ABSTRACT Although bone fragility may already be present at diagnosis of pediatric acute lymphoblastic leukemia (ALL), routine performance of dual-energy X-ray absorptiometry (DXA) in every child is not universally feasible. The aim of this study was to develop and validate a risk prediction model for low lumbar spine bone mineral density (LS BMD Z-score ≤ −2.0) at diagnosis, as an important indicator for fracture risk and further treatment-related BMD aggravation. Children with ALL (4–18 years), treated according to the Dutch Childhood Oncology Group protocol (DCOG-ALL9; model development; n = 249) and children from the Canadian Steroid-Associated Osteoporosis in the Pediatric Population cohort (STOPP; validation; n = 99) were included in this study. Multivariable logistic regression analyses were used to develop the prediction model and to confirm the association of low LS BMD at diagnosis with symptomatic fractures during and shortly after cessation of ALL treatment. The area under the receiver operating characteristic curve (AUC) was used to assess model performance. The prediction model for low LS BMD at diagnosis using weight (β = −0.70) and age (β = −0.10) at diagnosis revealed an AUC of 0.71 (95% CI, 0.63–0.78) in DCOG-ALL9 and 0.74 (95% CI, 0.63–0.84) in STOPP, and resulted in correct identification of 71% of the patients with low LS BMD. We confirmed that low LS BMD at diagnosis is associated with LS BMD at treatment cessation (OR 5.9; 95% CI, 3.2–10.9) and with symptomatic fractures (OR 1.7; 95% CI, 1.3–2.4) that occurred between diagnosis and 12 months following treatment cessation. In meta-analysis, LS BMD at diagnosis (OR 1.6; 95% CI, 1.1–2.4) and the 6-month cumulative glucocorticoid dose (OR 1.9; 95% CI, 1.1–3.2) were associated with fractures that occurred in the first year of treatment. In summary, a prediction model for identifying pediatric ALL patients with low LS BMD at diagnosis, as an important indicator for bone fragility, was successfully developed and validated. This can facilitate identification of future bone fragility in individual pediatric ALL patients. © 2021 American Society for Bone and Mineral Research (ASBMR).

Osteonecrosis and decline of bone density are serious side effects during and after treatment of childhood acute lymphoblastic leukemia. It is unknown whether osteonecrosis and low bone density occur together in the same patients, or whether these two osteogenic side-effects can mutually influence each other's development. Bone density and the incidence of symptomatic osteonecrosis were prospectively assessed in a national cohort of 466 patients with acute lymphoblastic leukemia (4-18 years of age) who were treated according to the dexamethasone-based Dutch Child Oncology Group-ALL9 protocol. Bone mineral density of the lumbar spine (BMDLS) (n= 466) and of the total body (BMDTB) (n=106) was measured by dual X-ray absorptiometry. Bone density was expressed as age-and gender-matched standard deviation scores. Thirty patients (6.4%) suffered from symptomatic osteonecrosis. At baseline, BMDLS and BMDTB did not differ between patients who did or did not develop osteonecrosis. At cessation of treatment, patients with osteonecrosis had lower mean BMDLS and BMDTB than patients without osteonecrosis (respectively, with osteonecrosis: -2.16 versus without osteonecrosis: -1.21, P<0.01 and with osteonecrosis: -1.73 versus without osteonecrosis: -0.57, P<0.01). Multivariate linear models showed that patients with osteonecrosis had steeper BMDLS and BMDTB declines during follow-up than patients without osteonecrosis (interaction group time, P<0.01 and P<0.01). We conclude that bone density status at the diagnosis of acute lymphoblastic leukemia does not seem to influence the occurrence of symptomatic osteonecrosis. Bone density declines from the time that osteonecrosis is diagnosed; this suggests that the already existing decrease in bone density during acute lymphoblastic leukemia therapy is further aggravated by factors such as restriction of weight-bearing activities and destruction of bone architecture due to osteonecrosis. Osteonecrosis can, therefore, be considered a risk factor for low bone density in children with acute lymphoblastic leukemia.

There is no consensus regarding how to manage osteonecrosis in pediatric acute lymphoblastic leukemia patients. Therefore, we performed a quality assessment of the literature with the result of a search strategy using the MESH terms osteonecrosis, children, childhood cancer, surgery, bisphosphonates, 6 hydroxymethyl-glutaryl CoA reductase inhibitors, anticoagulants and hyperbaric oxygen, and terms related to these MESH terms. A randomized controlled trial showed that osteonecrosis can be prevented by intermittent, instead of continuous, corticosteroid administration. The studies on interventions after onset of osteonecrosis were of low-quality evidence. Seven pediatric acute lymphoblastic leukemia studies described non-surgical interventions; bisphosphonates (n=5), hyperbaric oxygen therapy (n=1), or prostacyclin analogs (n=1). Safety and efficacy studies are lacking. Five studies focused on surgical interventions; none was of sufficient quality to draw definite conclusions. In conclusion, preventing osteonecrosis is feasible in a proportion of the pediatric acute lymphoblastic leukemia patients by discontinuous, instead of continuous, steroid scheduling. The questions as to how to treat childhood acute lymphoblastic leukemia patients with osteonecrosis cannot be answered as good-quality studies are lacking.

