Search

PCR of TCR/Ig gene rearrangements is considered the method of choice for minimal residual disease (MRD) quantification in BCP-ALL, but flow cytometry analysis of leukemia-associated immunophenotypes (FCM-MRD) is faster and biologically more informative. FCM-MRD performed in 18 laboratories across seven countries was used for risk stratification of 1487 patients with BCP-ALL enrolled in the NOPHO ALL2008 protocol. When no informative FCM-marker was available, risk stratification was based on real-time quantitative PCR. An informative FCM-marker was found in 96.2% and only two patients (0.14%) had non-informative FCM and non-informative PCR-markers. The overall 5-year event-free survival was 86.1% with a cumulative incidence of relapse (CIR 5y ) of 9.5%. FCM-MRD levels on days 15 (HzR 4.0, p < 0.0001), 29 (HzR 2.7, p < 0.0001), and 79 (HzR 3.5, p < 0.0001) associated with hazard of relapse adjusted for age, cytogenetics, and WBC. The early (day 15) response associated with CIR 5y adjusted for day 29 FCM-MRD, with higher levels in adults (median 2.4 × 10 -2 versus 5.2 × 10 -3 , p < 0.0001). Undetectable FCM- and/or PCR-MRD on day 29 identified patients with a very good outcome (CIR 5y  = 3.2%). For patients who did not undergo transplantation, day 79 FCM-MRD > 10 -4 associated with a CIR 5y  = 22.1%. In conclusion, FCM-MRD performed in a multicenter setting is a clinically useful method for MRD-based treatment stratification in BCP-ALL.

Minimal residual disease (MRD) measured by PCR of clonal IgH/TCR rearrangements predicts relapse in T-cell acute lymphoblastic leukemia (T-ALL) and serves as risk stratification tool. Since 10% of patients have no suitable PCR-marker, we evaluated flowcytometry (FCM)-based MRD for risk stratification. We included 274 T-ALL patients treated in the NOPHO-ALL2008 protocol. MRD was measured by six-color FCM and real-time quantitative PCR. Day 29 PCR-MRD (cut-off 10 -3 ) was used for risk stratification. At diagnosis, 93% had an FCM-marker for MRD monitoring, 84% a PCR-marker, and 99.3% (272/274) had a marker when combining the two. Adjusted for age and WBC, the hazard ratio for relapse was 3.55 (95% CI 1.4-9.0, p = 0.008) for day 29 FCM-MRD ≥ 10 -3 and 5.6 (95% CI 2.0-16, p = 0.001) for PCR-MRD ≥ 10 -3 compared with MRD < 10 -3 . Patients stratified to intermediate-risk therapy on day 29 with MRD 10 -4 -<10 -3 had a 5-year event-free survival similar to intermediate-risk patients with MRD < 10 -4 or undetectable, regardless of method for monitoring. Patients with day 15 FCM-MRD < 10 -4 had a cumulative incidence of relapse of 2.3% (95% CI 0-6.8, n = 59). Thus, FCM-MRD allows early identification of patients eligible for reduced intensity therapy, but this needs further studies. In conclusion, FCM-MRD provides reliable risk prediction for T-ALL and can be used for stratification when no PCR-marker is available.

We report the first large series (n = 596) of pediatric acute myeloid leukemia (AML) focusing on modal numbers (MN) from the population-based NOPHO-AML trials. Abnormal karyotypes were present in 452 cases (76%) and numerical aberrations were present in 40% (n = 237) of all pediatric AML. Among patients with an abnormal karyotype, the MN 46 was most common (n = 251; 56%) of which 36 (8%) were pseudodiploid with numerical aberrations, followed by MN 47 (n = 80; 18%) and MN 43-45 (n = 48; 8%). No cases had MN less than 43. Hyperdiploid AML with MN 48-65 comprised 11% of all cases and was associated with early onset (median age 2 years), female sex (57%), and a dominance of acute megakaryoblastic leukemia (AMKL) (29%). Hypodiploidy constituted 8% of all AML and was associated with older age (median age 9 years), male predominance (60%), FAB M2 (56%), and t(8;21)(q22;q22) (56%) with loss of sex chromosomes. Inferior outcome was observed for hypodiploid cases (5-year event-free survival 40% and 5-year overall survival 40%) but did not reach statistical significance. Chromosomes were gained in a nonrandom pattern, where chromosomes 8, 21, 19, and 6 were the most commonly gained. In conclusion, based on MNs, two cytogenetic subgroups with characteristic clinical features are described; hypodiploidy found in 8% and associated with high median age, male sex, t(8;21)(q22;q22), and FAB M2 and possibly associated with inferior outcome (P = 0.13), and hyperdiploidy with MN 48-65 in 11% associated with early onset, female sex, and AMKL., (© 2014 Wiley Periodicals, Inc.)

