Finn Wesenberg - Academia.edu (original) (raw)

Papers by Finn Wesenberg

Research paper thumbnail of Precise quantification of minimal residual disease at day 29 allows identification of children with acute lymphoblastic leukemia and an excellent outcome

Research paper thumbnail of Emotional Functioning and School Contentment in Adolescent Survivors of Acute Myeloid Leukemia, Infratentorial Astrocytoma, and Wilms Tumor

Journal of adolescent and young adult oncology, 2011

Purpose: Cancer in childhood may disrupt normal developmental processes and cause psychosocial pr... more Purpose: Cancer in childhood may disrupt normal developmental processes and cause psychosocial problems in adolescent survivors of childhood cancers (ACCSs). Previous studies report inconsistent findings. Study aims were to assess subjective well-being (SWB), psychological distress, and school contentment in survivors of three dissimilar childhood cancers. Patients and methods: Nordic patients treated for acute myeloid leukemia (AML), infratentorial astrocytoma (IA), and Wilms tumor (WT) in childhood from 1985 to 2001, aged ≥1 year at diagnosis, and aged 13-18 years at the time of study were eligible for this questionnaire-based survey that included items on SWB, psychological distress, school contentment, self-esteem, and personality traits; 65% (151/231) responded. An age-equivalent group from a Norwegian health survey (n=7910) served as controls. Results: The median age of ACCSs was 16 years; 52% were males. ACCSs reported better SWB (p=0.004) and self-esteem (p<0.001). They h...

Research paper thumbnail of How much is too much? Folinic acid rescue dose in children with acute lymphoblastic leukaemia

European journal of cancer (Oxford, England : 1990), 1991

The effect of folinic acid rescue dose on the event-free survival of 71 children with acute lymph... more The effect of folinic acid rescue dose on the event-free survival of 71 children with acute lymphoblastic leukaemia was examined in a retrospective clinical study. All patients, diagnosed between 1 January 1980 and 1 January 1989, were treated according to the Norwegian Pilot protocol which included eight courses of high dose (6-8 g/m2/24 h intravenous infusion) methotrexate. Following the infusion, a uniform dose of 75 mg (at 36 h after the beginning of the drug infusion) and 15 mg (at 39-106 h) folinic acid rescue was administered to all patients, at predetermined intervals. The uniformity of the rescue dose resulted in distribution of dosages in the range of 38-140 mg/m2 and 7.5-28 mg/m2 for the different periods, respectively, when the dose was recalculated on the basis of the body surface area of the individual patients. The event-free survival of children receiving less or more than 15 mg/m2 (75 mg/m2) rescue dose was compared. Although no significant difference was found, a t...

Research paper thumbnail of Increased uptake of social security benefits among long-term survivors of cancer in childhood, adolescence and young adulthood: a Norwegian population-based cohort study

Background: As the number of cancer survivors increases, their health and welfare have come into ... more Background: As the number of cancer survivors increases, their health and welfare have come into focus. Thus, long-term medical consequences of cancer at a young age (o25 years), obtained from social security benefit records, were studied.

Research paper thumbnail of Central Nervous System Disease in Childhood Acute Lymphoblastic Leukemia: Prognostic Factors and Results of Treatment

Pediatric Hematology and Oncology, 1991

In the five Nordic countries, 808 children 1 to 15 years of age (428 boys, 380 girls) were diagno... more In the five Nordic countries, 808 children 1 to 15 years of age (428 boys, 380 girls) were diagnosed with non-B acute lymphoblastic leukemia (ALL) from July 1981 through June 1986. Complete remission was achieved in 770 children (95%). Central nervous system (CNS) involvement at diagnosis was noticed in 34 children, of whom 26 achieved remission. Of these 26 patients 11 subsequently relapsed, 5 in the central nervous system. An interim analysis in January 1990 (observation time 3 1/2 to 8 1/2 years) revealed that isolated CNS relapse had occurred in 70 children (9.0%). Of these 70 patients, 12 out of 142 children (8.5%) had initially received irradiation and 58 out of 628 children (9.2%) only chemotherapy as CNS-prophylaxis. There was a significant higher risk for boys (12%) than for girls (6%) to relapse in the CNS compartment. Unfavorable prognostic factors for survival after isolated CNS relapse were short duration of first remission and male sex. In high-risk patients after an isolated CNS relapse, there was no difference in prognosis related to treatment with or without irradiation as initial CNS prophylaxis.

Research paper thumbnail of Superior treatment results in females with high-risk acute lymphoblastic leukemia in childhood

Acta Paediatrica, 1992

In this population-based study, 808 children aged 1-15 years from Denmark, Finland, Iceland, Norw... more In this population-based study, 808 children aged 1-15 years from Denmark, Finland, Iceland, Norway and Sweden, were diagnosed between July 1981 and June 1986 as suffering from non-B-cell acute lymphoblastic leukemia (ALL). The total population was 4.5 million children. Remission was achieved in 770/808 of the patients (95%). No sex difference in the remission rate was observed. The event free survival (EFS) at 102 months was 0.47 for males and 0.62 for females (p less than 0.001). There was no difference in EFS between males and females with standard-risk (0.58 and 0.60) or intermediate-risk (0.47 and 0.60) ALL, respectively. The EFS for females with high-risk ALL (0.68) was superior to that of males with high-risk ALL (0.31). Cox multivariant analysis showed that white blood cell count, sex, age and thrombocyte count were significant prognostic factors in all children. The intensified treatment according to the prognostic factors used in this study led to equal EFS for females with ALL from all risk groups. Males with high-risk ALL, however, did not benefit from the intensified treatment.

