Background
A high‐level expression of the CRLF2 gene is frequent in precursor B‐cell acute lymphoblastic leukemia (pB‐ALL) and can be caused by different genetic aberrations. The presence of the most ...frequent alteration, the P2RY8/CRLF2 fusion, was shown to be associated with a high relapse incidence in children treated according to ALL‐Berlin–Frankfurt–Münster (BFM) protocols, which is poorly understood. Moreover, the frequency of other alterations has not been systematically analyzed yet.
Procedure
CRLF2 mRNA expression and potential genetic aberrations causing a CRLF2 high expression were prospectively assessed in 1,105 patients treated according to the Associazione Italiana Ematologia Oncologia Pediatrica (AIEOP)–BFM ALL 2009 protocol. Additionally, we determined copy number alterations in selected B‐cell differentiation genes for all CRLF2 high‐expressing pB‐ALL cases, as well as JAK2 and CRLF2 mutations.
Results
A CRLF2 high expression was detected in 26/178 (15%) T‐cell acute lymphoblastic leukemia (T‐ALL) cases, 21 of them (81%) had been stratified as high‐risk patients by treatment response. In pB‐ALL, a CRLF2 high expression was determined in 91/927 (10%) cases; the P2RY8/CRLF2 rearrangement in 44/91 (48%) of them, supernumerary copies of CRLF2 in 18/91 (20%), and, notably, the IGH/CRLF2 translocation was detected in 16/91 (18%). Remarkably, 7 of 16 (44%) patients with IGH/CRLF2 translocation had already relapsed. P2RY8/CRLF2‐ and IGH/CRLF2‐positive samples (70 and 94%, respectively) were characterized by a high frequency of additional deletions in B‐cell differentiation genes such as IKZF1 or PAX5.
Conclusion
Our data suggest that this high frequency of genetic aberrations in the context of a high CRLF2 expression could contribute to the high risk of relapse in P2RY8/CRLF2‐ and IGH/CRLF2‐positive ALL.
Background
Assessment of minimal residual disease (MRD) is an integral component for response monitoring and treatment stratification in acute lymphoblastic leukemia (ALL). We aimed to evaluate the ...genomic ETV6‐RUNX1 fusion sites as a single marker for MRD quantification.
Procedure
In a representative, uniformly treated cohort of pediatric relapsed ALL patients (n = 52), ETV6‐RUNX1 fusion sites were compared to the current gold standard, immunoglobulin/T‐cell receptor (Ig/TCR) gene rearrangements.
Results
Primer/probe sets designed to ETV6‐RUNX1 fusions achieved significantly more frequent a sensitivity and a quantitative range of at least 10–4 compared to the gold standard with 100% and 73% versus 76% and 47%, respectively. The breakpoint sequence was identical at diagnosis and relapse in all tested cases. There was a high degree of concordance between quantitative MRD results assessed using ETV6‐RUNX1 and the highest Ig/TCR marker (Spearman's 0.899, P < .01) with differences >½ log‐step in only 6% of patients. A high proportion of ETV6‐RUNX1‐positive ALL relapses (40%) in our cohort showed a poor response to induction treatment at relapse, and therefore had an indication for hematopoietic stem cell transplantation, demonstrating the need of accurate identification of this subgroup.
Conclusions
ETV6‐RUNX1 fusion sites are highly sensitive and reliable MRD markers. Our data confirm that they are unaffected by clonal evolution and selection during front‐line and second‐line chemotherapy in contrast to Ig/TCR rearrangements, which require several markers per patient to compensate for the observed loss of target clones. In future studies, the genomic ETV6‐RUNX1 fusion can be used as single MRD marker.