Background: Although aberrant DNA methylation has been observed previously in acute lymphoblastic leukemia (ALL), the patterns of differential methylation have not been comprehensively determined in all subtypes of ALL on a genome-wide scale. The relationship between DNA methylation, cytogenetic background, drug resistance and relapse in ALL is poorly understood., Results: We surveyed the DNA methylation levels of 435,941 CpG sites in samples from 764 children at diagnosis of ALL and from 27 children at relapse. This survey uncovered four characteristic methylation signatures. First, compared with control blood cells, the methylomes of ALL cells shared 9,406 predominantly hypermethylated CpG sites, independent of cytogenetic background. Second, each cytogenetic subtype of ALL displayed a unique set of hyper- and hypomethylated CpG sites. The CpG sites that constituted these two signatures differed in their functional genomic enrichment to regions with marks of active or repressed chromatin. Third, we identified subtype-specific differential methylation in promoter and enhancer regions that were strongly correlated with gene expression. Fourth, a set of 6,612 CpG sites was predominantly hypermethylated in ALL cells at relapse, compared with matched samples at diagnosis. Analysis of relapse-free survival identified CpG sites with subtype-specific differential methylation that divided the patients into different risk groups, depending on their methylation status., Conclusions: Our results suggest an important biological role for DNA methylation in the differences between ALL subtypes and in their clinical outcome after treatment.

Background: The prognosis of acute lymphoblastic leukemia is poorer in adults than in children. Studies have indicated that young adults benefit from pediatric treatment, although no upper age limit has been defined., Design and Methods: We analyzed 749 patients aged 1-45 yr treated by the NOPHO ALL-2008 protocol. Minimal residual disease (MRD) on days 29 and 79, immunophenotype, white blood cell count (WBC), and cytogenetics were used to stratify patients to standard-, intermediate-, or high-risk treatment with or without hematopoietic stem cell transplantation., Results: Adults aged 18-45 had significantly lower WBCs at diagnosis compared with children aged 1-9 and 10-17 yr, but significantly more adults were stratified to high-risk chemotherapy (8%, 14%, 17%; P < 0.0001) or high-risk chemotherapy with transplantation (4%, 13%, 19%; P < 0.0001). This age-dependent skewing of risk grouping reflected more T-ALL (11%, 27%, 33%, P < 0.0001), poorer MRD response day 29 (MRD < 0.1%: 75%, 61%, 52%; P < 0.0001), and more MLL gene rearrangements (3%, 3%, 10%; P = 0.005) in older patients., Conclusions: Even if identical diagnostics, treatment, and risk stratification are implemented, more adults will be stratified to high-risk therapy, which should be considered when comparing pediatric and adult outcomes., (© 2013 John Wiley & Sons A/S.)

Purpose: To evaluate the early treatment response in children with acute myeloid leukemia (AML) using a response-guided induction strategy that includes idarubicin in the first course., Patients and Methods: All Nordic children with AML younger than 15 years (n = 151) were treated on the Nordic Society for Pediatric Hematology and Oncology (NOPHO) AML 2004 protocol. After the first course of idarubicin, cytarabine, etoposide, and 6-thioguanin, patients with good response were allowed hematologic recovery before the second course, whereas patients with a poor (≥ 15% blasts) or intermediate (5% to 14.9% blasts) were recommended to proceed immediately with therapy. Patients not in remission after the second course received fludarabine, cytarabine, and granulocyte colony-stimulating factor. Poor responders received allogeneic stem-cell transplantation (SCT) as consolidation., Results: Seventy-four percent of patients had good response, 17% had intermediate response, and 7% had poor response after the first course. The overall remission frequency was 97.4%, with 92% in remission after the second course. The rate of induction death was 1.3%. Patients with an intermediate response had a lower event-free survival of 35% compared with good (61%) and poor responders (82%)., Conclusion: The NOPHO-AML 2004 induction strategy gives an excellent remission rate with low toxic mortality in an unselected population. Outcome is worse in patients with intermediate response but may be improved by intensifying consolidation in this group using SCT.