Research paper thumbnail of Children with acute lymphoblastic leukaemia have high plasma levels of total homocysteine at time of diagnosis

Scandinavian Journal of Clinical & Laboratory Investigation, 2006

Cancer can induce venous thromboembolic complications for various reasons. As part of a greater s... more Cancer can induce venous thromboembolic complications for various reasons. As part of a greater study, acquired and congenital prothrombotic risk factors were investigated in children with leukaemia or non-Hodgkin&#39;s lymphoma and compared with similar investigations in children with congenital heart defects. Blood samples were taken from 60 children with newly diagnosed leukaemia or lymphoma and 133 children with congenital heart defects in the course of a scheduled cardiac catheterization. When children with cancer were in remission, analyses of acquired prothrombotic risk factors were repeated. Children with cancer were observed for symptoms of thromboembolism throughout their treatment period. Total homocysteine levels were significantly raised in children with cancer (median value 10.0 micromol/L) as compared with the levels in children with congenital heart diseases (5.0 micromol/L) (p&lt;0.001), while children with acute lymphoblastic leukaemia had the highest values. The median level of lipoprotein(a) was slightly increased in children with newly diagnosed leukaemia or lymphoma (105 mg/L versus 100 mg/L, p&lt;0.001), and levels of coagulation inhibitors were higher (p&lt;0.001). Total homocysteine levels normalized when children attained remission of cancer disease. Two children had symptoms of acute thrombosis. Raised concentrations of total homocysteine were frequent in children with newly diagnosed cancer, but this normalized when the children were in remission. The clinical significance of our observations and the impact on venous thromboembolism have yet to be defined.

Research paper thumbnail of Structural Chromosome Aberrations in Lymphocytes from Children Previously Treated for Wilms' Tumor or Hodgkin's Disease

Pediatric Hematology-Oncology, 1989

Nineteen children treated for Wilms&#39; tumor (thirteen cases) or Hodgkin&#39;s disease ... more Nineteen children treated for Wilms&#39; tumor (thirteen cases) or Hodgkin&#39;s disease (six cases) with cytostatic agents and/or radiotherapy were studied cytogenetically on lymphocytes cultivated from blood samples drawn after at least 1 year of complete remission after end of therapy. A reference group of children was matched for age, sex, and residence. The frequencies of sister chromatid exchange (5.4 versus 5.6 SCE/cell), and chromosome damage type gaps (6.6 versus 7.1%) and breaks (1.9 versus 1.9%) were not different in the two groups, but exchange type aberrations were more frequent in the patients (0.9 versus 0.06%). Fifty karyotypes were analyzed in all but two cases of Hodgkin&#39;s disease. The overall frequency of stable (3.1 versus 3.8%) and unstable (1.7 versus 1.4%) structural chromosome changes such as translocations, deletions, chromatid exchanges, and dicentrics were not different in the patient and the control groups. If the chromosome data reflect a general cancer risk, this risk cannot be considerably higher among the cancer-treated children.

Research paper thumbnail of DIAGNOSTIC VALUE OF FAMILY HISTORIES OF THROMBOSIS TO IDENTIFY CHILDREN WITH THROMBOPHILIA

Pediatric Hematology-Oncology, 2005

Thrombophilia screening is a time-consuming and expensive procedure. Information about thromboemb... more Thrombophilia screening is a time-consuming and expensive procedure. Information about thromboembolism among relatives may be a simple method to identify those at risk of having thrombophilia. In a cross-sectional clinical study the authors have investigated the role of such family histories to detect children with thrombophilia. In 202 children a family history of venous or arterial thromboembolism was recorded. The participants were either children with congenital heart defects at the time of a scheduled cardiac catheterization (n=134) or children with newly diagnosed cancer (n=68). Questions were answered, on the spot, by the parents, at the same time as blood samples for thrombophilia screening were taken. Questions about family history of thromboembolism were completed in 184 children, of whom 114 children (62%) were positive, and 35 of these had relatives with venous thromboembolic events. Only one child had an affected first-degree relative. Thrombophilic alterations were observed in 60 children (30%), and 25 of these were defined as inherited. A positive family history of venous origin increased the relative risk of a child having inherited thrombophilia to 2.35 (95% confidence interval 1.1--5.2). Information about familial arterial thromboembolism was not useful in spotting children with prothrombotic risk factors. These results indicate that questioning about family history of venous thromboembolism may identify children with genetic thrombophilia, but the association is not strong. The authors encourage similar larger-scale studies to enlighten the issue fully.

Research paper thumbnail of THROMBOTIC EFFECTS OF ASPARAGINASE IN TWO ACUTE LYMPHOBLASTIC LEUKEMIA PROTOCOLS (NOPHO ALL-1992 VERSUS NOPHO ALL-2000): A Single-Institution Study

Pediatric Hematology-Oncology, 2006

2 Asparaginase is essential in the treatment of lymphoproliferative malignancies, but it is assoc... more 2 Asparaginase is essential in the treatment of lymphoproliferative malignancies, but it is associated with several side effects. The objective of this study was to compare asparaginase-induced alterations of the coagulation inhibitors and the impact on central line-associated thrombosis in children treated according to 2 different asparaginase regimens. The study enrolled 30 children treated for acute lymphoblastic leukemia, and they were divided into 2 groups with respect to asparaginase preparation and protocol (NOPHO ALL-1992 versus NOPHO ALL-2000. The coagulation inhibitors antithrombin, protein C, and proteins S were measured prior to and during asparaginase therapy, and incidence of central line-associated thromboses was compared to evaluate the protocols' thrombogenicity. Thirteen children received Erwinia asparaginase and 17 children received E. coli asparaginase. Independent of protocol, the coagulation inhibitors were significantly reduced during asparaginase therapy (p < .001), and central line-associated thromboses were frequent. Four children developed thrombosis in the course of asparaginase therapy, and there was a correlation between asparaginase-induced fall of antithrombin and occurrence of new thromboses (p = .01). We thank S.O. Lie and E. Thalow for their enthusiasm and support of the study. We are grateful to Professor Brosstad and his laboratory for analysis of the coagulation inhibitors and other prothrombotic biochemical factors. We thank our statistician Marijke Veenstra for guidance and valuable advices. We are also grateful to all participating nurses, laboratory technicians, and doctors at the National and collaborating hospitals, but special thanks to the nurses at BK-3.

