22.10 Oncological Emergencies

Important oncological emergencies include hypercalcemia, superior venous caval obstruction, spinal cord compression and neutropenic sepsis.

22.10.1 Superior vena cava syndrome (SVCS)

Superior vena cava syndrome (SVCS) is the clinical expression for obstruction of blood flow through the SVC. Malignancy (90%) is the most frequent cause of SVC obstruction. SVC obstruction is a strong predictor of poor prognosis in patients with non–small cell lung cancer. SVC obstruction in cancer patients can result from

• Extrinsic compression of SVC
  • Lung Cancer (65%)
  • Lymphomas (15%)
  • Other cancers (10%)
• Intrinsic compression

Diagnostic Criteria

Common symptoms and physical findings of SVCS are:

• dyspnea
• headache
• oedema and change in colour in the areas drained by SVC(examples–face and upper limb)
• venous distension of neck, upper chest and arms
• cough
• Pemberton’s sign (development of facial flushing, distended neck and head superficial veins, inspiratory stridor and elevation of the jugular venous pressure (JVP) upon raising both of the patient’s arms above his/her head simultaneously, as high as possible (Pemberton’s maneuver)

Investigations:

• CXR
• CT scan Chest Abdomen and Pelvis
• Tissue diagnosis for appropriate treatment modality

Non-pharmacological treatment: Treatment of SVC syndrome is divided into supportive and definitive therapy

Supportive measures

• Head elevation–To decrease the hydrostatic pressure and thereby the edema. There are no data documenting the effectiveness of this manoeuvre, but it is simple and without risk.
• Glucocorticoid therapy (dexamethasone, 4 mg every 6 h) to relieve inflammation and oedema (to be avoided before biopsy if lymphoma is suspected as steroid induced tissue necrosis might obscure the diagnosis)
• Loop diuretics (Furosemide) are also commonly used, but it is unclear whether venous pressure distal to the obstruction is affected by small changes in right atrial pressure.

Definitive Therapy

• Radiation treatment to the malignant mass.
• Chemotherapy–in chemo sensitive cancers like lymphoma, germ cell tumours or small cell lung cancer
• SVC Stent–can be useful in cases of thrombosis and for patients not responding to cancer treatment
• Removal of central venous device.

Note: It is advisable to avoid placement of intravenous lines in the arms so that fluid is not injected into the already compressed SVC.

22.10.2 Hypercalcaemia

Hypercalcaemia refers to elevated calcium level in blood (normal range 2.2–2.6 mmol/L) that occurs in 10–20% patients with advanced cancers (most commonly in cancer of the breast, kidney, lung, prostate, head and neck and multiple myeloma)

Diagnostic Criteria

• Symptoms of hypercalcaemia include nausea, vomiting, constipation, polyuria and disorientation
• Psychiatric overtones (depression 30–40%, anxiety, cognitive dysfunction, insomnia, coma)
• Clinical evidence of volume contraction secondary to progressive dehydration may be apparent. Severe hypercalcaemia (above 3.75–4.0 mmol/L) is a medical emergency and a poor prognostic sign

Investigations include

• Specific biochemistry like PTH,
• ECG to detect arrhythmias and
• Imaging with Bone Scan or PET–CT scan to identify metastatic bone disease.

Pharmacological Treatment

Treat the hypercalcaemia first and the cause later:

• Hydration & dieresis: 1–2 litres of isotonic saline (NS) over 2 hours with 30–40 mg of furosemide expands intravascular volume and enhances calcium excretion.
  • In elderly and cardiac patients, rate of hydration needs to be slower.

• Bisphosphonates–via a complex mechanism inhibit osteoclast and in turn both normal and pathological bone resorption. Commonly used bisphosphonates are:

S: Zolendronic acid infused as 4mg in 100 mls of NS over 15 mins.

Normalisation of serum calcium occurs in 4–10 days and lasts 4–6 weeks. Therefore, if re–treatment is required, dose is repeated after 7 days

OR

S: Ibandronate 6 mg as 2 hour infusion or 50 mg (PO) daily

OR

S: Pamidronate 90 mg IV over 1–2 hours

22.10.3 Spinal–cord Compression

Spinal cord compression threatens mobility, independence and longevity in patients with metastatic cancer and may be the first presentation of curable malignancy in others. It most commonly occurs due to an enlarging vertebral metastasis encroaching on the epidural space or due to pathologic fracture of a vertebra infiltrated by malignancy.

Management

• Immobilising the patient and obtaining urgent MRI whole spine should be priorities.
• Corticosteroids should be initiated on suspicion of cord compression.
  A: Dexamethasone IV 10 mg immediately followed by 16 mg daily in divided doses.
• Bladder catheterisation is appropriate.
• Once spinal cord compression is confirmed, urgent neurosurgical opinion should be sought. There are potential improvements in outcomes for patients treated with surgery upfront, though appropriateness for this will depend upon spinal stability, patient and malignancy related factors.
• Radiotherapy: for patients who are not candidates for upfront surgery.
• Palliative dose: 8Gy single fraction or 20Gy/5fr or 30Gy/10fr.

Note: All patients suspicious for spinal cord compression should be referred to neurosurgeon and radiation oncologist as soon as possible.