| 1. |
- Juul-Dam, KL, et al.
(författare)
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Patient-Tailored Deep Sequencing of Peripheral Blood Enables Early Detection of Relapse in Childhood Acute Myeloid Leukemia
- 2019
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Ingår i: Blood Vpl 134 Suppl 1 1456. - : American Society of Hematology. - 0006-4971 .- 1528-0020.
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Konferensbidrag (refereegranskat)abstract
- Relapse remains a major therapeutic challenge in children with acute myeloid leukemia (AML). Outcome after relapse may improve if preemptive therapy is initiated at first evidence of leukemia regrowth. Early detection of imminent relapse requires molecular measurable residual disease (MRD) monitoring after therapy completion. Today, this is possible only in about 40% of children with AML that harbor genetic abnormalities applicable for quantification using standardized qPCR assays. To enable disease surveillance for all patients, we developed patient-tailored deep sequencing (DS) MRD analysis, which provides highly sensitive detection of leukemia-specific mutations. We investigated the potential of this method for early relapse detection in peripheral blood (PB), the only easily accessible source for MRD sampling in children. PB samples were collected at monthly intervals during follow-up from 45 children diagnosed with AML and treated according to The Nordic Society of Pediatric Haematology and Oncology (NOPHO)-DBH AML 2012 protocol between January 2013 and May 2016 in Denmark, Norway, Sweden and Finland (508 samples, median 11 samples/patient, range 3-27). Nine patients with relapse (median age 5 years, range 0-8) had available diagnostic and relapse material and were included in this study. The patients displayed core binding factor abnormalities (n=3), KMT2A-rearrangements (n=3), monosomy 7 (n=1) or normal karyotype (n=2) at AML diagnosis. Leukemia-specific single nucleotide variants (SNVs) were identified with exome sequencing (ES) of sorted leukemic cells with lymphocytes or remission PB as constitutive DNA template. A variant allele frequency (VAF) with 95% confidence interval including 50% indicates presence of the mutation in all leukemic cells at diagnosis. With the exception of 2 cases with only subclonal mutations at diagnosis, leukemia-specific SNVs with VAF of 50% at diagnosis and persistence at relapse were selected as MRD targets. MRD target mutations were quantified in PB samples preceding overt relapse using patient-tailored DS assays with sensitivity of VAF 0.02%. In diagnostic samples, ES identified 53 leukemia-specific SNVs (median 4 SNVs/patient, range 2-12) of which 33 were also present at relapse (median 2 SNVs/patient, range 1-9). The number of mutations identified at diagnosis increased with age (Rs 0.83, p=0.006). All patients had at least one leukemia-specific SNV detected at both diagnosis and relapse. Twenty-one MRD target mutations (median 2 SNVs/patient, range 1-3) were quantified in PB (55 samples, median sampling interval 28 days, range 11-80) using DS. In 8/9 patients, at least one SNV was detected in PB before overt relapse occurred. The first PB sample showing MRD positivity (median VAF 0.14%, range 0.03-0.44) preceded hematological relapse at a median interval of 3 months (range 0-7.9). In 6 patients not preemptively treated, the median doubling time based on VAF increments was 7 days, with great variability between individuals and genotypes (range 4-28 days). Three patients had molecular relapse diagnosed by qPCR used in clinical diagnostics and received individualized preemptive treatment. In these 3 patients, DS detected mutations in PB for >100 days preceding overt relapse and the doubling times were 14, 25 and 36 days. In conclusion, DS of leukemia-specific mutations at frequent intervals in PB enables early detection of relapse and ES at diagnosis may identify SNVs applicable for such longitudinal MRD monitoring. This approach facilitates molecular disease surveillance and initiation of preemptive therapy in AML patients without established qPCR targets.
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| 2. |
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| 3. |
- Bager, Ninna, et al.
(författare)
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Complex and monosomal karyotype are distinct cytogenetic entities with an adverse prognostic impact in paediatric acute myeloid leukaemia : A NOPHO-DBH-AML study
- 2018
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Ingår i: British Journal of Haematology. - : Wiley. - 0007-1048 .- 1365-2141. ; 183:4, s. 618-628
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Tidskriftsartikel (refereegranskat)abstract
- Data on occurrence, genetic characteristics and prognostic impact of complex and monosomal karyotype (CK/MK) in children with acute myeloid leukaemia (AML) are scarce. We studied CK and MK in a large unselected cohort of childhood AML patients diagnosed and treated according to Nordic Society for Paediatric Haematology and Oncology (NOPHO)-AML protocols 1993-2015. In total, 800 patients with de novo AML were included. CK was found in 122 (15%) and MK in 41 (5%) patients. CK and MK patients were young (median age 2.1 and 3.3 years, respectively) and frequently had FAB M7 morphology (24% and 22%, respectively). Refractory disease was more common in MK patients (15% vs. 4%) and stem cell transplantation in first complete remission was more frequent (32% vs. 19%) compared with non-CK/non-MK patients. CK showed no association with refractory disease but was an independent predictor of an inferior event-free survival (EFS; hazard ratio [HR] 1.43, P = 0.03) and overall survival (OS; HR 1.48, P = 0.01). MK was associated with a poor EFS (HR 1.57, P = 0.03) but did not show an inferior OS compared to non-MK patients (HR 1.14, P = 0.62). In a large paediatric cohort, we characterized AML with non-recurrent abnormal karyotype and unravelled the adverse impact of CK and MK on prognosis.
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| 4. |
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| 5. |
- Lohmann, Ditte J. A., et al.