Research paper thumbnail of Thyroid Function in Children after Cytostatic Treatment for Acute Leukemia

Pediatric Hematology-Oncology, 1988

Sixty-one children were examined for thyroid dysfunction as an adverse late effect after cessatio... more Sixty-one children were examined for thyroid dysfunction as an adverse late effect after cessation of antileukemic treatment. The aim of the study was to contribute to clarifying which types of therapy can cause this endocrine disorder. Our treatment protocols do not include cranial irradiation as CNS prophylaxis, but we give relatively intensive intrathecal methotrexate treatment. The results indicate that this cytostatic regimen alone does not cause thyroid dysfunction as an adverse late effect.

Research paper thumbnail of Oral anticoagulation with warfarin is significantly influenced by steroids and CYP2C9 polymorphisms in children with cancer

Pediatric Blood & Cancer, 2008

Clinical management of warfarin therapy is complex, and dosing algorithms do not include genetic ... more Clinical management of warfarin therapy is complex, and dosing algorithms do not include genetic factors or interactions with other drugs for warfarin dose determinations. We evaluated the interaction of warfarin and CYP2C9 polymorphisms and concomitant corticosteroids in 29 children with cancer. Children with heterozygous polymorphisms of CYP2C9 achieved target INR sooner and more frequently had INR above the target level, compared to children without mutations. Children on concomitant steroids had significantly lower warfarin requirements. Thus, awareness of CYP2C9 genotype and steroid-induced responsiveness to warfarin may be important when administrating oral anticoagulation in children.

Research paper thumbnail of Increased prevalence of chronic fatigue among survivors of childhood cancers: A population-based study

Pediatric Blood & Cancer, 2012

Fatigue is prevalent in adult cancer survivors but less studied in childhood cancer survivors. Ai... more Fatigue is prevalent in adult cancer survivors but less studied in childhood cancer survivors. Aims were to assess fatigue levels, prevalence of chronic fatigue (CF) and the association of CF with health-related quality of life (HRQoL) in survivors of acute myeloid leukemia (AML), infratentorial astrocytoma (IA), and Wilms tumor (WT) in childhood. Seventy percent (398/567) of Nordic patients treated for AML, IA, and WT between 1985 and 2001 at age &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;1 year responded to a postal survey, encompassing the Fatigue Questionnaire and the Short Form 36 (SF-36). Participants were divided into two groups at time of study; younger (YG, 13-18 years) and older (OG, 19-34 years). Respondents (19-34 years, n = 763) from a Norwegian general population (GP) survey served as controls for the OG. The OG [mean age was 24 years (SD 3.3)] had higher fatigue levels compared to the YG and the GP, especially the females (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05). There was also a higher prevalence of CF in the OG than in the GP (14 vs. 6%, P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001). Regardless of diagnosis, the OG with CF had poorer physical health (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05) on the SF-36 but better mental health (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05 and P = 0.001) relative to controls with CF. The prevalence of CF is higher among Nordic survivors of AML, IA, and WT than GP controls of similar age. CF is associated with impaired HRQoL in survivors. However, they reported better mental health than CF GP controls. This might indicate different underlying mechanisms of CF in the two populations.

Research paper thumbnail of Outcome after first relapse in children with acute lymphoblastic leukemia: A population-based study of 315 patients from the nordic society of pediatric hematology and oncology (NOPHO)

Medical and Pediatric Oncology, 1995

This study reports the outcome after relapse of acute lymphoblastic leukemia (ALL) in a populatio... more This study reports the outcome after relapse of acute lymphoblastic leukemia (ALL) in a population-based study of 809 children over 1 year of age diagnosed July 1981 through June 1986 and with non-B acute lymphoblastic leukemia in the five Nordic countries. By January 1994, 315 children had suffered at least one relapse. The bone marrow was involved in 216 cases. There were 69 isolated CNS relapses, 25 isolated testicular recurrences and five relapses in other extramedullary sites. Of the 315 children with relapse, 94 are still in a second complete remission 12-138 (median: 78) months after relapse. The overall probability of a second event free survival (P-2.EFS) and survival after relapse was 0.28 and 0.33 respectively. The probability of remaining in second remission at 11 years was significantly correlated to the duration of first remission (P &lt; 0.001), the site of relapse (P &lt; 0.001) and gender (P = 0.004). The P-2.EFS for early, intermediate, and late bone marrow involved relapses were 0.08, 0.19, and 0.50 respectively. For early, intermediate and late isolated CNS relapses the P-2.EFS were 0.21, 0.38 and 0.61, respectively. The P-2.EFS for boys with isolated testicular relapses was 0.69. Girls with isolated CNS relapse (P &lt; 0.001) and with bone marrow involved relapse (P = 0.04) had a significantly better prognosis than boys. Children with initial high risk criteria, especially T-ALL and mediastinal mass who relapsed, had a very poor prognosis. In this population-based study, about 30% of children with ALL obtained a long second remission and possible cure.

Research paper thumbnail of Prevalence of thrombophilia and central venous catheter-associated neck vein thrombosis in 41 children with cancer?a prospective study

Medical and Pediatric Oncology, 2002

Research paper thumbnail of Post-induction residual disease in translocation t(12;21)-positive childhood ALL

Medical and Pediatric Oncology, 2003

t(12;21)(p1 3;q22), the most frequent chromosomal translocation found in childhood acute lymphobl... more t(12;21)(p1 3;q22), the most frequent chromosomal translocation found in childhood acute lymphoblastic leukemia (ALL), occurs in approximately 25% of B-lineage ALL cases and has been claimed to carry a good prognosis. As part of the Nordic Society of Pediatric Hematology and Oncology (NOPHO) ALL-MRD 95 study, which includes children from Iceland, Norway, and Denmark diagnose d with ALL, patients were screened for the presence of t(12; 21) by reverse transcriptase-polymerase chain reaction (RT-PCR) at diagnosis, and their residual disease was quantified after 4 weeks of induction therapy (prednisolone, vincristine, doxorubicin, i.t. methotrexate) by a competitive, clone-specific, semi-nested PCR analysis. Among 96 children diagnosed with ALL, and quantified for post induction residual disease, 32 were t(12;21)-positive. The median residual disease was similar for B-precursor ALL patients with and without t(12;21) (0.009 vs. 0.03%, P = 0.12). Al though patients with t(12;21)-positive ALL have been claimed to have a good outcome, these data indicate that this does not reflect a high sensitivity to prednisolone, vincristine, and doxorubicin given during induction therapy.

