What are the signs, symptoms, and management strategies for oncologic emergencies?

Oncologic Emergencies: Recognition and Management

Definition and Overview

Oncologic emergencies are life-threatening conditions directly or indirectly related to cancer or its treatment that require immediate medical intervention to prevent death or permanent loss of function. 1 These emergencies demand rapid recognition and treatment, as delays can result in irreversible morbidity or mortality. 2

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Major Oncologic Emergencies

1. Malignant Spinal Cord Compression (MSCC)

Clinical Presentation Pattern

• Back pain (present in 83-95% of cases) - typically precedes neurologic symptoms by weeks to months, worsens with recumbency, and is often localized to the site of compression 3
• Progressive motor weakness in lower extremities (bilateral or unilateral) 3
• Sensory deficits including numbness, paresthesias, or sensory level 3
• Autonomic dysfunction: urinary retention, bowel incontinence, or erectile dysfunction (late findings indicating poor prognosis) 3
• Loss of ambulatory function - once present, only 10-20% regain ability to walk 2

Diagnostic Workup

• MRI of entire spine with gadolinium contrast is the gold standard - must be performed emergently within hours of presentation 2, 3
• Plain radiographs show vertebral abnormalities in only 53% of cases and are inadequate 2
• Neurologic examination documenting motor strength (0-5 scale), sensory level, reflexes, and sphincter tone 3

Management Algorithm

Immediate interventions (within 1 hour of diagnosis):

• Dexamethasone 10 mg IV bolus, followed by 16 mg daily in divided doses (for patients with neurologic deficits) 3
• Patients without neurologic deficits may receive lower doses (4-8 mg daily) 3
• Radiation oncology consultation emergently - treatment should begin within 24 hours 3

Definitive treatment:

• Radiation therapy: 30 Gy in 10 fractions or 20 Gy in 5 fractions for most patients 3
• Surgical decompression followed by radiation for: single site of compression, radioresistant tumors, spinal instability, or progressive neurologic decline during radiation 3
• Prognosis depends on ambulatory status at presentation - patients who are ambulatory at diagnosis have 80-90% chance of remaining ambulatory, while non-ambulatory patients have <10% chance of regaining function 2, 3

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2. Superior Vena Cava Syndrome (SVCS)

Clinical Presentation Pattern

• Facial and upper extremity edema (most common, present in 80% of cases) 2
• Dyspnea and orthopnea (60% of cases) 2
• Cough (50% of cases) 2
• Dilated chest wall and neck veins with visible collateral circulation 2
• Stridor, hoarseness, or dysphagia (indicate severe airway compromise) 2
• Cerebral edema symptoms: headache, confusion, visual changes (indicate life-threatening emergency) 3

Diagnostic Workup

• CT chest with IV contrast - demonstrates SVC obstruction and identifies underlying cause 2
• Tissue diagnosis via least invasive method: sputum cytology, thoracentesis, bronchoscopy, or CT-guided biopsy 2
• Do NOT delay treatment for tissue diagnosis if patient has severe symptoms (stridor, cerebral edema, hemodynamic instability) 3

Management Algorithm

Immediate supportive care:

• Elevate head of bed 30-45 degrees 2
• Supplemental oxygen to maintain SpO2 >92% 2
• Dexamethasone 4 mg IV every 6 hours (reduces vasogenic edema) 3
• Avoid IV access in upper extremities 2

Definitive treatment based on etiology:

• Small cell lung cancer or lymphoma: chemotherapy is first-line treatment (response within 7-14 days) 2, 3
• Non-small cell lung cancer: radiation therapy 30-40 Gy in 10-15 fractions 3
• Endovascular stenting for immediate relief in patients with severe symptoms or thrombus-related obstruction 2
• Anticoagulation if thrombus is present (unless contraindicated) 2

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3. Tumor Lysis Syndrome (TLS)

Clinical Presentation Pattern

• Occurs 12-72 hours after initiation of chemotherapy in patients with high tumor burden (particularly hematologic malignancies) 4, 5
• Nausea, vomiting, diarrhea, lethargy 4
• Muscle cramps, tetany, seizures (from hypocalcemia) 4
• Cardiac arrhythmias (from hyperkalemia) 4
• Oliguria or anuria (from acute kidney injury) 4
• Sudden death from cardiac arrhythmia or renal failure 4

