Oncologic Emergencies — Viva Defence

Long Case Viva Defence

The scenario

A 66-year-old man, a lifelong smoker, presents to the emergency department with a two-week history of progressive facial swelling, a one-week history of dyspnoea and a dry cough, and a three-day history of confusion. On examination he has facial and periorbital oedema, distended and non-pulsatile neck veins that do not fall with inspiration, prominent collateral veins over the anterior chest wall, and upper limb oedema. He is clubbed. He has a right upper lobe collapse on the chest radiograph. His observations are heart rate 108, blood pressure 132/78, respiratory rate 24, oxygen saturation 92 per cent on room air, temperature 37.1 degrees. His chest CT confirms a right upper lobe mass with mediastinal lymphadenopathy compressing the superior vena cava. His bloods show sodium 118 mmol per litre, potassium 4.0 mmol per litre, urea 6.0, creatinine 80, corrected calcium 3.0 mmol per litre, albumin 32. His serum osmolality is 250, urine osmolality 360, urine sodium 55. The parathyroid hormone is suppressed and the parathyroid hormone-related peptide is elevated. A bronchial biopsy confirms small cell lung cancer. ^[1]

Opening statement (SASPOP)

"This is Mr R, a 66-year-old lifelong smoker presenting with a two-week history of superior vena cava obstruction and a three-day history of confusion from metabolic derangement, in the setting of a newly diagnosed small cell lung cancer. He has three concurrent oncologic problems: (1) superior vena cava obstruction from the right upper lobe mass and mediastinal nodes, for which he needs symptom control and definitive cancer treatment; (2) severe symptomatic euvolaemic hyponatraemia (sodium 118) from syndrome of inappropriate antidiuretic hormone — small cell lung cancer is the classic cause — which I am correcting carefully to avoid osmotic demyelination; and (3) hypercalcaemia of malignancy at 3.0, a PTHrP-mediated humoral hypercalcaemia, which is contributing to his confusion. The unifying solution is treatment of the small cell lung cancer with chemotherapy, to which it is highly responsive. My immediate management is airway and breathing support, careful correction of the hyponatraemia with 3 per cent saline to a safe ceiling, intravenous fluids and zoledronic acid for the hypercalcaemia, a tissue diagnosis — which I already have — and urgent oncology review for the chemotherapy that will relieve the SVC obstruction and the SIADH. I am involving the palliative care team for symptom control and goals-of-care discussions." ^[1]

Problem list (numbered, prioritised)

1. Superior vena cava obstruction from the right upper lobe mass and mediastinal nodes — symptomatic and progressive.
2. Severe symptomatic SIADH (sodium 118 with confusion) from ectopic ADH production by the small cell lung cancer.
3. Hypercalcaemia of malignancy (corrected calcium 3.0, PTHrP-mediated) contributing to the confusion.
4. Newly diagnosed small cell lung cancer — the unifying diagnosis and the target of definitive therapy.
5. Hypoxaemia (oxygen saturation 92 per cent) from the right upper lobe collapse and the SVC-related venous congestion.
6. The communication and goals-of-care conversation, given the prognosis of extensive-stage small cell lung cancer. ^[1]

Integrated management plan

Pillar 1 — The SVC obstruction: "He is not stridulous and his observations are stable, so this is not an immediate airway emergency requiring a stent. I would sit him upright, give supplemental oxygen, and proceed to definitive treatment of the small cell lung cancer — small cell is chemosensitive and responds to platinum-etoposide within days to weeks, which will relieve the obstruction. The Rowell and Gleeson systematic review establishes that the priority is a tissue diagnosis and treatment of the underlying cancer ^[7]. I have the biopsy, so I would start the chemotherapy urgently. If he develops stridor, cerebral symptoms, or haemodynamic compromise, I would arrange urgent endovascular stenting for rapid relief. I would avoid upper-body central lines (use a femoral route if a line is needed) and anticoagulate if thrombosis is documented."

Pillar 2 — The SIADH: "The sodium of 118 with confusion is a medical emergency. I would give intravenous 3 per cent saline for this seizure-risk hyponatraemia, recheck the sodium frequently, and stop once he is safer — over-rapid correction risks osmotic demyelination. Once his confusion improves I would restrict free water. The definitive treatment is the chemotherapy, which will suppress the ectopic ADH production and often resolves the SIADH within weeks. I would avoid over-rapid correction with a vaptan in the acute phase." ^[7]

Pillar 3 — The hypercalcaemia: "I would give intravenous normal saline — guided by his volume status and his (normal) renal function — and then zoledronic acid 4 mg. The calcium will fall over 48 to 72 hours. For the first 48 hours, while the zoledronic acid takes effect, I would add calcitonin as a rapid but tachyphylaxis-limited bridge ^[8]. The PTHrP-mediated mechanism is confirmed by the low phosphate (if present), the suppressed PTH, and the elevated PTHrP. I would continue zoledronic acid or denosumab monthly as part of his supportive care."

