To review the impact of collaborative studies on advances in the biology and treatment of acute lymphoblastic leukemia (ALL) in children and adolescents.
A review of English literature on childhood ...ALL focusing on collaborative studies was performed. The resulting article was reviewed and revised by the committee chairs of the major ALL study groups.
With long-term survival rates for ALL approaching 90% and the advent of high-resolution genome-wide analyses, several international study groups or consortia were established to conduct collaborative research to further improve outcome. As a result, treatment strategies have been improved for several subtypes of ALL, such as infant, MLL-rearranged, Philadelphia chromosome-positive, and Philadelphia chromosome-like ALL. Many recurrent genetic abnormalities that respond to tyrosine kinase inhibitors and multiple genetic determinants of drug resistance and toxicities have been identified to help develop targeted therapy. Several genetic polymorphisms have been recognized that show susceptibility to developing ALL and that help explain the racial/ethnic differences in the incidence of ALL.
The information gained from collaborative studies has helped decipher the heterogeneity of ALL to help improve personalized treatment, which will further advance the current high cure rate and the quality of life for children and adolescents with ALL.
Dexamethasone could be more effective than prednisolone at similar anti-inflammatory doses in the treatment of childhood acute lymphoblastic leukemia. In order to check if this "superiority" of ...dexamethasone might be dose-dependent, we conducted a randomized phase III trial comparing dexamethasone (6 mg/m(2)/day) to prednisolone (60 mg/m(2)/day) in induction therapy. All newly diagnosed children and adolescents with acute lymphoblastic leukemia in the 58951 EORTC trial were randomized on prephase day 1 or day 8. The main endpoint was event-free survival; secondary endpoints were overall survival and toxicity. A total of 1947 patients with acute lymphoblastic leukemia were randomized. At a median follow-up of 6.9 years, the 8-year event-free survival rate was 81.5% in the dexamethasone arm and 81.2% in the prednisolone arm; the 8-year overall survival rates were 87.2% and 89.0% respectively. The 8-year incidences of isolated or combined central nervous system relapse were 2.9% and 4.5% in the dexamethasone and prednisolone arms, respectively. The incidence of grade 3-4 toxicities during induction and the frequency of osteonecrosis were similar in the two arms. In conclusion, dexamethasone and prednisolone, used respectively at the doses of 6 and 60 mg/m(2)/day during induction, were equally effective and had a similar toxicity profile. Dexamethasone decreased the 8-year central nervous system relapse incidence by 1.6%. This trial was registered at www.clinicaltrials.gov as #NCT00003728.
In a previous analysis of 326 children with Philadelphia chromosome (Ph) -positive acute lymphoblastic leukemia (ALL) treated between 1986 and 1996, hematopoietic stem-cell transplantation from ...HLA-matched related donors, but not from unrelated donors, offered a superior outcome than chemotherapy alone. To evaluate the impact of recent improvements in chemotherapy and transplantation, we performed a similar analysis on patients treated in the following decade.
We analyzed 610 patients with Ph-positive ALL treated between 1995 and 2005 without tyrosine kinase inhibitor therapy. The median follow-up duration was 6.3 years.
Complete remission was achieved in 89% of patients. The 7-year event-free survival and overall survival rates were superior in the present cohort compared with the previous cohort (32.0% ± 2.0% v 25.0% ± 3.0, respectively, P = .007; and 44.9% ± 2.2% v 36.0% ± 3.0%, respectively, P = .017). Compared with chemotherapy alone, transplantation with matched related donors or unrelated donors in first remission (325 patients) showed an advantage with increasing follow-up, suggesting greater protection against late relapses (hazard ratio at 5 years, 0.37; P < .001). In the multivariate Cox regression analysis accounting for treatment (transplantation v no transplantation), age, leukocyte count, and early response had independent impact on treatment outcome.
Clinical outcome of children and adolescents with Ph-positive ALL has improved with advances in transplantation and chemotherapy. Transplantations with matched related donors and unrelated donors were equivalent and offered better disease control compared with chemotherapy alone. Age, leukocyte count, and early treatment response were independent prognostic indicators. The results of this study will serve as a historical reference to evaluate the therapeutic impact of tyrosine kinase inhibitors on the outcome of Ph-positive ALL.
