Improved outcome in pediatric relapsed acute myeloid leukemia: results of a randomized trial on liposomal daunorubicin by the International BFM Study Group.

PURPOSE: In pediatric relapsed acute myeloid leukemia (AML), optimal reinduction therapy is unknown. Studies suggest that liposomal daunorubicin (DNX; DaunoXome; Galen, Craigavon, United Kingdom) is effective and less cardiotoxic, which is important in this setting. These considerations led to a randomized phase III study by the International Berlin-Frankfurt-Münster Study Group. PATIENTS AND METHODS: Patients with relapsed or primary refractory non-French-American-British type M3 AML who were younger than 21 years of age were eligible. Patients were randomly assigned to fludarabine, cytarabine, and granulocyte colony-stimulating factor (FLAG) or to FLAG plus DNX in the first reinduction course. The primary end point was status of the bone marrow (BM) sampled shortly before the second course of chemotherapy (the day 28 BM). Data are presented according to intention-to-treat for all 394 randomly assigned patients (median follow-up, 4.0 years). RESULTS: The complete remission (CR) rate was 64%, and the 4-year probability of survival (pOS) was 38% (SE, 3%). The day 28 BM status (available in 359 patients) was good (≤ 20% leukemic blasts) in 80% of patients randomly assigned to FLAG/DNX and 70% for patients randomly assigned to FLAG (P = .04). Concerning secondary end points, the CR rate was 69% with FLAG/DNX and 59% with FLAG (P = .07), but overall survival was similar. However, core-binding factor (CBF) AML treated with FLAG/DNX resulted in pOS of 82% versus 58% with FLAG (P = .04). Grade 3 to 4 toxicity was essentially similar in both groups. CONCLUSION: DNX added to FLAG improves early treatment response in pediatric relapsed AML. Overall long-term survival was similar, but CBF-AML showed an improved survival with FLAG/DNX. International collaboration proved feasible and resulted in the best outcome for pediatric relapsed AML reported thus far.

Agenesis and microdontia of permanent teeth as late adverse effects after stem cell transplantation in young children.

BACKGROUND: The objective of the current study was to examine the occurrence of tooth agenesis and microdontia in pediatric stem cell transplantation (SCT) recipients. METHODS: The impact of total body irradiation (TBI) and age at SCT on agenesis and microdontia of permanent teeth was examined in 55 patients from panoramic radiographs. Assessment A1 (for tooth agenesis and microdontia) excluded the third molars, and assessment A2 (for tooth agenesis) included the third molars. Patients were grouped according to TBI status (the TBI group vs. the non-TBI group) and age at SCT (patients age < or = 3.0 years [Group Y], patients ages 3.1-5.0 years [Group M], and patients age > or = 5.1 years [Group O]). RESULTS: From 1 to 12 teeth were missing in 77%, 40%, and 0% of patients (assessment A1) in Groups Y, M, and O, respectively (Group Y vs. Group M, P=0.055; Group Y vs. Group O, P < 0.001; and Group M vs. Group O, P=0.002), increasing to 83%, 78%, and 43%, respectively, when the third molars were included (assessment A2; P values were not significant). Correspondingly, 75%, 60%, and 13%, respectively, of patients had 1-12 microdontic teeth (assessment A1: Group Y vs. Group M, P=0.306; Group Y vs. Group O, P <0.001; and Group M vs. Group O, P=0.003). Recipient age at the time of SCT was found to have a negative correlation with the number of missing teeth (P=0.001) and microdontic teeth (P=0.005). TBI appeared to have little effect on the prevalence of tooth agenesis (assessment A1: TBI group, 32%; non-TBI group, 29%; assessment A2: TBI group, 72%; non-TBI group, 46%; P values were not significant) or on the prevalence of microdontia (assessment A1: TBI, 41%; non-TBI, 50%; P value was not significant). A tendency toward an increased number of affected teeth was noticed in the group of patients who received TBI. CONCLUSIONS: Depending on their age at SCT, 50-100% of pediatric SCT recipients will later present with agenesis and/or microdontia of permanent teeth that may jeopardize occlusal development. Young age (< or = 5.0 years) at SCT was found to be a stronger risk factor than TBI, although TBI caused additive impairment.

Disturbed root development of permanent teeth after pediatric stem cell transplantation. Dental root development after SCT.

BACKGROUND: Deficient dental root development has been reported after conventional pediatric anticancer therapy, but less information is available on stem cell transplantation (SCT) recipients. METHODS: Root-crown (R/C) ratios of fully developed permanent teeth were assessed from panoramic radiographs of 52 SCT recipients, who were treated when they were age < 10 years. Using standard deviation scores (SDSs), the authors compared the R/C ratios to the corresponding tooth and gender-specific values in a healthy population. The percentage of affected R/C ratios per individual was examined in a subgroup of 39 (SG39) patients with advanced tooth development. The effects of total body irradiation (TBI) and SCT age on the R/C ratios were studied in TBI and high-dose chemotherapy (HDC = non-TBI) groups and in 3 age groups (< or = 3.0 years, 3.1-5.0 years, > or = 5.1 years). RESULTS: Per individual, 77% of the fully developed permanent teeth were affected in SG39. At the tooth level, in 77% of the 945 teeth studied (52 patients), the R/C ratios were outside +/-2 SDSs. More teeth were affected in the TBI (85%) than in the non-TBI (55%) group (P < 0.001). The teeth of the patients who were ages 3.1-5.0 years old at SCT presented with the most severe aberrations of the R/C ratio (mean SDS = -4.4) whereas the teeth of the youngest (age < or = 3.0 years) and the oldest (age > or = 5.1 years) patients were equally affected (mean SDSs = -3.1 and -3.0, respectively). CONCLUSIONS: Disturbances of dental root growth always followed pediatric SCT. HDC alone intensely harmed root growth but TBI further increased the adverse effects that were most extensive in the patients 3.1-5.0 years at SCT. These sequelae should be taken into account during the lifelong dental follow-up to minimize the clinical consequences of dental injuries.