Objective: Of children diagnosed with cancer, approximately one fourth die of the disease or disease related complications. The aim of this study was to investigate survival and causes of death in children with cancer in Iceland., Methods: This study is retrospective; population based and includes all children, less than 18 years of age, diagnosed with cancer in Iceland from 1981 to 2006. Information was extracted from the Icelandic Cancer Registry, patients hospital records and data from Statistics Iceland., Results: Of 279 children diagnosed with cancer in the research period 215 were alive at the end of 2008. The overall 5-year survival was 81.2% and 10-year survival was 76.7%. There was not a significant survival difference with respect to age at diagnosis, year of diagnosis, gender or geographical residence. The small cohort size could be the explanation. Eleven individuals developed secondary neoplasm, eight of whom died. Sixteen of the 64 nonsurvivors were treated with curative intent until death, 12 of them died of therapy related complications., Conclusions: Survival rate in childhood cancer in Iceland is comparable to other Western countries. As previously reported, prognosis of patients with secondary neoplasm is unfavorable. Therapy related complications are the most common cause of death in patients treated with curative intent.

Aim: The aim of our study was to get epidemiological information on bacterial infections in children treated for ALL and to analyse which patients have an enhanced infection risk., Methods: Episodes of suspected or confirmed infections were evaluated during the first 12 months of treatment for childhood acute lymphoblastic leukaemia (ALL)., Results: The number of patients was 73 (43 boys). The median age was 4.6 years. A total of 179 episodes occurred, varying from none in six patients to eight in one. Bacteria were cultured in 57 episodes (31.8%), the most common being coagulase-negative staphylococci. The number of episodes fell significantly with increasing age for suspected and confirmed infections (p < 0.001 and p = 0.03). The proportion of confirmed infections was significantly higher (p < 0.001) in the first episodes. The average number of suspected infections was higher in girls than in boys (p = 0.03), but confirmed infections were not., Conclusion: Most of the serious infections occur early in the treatment and the number of suspected and confirmed infections falls with age. Suspicion of infection is more likely in girls, but the number of confirmed infections is equal in both sexes. Coagulase-negative staphylococcus was most commonly isolated, highlighting the importance of careful handling of central venous devices.

Introduction: Ten to twelve children with tumors or malignant diseases are diagnosed annually in Iceland. Cancer treatment can cause severe immune suppression, which makes the patients susceptible to serious infections. The aim of the current study was to evaluate sepsis in children with tumors or haematological malignancies, describe the types of bacteria cultured and their antibiotic susceptibilities, and collect information on associated risk factors., Materials and Methods: This was a retrospective study on all children 0-15 years of age in Iceland who were diagnosed with a tumor or malignant disease between 1991 and 2000. Information was gathered on diagnosis, treatment, blood cultures, blood tests, antibiotic use, presence of foreign bodies (such as CVC) and survival., Results: Hundred-and-eighteen children were diagnosed with cancer or benign central nervous system (CNS) tumors in Iceland during the period 1991-2000. Central nervous system tumors were most common (N=28, 23.7%), leukemia (N=21, 17.8%) and lymphoma (N=17, 14%) were the second and third. The mean age at diagnosis was 5.9 years. Sufficient data was found in the hospital records on 99 children who were included in the study. Five hundred and twenty two blood cultures were drawn from 51 of the 99 children during the period. The mean number of blood cultures per patient was 14.8 for children with leukemia, but 2.6 for children with solid tumors. Of all blood cultures, 63.6% were from a central venous catheter or a Port-A Catheter , 5% from a peripheral site, but 30% were undisclosed. Of the 522 blood cultures, 90 grew bacteria (17.2%). Coagulase-negative staphylococci were isolated from 53 blood cultures (60%) and Staphylococcus aureus from 12 (13%). Positive cultures were regarded as a definite or possible infection in 47 blood cultures (52%), contamination in 17 (18.9% ), but uncertain in 26 (27.7%). Over 60 percent of the blood cultures (N=302) were drawn when a child was neutropenic (ANC < or =1.0 *109/L). The mean length of neutropenic episodes was 9.0 days. The mean CRP level was 63.9 mg/L. The mean temperature was 38.8 degrees C. In 138 instances the child was receiving antibiotics at the time of culture (35.1%). Children with positive blood cultures had similar clinical and laboratory tests results as children with negative cultures., Conclusion: Gram-positive bacteria, especially coagulase-negative staphylococci, are much more common in children undergoing cancer therapy than Gram-negative bacteria. Results of blood tests appear to have low predictive values for blood culture results. No child died of a proven bacterial sepsis during the study period. Empiric antibiotic treatment at the Children s Hospital Iceland for children with malignant diseases is still effective.

