Tumor Lysis Syndrome Is Associated with Worse Outcomes in Adult Patients with Acute Lymphoblastic Leukemia.

Introduction: Tumor lysis syndrome (TLS) occurs frequently during induction therapy for acute lymphoblastic leukemia (ALL). Patients are categorized into intermediate- or high-risk based on the lactate dehydrogenase (LDH) value and white blood cell (WBC) count, according to an expert panel, although no effort has been made to analyze TLS in ALL and its potential consequences.

Methods: We retrospectively analyzed TLS, variables associated with its occurrence, and its impact on overall survival (OS) and mortality during induction in a cohort of ALL patients in their first induction regimen.

Results: A total of 138 patients were included, 52.9% were male and the median age at diagnosis was 34 years. Most of them were treated with hyper-CVAD (39.1%) or a modified CALGB 10403 regimen (37.7%). TLS was identified in 42 patients (30.4%), and half of them fulfilled criteria for clinical TLS (C-TLS). Median OS was the lowest in C-TLS patients. An LDH 3 times greater than its upper laboratory normal (ULN) value and a WBC count equal to or greater than 50×109/L were associated with TLS development, and being male, hyperuricemia and an LDH 3 times greater than its ULN value were associated with C-TLS development. C-TLS and acute kidney injury were associated with excess mortality during induction.

Conclusion: TLS was identified in almost one-third of ALL patients during induction therapy. Different thresholds for LDH value and WBC count as well as other variables could identify patients at risk of developing this complication, which is associated with shorter OS. C-TLS confers a higher risk for mortality during induction.