Research paper thumbnail of Methotrexate infusions in poor prognosis acute lymphoblastic leukemia: II. High-dose methotrexate (HDM) in acute lymphoblastic leukemia in childhood: A pilot study from April 1981

Medical and Pediatric Oncology, 1986

One hundred fifty-three children with ALL were diagnosed in Norway in the period August 1975-Dece... more One hundred fifty-three children with ALL were diagnosed in Norway in the period August 1975-December 1980. One hundred thirty-two of them received 3 infusions of methotrexate as consolidation therapy combined with methotrexate intrathecally as CNS prophylaxis. Eleven (44%) of the total 25 methotrexate cases with WBC above 50 X 10(9)/L were in CCR after 4 1/2-10 years. Two more cases had discontinued therapy, while in second remission. The event-free survival of all diagnosed 32 children in Norway with WBC above 50 X 10(9)/L was 37%. Seven infants below the age of 1 year are included in the 32 cases.

Research paper thumbnail of In vitro cellular drug resistance adds prognostic information to other known risk-factors in childhood acute lymphoblastic leukemia

Leukemia Research, 2011

Key words: acute lymphoblastic leukemia childhood in vitro drug resistance MRD prognostic factors... more Key words: acute lymphoblastic leukemia childhood in vitro drug resistance MRD prognostic factors a b s t r a c t Leukemic cells from 230 children with newly diagnosed B-cell precursor ALL were tested for in vitro drug resistance to a panel of anti-cancer drugs. Minimal residual disease (MRD) was measured by RQ-PCR. During follow-up, 24 relapses occurred in the 159 children with MRD <0.1% day 29. The risk of any relapse was correlated to vincristine and doxorubicin resistance, with a relative risk of 3.7 (95% CI 1.3-10.5; p = 0.016) for patients resistant to both drugs. There was a significant correlation also for the subgroup with extra-medullary relapses. Our findings indicate that analysis of drug resistance can add prognostic information to other known risk-factors including MRD.

Research paper thumbnail of Deletion of the Ink4-locus (the p16ink4a, p14ARF and p15ink4b genes) predicts relapse in children with ALL treated according to the Nordic protocols NOPHO-86 and NOPHO-92

Leukemia, 2002

Inactivation of the Ink4 gene locus locus on 9p comprising the tumour suppressor gene p16ink4a an... more Inactivation of the Ink4 gene locus locus on 9p comprising the tumour suppressor gene p16ink4a and its neighbours p14ARF and p15ink4b is common in childhood acute lymphoblastic leukaemia (ALL), but the prognostic significance is controversial. DNA from 230 patients was retrospectively analysed by Southern blotting, single strand conformation polymorphism (SSCP) and sequencing techniques. The results were correlated with clinical characteristics and outcome. One hundred and ninetyfour fully analysed patients, similarly treated using the Nordic NOPHO-86 or the current NOPHO-92 protocols, were included in the outcome analysis. Deletions approached a minimally deleted region between the p16ink4a and p15ink4b genes, making the p14ARF gene the most commonly deleted coding sequence. Bi-allelic deletion was associated with high white blood cell count (WBC) (P Ͻ 0.001), T cell phenotype (P Ͻ 0.001) and mediastinal mass (P Ͻ 0.001). Patients with Ink4 locus bi-allelic deletions had an inferior pEFS (P Ͻ 0.01) and multivariate analysis indicated that bi-allelic deletion of the p16ink4a and the p14ARF genes was an independent prognostic risk factor (P Ͻ 0.05). Sub-group analysis revealed a pronounced impact of deletion status for high-risk patients, ie with high WBC. Deletion-status and clinical risk criteria (WBC) could thus be combined to further differentiate risk within the highrisk group. The analysis of the Ink4 locus adds independent prognostic information in childhood ALL treated by Nordic protocols and may help in selection of patients for alternative treatment.

Research paper thumbnail of The degree of myelosuppression during maintenance therapy of adolescents with B-lineage intermediate risk acute lymphoblastic leukemia predicts risk of relapse

Leukemia, 2010

Drug doses, blood levels of drug metabolites and myelotoxicity during 6-mercaptopurine/methotrexa... more Drug doses, blood levels of drug metabolites and myelotoxicity during 6-mercaptopurine/methotrexate (MTX) maintenance therapy were registered for 59 adolescents (X10 years) and 176 non-adolescents (o10 years) with B-cell precursor acute lymphoblastic leukemia (ALL) and a white blood cell count (WBC) o50 Â 10 9 /l at diagnosis. Event-free survival was lower for adolescents than non-adolescents (pEFS 12y :0.71 vs 0.83, P ¼ 0.04). For adolescents staying in remission, the mean WBC during maintenance therapy (mWBC) was related to age (r S ¼ 0.36, P ¼ 0.02), which became nonsignificant for those who relapsed (r S ¼ 0.05, P ¼ 0.9). The best-fit multivariate Cox regression model to predict risk of relapse included mWBC and thiopurine methyltransferase activity, which methylates mercaptopurine and reduces the intracellular availability of cytotoxic 6-thioguanine nucleotides (coefficient: 0.11, P ¼ 0.02). The correlation of mWBC to the risk of relapse was more pronounced for adolescents (coefficient ¼ 0.65, P ¼ 0.003) than for non-adolescents (coefficient ¼ 0.42, P ¼ 0.04). Adolescents had higher mean neutrophil counts (P ¼ 0.002) than nonadolescents, but received nonsignificantly lower mercaptopurine and MTX doses during maintenance therapy. Red blood cell MTX levels were significantly related to the dose of MTX among adolescents who stayed in remission (r S ¼ 0.38, P ¼ 0.02), which was not the case for those who developed a relapse (r S ¼ 0.15, P ¼ 0.60). Thus, compliance to maintenance therapy may influence the risk of relapse for adolescents with ALL.

