude/treat life-threatening causes: PE (anticoagulation), tamponade (urgent pericardiocentesis), SVC obstruction (dexamethasone + urgent oncology/radiation input +/- stenting)

2. Treat the identified mechanism

By cause
  • Malignant pleural effusion: therapeutic drainage; indwelling pleural catheter preferred over repeated thoracocentesis or talc pleurodesis for recurrent effusions with reasonable prognosis - allows ambulatory drainage
  • Pericardial effusion/tamponade: urgent pericardiocentesis +/- pericardial window for recurrence
  • SVC obstruction: dexamethasone to reduce oedema, urgent radiotherapy or endovascular stenting depending on tumour type/chemosensitivity, treat any associated thrombus
  • Radiation pneumonitis: corticosteroids for symptomatic disease
  • Immune checkpoint inhibitor pneumonitis: hold the checkpoint inhibitor, corticosteroids (dose per severity grade), escalate immunosuppression (e.g. infliximab, mycophenolate) if steroid-refractory - graded per irAE management algorithms
  • Cardiotoxicity: cardio-oncology input, heart failure therapy, consider changing/ceasing the causative agent
  • Anaemia: transfusion if symptomatic/severe, treat underlying cause
  • Airway obstruction: bronchoscopic intervention (stenting, debulking), radiotherapy
Supportive/palliative measures (all patients, alongside cause-directed treatment)
  • Oxygen if hypoxic (limited benefit for breathlessness if not hypoxic)
  • Opioids - reduce the sensation of breathlessness independent of treating the cause, low-dose and titrated
  • Fan therapy (facial airflow), breathing techniques, anxiolytics for a significant anxiety component (low-dose benzodiazepine adjunct)
  • Early palliative care involvement for refractory dyspnoea in advanced disease

Traps

  • Relying on D-dimer to exclude PE in active malignancy - poor specificity, CTPA needed if clinical suspicion
  • Missing immune checkpoint inhibitor pneumonitis because the drug was stopped months earlier
  • Attributing dyspnoea to "anxiety" or "deconditioning" without excluding effusion, PE, or SVC obstruction first
  • Delaying pericardiocentesis while pursuing extensive imaging in a tamponade physiology patient
  • Not offering opioids for symptomatic breathlessness relief because the underlying cause cannot be fully reversed

Talk track

Exclude the emergencies first - PE, tamponade, SVC obstruction - then work through direct tumour effects, treatment-related causes (checkpoint inhibitor and radiation pneumonitis, cardiotoxicity), and ordinary comorbid causes that are easy to overlook in a cancer patient (anaemia, COPD, heart failure). Treat the mechanism specifically, and run low-dose opioids, oxygen only if hypoxic, and non-pharmacological measures in parallel regardless of cause once life-threats are excluded.

8 of 8 sections written · drafted 2026-09-13