Physicians Compliance During Maintenance Therapy in Children with Down Syndrome and Acute Lymphoblastic Leukemia.

Abstract

AbstractAbstract 2577Children with Down syndrome (DS) and acute lymphoblastic leukemia (ALL) have an inferior prognosis compared to non-DS ALL patients. We reviewed Methotrexate (MTX)/Mercaptopurine (6MP) maintenance therapy data for children with DS treated according to the NOPHO ALL92 or the NOPHO ALL2000 protocols between 1992 and 2007. The five year event-free survival (pEFS5y) for the DS patients was inferior to the non-DS patients (0.50 ± 0.07 vs 0.77 ± 0.01, p<0.001). The 48 DS patients in 1st remission at the beginning of maintenance therapy had pEFS10y below the 522 non-DS control patients (pEFS10y: 0.58, 95%-CI 0.43–0.77 vs. 0.83, 95%-CI 0.80–0.86, p<0.0001). The DS patients received lower median doses of MTX (Median: 11.8 vs 15.4, p<0.0001) and 6MP (median: 45.6 vs. 59.4, p<0.0001). In Cox regression analysis male gender, presence of DS, and high median maintenance therapy white blood cell levels (mWBC) were associated with increased risk for relapse. The mWBC hazard ratio for DS-ALL patients was 2.0, p<0.0005). This supports that DS children with ALL should be treated as vigorously as non-DS ALL patients. Obtaining WBC levels within target range could potentially increase their cure rates. [Display omitted] Non-DS513464443433418DS472519126 Disclosures:No relevant conflicts of interest to declare.