Pillar 4 — The small cell lung cancer: "Extensive-stage small cell lung cancer is treated with platinum-based chemotherapy (cisplatin or carboplatin with etoposide), with the addition of atezolizumab or durvalumab (an anti-PD-L1 checkpoint inhibitor) in the first-line setting per the IMpower133 and CASPIAN trials, which improved overall survival. Prophylactic cranial irradiation is considered for limited-stage disease in complete response, and is debated in extensive-stage disease. He would be referred to a medical oncologist for the regimen and the staging (a CT chest, abdomen and pelvis, and an MRI or CT of the brain for staging)." ^[6]

Pillar 5 — Hypoxaemia and supportive care: "Supplemental oxygen, treat any infection, DVT prophylaxis, and symptom control (analgesia, antiemetics). I would involve the palliative care team early, both for symptom control and for the goals-of-care conversation, given the prognosis of extensive-stage small cell lung cancer (median survival 12 to 13 months with modern therapy)." ^[5]

Pillar 6 — Communication and goals of care: "I would speak with Mr R and his family in plain language about the diagnosis, the prognosis, and the treatment plan. I would frame the chemotherapy as both the treatment of the cancer and the relief of the three emergencies (the SVC obstruction, the SIADH, and the hypercalcaemia), and I would be honest about the prognosis and the goals of care. I would document the agreed plan and review it at every transition." ^[4]

Probing questions the examiner would ask

Q: Why are you not stenting his SVC immediately? ^[7]

A: "Because he is not stridulous, has no cerebral symptoms, and is haemodynamically stable. The priority in the stable patient is a tissue diagnosis and treatment of the underlying cancer — small cell lung cancer responds to chemotherapy within days to weeks, and the chemotherapy is also his definitive systemic therapy. Stenting is reserved for severe or life-threatening obstruction (stridor, cerebral symptoms, haemodynamic compromise) or for obstruction refractory to cancer-directed therapy. Stenting before a tissue diagnosis is appropriate only when rapid relief is essential. If his obstruction worsens or he develops stridor while awaiting the chemotherapy, I would stent him ^[7]."

Q: He develops a seizure while you are correcting the sodium. What do you do? ^[6]

A: "I would give intravenous lorazepam 4 mg to terminate the seizure, then give 3 per cent saline to treat the seizure-risk hyponatraemia. The rate of correction must be controlled to avoid osmotic demyelination. The seizure is the hallmark of severe hyponatraemia and mandates hypertonic saline — the rate of correction must be controlled to avoid osmotic demyelination, which is the devastating complication of over-rapid correction." ^[5]

Q: How would your management change if the biopsy had shown a non-small cell lung cancer rather than small cell? ^[4]

A: "The SVC obstruction would be managed the same way in the stable patient — treat the underlying cancer, reserving the stent for severe obstruction. The difference is the cancer treatment: non-small cell lung cancer is treated with chemo-radiotherapy for locally advanced disease, or with immunotherapy and chemotherapy for metastatic disease, guided by the PD-L1 status and the molecular profile (EGFR, ALK, ROS1, KRAS). The SIADH is far less common in non-small cell lung cancer (it is the hallmark of small cell), so if he had non-small cell with a sodium of 118 I would look hard for another cause of the hyponatraemia — a drug, an adrenal insufficiency, a gastrointestinal loss — before attributing it to the cancer. The hypercalcaemia, however, is more common in non-small cell (particularly squamous cell, the classic PTHrP-secreter) than in small cell." ^[7]

Q: What is the prognosis, and how does it shape your management? ^[6]

A: "Extensive-stage small cell lung cancer has a median survival of about 12 to 13 months with platinum-etoposide and an anti-PD-L1 agent, and a 5-year survival of under 10 per cent. This shapes my management in two ways. First, the three emergencies are potentially reversible with the chemotherapy, so I treat them aggressively — the goal is symptom relief and the best possible quality of the remaining time. Second, I involve the palliative care team early, not for end-of-life care but for symptom control, prognostic framing, and family support throughout the illness trajectory. If he deteriorates despite the chemotherapy or if he declines further treatment, the goal shifts to comfort care with a dignified death, supported by palliative care." ^[5]

Q: What is the role of prophylactic cranial irradiation in this patient? ^[4]

A: "Prophylactic cranial irradiation reduces the incidence of brain metastases and improves survival in limited-stage small cell lung cancer in complete response after chemoradiotherapy. In extensive-stage disease, its role is debated: it reduces brain metastases but the survival benefit is less clear in the era of effective systemic therapy and MRI surveillance. The EORTC trial showed a survival benefit in extensive-stage disease, but more recent studies question the magnitude in patients who receive regular MRI surveillance and salvage radiotherapy at the time of metastasis. The decision is made with the oncologist and the patient, weighing the small survival benefit against the cognitive late effects of whole-brain radiotherapy." ^[7]

Communication and shared decision-making

"I would sit with Mr R and his family in a quiet room and speak in plain language. I would explain that the cancer in his lung has caused three problems — the swelling in his face and arms, the low sodium that made him confused, and the high calcium — and that the chemotherapy I am recommending will treat the cancer and all three of these problems. I would be honest that this is an extensive-stage small cell lung cancer, that the chemotherapy can control the disease for a period but is unlikely to cure it, and that the aim is to give him the best possible quality of the time he has. I would ask what matters most to him now, whether there are things he wants to do or people he wants to see, and I would build the treatment plan around his priorities. I would involve the palliative care team for symptom control and family support, and I would document the shared decisions and review them as his clinical picture evolves." ^[6]