Osteonecrosis (ON) is a common and debilitating side effect of anti-leukemic treatment in children with acute lymphoblastic leukemia (ALL). However, the impact of leukemia itself on ON development ...remains elusive. We analyzed 76 children enrolled in the ongoing OPAL trial, who had magnetic resonance imaging (MRI) studies at diagnosis. MRI screening revealed 14 osteonecrotic lesions (5 × hips, 9 × knees) of any grade (I-III) in 7 (9.2%) patients. Six months on, the number of ON per patient increased (1 patient), remained constant (2), and decreased (2). The severity increased from grade I to II in two patients, remained constant (1), completely resolved (2), and decreased from grade III to osteoedema (1). No differences between adolescents initially presenting with/without ON were observed concerning age, pubertal stage, body mass index, leukemia characteristics, and clinical presentation. In MRI screening, a remarkable number of adolescents with ALL present with ON at diagnosis. The course of these ON remains highly unpredictable.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
With achievable survival rates of above 90%, non-leukemic events gather a high proportion of treatment failure causes with infections forming the majority. We analysed the incidence and outcome of ...reported invasive fungal infections as serious adverse events (SAE according to NIH criteria) in study ALL-BFM 2000 with the aim to characterize risk factors to optimize antifungal prophylaxis and treatment. A total of 4867 patients with ALL were enrolled from August 1999 to May 2010. Analysis of (mandatory) SAE reporting revealed 144 cases (3%). Fungal infections related to hematopoietic stem cell transplantation were excluded. According to the EORTC/MSG classification 65 (1.3%) were proven, 53 (1.1%) probable/possible and 26 (0.5%) not classifiable. There were 19 (0.4%) deaths and 41 (0.8%) events were classified as life threatening according to FDA definition. Positive mycological results were available in 98 cases: Aspergillus ssp. in 72, Candida ssp. in 21, Mucor in 3, Rhizopus and Fusarium in 1 case each. Fatality occurred in 16 cases with Aspergillus (22%) and in 1 each of the other species. Out of 41 life-threatening infections 30 were due to Aspergillus, 5 to Candida and 4 to the other species. Regarding all fungal infections, there was a significantly rising risk with increasing age (7.2% >15 y, 4.8% 10-<15 and 2.1% >1-< 10y; p<0.001), significance of age-dependent differences remained conserved for the life-threatening and fatal infections. Additionally, female gender appeared to impose a significant higher risk (all fungal infections, 2.4 vs. 3.7%, p=0.005). With respect to the treatment phase, the risk of fungal events was highest during induction, especially in the case of delayed treatment response, and during intensive block chemotherapy in the high-risk arm. This study on a very large population of children with ALL demonstrates that invasive fungal infections represent an important cause of morbidity and mortality in this cohort, giving support to reflect prophylactic measures for patients at high risk in the future.
No relevant conflicts of interest to declare.
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Background: Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (ALL) accounts for about 3% of pediatric ALL and has a poor prognosis. Advances of treatment due to the tyrosine ...kinase inhibitor imatinib have improved the cure rates. According to recent guidelines in the amended European intergroup trial on Ph+ ALL (EsPhALL), patients with rapid minimal residual disease (MRD) response and negativity during further treatment are no longer eligible for allogeneic stem cell transplantation (alloSCT). This down-grading of therapy in a circumscribed patient cohort with favorable prognosis is a desirable development as stem cell transplantation still implies a considerable risk of toxicity. These guidelines refer to MRD by immunoglobulin/T-cell receptor (Ig/TCR) gene rearrangements and do not consider monitoring of the BCR/ABL fusion transcript as long as informative results for Ig/TCR MRD are available. However, discrepancies between the results of the two methods occur. This complicates the decision on alloSCT indication if Ig/TCR MRD becomes negative while the BCR/ABL fusion transcript remains detectable.
Objectives/Methods: We therefore evaluated the prognostic relevance of this specific combination of findings, i.e. the continuous negativity for Ig/TCR MRD and persistently positive results for BCR/ABL after the second intensive consolidation block or later, in 16 pediatric patients with Ph+ ALL. They were identified among 139 German and Austrian Ph+ patients treated in the ALL-BFM 2000 or EsPhALL trial from August 1, 1999 to July 31, 2013. Twelve out of the 16 patients received imatinib in first-line treatment intermittently as previously described in the EsPhALL protocol (Biondi A et al Lancet Oncol. 2012) or continuously as recommended by the amended EsPhALL protocol.
Results: Eight of the 16 identified patients received an alloSCT in first complete remission (1st CR), whereas the remaining eight patients were treated with chemotherapy only. Of the eight patients with alloSCT, seven are in first continuous complete remission (1st CCR) with median EFS of 7.6 years, one patient died after second relapse. In the group of eight patients without alloSCT three are in 1st CCR with a median EFS of 2.6 years, four patients are in 2nd CR after relapse (3/4 had alloSCT in 2nd CR, median EFS 4.7 years), and one patient with Down syndrome died of an infectious complication. Remarkably, two patients of the latter group (both with M-BCR) showed a protracted increase of BCR/ABL copy numbers over several years with neither morphological signs of relapse nor Ig/TCR MRD based reappearance. One of them eventually suffered a relapse 5 years after diagnosis, one is still in 1st CCR with EFS of 5.2 years.
Conclusion: The data suggest that patients with Ig/TCR MRD negativity and persistently detectable BCR/ABL fusion transcript have a high risk of relapse when treated with chemotherapy only and may benefit from alloSCT. However, patient numbers are currently too small to deduce recommendations from this observation. Further investigation of a larger cohort with longer follow-up is needed to confirm the prognostic importance of BCR/ABL fusion transcript monitoring in addition to Ig/TCR MRD, especially considering a potential additional impact of the recently implemented continuous imatinib treatment. One additional patient would have met the diagnostic inclusion criteria of this analysis. He had an extensive increase of BCR/ABL fusion transcript at the end of maintenance treatment while being in morphological remission and negative for Ig/TCR MRD. This patient proved to be BCR/ABL positive in granulocytes revealing a chronic myeloid leukemia (CML) misdiagnosed as ALL during initial blast crisis. This indicates that an underlying CML might be taken into consideration also in other patients of the analyzed cohort. In consequence, BCR/ABL in granulocytes is now tested in all newly diagnosed Ph+ ALL patients in Germany to ensure the differentiation of BCR/ABL positive ALL vs. CML in blast crisis.
