Cancer and its treatments can trigger life-threatening emergencies. We can categorize these medical oncologic emergencies as metabolic, haematological, structural, or treatment-related complications. With approximately 14.5 million cancer patients in the U.S. (estimated to reach 19 million by 2024), it is imperative for clinicians and physicians to not only recognise these oncologic emergencies when they arise but also to provide urgent and effective care. These emergencies may develop gradually over months or escalate rapidly within hours. Early diagnosis can be challenging since cancer often goes undetected until complications arise.
Febrile Neutropenia
Febrile neutropenia often arises as a side effect of cytotoxic therapy, particularly in cancer patients undergoing chemotherapy. Chemotherapy suppresses bone marrow function, reducing the body’s ability to fight infections and making neutropenia alarmingly common, especially for those with hematological malignancies. The condition manifests when patients have a low white blood cell count and develop a fever, defined as a single oral temperature above 38.3°C (101°F) or a sustained temperature of 38°C (100.4°F) for at least one hour, accompanied by an absolute neutrophil count (ANC) below 1,500 cells/μL (severe cases have ANCs under 500 cells/μL). Without prompt treatment, febrile neutropenia can lead to life-threatening infections, carrying a mortality rate of around 5% for solid tumors and 11% for hematological malignancies.
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Causes
Chemotherapy drugs like anthracyclines, taxanes, and alkylating agents; primarily cause febrile neutropenia by directly damaging bone marrow cells that produce neutrophils. Infections (bacterial, viral like HIV or hepatitis, or fungal) also trigger the condition. Additionally, autoimmune disorders, cancers affecting blood cells, antibiotics (e.g., penicillin), antivirals, thyroid medications, and psychiatric drugs can exacerbate neutropenia. Central venous catheters and stem cell transplants increase infection risk by providing entry points for pathogens.
Treatment
Doctors quickly administer broad-spectrum antibiotics, especially to high-risk patients requiring hospital care and intravenous drugs like cefepime or meropenem. Lower-risk patients may receive oral antibiotics such as ciprofloxacin with amoxicillin-clavulanate. Healthcare providers take blood, urine, and catheter site cultures to identify the infection’s cause.
They add antifungal medications if the fever persists beyond 3–7 days, addressing potential Candida infections. Treatment continues until the patient remains fever-free for 48 hours and their neutrophil count improves. Rapid antibiotic administration, within 30 minutes of diagnosis, significantly improves survival rates. Oncologists and infectious disease specialists collaborate to provide personalized care, particularly in complex cases.
Hypercalcaemia
Hypercalcaemia is a condition where there is too much calcium in the blood. This oncological emergency is the most common metabolic complication in cancer patients, affecting 10–30% of individuals with malignancies like breast cancer, lung cancer, multiple myeloma, and non-Hodgkin’s lymphoma. This condition often signals advanced cancer and uncontrolled tumor growth, making it a poor prognostic indicator. Symptoms of hypercalcaemia can mimic those of terminal cancer and may include nausea, vomiting, fatigue, confusion, excessive thirst, frequent urination, and bone pain. If left untreated, it can lead to severe complications such as kidney failure, irregular heartbeats, or even coma.
Causes
Hypercalcaemia in cancer patients often arises from three main sources. In roughly 80% of cases, tumors trigger this issue by releasing a substance called PTHrP. This substance acts like the parathyroid hormone, pulling calcium from bones and increasing its absorption. Cancer can also directly invade bone, destroying it and flooding the bloodstream with calcium; this accounts for about 20% of instances. In rare cases, hypercalcaemia can be caused by lymphomas or other factors elevate vitamin D production, further contributing to high calcium. Multiple myeloma and squamous cell carcinomas, especially those affecting the lung, head, and neck, often cause this condition by directly damaging bone or disrupting calcium balance.
Treatments
Careful monitoring accompanies treatment; clinicians regularly check calcium levels, kidney function, and hydration status. Anti-nausea drugs manage symptoms like vomiting. In severe or persistent cases, calcitonin or dialysis may rapidly lower calcium. Ultimately, treating the underlying cancer remains essential for lasting control, hypercalcaemia often returns if the malignancy persists.