Laboratory Criteria (Cairo-Bishop Definition)

Laboratory TLS requires ≥2 of the following within 3 days before or 7 days after chemotherapy:

• Uric acid ≥8 mg/dL or 25% increase from baseline 4
• Potassium ≥6 mEq/L or 25% increase from baseline 4
• Phosphorus ≥4.5 mg/dL or 25% increase from baseline 4
• Calcium ≤7 mg/dL or 25% decrease from baseline 4

Clinical TLS = Laboratory TLS plus:

• Creatinine ≥1.5× upper limit of normal 4
• Cardiac arrhythmia or sudden death 4
• Seizure 4

Diagnostic Workup

Before initiating chemotherapy in high-risk patients:

• Complete metabolic panel (potassium, phosphorus, calcium, uric acid, creatinine, BUN) 4
• LDH (marker of tumor burden) 4
• CBC with differential 4
• ECG (assess for hyperkalemia changes: peaked T waves, widened QRS) 4
• Monitor labs every 4-6 hours for first 24-48 hours after chemotherapy initiation 4

Management Algorithm

Prevention (for high-risk patients before chemotherapy):

• Aggressive IV hydration: 3 L/m²/day (200-300 mL/m²/hour) with normal saline or D5W 0.45% NaCl 4
• Target urine output >100 mL/m²/hour (2-3 mL/kg/hour) 4
• Allopurinol 300 mg/m² daily (maximum 800 mg/day) starting 24-48 hours before chemotherapy 4
• OR Rasburicase 0.2 mg/kg IV once daily (preferred for patients with baseline hyperuricemia >7.5 mg/dL or high tumor burden) 4
• Avoid alkalinization of urine - increases risk of calcium phosphate precipitation 4

Treatment of established TLS:

• Immediate aggressive IV hydration as above 4
• Rasburicase 0.2 mg/kg IV (rapidly lowers uric acid within 4 hours) 4
• Hyperkalemia management:
  • Calcium gluconate 10% 10-20 mL IV over 2-5 minutes (if ECG changes present) 4
  • Regular insulin 10 units IV with 50 mL D50W 4
  • Sodium polystyrene sulfonate 15-30 g PO or 50 g PR 4
• Hyperphosphatemia management:
  • Phosphate binders: sevelamer 800-1600 mg PO TID with meals 4
  • Avoid calcium-containing binders (risk of calcium-phosphate precipitation) 4
• Hemodialysis indications:
  • Refractory hyperkalemia >6 mEq/L 4
  • Symptomatic hypocalcemia 4
  • Hyperphosphatemia >10 mg/dL 4
  • Uric acid >10 mg/dL 4
  • Oliguria/anuria 4
  • Volume overload 4

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4. Hypercalcemia of Malignancy

Clinical Presentation Pattern

Mild hypercalcemia (10.5-12 mg/dL):

• Often asymptomatic or subtle symptoms 4
• Fatigue, constipation, polyuria 4

Moderate hypercalcemia (12-14 mg/dL):

• Nausea, vomiting, anorexia 4
• Confusion, lethargy 4
• Muscle weakness 4

Severe hypercalcemia (>14 mg/dL):

• Altered mental status, obtundation, coma 4
• Severe dehydration 4
• Cardiac arrhythmias, shortened QT interval 4
• Acute kidney injury 4
• Pancreatitis 4

Diagnostic Workup

• Corrected calcium = measured calcium + 0.8 × (4.0 - albumin) 4
• Ionized calcium (most accurate) 4
• PTH level (low in malignancy-related hypercalcemia) 4
• PTHrP level (elevated in humoral hypercalcemia of malignancy) 4
• 25-OH vitamin D and 1,25-OH vitamin D (if lymphoma suspected) 4
• ECG (shortened QT interval, arrhythmias) 4
• BUN, creatinine (assess renal function) 4

Management Algorithm

Immediate treatment (for calcium >12 mg/dL or symptomatic):

• Aggressive IV hydration: normal saline 200-500 mL/hour (goal 3-6 L in first 24 hours) 4
• Monitor for volume overload, especially in patients with cardiac or renal disease 4
• Calcitonin 4 units/kg IM or SC every 12 hours (rapid onset within 4-6 hours, but tachyphylaxis develops after 48 hours) 4

