Chapter 7-11: Diseases & Pathophysiology in Oncology

ONCOLOGIC EMERGENCIES

Increased intracranial pressure (ICP) from brain lesions

• Pathophysiology: Either primary brain tumor or metastasis causing vasogenic edema, leading to ↑ICP

• Symptoms: Headache, blurry vision, focal neurologic deficits, stroke

• Diagnosis: NCHCT vs. contrast MRI depending on urgency (MRI superior)

• Treatment: Mannitol, steroids, emergent neurosurgical intervention or radiation. Call neurosurgery and radiation oncology.

Neoplastic epidural spinal cord compression

• Pathophysiology: Compression of spinal cord from lesions in vertebral bones >> paraspinal mass extending locally into epidural space. Annual incidence is 3–5% among patients with metastatic cancer. ~50% cases from prostate, lung, and breast cancer.

• Symptoms: Back or SI joint pain, asymmetric leg weakness, saddle anesthesia, urinary retention, fecal incontinence (bowel/bladder problems are typically late findings)

• Diagnosis: Urgent MRI total spine with and without contrast

• Treatment: Call neurosurgery +/𠄴 radiation oncology ASAP. Start steroids (e.g., dexamethasone 10mg ×1 then 4mg Q6hr). Usually requires emergent neurosurgical intervention and/or radiation therapy

Superior vena cava (SVC) syndrome

• Pathophysiology: Extrinsic compression of the SVC by a tumor or mediastinal lymph nodes that cause increased upper body venous pressure. Most common in NSCLC, small cell lung cancer, NHL.

• Symptoms: Sudden appearance of dilated veins on the chest = herald onset of SVC syndrome. Patients may also have facial swelling, “head fullness,” SOB, blurry vision, hypotension (↓venous return to right atrium).

• Diagnosis: Imaging demonstrates SVC compression by tumor

• Treatment: If life-threatening symptoms (e.g., stridor, CNS symptoms) are present, consider endovascular stent, radiation, or rarely tumor resection. If no life-threatening symptoms are present, chemotherapy alone may be sufficient for chemotherapy-responsive tumors (e.g., SCLC, lymphoma). Anticoagulate if thrombus detected.

Hypercalcemia of malignancy

• Pathophysiology: Multiple possible mechanisms

  • - Tumor secretion of PTHrP (most common) – often SCC of lung, breast cancer, RCC

  • - Osteolytic metastases, which cause increased bone turnover – commonly MM, breast cancer

  • - Tumor production of 1,25-OH Vit D – Hodgkin’s and NH lymphoma

• Symptoms: “Stones, groans, moans, psychiatric overtones” – kidney stones, nausea, vomiting, abdominal pain, bony pain, AMS

• Diagnosis: ↑Ca²⁺ level (corrected for albumin), dehydration (↑Cr, ↑Na⁺)

• Treatment:

  • - Aggressive hydration (200–300 mL/hr to maintain UOP of 100–150 ml/hr). Caution in heart failure and volume overload. Generally only use diuretics if there is concern for iatrogenic hypervolemia. Effect seen: Hours.

  • - Calcitonin 4IU/kg Q6–12 hrs for up to 48 hrs (patients will develop tachyphylaxis after 48 hrs of therapy). Effect seen: Hours to days.

  • - Bisphosphonate: Usually zoledronic acid. One-time dose, so full dose ok in renal dysfunction and no dental evaluation needed prior to treatment. Effect seen: 2–4 days.

  • - Denosumab: Monoclonal antibody to RANK-ligand → blocks activation of osteoclasts, which promote bone breakdown and Ca²⁺ release. Generally, bisphosphonates are preferred over denosumab for acute treatment of hypercalcemia of malignancy. Effect seen: 4–10 days.

Neutropenic fever

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