Research paper thumbnail of Precise quantification of minimal residual disease at day 29 allows identification of children with acute lymphoblastic leukemia and an excellent outcome

Research paper thumbnail of Emotional Functioning and School Contentment in Adolescent Survivors of Acute Myeloid Leukemia, Infratentorial Astrocytoma, and Wilms Tumor

Journal of adolescent and young adult oncology, 2011

Purpose: Cancer in childhood may disrupt normal developmental processes and cause psychosocial pr... more Purpose: Cancer in childhood may disrupt normal developmental processes and cause psychosocial problems in adolescent survivors of childhood cancers (ACCSs). Previous studies report inconsistent findings. Study aims were to assess subjective well-being (SWB), psychological distress, and school contentment in survivors of three dissimilar childhood cancers. Patients and methods: Nordic patients treated for acute myeloid leukemia (AML), infratentorial astrocytoma (IA), and Wilms tumor (WT) in childhood from 1985 to 2001, aged ≥1 year at diagnosis, and aged 13-18 years at the time of study were eligible for this questionnaire-based survey that included items on SWB, psychological distress, school contentment, self-esteem, and personality traits; 65% (151/231) responded. An age-equivalent group from a Norwegian health survey (n=7910) served as controls. Results: The median age of ACCSs was 16 years; 52% were males. ACCSs reported better SWB (p=0.004) and self-esteem (p<0.001). They h...

Research paper thumbnail of How much is too much? Folinic acid rescue dose in children with acute lymphoblastic leukaemia

European journal of cancer (Oxford, England : 1990), 1991

The effect of folinic acid rescue dose on the event-free survival of 71 children with acute lymph... more The effect of folinic acid rescue dose on the event-free survival of 71 children with acute lymphoblastic leukaemia was examined in a retrospective clinical study. All patients, diagnosed between 1 January 1980 and 1 January 1989, were treated according to the Norwegian Pilot protocol which included eight courses of high dose (6-8 g/m2/24 h intravenous infusion) methotrexate. Following the infusion, a uniform dose of 75 mg (at 36 h after the beginning of the drug infusion) and 15 mg (at 39-106 h) folinic acid rescue was administered to all patients, at predetermined intervals. The uniformity of the rescue dose resulted in distribution of dosages in the range of 38-140 mg/m2 and 7.5-28 mg/m2 for the different periods, respectively, when the dose was recalculated on the basis of the body surface area of the individual patients. The event-free survival of children receiving less or more than 15 mg/m2 (75 mg/m2) rescue dose was compared. Although no significant difference was found, a t...

Research paper thumbnail of Increased uptake of social security benefits among long-term survivors of cancer in childhood, adolescence and young adulthood: a Norwegian population-based cohort study

Background: As the number of cancer survivors increases, their health and welfare have come into ... more Background: As the number of cancer survivors increases, their health and welfare have come into focus. Thus, long-term medical consequences of cancer at a young age (o25 years), obtained from social security benefit records, were studied.

Research paper thumbnail of Central Nervous System Disease in Childhood Acute Lymphoblastic Leukemia: Prognostic Factors and Results of Treatment

Pediatric Hematology and Oncology, 1991

In the five Nordic countries, 808 children 1 to 15 years of age (428 boys, 380 girls) were diagno... more In the five Nordic countries, 808 children 1 to 15 years of age (428 boys, 380 girls) were diagnosed with non-B acute lymphoblastic leukemia (ALL) from July 1981 through June 1986. Complete remission was achieved in 770 children (95%). Central nervous system (CNS) involvement at diagnosis was noticed in 34 children, of whom 26 achieved remission. Of these 26 patients 11 subsequently relapsed, 5 in the central nervous system. An interim analysis in January 1990 (observation time 3 1/2 to 8 1/2 years) revealed that isolated CNS relapse had occurred in 70 children (9.0%). Of these 70 patients, 12 out of 142 children (8.5%) had initially received irradiation and 58 out of 628 children (9.2%) only chemotherapy as CNS-prophylaxis. There was a significant higher risk for boys (12%) than for girls (6%) to relapse in the CNS compartment. Unfavorable prognostic factors for survival after isolated CNS relapse were short duration of first remission and male sex. In high-risk patients after an isolated CNS relapse, there was no difference in prognosis related to treatment with or without irradiation as initial CNS prophylaxis.

Research paper thumbnail of Superior treatment results in females with high-risk acute lymphoblastic leukemia in childhood

Acta Paediatrica, 1992

In this population-based study, 808 children aged 1-15 years from Denmark, Finland, Iceland, Norw... more In this population-based study, 808 children aged 1-15 years from Denmark, Finland, Iceland, Norway and Sweden, were diagnosed between July 1981 and June 1986 as suffering from non-B-cell acute lymphoblastic leukemia (ALL). The total population was 4.5 million children. Remission was achieved in 770/808 of the patients (95%). No sex difference in the remission rate was observed. The event free survival (EFS) at 102 months was 0.47 for males and 0.62 for females (p less than 0.001). There was no difference in EFS between males and females with standard-risk (0.58 and 0.60) or intermediate-risk (0.47 and 0.60) ALL, respectively. The EFS for females with high-risk ALL (0.68) was superior to that of males with high-risk ALL (0.31). Cox multivariant analysis showed that white blood cell count, sex, age and thrombocyte count were significant prognostic factors in all children. The intensified treatment according to the prognostic factors used in this study led to equal EFS for females with ALL from all risk groups. Males with high-risk ALL, however, did not benefit from the intensified treatment.