In severe cases or when hypercalcaemia is resistant to initial treatments, newer therapies such as monoclonal antibodies or calcimimetics may be used. Treating the underlying cancer is imperative for long-term management since hypercalcaemia often recurs if the malignancy remains uncontrolled.
Tumor Lysis Syndrome
Tumor lysis syndrome (TLS) is a life-threatening condition that occurs when cancer cells break down rapidly, releasing their contents into the bloodstream. This sudden release overwhelms the body’s ability to maintain normal blood chemistry, leading to dangerous metabolic imbalances such as high levels of uric acid (hyperuricemia), potassium (hyperkalemia), and phosphate (hyperphosphatemia), along with low calcium levels (hypocalcemia).
TLS is most commonly seen in patients with blood cancers like acute lymphoblastic leukemia (ALL) and Burkitt’s lymphoma, especially after starting chemotherapy or other cancer treatments. It can also occur at random in rare cases. If this oncological emergency is left untreated, TLS can cause kidney failure, seizures, heart rhythm problems, and even death.
Causes
TLS occurs when a large number of cancer cells are destroyed quickly, due to treatments like chemotherapy, radiation therapy, or targeted therapies. The rapid breakdown of these cells releases intracellular substances such as potassium, phosphate, and uric acid into the bloodstream. This overwhelms the kidneys’ ability to rid the body of these substances, leading to metabolic disturbances. TLS is more likely in cancers such as leukemias and aggressive lymphomas. Additional risk factors include large tumor size, poor kidney function before treatment, dehydration, and high levels of lactate dehydrogenase (LDH) or uric acid prior to therapy.
Treatment
Tumor Lysis Syndrome (TLS) is managed by first assessing a patient’s risk before starting cancer treatment; which guides subsequent care. Clinicians will closely monitor low-risk patients, while proactively hydrating medium-risk patients and prescribe medications like allopurinol to control uric acid. For high-risk individuals, clinicians will administer rasburicase, a drug that rapidly breaks down uric acid, along with aggressive hydration to help the kidneys function.
When TLS develops despite preventative measures, clinicians use intravenous fluids to flush out excess substances and rasburicase to manage uric acid. They treat low calcium levels with calcium gluconate, and dialysis may quickly remove toxins in severe cases. Heart monitoring is performed to detect and manage rhythm problems caused by electrolyte shifts.
Hyperviscosity Syndrome
Hyperviscosity syndrome is rare but potentially deadly clinical condition arising from an heightened concentration of serum proteins (e.g., in Waldenström macroglobulinemia or multiple myeloma) or cellular components (e.g., white blood cells in acute leukemias or polycythemias). This imbalance results in increased blood viscosity, leading to areas of the body not receiving enough blood to meet its needs and subsequently leading to end-organ dysfunction.
A common presentation of hyperviscosity syndrome involves symptoms such as bleeding under the skin or mucous membranes, changes in vision, and localized neurological problems. Doctors should consider hyperviscosity syndrome when patients have significantly high white blood cell counts (over 100,000 per microliter). They should also consider it with high hemoglobin levels (near 200 grams per liter). Finally, look for signs indicating reduced blood flow.
Causes
The development of hyperviscosity syndrome is often due to the overproduction of specific proteins, such as immunoglobulins, or an excessive number of circulating cells. This can be seen in conditions like Waldenström macroglobulinemia, where divergent immunoglobulin production significantly increases serum viscosity. Similarly, leukemic processes characterized by high white blood cell counts and polycythemia, noted by increased hemoglobin levels, contribute to the syndrome’s pathogenesis. The resultant increase in blood viscosity slows down blood circulation. Furthermore, certain infections and pharmacological interventions may exacerbate the condition.
Treatment
Healthcare providers actively manage hyperviscosity syndrome by focusing initial treatment on diluting the blood’s viscosity through intravenous fluid administration. They effectively mitigate protein overload by performing plasmapheresis, a procedure that filters out excess proteins present in blood plasma. Additionally, they may conduct leukapheresis, separating white blood cells from a blood sample and returning the blood back into circulation, reducing the abnormal white blood cell count.
