Oncological Emergencies Overview

Oncological Emergencies

Oncological emergencies are life-threatening complications that can occur during cancer treatment or stem from the underlying malignancy itself. These emergencies require prompt attention and often involve the collaborative efforts of an oncologist, emergency physician, and other specialists to manage effectively. Some of the most common oncological emergencies include tumor lysis syndrome, hypercalcemia of malignancy, spinal cord compression, and superior vena cava syndrome.

Tumor Lysis Syndrome

Tumor lysis syndrome (TLS) occurs when cancer cells are rapidly broken down by chemotherapy. This can lead to a rapid release of intracellular contents into the bloodstream, causing metabolic disturbances such as hyperkalemia, hyperphosphatemia, hypocalcemia, and acute kidney injury. The risk factors for TLS include high tumor burden, large cell size, and higher rates of proliferation. It is more commonly associated with hematologic malignancies like non-Hodgkin's lymphoma and leukemias but can occur in solid tumors as well.

Management of TLS includes aggressive hydration, administration of allopurinol or rasburicase to prevent complications related to phosphate and uric acid elevations, and monitoring of electrolytes and renal function. In some cases, renal replacement therapy may be necessary if severe acidosis, hyperkalemia, or volume overload presents.

Hypercalcemia of Malignancy

Hypercalcemia in patients with cancer can result from multiple sources including increased bone resorption due to osteoclast activation, parathyroid hormone–related peptide production, or ectopic PTHrP secretion by breast or lung cancer cells. This condition can cause symptoms like fatigue, dehydration, nephrolithiasis, cardiac arrhythmias, and neurological issues. Non-small cell lung cancer, small cell lung cancer, and breast cancer are among the most frequent causes of hypercalcemia in patients with advanced cancer.

The management of hypercalcemia involves restoring fluid balance, correcting any electrolyte imbalances, and addressing the primary source of calcium excess. Medications such as calcitonin, zoledronic acid, or denosumab may also be used to control the extent of bone resorption.

Spinal Cord Compression

Spinal cord compression (SCC) occurs when there is pressure on the spinal cord caused by a vertebral body fracture or neoplastic invasion by tumor cells. Symptoms can vary depending on the level of the spine affected but generally include pain that radiates down one or both legs, weakness, sensory loss, and bowel or bladder dysfunction. Metastatic cancer is the most frequent cause of spinal cord compression, with lung and breast cancers being the most common primary tumors.

The management of SCC involves immediate stabilization of the spine, administration of corticosteroids to reduce edema around the spinal cord, and management of any neurological deficits. If possible, definitive treatment of the underlying malignancy should also be pursued.

Superior Vena Cava Syndrome

Superior vena cava syndrome (SVCS) occurs when the superior vena cava (SVC) is obstructed by a malignant process, often a lung cancer or lymphoma. This can lead to swelling of the face, neck, and upper extremities, as well as dyspnea and cough. Non-small cell lung cancer and lymphomas are the most common causes of SVCS.

Management of SVCS involves symptomatic relief, such as diuretics for edema, and treatment of the underlying malignancy. In some cases, stent placement or radiation therapy may help relieve the obstruction.

In conclusion, oncological emergencies are potentially life-threatening complications that can arise during cancer treatment or from the cancer itself. Prompt recognition and management of these emergencies are crucial for patient survival and quality of life. A multidisciplinary approach, involving oncologists, emergency physicians, and other specialists, is often required to effectively manage these complex cases.