[The Factors Affecting Relapse in Pediatric B-cell Acute Lymphoblastic Leukemia Patients without Prognostic Fusion...

To analyze the efficacy of children with B-cell acute lymphoblastic leukemia (B-ALL) without prognostic fusion genes treated by CCLG-ALL 2008, and investigate the related factors affecting the recurrence of the patients.

B-ALL patients without prognostic fusion genes treated by the protocol of CCLG-ALL 2008 in our hospital from March 2008 to December 2012 were retrospectively analyzed. Follow-up time was ended in August 31, 2019. The median follow-up time was 92 months (range 0-136 months). Kaplan-Meier was used to detect the RFS, and COX multivariate regression analysis was employed to identify the independent factors affecting the recurrence of the patients.

There were 140 males and 99 females enrolled in this study. The ratio of male to female was 1.41∶1. The median age was 4.4 years old and the median number of WBC at initial stage was 4.98×10⁹/L. There were 77 cases relapsed during the observation while 162 without relapsed, 16 cases lost to follow-up and 72 cases died. The recurrence and mortality rate was 32.22% and 30.1%, respectively, in which 45 cases died of recurrence (62.5% of the total deaths). Univariate analysis showed that the age≥6 years old, WBC >100×10⁹/L, the bone marrow blasts on day 15≥25%, the bone marrow minimal residual disease (MRD) at week 12 >10^-4, and the higher risk were the main factors affecting the recurrence of the patients (P<0.05). Multivariate COX regression analysis showed that age≥6 years old, WBC >100×10⁹/L, bone marrow MRD >10^-4 at the 12th week were the independent risk factors affecting recurrence of the patients.

Age, initial WBC, and bone marrow MRD at the 12th week were correlated with recurrence in children with B-ALL without prognostic fusion genes, which can be used as prognostic indices of recurrence risk in clinical.