[Abstract]Objective To explore the relationship between the involvement of central nervous system by flow cytometry and prognosis in childhood acute lymphoblastic leukemia (ALL) by CCLG-ALL 2008 scheme. Methods We retrospectively assessed the data of 601 cases of children with acute lymphoblastic leukemia in our institute from Apr 2008 to Jun 2013 and analysed the effect of central nervous system involvement by flow cytometry on their prognosis. All patients who had cerebrospinal fluid (CSF) positive by flow cytometry had been done intrathecal therapy until CSF got negative. Results Among these 601 cases at diagnosis, the mean age of onset was 5.7(0.4-15.0) years old. Male and female were 368:233(1.6: 1). 50 cases (8.3%), 12 cases (2.0%) had central nervous system involvement at diagnosis and consolidation therapy. We followed these cases until Dec 2016. The median time of follow-up was 59(1-104) months. The number of lost case was 17 (2.8%), 584(97.2%) cases could be estimated. There was statistically significance difference in 5-year overall survival(OS)in CSF positive and negative by flow cytomety at diagnosis(82.0±1.7% & 70.3±6.7%, X2=4.853 P=0.028). there were no statistically significant difference in event free survival(EFS)and relapse free survival(RFS) in these two groups at diagnosis(X2=2.983 P=0.084 & X2=0.280 P=0.596).During the consolidation therapy, there were significant difference in 5-year OS, EFS, RFS with central nervous system involvement or not by flow cytometry(81.3±1.6% & 50.0±14.4%, X2=9.611 P=0.002; 92.8±1.1% & 38.9±14.7%, X2=14.741 P=0.000; 96.6±0.8% & 40.0±14.6%, X2=29.033 P=0.000). Conclusions No matter at diagnosis or consolidation period in childhood ALL, central nervous system involvements by flow cytometry were all poor prognosis factors. CSF positive by flow cytometry is an indicator for intensified CNS-directed therapy.


No relevant conflicts of interest to declare.

Author notes


Asterisk with author names denotes non-ASH members.