Asparaginase is an essential component of combination chemotherapy for childhood acute lymphoblastic leukemia and non-Hodgkin lymphoma. The value of asparaginase was further addressed in a group of ...non-very high-risk patients by comparing prolonged (long-asparaginase)
standard (short-asparaginase) native
asparaginase treatment in a randomized part of the phase III 58951 trial of the European Organization for Research and Treatment of Cancer Children's Leukemia Group. The main endpoint was disease-free survival. Overall, 1,552 patients were randomly assigned to long-asparaginase (775 patients) or short-asparaginase (777 patients). Patients with grade ≥2 allergy to native
asparaginase were switched to equivalent doses of
or pegylated
asparaginase. The 8-year disease-free survival rate (±standard error) was 87.0±1.3% in the long-asparaginase group and 84.4±1.4% in the short-asparaginase group (hazard ratio: 0.87;
=0.33) and the 8-year overall survival rate was 92.6±1.0% and 91.3±1.2% respectively (hazard ratio: 0.89;
=0.53). An exploratory analysis suggested that the impact of long-asparaginase was beneficial in the National Cancer Institute standard-risk group with regards to disease-free survival (hazard ratio: 0.70;
=0.057), but far less so with regards to overall survival (hazard ratio: 0.89). The incidences of grade 3-4 infection during consolidation (25.2%
14.4%) and late intensification (22.6%
15.9%) and the incidence of grade 2-4 allergy were higher in the long-asparaginase arm (30%
21%). Prolonged native
asparaginase therapy in consolidation and late intensification for our non-very high-risk patients did not improve overall outcome but led to an increase in infections and allergy.
Juvenile myelomonocytic leukemia (JMML) is a rare and aggressive stem cell disease of early childhood. RAS activation constitutes the core component of oncogenic signaling. In addition, leukemic ...blasts in one-fourth of JMML patients present with monosomy 7, and more than half of patients show elevated age-adjusted fetal hemoglobin (HbF) levels. Hematopoietic stem cell transplantation is the current standard of care and results in an event-free survival rate of 50% to 60%, indicating that novel molecular-driven therapeutic options are urgently needed. Using gene expression profiling in a series of 82 patient samples, we aimed at understanding the molecular biology behind JMML and identified a previously unrecognized molecular subgroup characterized by high LIN28B expression. LIN28B overexpression was significantly correlated with higher HbF levels, whereas patients with monosomy 7 seldom showed enhanced LIN28B expression. This finding gives a biological explanation of why patients with monosomy 7 are rarely diagnosed with high age-adjusted HbF levels. In addition, this new fetal-like JMML subgroup presented with reduced levels of most members of the let-7 microRNA family and showed characteristic overexpression of genes involved in fetal hematopoiesis and stem cell self-renewal. Lastly, high LIN28B expression was associated with poor clinical outcome in our JMML patient series but was not independent from other prognostic factors such as age and age-adjusted HbF levels. In conclusion, we identified elevated LIN28B expression as a hallmark of a novel fetal-like subgroup in JMML.
•LIN28B is overexpressed in about half of juvenile myelomonocytic leukemia patients and defines a novel fetal-like disease subgroup.•LIN28B expression is correlated with high fetal hemoglobin levels and the absence of monosomy 7.
Objective To evaluate long-term growth and final height (FH) in survivors of childhood acute lymphoblastic leukemia (ALL) who were treated without cranial radiation therapy and underwent evaluation ...of growth hormone (GH) status at the end of treatment. Study design Data on longitudinal growth (collected at the start of treatment, end of treatment, and 1 year thereafter) and FH of 67 adult survivors of childhood ALL who had been treated according to European Organisation for Research and Treatment of Cancer 58831/2 protocols with chemotherapy as the only treatment modality were reviewed retrospectively. Height data were expressed as SDS for national references. The relative role of sex, age at diagnosis, intensity of chemotherapeutic regimen, and GH status at the end of treatment as contributing factors were analyzed. Results A modest but significant loss in FH (change in SDS ΔSDS = −0.59 ± 0.86; P < .001) was found. Two-thirds of the height deficit observed from diagnosis until FH occurred during treatment. The height deficit was more severe in the male patients ( P = .036). The ΔSDS for height from diagnosis to FH was not correlated with age at diagnosis or intensity of treatment. No correlation was found between the results of the GH stimulation test and ΔSDS for height from diagnosis or the end of treatment to FH. Conclusion Adult survivors of childhood ALL treated with chemotherapeutic regimens of moderate intensity without cranial radiation therapy exhibit a modest loss in SDS for height at FH irrespective of GH status at the cessation of treatment.