Background: The prognosis in childhood non-Hodgkin lymphoma (NHL) has improved dramatically during recent decades. The authors report the results from a 6-year population-based study of clinical characteristics and treatment results of NHL from the five Nordic countries., Methods: All children younger than 15 years of age at diagnosis with NHL diagnosed from 1995 to 2000 were stratified and treated according to immunophenotypic classification and stage of disease., Results: A total of 230 patients were diagnosed with primary NHL, which gives an annual incidence of 0.9/100.000 children, with a median age of 8 years. Seven percent of the children were below 3 years of age at diagnosis. The male/female ratio was 2.3 and was unrelated to age. Patients with pre-B and T-cell NHL constituted 33%, B-cell NHL 53%, and anaplastic large cell lymphoma (ALCL) 14%. According to Murphy's classification, 14% had stage 1, 17% stage 2, 50% stage 3, and 19% stage 4 disease, 12 of whom (28%) had central nervous involvement (CNS) at diagnosis. By January 1, 2003, four children had died during induction, three children died in remission (2, 6, and 26 months from diagnosis), and 24 children experienced a relapse. At 5 years, the probability of event-free survival (p-EFS) was 86+/-2% for all children. The 5-year p-EFS values for stages 1 through 4 were 94%, 97%, 83%, and 79%, respectively. The 5-year p-EFS values were 91% for B-cell, 87% for pre-B, 81% for ALCL, and 79% for T-cell NHL. The 12 patients with CNS involvement at diagnosis had a significantly poorer outcome than stage 4 patients with CNS involvement (p-EFS = 50% vs. 90%, P < 0.01). The 218 patients without CNS disease at diagnosis had a 5-year p-EFS of 88%., Conclusions: With modern intensive chemotherapy, more than 85% of NHL patients will achieve long-lasting first remission. In the future, preventing death during induction and remission and improving therapy for patients with CNS disease would have a major impact on the overall p-EFS.

Introduction: The treatment of childhood leukemia has improved substantially over the last decades and now 65-75% of the patients recover. With increasing number of survivors it is important to know the long-term and late effects of leukemia and leukaemia treatment., Patients: Of the 31 children diagnosed with leukemia in Iceland from 1981 to 1990, twenty were enrolled in the study. Average age at enrollment was16 years and 8 months (16:8) and average time since treatment ended was 8:3., Methods: The study was carried out at the Children's Hospital at the University Hospital Iceland where patients were examined and data was gathered on height, weight, hearing, cognitive functions, bloodvalues, immunoglobulins and renal, endocrine, heart, liver and respiratory functions., Results: The children studied were on average 0.48 standard deviations below target height and their body-mass index was higher at the time of study than at diagnosis. Two children had obvious obstructive lung disease. No abnormalities were found in complete blood count nor heart, liver or kidney functions. Two patients were found to have impaired hearing not attributable to acoustic trauma. In some cases abnormal values were found in immunoglobulin classes and 12 patients had decreased serum IgG2. Six needed remedial reading lessons. Three patients needed hormone replacement therapy., Discussion: Minor impact on height and weight was found but the effects on lungs and hearing were inconclusive. Despite markedly decreased serum IgG2 the patients were not more prone to infections. The most obvious effects were on the endocrine system and performance at school. We conclude that the sequelae of childhood leukemia treatment in Iceland are significant and long-lasting, underlining the necessity of a careful long-term follow-up.