Definitive treatment (after rehydration):

• Zoledronic acid 4 mg IV over 15 minutes (preferred bisphosphonate, lowers calcium in 2-4 days, duration 2-4 weeks) 4
• OR Pamidronate 60-90 mg IV over 2-4 hours (based on severity: 60 mg for calcium 12-13.5 mg/dL, 90 mg for calcium >13.5 mg/dL) 4
• Denosumab 120 mg SC (for bisphosphonate-refractory hypercalcemia or renal insufficiency) 4

Adjunctive therapy:

• Furosemide 20-40 mg IV every 6-12 hours ONLY after adequate rehydration (prevents volume overload, does NOT enhance calcium excretion significantly) 4
• Treat underlying malignancy 4

Refractory hypercalcemia:

• Hemodialysis (for severe hypercalcemia >18 mg/dL with renal failure) 4
• Glucocorticoids (effective only in hematologic malignancies): prednisone 40-100 mg daily 4

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5. Syndrome of Inappropriate Antidiuretic Hormone (SIADH)

Clinical Presentation Pattern

Mild hyponatremia (130-135 mEq/L):

• Often asymptomatic 4
• Mild nausea, headache 4

Moderate hyponatremia (120-129 mEq/L):

• Nausea, vomiting 4
• Confusion, lethargy 4
• Muscle cramps 4

Severe hyponatremia (<120 mEq/L):

• Seizures, coma 4
• Respiratory arrest 4
• Acute hyponatremia (<48 hours) carries higher risk of cerebral edema and death 4

Diagnostic Criteria

SIADH diagnosis requires ALL of the following:

• Hyponatremia with serum osmolality <280 mOsm/kg 4
• Urine osmolality >100 mOsm/kg (inappropriately concentrated) 4
• Urine sodium >40 mEq/L (with normal salt intake) 4
• Clinical euvolemia (no edema, no dehydration) 4
• Normal thyroid, adrenal, and renal function 4

Additional workup:

• Serum and urine osmolality 4
• Serum and urine sodium 4
• BUN, creatinine 4
• TSH, cortisol (rule out hypothyroidism and adrenal insufficiency) 4

Management Algorithm

Acute symptomatic hyponatremia (seizures, altered mental status):

• 3% hypertonic saline 100 mL IV bolus over 10 minutes 4
• Repeat bolus if symptoms persist (maximum 2-3 boluses) 4
• Goal: increase sodium by 4-6 mEq/L in first 4-6 hours (stops acute symptoms) 4
• Do NOT correct >8-10 mEq/L in 24 hours (risk of osmotic demyelination syndrome) 4
• Monitor sodium every 2-4 hours 4

Chronic or asymptomatic hyponatremia:

• Fluid restriction to 500-1000 mL/day (first-line treatment) 4
• Demeclocycline 300-600 mg PO twice daily (induces nephrogenic diabetes insipidus, onset 3-5 days) 4
• Tolvaptan 15 mg PO daily (V2 receptor antagonist, use only in hospital setting with frequent sodium monitoring) 4
• Treat underlying malignancy 4
• Correct sodium by maximum 6-8 mEq/L per day 4

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6. Febrile Neutropenia

Clinical Presentation Pattern

• Single oral temperature ≥38.3°C (101°F) OR temperature ≥38.0°C (100.4°F) for ≥1 hour 2
• Absolute neutrophil count (ANC) <500 cells/μL OR ANC <1000 cells/μL with predicted decline to <500 cells/μL 2
• May have minimal signs of infection due to lack of inflammatory response 2
• Common sources: lungs, urinary tract, skin/soft tissue, bloodstream, GI tract 2
• Septic shock develops in 10-20% of cases with mortality 30-50% 2

Diagnostic Workup

Must be completed within 1 hour of presentation:

• Two sets of blood cultures (one from central line if present, one peripheral) 2
• CBC with differential 2
• Comprehensive metabolic panel 2
• Chest X-ray (even without respiratory symptoms) 2
• Urinalysis and urine culture 2
• Cultures from any suspected infection site (wound, diarrhea, etc.) 2