T-cell acute lymphoblastic leukemia arises from the leukemic transformation of developing thymocytes and results from cooperative genetic lesions. Inactivation of the PHF6 gene is frequently observed ...in T-cell acute lymphoblastic leukemia, suggesting an important tumor suppressive role for PHF6 in the pathobiology of this leukemia. Although the precise function of PHF6 is still unknown, this gene is most likely involved in chromatin regulation, a strongly emerging theme in T-cell acute lymphoblastic leukemia. In this context, our previous description of a cooperative microRNA regulatory network controlling several well-known T-cell acute lymphoblastic leukemia tumor suppressor genes, including PHF6, is of great importance. Given the high frequency of PHF6 lesions in T-cell acute lymphoblastic leukemia and the integration of PHF6 in this microRNA regulatory network, we aimed to identify novel oncogenic microRNAs in T-cell acute lymphoblastic leukemia which suppress PHF6. To this end, we performed an unbiased PHF6 3'UTR-microRNA library screen and combined the results with microRNA profiling data of samples from patients with T-cell acute lymphoblastic leukemia and normal thymocyte subsets. We selected miR-128-3p as a candidate PHF6-targeting, oncogenic microRNA and demonstrated regulation of PHF6 expression upon modulation of this microRNA in T-cell acute lymphoblastic leukemia cell lines. In vivo evidence of an oncogenic role of this microRNA in T-cell acute lymphoblastic leukemia was obtained through accelerated leukemia onset in a NOTCH1-induced T-cell acute lymphoblastic leukemia mouse model upon miR-128-3p over-expression. We conclude that miR-128-3p is a strong novel candidate oncogenic microRNA in T-cell acute lymphoblastic leukemia which targets the PHF6 tumor suppressor gene.
Introduction
Late cardiotoxicity is a known complication of anthracycline therapy but the long-term effects of low cumulative doses are not well documented. We studied late cardiotoxicity in ...survivors of childhood acute lymphoblastic leukemia (ALL) treated with low anthracycline doses 10 to 20 years earlier.
Methods
Seventy-seven ALL survivors who received a cumulative anthracycline dose <250 mg/m² and were at least 10 years after treatment were evaluated for signs of clinical heart failure. Cardiac function was assessed by echocardiography including tissue Doppler measurements of the septal mitral annulus in 37 ALL survivors 10.6–18.3 years (median 13.3 years) after anthracycline treatment with cumulative doses of 180 (
n
= 19) or 240 mg/m² (
n
= 18). The control group consisted of 30 healthy volunteers matched for age, sex, BSA, and BMI.
Results
No clinical relevant cardiotoxicity was found. Left ventricular shortening fraction (SF) was significantly reduced in male ALL survivors. Three of the 19 male ALL survivors had an SF below 30%. Male ALL survivors showed a significantly lower early filling velocity to atrial contraction velocity ratio but myocardial velocity during early filling was comparable between patients and controls. ALL survivors had a significantly longer isovolumetric relaxation time (IVRT). Thirty percent of the ALL survivors have an abnormal IVRT compared to the normal range of the controls.
Conclusion and implications for cancer survivors
At a median of 13.3 years after exposure to cumulative doses of anthracyclines of 180 or 240 mg/m², no clinical relevant cardiotoxicity was found but subclinical cardiac abnormalities were present in 30% of the patients.
Ethyl tert-butyl ether (ETBE) enrichment was obtained by adding contaminated groundwater to a mineral medium containing ETBE as the sole carbon and energy source. ETBE was completely degraded to ...biomass and CO₂ with a transient production of tert-butanol (TBA) and a final biomass yield of 0.37 ± 0.08 mg biomass (dry weight).mg⁻¹ ETBE. Two bacterial strains, IFP 2042 and IFP 2049, were isolated from the enrichment, and their 16S rRNA genes (rrs) were similar to Rhodococcus sp. (99 % similarity to Rhodococcus erythropolis) and Bradyrhizobium sp. (99 % similarity to Bradyrhizobium japonicum), respectively. Rhodococcus sp. IFP 2042 degraded ETBE to TBA, and Bradyrhizobium sp. IFP 2049 degraded TBA to biomass and CO₂. A mixed culture of IFP 2042 and IFP 2049 degraded ETBE to CO₂ with a biomass yield similar to the original ETBE enrichment (0.31 ± 0.02 mg biomass.mg⁻¹ ETBE). Among the genes previously described to be involved in ETBE, MTBE, and TBA degradation, only alkB was detected in Rhodococcus sp. IFP 2042 by PCR, and none were detected in Bradyrhizobium sp. IFP 2049.
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