(författare)
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Effect of age and body weight on toxicity and sur vival in pediatric acute myeloid leukemia : results from NOPHO-AML 2004
- 2016
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Ingår i: Haematologica. - : Ferrata Storti Foundation (Haematologica). - 0390-6078 .- 1592-8721. ; 101:11, s. 1359-1367
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Tidskriftsartikel (refereegranskat)abstract
- Treatment for pediatric acute myeloid leukemia is very toxic and the association between outcome and age and Body Mass Index is unclear. We investigated effect of age and Body Mass Index on toxicity and survival in pediatric acute myeloid leukemia. We studied all patients who completed first induction course of NOPHO-AML 2004 (n= 318). Toxicity following induction and consolidation courses (n= 6) was analyzed. The probabilities of toxicity and death were determined using time-to-event analyses with Cox multivariate proportional hazard regression for comparative analyses. Age 10-17 years was associated with sepsis with hypotension [hazard ratio 2.3 (95% confidence interval 1.1-4.6)]. Being overweight (> 1 standard deviation) was associated with requiring supplemental oxygen [1.9 (1.0-3.5)]. The 5-year event-free and overall survival were 47% and 71%. Children aged 10-17 years showed a trend for inferior 5-year overall survival compared to children aged 29 (64% vs. 76%; P= 0.07). Infants showed a trend for superior 5-year event-free survival (66% vs. 43%; P= 0.06). Overweight children aged 10-17 years showed a trend for superior survival [5-year event-free survival 59% vs. 40% (P= 0.09) and 5-year overall survival 78% vs. 56% (P= 0.06)] compared to healthy weight children aged 10-17 years. In conclusion, children aged 10-17 years and overweight children had a higher risk of grade 3-4 toxicity. Children aged 10-17 years showed inferior survival, but, unexpectedly, in this age group overweight children tended to have increased survival. This suggests different pharmacokinetics of chemotherapeutic drugs in adolescents and warrants further studies.
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| 8. |
- Oskarsson, Trausti, et al.
(författare)
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Relapsed childhood acute lymphoblastic leukemia in the Nordic countries : prognostic factors, treatment and outcome
- 2016
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Ingår i: Haematologica. - Pavia, Italy : Ferrata Storti Foundation (Haematologica). - 0390-6078 .- 1592-8721. ; 101:1, s. 68-76
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Tidskriftsartikel (refereegranskat)abstract
- Relapse is the main reason for treatment failure in childhood acute lymphoblastic leukemia. Despite improvements in the up-front therapy, survival after relapse is still relatively poor, especially for high-risk relapses. The aims of this study were to assess outcomes following acute lymphoblastic leukemia relapse after common initial Nordic Society of Paediatric Haematology and Oncology protocol treatment; to validate currently used risk stratifications, and identify additional prognostic factors for overall survival. Altogether, 516 of 2735 patients (18.9%) relapsed between 1992 and 2011 and were included in the study. There were no statistically significant differences in outcome between the up-front protocols or between the relapse protocols used, but an improvement over time was observed. The 5-year overall survival for patients relapsing in the period 2002-2011 was 57.5 +/- 3.4%, but 44.7 +/- 3.2% (P<0.001) if relapse occurred in the period 1992-2001. Factors independently predicting mortality after relapse included short duration of first remission, bone marrow involvement, age ten years or over, unfavorable cytogenetics, and Down syndrome. T-cell immunophenotype was not an independent prognostic factor unless in combination with hyperleukocytosis at diagnosis. The outcome for early combined pre-B relapses was unexpectedly poor (5-year overall survival 38.0 +/- 10.6%), which supports the notion that these patients need further risk adjustment. Although survival outcomes have improved over time, the development of novel approaches is urgently needed to increase survival in relapsed childhood acute lymphoblastic leukemia.
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| 10. |
- Pilheden, Mattias, et al.
(författare)
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Duplex sequencing uncovers recurrent low-frequency cancer-associated mutations in infant and childhood KMT2A-rearranged acute leukemia
- 2022
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Ingår i: HemaSphere. - : Wolters Kluwer. - 2572-9241. ; 6:10
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Tidskriftsartikel (refereegranskat)abstract
- Infant acute lymphoblastic leukemia (ALL) with KMT2A-gene rearrangements (KMT2A-r) have few mutations and a poor prognosis. To uncover mutations that are below the detection of standard next-generation sequencing (NGS), a combination of targeted duplex sequencing and NGS was applied on 20 infants and 7 children with KMT2A-r ALL, 5 longitudinal and 6 paired relapse samples. Of identified nonsynonymous mutations, 87 had been previously implicated in cancer and targeted genes recurrently altered in KMT2A-r leukemia and included mutations in KRAS, NRAS, FLT3, TP53, PIK3CA, PAX5, PIK3R1, and PTPN11, with infants having fewer such mutations. Of identified cancer-associated mutations, 62% were below the resolution of standard NGS. Only 33 of 87 mutations exceeded 2% of cellular prevalence and most-targeted PI3K/RAS genes (31/33) and typically KRAS/NRAS. Five patients only had low-frequency PI3K/RAS mutations without a higher-frequency signaling mutation. Further, drug-resistant clones with FLT3D835H or NRASG13D/G12S mutations that comprised only 0.06% to 0.34% of diagnostic cells, expanded at relapse. Finally, in longitudinal samples, the relapse clone persisted as a minor subclone from diagnosis and through treatment before expanding during the last month of disease. Together, we demonstrate that infant and childhood KMT2A-r ALL harbor low-frequency cancer-associated mutations, implying a vast subclonal genetic landscape.
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