Research paper thumbnail of Children with acute lymphoblastic leukaemia have high plasma levels of total homocysteine at time of diagnosis

Scandinavian Journal of Clinical & Laboratory Investigation, 2006

Cancer can induce venous thromboembolic complications for various reasons. As part of a greater s... more Cancer can induce venous thromboembolic complications for various reasons. As part of a greater study, acquired and congenital prothrombotic risk factors were investigated in children with leukaemia or non-Hodgkin&#39;s lymphoma and compared with similar investigations in children with congenital heart defects. Blood samples were taken from 60 children with newly diagnosed leukaemia or lymphoma and 133 children with congenital heart defects in the course of a scheduled cardiac catheterization. When children with cancer were in remission, analyses of acquired prothrombotic risk factors were repeated. Children with cancer were observed for symptoms of thromboembolism throughout their treatment period. Total homocysteine levels were significantly raised in children with cancer (median value 10.0 micromol/L) as compared with the levels in children with congenital heart diseases (5.0 micromol/L) (p&lt;0.001), while children with acute lymphoblastic leukaemia had the highest values. The median level of lipoprotein(a) was slightly increased in children with newly diagnosed leukaemia or lymphoma (105 mg/L versus 100 mg/L, p&lt;0.001), and levels of coagulation inhibitors were higher (p&lt;0.001). Total homocysteine levels normalized when children attained remission of cancer disease. Two children had symptoms of acute thrombosis. Raised concentrations of total homocysteine were frequent in children with newly diagnosed cancer, but this normalized when the children were in remission. The clinical significance of our observations and the impact on venous thromboembolism have yet to be defined.

Research paper thumbnail of Structural Chromosome Aberrations in Lymphocytes from Children Previously Treated for Wilms' Tumor or Hodgkin's Disease

Pediatric Hematology-Oncology, 1989

Nineteen children treated for Wilms&#39; tumor (thirteen cases) or Hodgkin&#39;s disease ... more Nineteen children treated for Wilms&#39; tumor (thirteen cases) or Hodgkin&#39;s disease (six cases) with cytostatic agents and/or radiotherapy were studied cytogenetically on lymphocytes cultivated from blood samples drawn after at least 1 year of complete remission after end of therapy. A reference group of children was matched for age, sex, and residence. The frequencies of sister chromatid exchange (5.4 versus 5.6 SCE/cell), and chromosome damage type gaps (6.6 versus 7.1%) and breaks (1.9 versus 1.9%) were not different in the two groups, but exchange type aberrations were more frequent in the patients (0.9 versus 0.06%). Fifty karyotypes were analyzed in all but two cases of Hodgkin&#39;s disease. The overall frequency of stable (3.1 versus 3.8%) and unstable (1.7 versus 1.4%) structural chromosome changes such as translocations, deletions, chromatid exchanges, and dicentrics were not different in the patient and the control groups. If the chromosome data reflect a general cancer risk, this risk cannot be considerably higher among the cancer-treated children.

Research paper thumbnail of DIAGNOSTIC VALUE OF FAMILY HISTORIES OF THROMBOSIS TO IDENTIFY CHILDREN WITH THROMBOPHILIA

Pediatric Hematology-Oncology, 2005

Thrombophilia screening is a time-consuming and expensive procedure. Information about thromboemb... more Thrombophilia screening is a time-consuming and expensive procedure. Information about thromboembolism among relatives may be a simple method to identify those at risk of having thrombophilia. In a cross-sectional clinical study the authors have investigated the role of such family histories to detect children with thrombophilia. In 202 children a family history of venous or arterial thromboembolism was recorded. The participants were either children with congenital heart defects at the time of a scheduled cardiac catheterization (n=134) or children with newly diagnosed cancer (n=68). Questions were answered, on the spot, by the parents, at the same time as blood samples for thrombophilia screening were taken. Questions about family history of thromboembolism were completed in 184 children, of whom 114 children (62%) were positive, and 35 of these had relatives with venous thromboembolic events. Only one child had an affected first-degree relative. Thrombophilic alterations were observed in 60 children (30%), and 25 of these were defined as inherited. A positive family history of venous origin increased the relative risk of a child having inherited thrombophilia to 2.35 (95% confidence interval 1.1--5.2). Information about familial arterial thromboembolism was not useful in spotting children with prothrombotic risk factors. These results indicate that questioning about family history of venous thromboembolism may identify children with genetic thrombophilia, but the association is not strong. The authors encourage similar larger-scale studies to enlighten the issue fully.

Research paper thumbnail of THROMBOTIC EFFECTS OF ASPARAGINASE IN TWO ACUTE LYMPHOBLASTIC LEUKEMIA PROTOCOLS (NOPHO ALL-1992 VERSUS NOPHO ALL-2000): A Single-Institution Study

Pediatric Hematology-Oncology, 2006

2 Asparaginase is essential in the treatment of lymphoproliferative malignancies, but it is assoc... more 2 Asparaginase is essential in the treatment of lymphoproliferative malignancies, but it is associated with several side effects. The objective of this study was to compare asparaginase-induced alterations of the coagulation inhibitors and the impact on central line-associated thrombosis in children treated according to 2 different asparaginase regimens. The study enrolled 30 children treated for acute lymphoblastic leukemia, and they were divided into 2 groups with respect to asparaginase preparation and protocol (NOPHO ALL-1992 versus NOPHO ALL-2000. The coagulation inhibitors antithrombin, protein C, and proteins S were measured prior to and during asparaginase therapy, and incidence of central line-associated thromboses was compared to evaluate the protocols' thrombogenicity. Thirteen children received Erwinia asparaginase and 17 children received E. coli asparaginase. Independent of protocol, the coagulation inhibitors were significantly reduced during asparaginase therapy (p < .001), and central line-associated thromboses were frequent. Four children developed thrombosis in the course of asparaginase therapy, and there was a correlation between asparaginase-induced fall of antithrombin and occurrence of new thromboses (p = .01). We thank S.O. Lie and E. Thalow for their enthusiasm and support of the study. We are grateful to Professor Brosstad and his laboratory for analysis of the coagulation inhibitors and other prothrombotic biochemical factors. We thank our statistician Marijke Veenstra for guidance and valuable advices. We are also grateful to all participating nurses, laboratory technicians, and doctors at the National and collaborating hospitals, but special thanks to the nurses at BK-3.