In cases of polycythemia, they lower hemoglobin levels through phlebotomy, or blood removal. Importantly, they avoid administering red blood cell and platelet transfusions, as these can potentially exacerbate hyperviscosity. Furthermore, they address underlying malignancies, such as leukemia or multiple myeloma, by administering targeted chemotherapy. Hospitalization and consultation with specialists in hematology and oncology are typically required to address the underlying causes and ensure comprehensive patient care.
Mucositis
Mucositis is a painful inflammation and ulceration of the mucous membranes lining the digestive tract. This oncological emergency is commonly caused by cancer treatments such as chemotherapy and radiotherapy. It can occur anywhere along the gastrointestinal (GI) tract, but oral mucositis, which affects the mouth, is the most frequent and debilitating type. This condition impacts many cancer patients, especially those undergoing high-dose chemotherapy, hematopoietic stem cell transplantation (HSCT), or radiotherapy for head and neck cancers.
Severe mucositis can lead to difficulty eating or drinking, weight loss, infections, and delays in cancer treatment, significantly hindering the patients’ quality of life. Symptoms of oral mucositis include soreness in the mouth or throat, difficulty swallowing, dry mouth, thick saliva, and visible white patches or pus on the tongue or gums. In severe cases, eating or drinking becomes impossible due to extreme pain.
Causes
The primary cause of mucositis is chemotherapy and radiotherapy used to treat cancer. These treatments target rapidly dividing cancer cells but also harm healthy epithelial cells lining the GI tract. Certain chemotherapy drugs, such as 5-fluorouracil (5-FU) and irinotecan, are particularly associated with mucositis. Radiotherapy to areas like the head, neck, pelvis, or abdomen increases the risk significantly. Other factors contributing to mucositis include high treatment doses, prolonged therapy cycles, poor oral hygiene, dehydration, and pre-existing conditions like diabetes.
Treatment
Managing mucositis involves relieving symptoms and promoting healing while continuing cancer treatment. Pain relief is a priority and may include mouthwashes, sprays, gels, or systemic painkillers. Moisturizing sprays or gels can help alleviate dry mouth symptoms. Medications like allopurinol may be prescribed to reduce inflammation in mild cases. For severe mucositis, low-level laser therapy can be used to prevent tissue damage and promote healing. Maintaining good oral hygiene is important to reduce infection risks.
Graft-Versus-Host Disease
Graft-versus-host disease (GVHD) is a serious medical oncological emergency that occurs after a stem cell or bone marrow transplant, where donor cells attack the recipient’s healthy tissues. This immune response can cause widespread inflammation and damage to organs such as the skin, liver, and gastrointestinal tract.
The skin is mostly affected, which a maculopapular rash forms on the skin. In severe cases, GVHD may exhibit a similar appearance to toxic epidermal necrolysis, with blistering and the peeling of the skin. GVHD is classified into two types: acute, which occurs within the first 100 days after the transplant, and chronic, which develops later and can last for years. The severity of GVHD varies from mild to life-threatening, making early detection and treatment extremely important.
Causes
GVHD is triggered by the immune system’s response to foreign tissue. Donor T-cells in the graft identify the recipient’s healthy cells as threats and attack them. This immune reaction is more likely when there is a mismatch between donor and recipient tissue types or when immunosuppressive medications are insufficient. Risk factors include unrelated donors, older age, and high-intensity conditioning treatments before transplantation.
Treatment
The treatment for GVHD focuses on controlling the immune response and relieving symptoms. Doctors often use immunosuppressive drugs like corticosteroids to reduce inflammation caused by the donor cells’ attack. Severe cases may require different types of treatment, such as monoclonal antibodies or extracorporeal photopheresis, to suppress immune activity. Healthcare providers manage symptoms like skin rashes, diarrhea, or liver dysfunction using specialized treatments. Early intervention by a multidisciplinary team improves outcomes and helps prevent complications.
Neutropenic Enterocolitis
Neutropenic enterocolitis, as known as Typhlitis, is an oncological emergency that primarily occurs in immunosuppressed patients who are undergoing chemotherapy for breast, lung, colorectal cancers. It also commonly appears in patients with lymphoma or leukemia Neutropenic enterocolitis affects the small and large intestines causing the inflammation of these areas and eventually leads to necrosis.