Objective: Tumours in the central nervous system are the second most common malignant diseases in children. With improved treatment, the number of survivors is increasing. Therefore, better knowledge of the long-term effects of the disease and the therapy is needed. The aim of the current study was to find the incidence of central nervous system tumours in Iceland, evaluate the treatment results and study the long-term effects on the individuals., Material and Methods: Data on diagnosis and treatment as well as demographic data were gathered from hospital records from the Reykjavik City Hospital and The University Hospital and operating lists at the Department of Neurosurgery were reviewed. On survivors, physical examination was carried out, blood tests and urine-analysis were done and hearing was tested. Social adaptation, school performance, memory, concentration and general well being were studied by a questionnaire., Results: In the years 1970-1995, 57 children, aged 16 and younger, were diagnosed in Iceland with central nervous system tumours, 30 girls and 27 boys. Two children with brain metastases were excluded. Of the 55 individuals, 38 are alive today, 19 girls and 19 boys. Seventeen children had astrocytoma, grade 1 or 2 and seven had astrocytoma of grade 3 or 4. Seven children had medulloblastoma, other tumours were less common. Four patients with benign tumours in the spine were excluded from the study; three are living abroad and three refused participation. Therefore, 28 patients were included in the further study, 15 males and 13 females. The mean age at diagnoses was 7 years and 8 months (7:8) (median 6:7 years, span 0:0-15:11), the mean age at study was 21:4 years (median 20:2 years, span 7:6-39:9) and the mean time from diagnosis until study was 12:8 years (median 11:5 years, span 2:5-26:3). The mean standard deviation score for height (SDS) was -0.63 at the time of study, five of the patients had SDS below two. Five individuals need hormone replacement therapy and one patient has scoliosis. Three patients have disabilities; two of those are incapable of activities of daily life. Three patients have hearing impairment; one of them is also blind. Of five patients who had seizures when diagnosed, two still have convulsions. Of 28 patients, twelve (43%) had learning difficulties in school and ten (36%) needed remedial teaching., Conclusions: The incidence of central nervous tumours in Icelandic children is comparable to what has been reported in other countries. The results of the treatment are similar to what has been found in the other Nordic countries which maybe better than in other countries. The most prominent long-term effects among the survivors are endocrine dysfunctions and specific learning disabilities. Other, severe long-term complications are rare but have considerable effect on the individuals. We emphazise that organised, long-term follow-up is essential for these individuals, paying special attention to learning difficulties and endocrine dysfunction.

The platelet GPIb-V-IX complex is the receptor for the initial binding of von Willebrand factor (vWF) mediating platelet adhesion. The complex is composed of four membrane-spanning glycoproteins (GP): GPIbalpha, GPIbbeta, GPIX, and GPV. Bernard-Soulier syndrome results from a qualitative or quantitative defect in one or more components of the platelet membrane GPIb-V-IX complex. We describe the molecular basis of a novel Bernard-Soulier syndrome variant in two siblings in whom GPIbalpha was not detected on the platelet surface but that was present in a soluble form in plasma. DNA sequence analysis showed that the affected individuals were compound heterozygotes for two mutations. One, inherited from a maternal allele, a T777 --> C point mutation in GPIbalpha converting Cys65 --> Arg within the second leucine rich repeat, the other, a single nucleotide substitution (G2078 --> A) for the tryptophan codon (TGG) causing a nonsense codon (TGA) at residue 498 within the transmembrane region of GPIbalpha, inherited from a mutant paternal allele. The Bernard-Soulier phenotype was observed in siblings who were compound heterozygotes for these two mutations. Although GPIbalpha was not detected on the surface of the patient's platelets, soluble GPIbalpha could be immunoprecipitated from plasma. When plasmids encoding GPIbalpha containing the Cys65 --> Arg mutation were transiently transfected into Chinese hamster ovary (CHO) cells stably expressing the GPbeta-IX complex (CHObetaIX), the expression of GPIbalpha was similar to the wild-type (WT) GPIbalpha, but did not bind vWF. When plasmids encoding GPIbalpha containing the Trp498 --> stop were transiently transfected into CHObetaIX, the surface expression of GPIbalpha was barely detectable compared with the WT GPIbalpha. Thus, this newly described compound heterozygous defect produces Bernard-Soulier syndrome by a combination of synthesis of a nonfunctional protein and of a truncated protein that fails to insert into the platelet membrane and is found circulating in plasma.

Purpose: The comparable health-care organizations and common Cancer Registry for childhood malignancies in the five Nordic countries offered an opportunity to conduct an epidemiological study on a reasonable number of childhood non-Hodgkin's lymphoma (NHL) cases collected in a population-based manner., Material and Methods: All childhood cases (0-14.9 years at diagnosis) reported during the 5-year period of 1985-1989 to the Nordic Society of Pediatric Hematology and Oncology (NOPHO) Cancer Registry for childhood malignancies were reviewed and analyzed according to age, Murphy's stage, gender, site, and survival., Results: The annual incidence of NHL is 0.7 per 100,000 children in the five Nordic countries, constituting 5% of all childhood malignancies. Age distribution was even; the male/female ratio was 3:1. Age and stage were shown by Cox regression analysis to be independent prognostic factors. Older age and lower stage affected outcome favorably. The stage and site distribution was similar to previous reports. Survival data were in accordance with those expected with modern treatment protocols., Conclusions: The incidence and relative frequency of NHL in childhood in the five Nordic countries is in agreement with previously reported data, but the even distribution of cases throughout childhood is a new finding. Older age at onset and stage of disease affect outcome favorably, whereas male gender contrary to acute lymphoblastic leukemia was not found to affect outcome.