What is the management approach for a patient with malignancy and elevated White Blood Cell (WBC) count?

From the Guidelines

Management of a patient with malignancy and elevated white blood cell count requires immediate cytoreduction with hydroxyurea or leukapheresis, hydration, and allopurinol to prevent tumor lysis syndrome, followed by specific treatment of the underlying malignancy based on cancer type, stage, and patient factors. For patients with significant leukocytosis (WBC >50,000/μL) and symptoms of leukostasis, such as respiratory distress or neurological changes, immediate cytoreduction is necessary 1. This can be achieved with hydroxyurea (starting at 1-2 g orally twice daily, adjusted based on response) or leukapheresis in severe cases. Some key considerations in the management of malignancy and elevated WBC count include:

• Determining the cause of the elevated WBC count, which may be due to the malignancy itself, infection, leukemoid reaction, or paraneoplastic syndrome
• Hydration with intravenous fluids (typically 2-3 L/day of normal saline) to prevent tumor lysis syndrome, particularly in hematologic malignancies
• Administration of allopurinol (300 mg orally daily) to prevent hyperuricemia
• Specific treatment of the underlying malignancy, which depends on cancer type, stage, and patient factors
• Chemotherapy regimens appropriate for the specific diagnosis should be initiated promptly for hematologic malignancies causing leukocytosis
• Supportive care, including infection prophylaxis, nutritional support, and management of symptoms, is also important
• Regular monitoring of complete blood counts, renal function, and electrolytes is necessary to assess response to treatment and detect complications early 1. The elevated WBC count typically improves with successful treatment of the underlying malignancy. In high-risk patients (WBC count >10 × 10^9/L), two potential treatment options are available, including ATRA plus ATO with the addition of some cytoreductive chemotherapy 1.

From the FDA Drug Label

Following administration of Vincristine Sulfate Injection, some individuals may have a fall in the white blood cell count or platelet count, particularly when previous therapy or the disease itself has reduced bone–marrow function Therefore, a complete blood count should be done before administration of each dose.

The management approach for a patient with malignancy and elevated White Blood Cell (WBC) count involves careful consideration of the patient's bone marrow function and close monitoring of their complete blood count before each dose of vincristine sulfate.

• Key considerations include the potential for vincristine sulfate to cause a fall in WBC count or platelet count, especially in patients with preexisting bone marrow dysfunction.
• Dosage modification may be necessary based on clinical evaluation and laboratory tests, such as complete blood counts 2.

From the Research

Malignancy and Elevated WBC Count

• Malignancy can be associated with an elevated White Blood Cell (WBC) count, and the management approach for a patient with malignancy and elevated WBC count depends on the underlying cause of the elevation 3.
• The evaluation of patients with leukocytosis involves using age- and pregnancy-specific normal ranges for the WBC count, and a repeat complete blood count with peripheral smear may provide helpful information 3.
• Symptoms suggestive of a hematologic malignancy include fever, weight loss, bruising, or fatigue, and if malignancy cannot be excluded or another more likely cause is not suspected, referral to a hematologist/oncologist is indicated 3.

Management of Malignancy with Elevated WBC Count

• The management of malignancy with elevated WBC count involves treating the underlying cause of the elevation, which may include chemotherapy, radiation therapy, or other targeted therapies 4, 5.
• In patients with acute lymphoblastic leukemia, induction chemotherapy with vincristine, prednisone, and an anthracycline can achieve a remission rate of 70-80% 5.
• In patients with chronic lymphocytic leukemia, the M-2 protocol (vincristine, cyclophosphamide, BCNU, melphalan, and prednisone) can achieve a complete remission rate of 17% and a partial response rate of 44% 4.

Prognostic Factors

• Prognostic factors for patients with malignancy and elevated WBC count include the type and stage of cancer, the degree of elevation of the WBC count, and the presence of other symptoms such as fever, weight loss, or bruising 5, 6.
• In patients with resectable colorectal cancer, the pre-treatment basophil count and post-/pre-treatment neutrophil ratio may be potential prognostic factors for overall survival 7.
• A high WBC count at diagnosis can be associated with a poorer prognosis in some types of cancer, and the use of WBC counts as a prognostic marker is being investigated in various studies 7.