Management Algorithm

Immediate empiric antibiotics (within 1 hour):

• Monotherapy with antipseudomonal beta-lactam:
  • Cefepime 2 g IV every 8 hours (preferred) 2
  • OR Piperacillin-tazobactam 4.5 g IV every 6 hours 2
  • OR Meropenem 1 g IV every 8 hours (if high risk for resistant organisms) 2

Add vancomycin 15-20 mg/kg IV every 8-12 hours if:

• Hemodynamic instability or septic shock 2
• Pneumonia on chest X-ray 2
• Skin/soft tissue infection 2
• Suspected catheter-related infection 2
• Known MRSA colonization 2
• Mucositis (risk of viridans streptococci) 2

Add antifungal coverage (after 4-7 days of persistent fever despite antibiotics):

• Caspofungin 70 mg IV loading dose, then 50 mg IV daily 2
• OR Micafungin 100 mg IV daily 2
• OR Voriconazole 6 mg/kg IV every 12 hours × 2 doses, then 4 mg/kg IV every 12 hours 2

Duration of therapy:

• Continue antibiotics until ANC >500 cells/μL and patient afebrile for 24-48 hours 2
• Minimum 7 days even if ANC recovers earlier 2

G-CSF consideration:

• Filgrastim 5 mcg/kg SC daily OR pegfilgrastim 6 mg SC once (for high-risk patients: age >65, pneumonia, hypotension, multiorgan dysfunction, invasive fungal infection) 2

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7. Disseminated Intravascular Coagulation (DIC)

Clinical Presentation Pattern

• Bleeding manifestations (most common): 4, 5
  • Petechiae, purpura, ecchymoses 4
  • Oozing from venipuncture sites, IV sites, surgical wounds 4
  • Mucosal bleeding (gingival, GI, GU) 4
  • Intracranial hemorrhage (life-threatening) 4
• Thrombotic manifestations: 4
  • Acral cyanosis (fingers, toes, nose, ears) 4
  • Venous thromboembolism 4
  • Acute kidney injury 4
  • Altered mental status (from microvascular thrombosis) 4

Diagnostic Workup

Laboratory criteria (no single test is diagnostic):

• Platelet count <100,000/μL or rapidly declining 4, 5
• Prolonged PT (>3 seconds above control) and aPTT 4
• Elevated D-dimer (>500 ng/mL) 4
• Low fibrinogen (<100 mg/dL) 4
• Elevated fibrin degradation products 4
• Microangiopathic hemolytic anemia: schistocytes on peripheral smear, elevated LDH, low haptoglobin 4

DIC scoring system (International Society on Thrombosis and Haemostasis):

• Platelet count: >100,000 = 0 points; 50,000-100,000 = 1 point; <50,000 = 2 points 4
• D-dimer: no increase = 0; moderate increase = 2; strong increase = 3 4
• PT prolongation: <3 sec = 0; 3-6 sec = 1; >6 sec = 2 4
• Fibrinogen: >100 mg/dL = 0; <100 mg/dL = 1 4
• Score ≥5 = overt DIC 4

Management Algorithm

Primary treatment:

• Treat underlying malignancy (chemotherapy for acute promyelocytic leukemia, antibiotics for sepsis, etc.) - this is the ONLY definitive treatment 4, 5

Supportive care for bleeding:

• Platelet transfusion: maintain platelets >50,000/μL if active bleeding, >20,000/μL if no bleeding 4
• Fresh frozen plasma 10-15 mL/kg (if PT/aPTT >1.5× normal and active bleeding) 4
• Cryoprecipitate 1 unit per 10 kg (if fibrinogen <100 mg/dL) 4
• Goal fibrinogen >100 mg/dL 4

Anticoagulation (controversial, use only in specific situations):

• Heparin 5-10 units/kg/hour IV (for predominant thrombotic manifestations without active bleeding) 4
• Consider in acute promyelocytic leukemia with DIC before starting chemotherapy 4
• Do NOT use if active bleeding or platelet count <50,000/μL 4

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8. Bowel Obstruction and Perforation in Colorectal Cancer

Clinical Presentation Pattern

Obstruction:

• Colicky abdominal pain 1
• Abdominal distension 1
• Nausea, vomiting (more prominent in proximal obstruction) 1
• Obstipation (complete obstruction) 1
• High-pitched bowel sounds or absent bowel sounds 1

Perforation:

• Sudden severe abdominal pain 1
• Peritoneal signs: rigidity, rebound tenderness, guarding 1
• Fever, tachycardia, hypotension (septic shock) 1
• Free peritonitis (perforation proximal to tumor) has mortality 19-65% 1
• Contained perforation (at tumor site) has mortality 0-24% 1

Diagnostic Workup

• CT abdomen/pelvis with IV contrast (95% sensitivity for perforation, 90% sensitivity for site) 1
• Abdominal X-ray (only 53% sensitivity for perforation - inadequate) 1
• Abdominal ultrasound (92% sensitivity for perforation but only 53% for site) 1
• Do NOT perform colonoscopy or contrast enema in suspected perforation 1
• Lactate level (marker of bowel ischemia and sepsis) 1
• Blood cultures 1

Management Algorithm

Immediate resuscitation (for perforation with sepsis):

• Aggressive IV fluid resuscitation 1
• Broad-spectrum antibiotics within 1 hour: 1
  • Piperacillin-tazobactam 4.5 g IV every 6 hours 1
  • OR Meropenem 1 g IV every 8 hours plus metronidazole 500 mg IV every 8 hours 1
• Source control surgery as soon as patient stabilized (within 6-12 hours) 1

Surgical management - Right-sided lesions:

• Right colectomy with ileocolic anastomosis (if patient stable, good bowel perfusion, no significant fecal contamination) 1
• Right colectomy with terminal ileostomy (if patient unstable, poor bowel perfusion, or significant contamination) 1
• Loop ileostomy only (for severely unstable patients who cannot tolerate resection) 1
• Delay stoma creation if open abdomen required 1

Surgical management - Left-sided lesions:

• Hartmann's procedure (resection with end colostomy, rectal stump) - procedure of choice for unstable patients 1
• Loop transverse colostomy (for severely unstable patients) 1
• Delay stoma creation if open abdomen required 1
• Oncologic resection should be performed when possible (similar long-term outcomes to elective cases if adequate lymph node harvest achieved) 1

Key surgical principles:

• Patient safety takes priority over oncologic principles 1
• Damage control surgery for exhausted patients: perform only procedures they can tolerate 1
• Anastomotic leak rate in emergency: 4-13% (vs 0.5-4.6% elective) 1
• Mortality in emergency: 7% (vs 5.3% elective) 1
• Only small proportion of patients undergo stoma reversal 1

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Common Pitfalls and Caveats

Spinal cord compression:

• Do NOT wait for MRI to start dexamethasone - begin immediately upon clinical suspicion 3
• Ambulatory status at presentation is the strongest predictor of outcome - delays in diagnosis result in permanent paralysis 2, 3

Tumor lysis syndrome:

• Do NOT alkalinize urine - increases calcium-phosphate precipitation and worsens renal injury 4
• Rasburicase is contraindicated in G6PD deficiency - causes severe hemolysis 4

Hypercalcemia:

• Do NOT give furosemide before adequate rehydration - worsens dehydration and hypercalcemia 4
• Bisphosphonates require 2-4 days to work - use calcitonin for immediate effect 4

Febrile neutropenia:

• Do NOT wait for culture results to start antibiotics - mortality increases significantly with each hour of delay 2
• Patients may not mount typical inflammatory response - absence of fever does not exclude infection 2

SIADH:

• Do NOT correct sodium >8-10 mEq/L in 24 hours - risk of osmotic demyelination syndrome (locked-in syndrome, quadriplegia, death) 4
• Tolvaptan should only be used in hospital with frequent sodium monitoring - risk of overcorrection 4

DIC:

• Do NOT give heparin if active bleeding or platelets <50,000/μL - will worsen bleeding 4
• Transfusion alone without treating underlying cause is futile - "pouring fuel on the fire" 4, 5

Bowel perforation:

• Do NOT delay surgery for complete oncologic workup - immediate patient safety takes priority 1
• Perforation proximal to tumor has 60% mortality vs 37% at tumor site - recognize this higher-risk scenario 1