No relevant conflicts of interest to declare.
Osteonecrosis (ON) is a debilitating side effect of anti-leukemic treatment. Thus far, the role of leukemic infiltration (LI) of bone is unclear. The first 30 children aged ≥10 years, who were ...enrolled in the ongoing OPAL trial and had MRI studies at diagnosis and at 6 months, were analyzed. MRI revealed extensive LIs in 24 (80%) patients. The signal abnormalities changed back to a physiological signal in 29 out of 30 children at 6 months. Of the 24 children with LIs at diagnosis, 3 (12.5%) developed ON ≥ II, whereas 4 (66.7%) patients without LIs subsequently developed ON ≥ II (p = .016). No differences between children initially presenting with/without LIs were observed concerning age, pubertal stage, white blood count, immunophenotype, and clinical presentation. Initial radiological LI of bone and, thus, single MRI at diagnosis cannot identify children at high risk of developing radiological ON at 6 months into treatment.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
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Acute leukemia (AL) of ambiguous lineage (AMBI-L) comprises up to 5% of AL cases in both children and adults. Although several definitions exist, a general treatment guideline has been missing. ...Single country studies usually report fewer than 50 cases of children or adults. Accordingly, the international iBFM AMBI2012 Study/Registry collected 275 AMBI-L cases in patients <18y from Australia, Austria, Brazil, Czechia, Germany, Greece, Israel, Italy, Netherlands, NOPHO (Denmark, Estonia, Finland, Norway, Sweden, Iceland, Latvia and Lithuania), PINDA (Chile), Poland, SAHOP (Argentina), Slovakia, St. Jude’s Children Research Hospital (USA), Texas Children’s Cancer Center (USA), Ukraine and United Kingdom. Each center/country reported all consecutive patients with AMBI-L from a 2 to 13 year period ending May 31, 2015. Apart from the study itself, the central database served also as a basis for consulting individual patients during the diagnostic workup. Preliminary results of this study were first introduced in ASH 2015 and now the complete detailed analysis of updated findings including significance of immunophenotype, molecular genetics, blast clearance and transplant are shown.
In total, 275 patients were included in the study. Of these, 240 fulfilled the definitions of biphenotypic/mixed phenotype AL, partially overlapping with cases in whom two clones had been identified (n=68) and 15 cases presented with undifferentiated AL. Most patients started their treatment with an ALL-type protocol (n=161), 79 with AML therapy, 27 with a combined regimen, including the Interfant protocols, 2 patients were not treated, 2 received other treatment, and in 4 patients such information was missing. The 5yEFS of the entire cohort was 56±3.7% and 5y overall survival was 67±3.3%. Patients treated by ALL-type protocols had superior 5 year event free survival (5yEFS) (70±4.6%, n=158) compared to those who started AML-type treatment (5yEFS: 40±6.4%, n=78) or hybrid ALL/AML treatment (5yEFS: 50±11%, n=27). Although protocol selection was likely biased, we recommend ALL treatment, when diagnostic findings, including molecular genetics, fail to indicate AML therapy.
Although myeloperoxidase (MPO) has been used as the ultimate marker of myeloid lineage, patients who started with ALL-type treatment demonstrated a better prognosis even among cases classified as MPOpos/part pos (Fig. 1). These differences by initial choice of treatment are most prominent when CD19pos/part pos cases are analyzed regardless of the overall lineage (Fig. 2). This shows that at least for CD19pos/part pos cases in the absence of RUNX1/RUNX1T1 fusion, treatment should not start with current AML-type protocols.
Until week 12, patients with higher leukemia burden were slightly overrepresented compared to non-AMBI ALL patients (data not shown). In addition, patients with higher residual disease had a much poorer prognosis. Thus, Prednisone poor and good responders (based on day 8 blood blast counts) had a 5yEFS of 50±9.7%, n=38 and 81±5.8%, n=82, respectively (p=0.005). By day 15 bone marrow (BM), only cutoffs of 10-4 and 10-3 were analyzed and neither showed significant associations with EFS. At the end of induction, patients with BM residual disease ≥10-3 had a 5yEFS of 51±10%, n=49 compared to 90±4.3% for those with lower levels, n=75 (p=0.0002). Especially higher residual disease at week 12 was associated with an extremely poor EFS (Fig. 3). Early identification of patients with inadequate response and designing alternative treatment for them is our important challenge.