Research paper thumbnail of Thyroid Function in Children after Cytostatic Treatment for Acute Leukemia

Pediatric Hematology-Oncology, 1988

Sixty-one children were examined for thyroid dysfunction as an adverse late effect after cessatio... more Sixty-one children were examined for thyroid dysfunction as an adverse late effect after cessation of antileukemic treatment. The aim of the study was to contribute to clarifying which types of therapy can cause this endocrine disorder. Our treatment protocols do not include cranial irradiation as CNS prophylaxis, but we give relatively intensive intrathecal methotrexate treatment. The results indicate that this cytostatic regimen alone does not cause thyroid dysfunction as an adverse late effect.

Research paper thumbnail of Oral anticoagulation with warfarin is significantly influenced by steroids and CYP2C9 polymorphisms in children with cancer

Pediatric Blood & Cancer, 2008

Clinical management of warfarin therapy is complex, and dosing algorithms do not include genetic ... more Clinical management of warfarin therapy is complex, and dosing algorithms do not include genetic factors or interactions with other drugs for warfarin dose determinations. We evaluated the interaction of warfarin and CYP2C9 polymorphisms and concomitant corticosteroids in 29 children with cancer. Children with heterozygous polymorphisms of CYP2C9 achieved target INR sooner and more frequently had INR above the target level, compared to children without mutations. Children on concomitant steroids had significantly lower warfarin requirements. Thus, awareness of CYP2C9 genotype and steroid-induced responsiveness to warfarin may be important when administrating oral anticoagulation in children.

Research paper thumbnail of Increased prevalence of chronic fatigue among survivors of childhood cancers: A population-based study

Pediatric Blood & Cancer, 2012

Fatigue is prevalent in adult cancer survivors but less studied in childhood cancer survivors. Ai... more Fatigue is prevalent in adult cancer survivors but less studied in childhood cancer survivors. Aims were to assess fatigue levels, prevalence of chronic fatigue (CF) and the association of CF with health-related quality of life (HRQoL) in survivors of acute myeloid leukemia (AML), infratentorial astrocytoma (IA), and Wilms tumor (WT) in childhood. Seventy percent (398/567) of Nordic patients treated for AML, IA, and WT between 1985 and 2001 at age &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;1 year responded to a postal survey, encompassing the Fatigue Questionnaire and the Short Form 36 (SF-36). Participants were divided into two groups at time of study; younger (YG, 13-18 years) and older (OG, 19-34 years). Respondents (19-34 years, n = 763) from a Norwegian general population (GP) survey served as controls for the OG. The OG [mean age was 24 years (SD 3.3)] had higher fatigue levels compared to the YG and the GP, especially the females (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05). There was also a higher prevalence of CF in the OG than in the GP (14 vs. 6%, P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001). Regardless of diagnosis, the OG with CF had poorer physical health (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05) on the SF-36 but better mental health (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05 and P = 0.001) relative to controls with CF. The prevalence of CF is higher among Nordic survivors of AML, IA, and WT than GP controls of similar age. CF is associated with impaired HRQoL in survivors. However, they reported better mental health than CF GP controls. This might indicate different underlying mechanisms of CF in the two populations.

Research paper thumbnail of Outcome after first relapse in children with acute lymphoblastic leukemia: A population-based study of 315 patients from the nordic society of pediatric hematology and oncology (NOPHO)

Medical and Pediatric Oncology, 1995

This study reports the outcome after relapse of acute lymphoblastic leukemia (ALL) in a populatio... more This study reports the outcome after relapse of acute lymphoblastic leukemia (ALL) in a population-based study of 809 children over 1 year of age diagnosed July 1981 through June 1986 and with non-B acute lymphoblastic leukemia in the five Nordic countries. By January 1994, 315 children had suffered at least one relapse. The bone marrow was involved in 216 cases. There were 69 isolated CNS relapses, 25 isolated testicular recurrences and five relapses in other extramedullary sites. Of the 315 children with relapse, 94 are still in a second complete remission 12-138 (median: 78) months after relapse. The overall probability of a second event free survival (P-2.EFS) and survival after relapse was 0.28 and 0.33 respectively. The probability of remaining in second remission at 11 years was significantly correlated to the duration of first remission (P &lt; 0.001), the site of relapse (P &lt; 0.001) and gender (P = 0.004). The P-2.EFS for early, intermediate, and late bone marrow involved relapses were 0.08, 0.19, and 0.50 respectively. For early, intermediate and late isolated CNS relapses the P-2.EFS were 0.21, 0.38 and 0.61, respectively. The P-2.EFS for boys with isolated testicular relapses was 0.69. Girls with isolated CNS relapse (P &lt; 0.001) and with bone marrow involved relapse (P = 0.04) had a significantly better prognosis than boys. Children with initial high risk criteria, especially T-ALL and mediastinal mass who relapsed, had a very poor prognosis. In this population-based study, about 30% of children with ALL obtained a long second remission and possible cure.

Research paper thumbnail of Prevalence of thrombophilia and central venous catheter-associated neck vein thrombosis in 41 children with cancer?a prospective study

Medical and Pediatric Oncology, 2002

Research paper thumbnail of Post-induction residual disease in translocation t(12;21)-positive childhood ALL

Medical and Pediatric Oncology, 2003

t(12;21)(p1 3;q22), the most frequent chromosomal translocation found in childhood acute lymphobl... more t(12;21)(p1 3;q22), the most frequent chromosomal translocation found in childhood acute lymphoblastic leukemia (ALL), occurs in approximately 25% of B-lineage ALL cases and has been claimed to carry a good prognosis. As part of the Nordic Society of Pediatric Hematology and Oncology (NOPHO) ALL-MRD 95 study, which includes children from Iceland, Norway, and Denmark diagnose d with ALL, patients were screened for the presence of t(12; 21) by reverse transcriptase-polymerase chain reaction (RT-PCR) at diagnosis, and their residual disease was quantified after 4 weeks of induction therapy (prednisolone, vincristine, doxorubicin, i.t. methotrexate) by a competitive, clone-specific, semi-nested PCR analysis. Among 96 children diagnosed with ALL, and quantified for post induction residual disease, 32 were t(12;21)-positive. The median residual disease was similar for B-precursor ALL patients with and without t(12;21) (0.009 vs. 0.03%, P = 0.12). Al though patients with t(12;21)-positive ALL have been claimed to have a good outcome, these data indicate that this does not reflect a high sensitivity to prednisolone, vincristine, and doxorubicin given during induction therapy.

