Diagnostic cerebrospinal fluid examination in children with acute lymphoblastic leukemia:: Significance of low leukocyte counts with blasts or traumatic lumbar puncture

Purpose : To determine the significance of leukemic blasts or traumatic lumbar puncture (TLP) in diagnostic CSF of children enrolled in the Berlin-Frankfurt-Munster (BFM) Acute Lymphoblastic Leukemia-BFM-95 trial. Patients and Methods: A total of 2,021 patients were retrospectively evaluated according to initial central nervous system (CNS) status. Patients were classified as follows: CNS1 (CNS negative, n = 1,605), CNS2 (less than or equal to 5 WBC/muL CSF with blasts, n = 103), CNS3 (CNS positive, n = 58), TLP + (TLP with blasts, n = 135), or TLP- (TLP without blasts, n = 111). Patients with CNS2 and TLP + status were eligible for two additional doses of intrathecal (IT) methotrexate (MTX). CNS3 patients received additional IT MTX and cranial irradiation (18 Gy). Results: CNS2, CNS3, and TLP + groups contained a higher percentage of patients with unfavorable characteristics. Cox regression analysis identified TLP + and CNS3 status as prognostically significant (CNS3): risk ratio (RR) = 2.3; 95% confidence interval [CI], 1.4 to 3.6, P = .0005; TLP +: RR = 1.5; 95% Cl, 1.02 to 2.2; P = .04. Overall 5-year event-free survival (EFS) is 79, for CNS1 it is 80%, and for TLP- it is 83%. CNS2 patients have an EFS of 80%, but the cumulative incidence of relapses with CNS involvement is higher compared with CNS1 patients (0.10 v 0.04). TLP + patients have a significantly reduced EFS (73%, P = .003) because of an increased incidence of CNS relapses. CNS3 patients suffer from more systemic and CNS relapses (EFS 50%). Conclusion: CNS2 patients have the same prognosis as patients with CNS 1 status, whereas the EFS of TLP + patients is inferior to CNS 1 but superior to CNS3 patients (P = .001). Both subgroups may have benefitted from additional IT MTX. (C) 2003 by American Society of Clinical Oncology.