No overall benefit of transplantation was seen in patients who started on ALL treatment or hybrid ALL/AML treatment. Again, this may be caused by a biased selection of more severe cases for transplant. In patients who started with AML treatment, transplant appeared to improve prognosis (Fig. 4).
This study provides the basis for improved treatment of future patients with AMBI-L, with more accurate diagnostics.
OH, AL, IJ, EM and JS were supported by Czech Health Research Council 15-28525A.
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Bleckmann:JazzPharma: Other: financial support of travel costs. Moricke:JazzPharma: Honoraria, Other: financial support of travel costs. Inaba:Arog: Research Funding. Kattamis:Novartis: Honoraria, Research Funding; ApoPharma: Honoraria. Reinhardt:Boehringer Ingelheim: Membership on an entity's Board of Directors or advisory committees; Celgene: Research Funding; Jazz Pharma: Other: Travel Accomodation; Celgene: Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees.
Up to 5% of patients with acute leukemia (AL) are diagnosed as AL of ambiguous lineage. The ambiguous lineage ALs consist of mixed phenotype AL (MPAL, or biphenotypic AL, BAL), bilineal AL, switching ...AL and rare, undifferentiated ALs. From a molecular genetic point of view, they overlap with several molecular genetic subsets such as AL with MLL rearrangements or early T precursor AL. As no general treatment strategy exists, these patients have been variably treated with lymphoblastic (ALL)- , myeloid (AML)- or combined (hybrid) therapy, with or without stem cell transplant. They are often unreported as they are excluded from standard protocols. So far, attempts to shed more light on these patients has largely focused on definitions of ambiguous lineage AL. Only limited therapeutic observations have been possible in studies on this AL subset, usually reporting 50 or fewer pediatric/adult patients. In order to facilitate more detailed analyses, we have created an international study "iBFM AMBI2012 Study/Registry".
In this study, patients under 18 years at diagnosis are eligible. Each center/country was asked to report all consecutive patients with ambiguous lineage AL, from a 2- to 13-year period ending May 31, 2015. The definitions included those with WHO and EGIL criteria and remained unchanged throughout the study. Complete information on type of treatment, follow up and immunophenotype was requested. Where available (n=101 at the time of this abstract uploading), raw cytometric FCS data files were stored centrally for review. Apart from the study itself, the central database served also as a basis for consulting individual patients during the diagnostic workup. Furthermore, data on fusion genes, cytogenetics, treatment response and availability of specimens for collateral studies were also collected.
In total, 247 patients from Australia, Austria, Brazil, Czechia, Germany, Greece, Israel, Netherlands, NOPHO (Denmark, Estonia, Finland, Norway, Sweden, Iceland and Lithuania), PINDA (Chile), Poland, SAHOP (Argentina), Slovakia, St. Jude Children's Research Hospital (USA), Ukraine and United Kingdom are reported. Among those, 222 fulfilled the definitions of MPAL/BAL, partially overlapping with cases in whom two clones had been identified (n=47) and 14 cases presented with undifferentiated AL. Most of them, consistent with our general treatment guideline (Figure 1), started their treatment with an ALL type of protocol (n=150), 60 patients started on AML therapy, 8 patients received a combined regimen including the Interfant protocols, 2 patients were not treated, 13 received other treatment, and this information is missing in 9 patients (additional 5 pts. started on ALL treatment but their follow up information is incomplete). The 5 year event free survival of the entire cohort was 55±4% and its separation by first type of treatment is shown in Figure 2.
In a collateral study, we set up a qPCR array on 90 genes that are characteristic of the lymphoid or myeloid lineages and/or are thought to be involved in their regulation. Using this array, sorted cells of granulocytic, monocytic, T, and B lineages at various stages of development (17 stages total) were analyzed and compared to samples of AL including 6 samples of MPAL of precursor B/myeloid phenotype. Although this array did not show a general deregulation in the MPAL genome compared to that in AL or healthy cells, subtle changes were seen such as decrease of CEBPE and LILRA2 gene expression, in comparison to classical B precursor ALL.
Overall, our data shows that the general treatment guideline (Figure 1), which favors ALL treatment is justified by the outcome. However, although this study is larger than those published, caution is needed during its interpretation due to variations in diagnostics and treatment among the participating countries. Therefore, our data should be viewed as a basis for non-ambiguous treatment guidelines that will direct each patient to either ALL or AML treatment. These guidelines will be tested prospectively. In addition, the framework of this study is being used as a basis of consulting new AL cases with diagnostic uncertainties. Furthermore, it serves as a data resource for biologic studies.
Supported by AZV 15-28525A, UNCE 204012, NT/14534-3, NT/13462-4, P302/12/G101.
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Kattamis:Novartis: Research Funding, Speakers Bureau; ApoPharma: Speakers Bureau.
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