Research paper thumbnail of Methotrexate infusions in poor prognosis acute lymphoblastic leukemia: II. High-dose methotrexate (HDM) in acute lymphoblastic leukemia in childhood: A pilot study from April 1981

Medical and Pediatric Oncology, 1986

One hundred fifty-three children with ALL were diagnosed in Norway in the period August 1975-Dece... more One hundred fifty-three children with ALL were diagnosed in Norway in the period August 1975-December 1980. One hundred thirty-two of them received 3 infusions of methotrexate as consolidation therapy combined with methotrexate intrathecally as CNS prophylaxis. Eleven (44%) of the total 25 methotrexate cases with WBC above 50 X 10(9)/L were in CCR after 4 1/2-10 years. Two more cases had discontinued therapy, while in second remission. The event-free survival of all diagnosed 32 children in Norway with WBC above 50 X 10(9)/L was 37%. Seven infants below the age of 1 year are included in the 32 cases.

Research paper thumbnail of In vitro cellular drug resistance adds prognostic information to other known risk-factors in childhood acute lymphoblastic leukemia

Leukemia Research, 2011

Key words: acute lymphoblastic leukemia childhood in vitro drug resistance MRD prognostic factors... more Key words: acute lymphoblastic leukemia childhood in vitro drug resistance MRD prognostic factors a b s t r a c t Leukemic cells from 230 children with newly diagnosed B-cell precursor ALL were tested for in vitro drug resistance to a panel of anti-cancer drugs. Minimal residual disease (MRD) was measured by RQ-PCR. During follow-up, 24 relapses occurred in the 159 children with MRD <0.1% day 29. The risk of any relapse was correlated to vincristine and doxorubicin resistance, with a relative risk of 3.7 (95% CI 1.3-10.5; p = 0.016) for patients resistant to both drugs. There was a significant correlation also for the subgroup with extra-medullary relapses. Our findings indicate that analysis of drug resistance can add prognostic information to other known risk-factors including MRD.

Research paper thumbnail of Deletion of the Ink4-locus (the p16ink4a, p14ARF and p15ink4b genes) predicts relapse in children with ALL treated according to the Nordic protocols NOPHO-86 and NOPHO-92

Leukemia, 2002

Inactivation of the Ink4 gene locus locus on 9p comprising the tumour suppressor gene p16ink4a an... more Inactivation of the Ink4 gene locus locus on 9p comprising the tumour suppressor gene p16ink4a and its neighbours p14ARF and p15ink4b is common in childhood acute lymphoblastic leukaemia (ALL), but the prognostic significance is controversial. DNA from 230 patients was retrospectively analysed by Southern blotting, single strand conformation polymorphism (SSCP) and sequencing techniques. The results were correlated with clinical characteristics and outcome. One hundred and ninetyfour fully analysed patients, similarly treated using the Nordic NOPHO-86 or the current NOPHO-92 protocols, were included in the outcome analysis. Deletions approached a minimally deleted region between the p16ink4a and p15ink4b genes, making the p14ARF gene the most commonly deleted coding sequence. Bi-allelic deletion was associated with high white blood cell count (WBC) (P Ͻ 0.001), T cell phenotype (P Ͻ 0.001) and mediastinal mass (P Ͻ 0.001). Patients with Ink4 locus bi-allelic deletions had an inferior pEFS (P Ͻ 0.01) and multivariate analysis indicated that bi-allelic deletion of the p16ink4a and the p14ARF genes was an independent prognostic risk factor (P Ͻ 0.05). Sub-group analysis revealed a pronounced impact of deletion status for high-risk patients, ie with high WBC. Deletion-status and clinical risk criteria (WBC) could thus be combined to further differentiate risk within the highrisk group. The analysis of the Ink4 locus adds independent prognostic information in childhood ALL treated by Nordic protocols and may help in selection of patients for alternative treatment.

Research paper thumbnail of The degree of myelosuppression during maintenance therapy of adolescents with B-lineage intermediate risk acute lymphoblastic leukemia predicts risk of relapse

Leukemia, 2010

Drug doses, blood levels of drug metabolites and myelotoxicity during 6-mercaptopurine/methotrexa... more Drug doses, blood levels of drug metabolites and myelotoxicity during 6-mercaptopurine/methotrexate (MTX) maintenance therapy were registered for 59 adolescents (X10 years) and 176 non-adolescents (o10 years) with B-cell precursor acute lymphoblastic leukemia (ALL) and a white blood cell count (WBC) o50 Â 10 9 /l at diagnosis. Event-free survival was lower for adolescents than non-adolescents (pEFS 12y :0.71 vs 0.83, P ¼ 0.04). For adolescents staying in remission, the mean WBC during maintenance therapy (mWBC) was related to age (r S ¼ 0.36, P ¼ 0.02), which became nonsignificant for those who relapsed (r S ¼ 0.05, P ¼ 0.9). The best-fit multivariate Cox regression model to predict risk of relapse included mWBC and thiopurine methyltransferase activity, which methylates mercaptopurine and reduces the intracellular availability of cytotoxic 6-thioguanine nucleotides (coefficient: 0.11, P ¼ 0.02). The correlation of mWBC to the risk of relapse was more pronounced for adolescents (coefficient ¼ 0.65, P ¼ 0.003) than for non-adolescents (coefficient ¼ 0.42, P ¼ 0.04). Adolescents had higher mean neutrophil counts (P ¼ 0.002) than nonadolescents, but received nonsignificantly lower mercaptopurine and MTX doses during maintenance therapy. Red blood cell MTX levels were significantly related to the dose of MTX among adolescents who stayed in remission (r S ¼ 0.38, P ¼ 0.02), which was not the case for those who developed a relapse (r S ¼ 0.15, P ¼ 0.60). Thus, compliance to maintenance therapy may influence the risk of relapse for adolescents with ALL.