Oncologic Emergencies

There are 4 major Oncologic emergencies which are vital to recognize and treat immediately. They include:

1.) Tumor Lysis Syndrome: the set of metabolic abnormalities that result from acute destruction of neoplastic cells and release their intercellular products into the circulation. The high rate of cell turnover overwhelms the body's normal homeostatic mechanisms for handling potassium, calcium, phosphorous, and uric acid, leading to: Hyperuricemia, Hyperkalemia, Hypocalcemia, and Uremia. This emergency most commonly occurs in hematologic malignancies, but it also is dependent upon several other factors, such as: extent of disease, type of treatment, patients pre-existing renal function. These patients may present with the following symptoms: uric acid deposition in distal tubules of kidneys resulting in impaired renal function might cause decreased urination; low calcium might cause decreased urination, agitation, muscle tetany, and bone pain; Hyperkalemia may present as cardiac arrhythmia and sudden death. The treatment for tumor lysis syndrome is prophylaxis first and foremost with IV fluids (good hydration)

2.) Hypercalcemia of Malignancy: occurs most often in lung, breast, and hematologic cancers. Symptoms depend on the degree of Hypercalcemia and how quickly it develops. Acute symptoms include nausea, vomitting, constipation, polyuria, polydipsia, muscle weakness, acute renal insufficiency and mental status changes. Chronic symptoms include kidney stones, bone pain, and depression. The causes of Hypercalcemia include secretion of parathyroid-hormone related peptide (classically seen in squamous cell lung cancer), abnormal production of calcitriol (most often seen in lymphomas) due to the deregulated conversion of 25-vitamin D to 1, 25-vitamin D, and direct tumor invasion into boney structures (due to tumor cells secretion of IL-1, IL-6, and TNF which causes osteoclastic activity to increase thereby releasing calcium from the bone into the bloodstream). Treatment of Hypercalcemia of malignancy is first and foremost hydration (IV fluids), with adjuvant therapy inclusive of diuretics (lasix to increase renal excretion of calcium), bisphosphonates (pamidronate to produce a sustained decrease in calcium level by inhibiting osteoclastic activity and calcium resorption from bone), calcitonin (rapid onset of action to decrease osteoclastic activity - adverse effects include hypersensitivity reactions and tachyphylaxis), Gallium nitrate and Plicamycin are used very infrequently as they are highly toxic, steroids (short term and especially useful in lymphoma and myeloma), and dialysis if necessary.

3.) Superior Vena Cava Syndrome: results from an increase in central venous pressure caused by vena caval obstruction. This relatively rare complication most commonly occurs in cancers such as: small cell lung cancer, lymphoma, breast, and other mediastinal metastatic lesions. Symptoms include cough, dyspnea, and dysphagia combined with swelling and discoloration of the neck, face, and upper extremities. Depending on the site of disease, both vocal cord paralysis and Horner syndrome (ptosis of upper eyelid, constriction of pupil, anhidrosis and flushing of the affected side of the face) can occur. Treatment consists of elevating the head of the bed and giving diuretics and corticosteroids (corticosteroids are most useful in lymphoma). Chemo and radiation are important components to therapy after a tissue biopsy has confirmed this diagnosis (unless it is life threatening, then you may forgo the biopsy). Furthermore, intravenous stenting can relieve symptoms such as dyspnea for many patients, and anticoagulation may be beneficial as thrombus formation occurs in up to 50% of patients with superior vena cava syndrome (although its effect on survival has not been well documented, it has use in bringing symptommatic relief).

4.) Spinal Cord Compression: occurs in roughly 5% of all cancer patients, most often in cancers of the prostate, lung, and breast (high propensity for bony metastases). Although it is not immediately life threatening unless it involves level C3 or above, spinal cord compression may lead to profound and permanent morbidity. Initial symptoms include pain (present in 96% of patients with spinal cord compression)- the pain is often increased while in the supine position and decreases when upright. Other symptoms include weakness, sensory deficits, and autonomic dysfunction. If not treated promptly, it may progress to paraplegia and/or loss of sphincter control. The diagnosis is critical to make in a timely fashion in order to prevent significant morbidity. It is necessary to obtain an MRI without contrast in any patient with a known or suspected malignancy who presents with a new pain pattern or neurologic deficits. Treatment must be rapid, and includes corticosteroids (to decrease edema that may compress vasculature or the nerves directly) - preferred corticosteroid is dexamethasone 4mg, IV bolus, q6h; radiation therapy, particularly if the primary tumor is radio-sensitive (such as prostate, lung, and breast) - obtain a STAT radiation-oncology consult; Chemotherapy may be an option in highly chemo-sensitive cancers (such as pediatric neuroblastoma); and finally surgery is the remaining option if a tissue diagnosis is needed, the area has previously received maximal irradiation, spinal stabilization is needed, or other treatments are not working. (Other non-malignant causes of spinal cord compression include osteoporotic compression fractures and spinal abscesses.)

Other Emergencies Include:
5.) Strokes and Seizures: occur in 7% and 2%, respectively, of cancer patients. Strokes may be embolic or hemorrhagic, and the patient must be stabilized prior to treatment of radiation or steroids, or antiplatelet/anticoagulation/thrombolytic therapy. Also, anticonvulsants have not been shown to be effective in controlling seizures in malignancy, with the exception of melanoma brain metastasis or leptomeningeal metastasis.

6.) Extravasation of Chemotherapeutic Drugs: may cause pain, redness, swelling, and even necrosis in the skin surrounding the injection site. Therapy is to discontinue the chemotherapy and to aspirate the line and administer an antidote as applicable. Common drugs which cause this include anthracyclines (doxorubicin) and vinca alkaloids (vincristine).

7.) Neutropenic Fever: definied as neutorpenia lower than 500/mL plus a single temperature of 38.3 or higher, or a temperature of 38.0 or higher lasting over 1 hour. Begin broad-spectrum antibiotics immediately and continue until the absolute neutrophil count exceeds 0.5x10^9/L and the patient is afebrile. Without treatment, this emergency has a mortality rate of 50%.

8.) Dehydration: is common and is often overlooked by healthcare professionals. It is often caused by emesis, diarhhea, and mucositis. Treat with IV fluids, anti-emetics, and anti-diarrheal medications and consider a change in chemotherapy choice.

9.) Anaphylaxis and Capillary Leak: particularly if using systemic interleukin 2 (IL-2), which may cause severe hypotension. Closely monitor in the ICU, discontinue IL-2 treatment, administer IV fluids and phenylephrine to treat the hypotension.

10.) Hemorrhagic Cystitis: Most often occurs with the usage of the chemotherapeutic drugs, cyclophosphamide and ifosfamide, which cause severe bladder hemorrhage due to the toxic metabolites which are excreted by the kidney. This is more common to occur when the urinary output is low, as it may contact the bladder wall more freely. Thus, hydration is key to prevention. Another preventative measure is to administer the drug Mensa during chemotherapy infusion. If severe, a 3-way urinary catheter may be used to continuously flush the bladder.




My cousin's recent surgery was due to #4, spinal cord compression on the C6-T2 area.

*Reference: "Oncologic Emergencies for the Internist" from the Cleveland Clinic Journal of Medicine, Volume 69, Number 3. March 2002.