Incidence and Risk Factors for Hypertension during Induction Chemotherapy for Pediatric Acute Lymphoblastic Leukemia

Background: The most common form of cancer in children is acute leukemia, with acute lymphoblastic leukemia (ALL) comprising approximately seventy-five percent of these. The initial month of therapy (induction) for all children with ALL includes high dose steroids. One of the side effects of these steroids is hypertension.

Objective: To determine the incidence and risk factors of hypertension during induction chemotherapy for acute lymphoblastic leukemia in children.

Methods: Retrospective analysis was performed of data collected from all children diagnosed with acute lymphoblastic leukemia (ALL) at Hershey Medical Center (HMC) in 2004 and 2005 (n = 37). Each blood pressure from presentation through the four weeks of induction was recorded. To minimize the effect of a single high blood pressure measurement, median systolic and diastolic pressures were determined for each of the four weeks of induction therapy. These pressures were compared to published age matched norms. For each patient and each week of therapy, the percentile (<50, 50–90, 90–95, >99) was determined.

Results: Thirty-seven children (21 male, 16 female) met study criteria, with a median age of five. Thirteen of these patients received prednisone and twenty-four received dexamethasone. Overall, 95% of children had mean systolic or diastolic pressures >90^th percentile, 81 had pressures >95^th percentile, and 51% were above the 99^th percentile for at least one week of induction. By contrast, only 32%, 19%, and 11% had pressures at these levels at initial presentation. The incidence of significant hypertension increased significantly during the four weeks of induction. Only three children (10%) with pressures above the 95^th percentile were clearly noted in the medical record to be hypertensive, and only two children (6.7%) with pressures this high were treated.

Conclusions: Hypertension is common and underrecognized during induction chemotherapy for childhood ALL. The incidence of hypertension increases weekly during induction chemotherapy.