Pretreatment grade 4 thrombocytopenia is an independent prognostic factor in adult acute lymphoblastic leukemia: an extended analysis of a single-center retrospective study

Abstract

Objectives: Low pretreatment platelet count is negatively associated with overall survival (OS) of certain subtypes of acute lymphoblastic leukemia (ALL). However, the prognostic impact of the grade of thrombocytopenia on OS and disease-free survival (DFS) has never been explored. Methods: We conducted an extended analysis of a retrospective study. Newly diagnosed adults with ALL was enrolled in this study. The grade of thrombocytopenia was evaluated in accordance with the Common Terminology Criteria for Adverse Events (CTCAE) version 3.0. Prognostic impacts were assessed by the hazard ratios (HRs) and 95% confidence intervals (CIs) obtained from univariate and multivariate Cox proportional hazards regression analyses. Results: A total of 90 participants were included in this study. There were 18 cases with grade 4 thrombocytopenia among the 71 participants presented with thrombocytopenia of any grade. Both univariate and multivariate Cox regression analyses suggested the independent negative prognostic impact of grade 4 thrombocytopenia on both OS (HR = 4.73, 95% CI = 1.95-11.52) and DFS (HR = 9.82, 95% CI = 3.14-30.76) of adult ALL, using the cohort of patients with no thrombocytopenia as a reference. In addition, treatment regimen, cytogenetic profile, time to treatment, and platelet count were independent prognostic factors of the OS. We also found that treatment regimen, cytogenetic profile, and peripheral blood blast percentage were independent prognostic factors of the DFS. Conclusion: Grade 4 thrombocytopenia was a negative prognostic factor for both overall survival and disease-free survival of adults with acute lymphoblastic leukemia.