It may also present symptoms such as diarrhea, fever, melena and abdominal pain due to the bowel walls thickening. In severe cases of neutropenic enterocolitis, mortality rates are as high as 100% if left untreated. This emphasises the importance of administering urgent treatment when symptoms present themselves.
Causes
Researchers don’t definitively know the underlying cause of neutropenic enterocolitis. However, it is strongly linked with neutropenia. Neutropenia means a deficiency in neutrophils. These are white blood cells that fight infection. Several factors contribute to its development, most notably severe neutropenia, which commonly arises in patients undergoing chemotherapy for cancer, those with bone marrow disorders like leukemia or aplastic anemia, and individuals receiving stem cell transplants.
Treatment
Diagnosis is achieved through CT scans, which can aid in identifying bowel wall thickening, inflammation of the intestines or fat stranding. Treatment includes broad-spectrum antibiotics, using devices to maintain blood circulation and bowel rest. If these treatments are started early, it should lead to the subsiding of symptoms and increased survival rates in patients.
Superior Vena Cava Syndrome
Superior Vena Cava (SVC) syndrome that occurs in patients with cancer due to the compression of the superior vena cava. The superior vena cava is a large vein that carries deoxygenated blood from the upper body (head, neck, arms, and chest) back to the heart. This compression obstructs or restricts blood flow, leading to a buildup of pressure in the area above the blockage. Symptoms include facial swelling and shortness of breath with airway compression, cerebral edema and pleural effusion possibly developing. It’s a serious complication, particularly for people with cancer.
Causes
The most common cause of this oncological emergency is cancer, particularly lung cancer and non-Hodgkin’s lymphoma. These cancers can directly compress the vein, invade its walls, or enlarge nearby lymph nodes. Non-cancerous causes include blood clots from intravenous devices like catheters or pacemakers. Other contributing factors may include infections or inflammatory conditions. These blockages disrupt blood flow, leading to symptoms such as swelling of the face and neck, shortness of breath, and visible chest vein distension.
Treatment
Treatment for Superior Vena Cava (SVC) syndrome usually follows a systematic approach. First, clinicians aim to relieve symptoms. Ultimately, they should address the underlying cause. Doctors initially use corticosteroids like dexamethasone. These medications rapidly reduce swelling and inflammation. This provides temporary relief to the patient. However, this does not target the tumor itself. Definitive treatments, particularly radiation therapy (which shrinks the compressing tumor) and chemotherapy (which tackles the cancer cells). Stenting, which is placing a small mesh tube within the SVC to improve blood flow, offers symptomatic relief. In certain situations, surgical removal of the tumor may also be an option.
Spinal cord compression
Pressure can cause spinal cord compression. Cancer sometimes spreads from other parts of the body into the spine. Broken vertebrae also occasionally cause this compression. Cancers that frequently spread to the bone and cause this type of compression often originate in the breast, kidney, thyroid, prostate, or lungs. This oncological emergency should be diagnosed with urgency and requires immediate treatment to prevent permanent damage and disability.
Causes
This oncological emergency usually arises from cancer that has spread from elsewhere in the body, metastatic spread. This commonly affects patients with cancers originating in the breast, kidney, thyroid, prostate, or lung. Cancer can press on the spinal cord either by spreading outside of it (extradural spread) or by directly invading the vertebrae, the bones making up the spine. Vertebral crush fractures can also cause compression. These breaks occur in the vertebra. Weakened bones make fractures more likely, although they are uncommon. Cancer treatment or other factors can weaken bones.
Treatment
Healthcare professionals should urgently consult specialists when they suspect spinal metastases. They should also consult specialists if neurological symptoms are present. Treatment typically combines several approaches: radiotherapy to shrink tumors and relieve pressure, corticosteroids like dexamethasone to manage swelling, and sometimes surgery to remove tumors or bone fragments that are compressing the spinal cord.
Conclusion
For clinicians it is extremely vital to be able to recognize these 9 critical oncological emergencies to deliver proper care with urgency. Timely intervention of these emergencies is vital especially for people with cancer. Prompt diagnosis and treatment significantly improve outcomes; therefore, we urge readers experiencing concerning symptoms to seek immediate medical attention. This information serves as an overview only and is not a substitute for professional medical advice. It’s imperative to consult healthcare providers for accurate diagnoses and personalized care.
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