Body mass index and change in body mass index during treatment may influence treatment outcome of pediatric patients with acute lymphoblastic leukemia. However, previous studies in pediatric acute lymphoblastic leukemia reported contradictory results. We prospectively collected data on body composition from a cohort of newly diagnosed Dutch pediatric patients with acute lymphoblastic leukemia (n=762, age 2-17 years). Patients were treated from 1997-2004 and the median follow-up was 9 years (range, 0-10). Body mass index at diagnosis was expressed as age-and gender-matched standard deviation scores and on the basis of these scores the patients were categorized as being underweight, of normal weight or overweight. Multivariate analyses showed that patients who were underweight (8%) had a higher risk of relapse [hazard ratio: 1.88, 95% confidence interval (1.13-3.13)], but similar overall survival and event-free survival as patients who had a normal weight or who were overweight. Patients with loss of body mass index during the first 32 weeks of treatment had a similar risk of relapse and event-free survival, but decreased overall survival [hazard ratio: 2.10, 95% confidence interval (1.14-3.87)] compared to patients without a loss of body mass index. In addition, dual X-ray absorptiometry scans were performed in a nested, single-center cohort. Data from these scans revealed that a loss of body mass consisted mainly of a loss of lean body mass, while there was a gain in the percentage of fat. In conclusion, being underweight at diagnosis is a risk factor for relapse, and a decrease in body mass index early during treatment is associated with decreased survival. In addition, loss of body mass during treatment seems to consist mainly of a loss of lean body mass. This study was approved by the Medical Ethical Committee in 1996 (trial number NTR460/SNWLK-ALL-9).

Purpose: Osteopenia is a potential complication of childhood cancer treatment, but the magnitude of this problem in survivors is unknown. We examined (determinants of) bone mineral density (BMD) status in long-term survivors of adult childhood cancer (CCS).

Methotrexate (MTX) is an effective and toxic chemotherapeutic drug in the treatment of pediatric acute lymphoblastic leukemia(ALL). In this prospective study, we aimed to identify metabolic and genetic determinants of MTX toxicity. One hundred and thirty-four Dutch pediatric ALL patients were treated with four high infusions MTX (HD-MTX: 5 g m−2) every other week according to the DCOG-ALL-10 protocol. Mucositis (National Cancer Institute grade ⩾3) was the most frequent occurring toxicity during the HD-MTX phase (20%) and occurred especially after the first MTX course. Mucositis was not associated with plasma MTX, plasma folate or plasma homocysteine levels. Patients with mucositis had higher erythrocyte folate levels at the start of protocol M than patients without mucositis (median 1.4 vs 1.2 μmol l−1, P<0.008), this could reflect an increased MTX uptake in mucosal cells of patients with mucositis. From 17 single-nucleotide polymorphisms in the MTX pathway, only patients with the wild-type variant of rs7317112 SNP in the ABCC4 gene had more mucositis (AA (39%) vs AG/GG (15%), P=0.016). We found no evidence that erythrocyte folate levels mediate in the association between the rs7317112 and mucositis.

More than 45 % of long-term childhood cancer survivors (CCS) were diagnosed with osteopenia. Our data suggest that greater awareness for osteopenia is warranted in long-term CCS, especially in survivors who are older than 30 years, male, and underweight and were treated with cranial-spinal radiotherapy and/or steroids.

Acute lymphoblastic leukemia (ALL) is the most frequently occurring type of cancer in children, which currently, due to optimized stratification and treatment regimens, has been become curable in 80-90% of all cases (1). The increasing number of long term survivors has resulted in gain of knowledge and increased awareness of complications that may already occur during treatment as well as later in life.

PURPOSE:To elucidate incidence and risk factors of bone mineral density and fracture risk in children with Acute Lymphoblastic Leukemia (ALL). METHODS:Prospectively, cumulative fracture incidence, calculated from diagnosis until one year after cessation of treatment, was assessed in 672 patients. This fracture incidence was compared between subgroups of treatment stratification and age subgroups (Log-Rank test). Serial measurements of bone mineral density of the lumbar spine (BMDLS) were performed in 399 ALL patients using dual energy X-ray absorptiometry. We evaluated risk factors for a low BMD (multivariate regression analysis). Osteoporosis was defined as a BMDLS≤-2 SDS combined with clinical significant fractures. RESULTS:The 3-year cumulative fracture incidence was 17.8%. At diagnosis, mean BMDLS of ALL patients was lower than of healthy peers (mean BMDLS=-1.10 SDS, P<0.001), and remained lower during/after treatment (8months: BMDLS=-1.10 SDS, P<0.001; 24months: BMDLS=-1.27 SDS, P<0.001; 36months: BMDLS=-0.95 SDS, P<0.001). Younger age, lower weight and B-cell-immunophenotype were associated with a lower BMDLS at diagnosis. After correction for weight, height, gender and immunophenotype, stratification to the high risk (HR)-protocol arm and older age lead to a larger decline of BMDLS (HR group: β=-0.52, P<0.01; age: β=-0.16, P<0.001). Cumulative fracture incidences were not different between ALL risk groups and age groups. Patients with fractures had a lower BMDLS during treatment than those without fractures. Treatment-related bone loss was similar in patients with and without fractures (respectively: ΔBMDLS=-0.36 SDS and ΔBMDLS=-0.12 SDS; interaction group time, P=0.30). Twenty of the 399 patients (5%) met the criteria of osteoporosis. CONCLUSION:Low values of BMDLS at diagnosis and during treatment, rather than the treatment-related decline of BMDLS, determine the increased fracture risk of 17.8% in children with ALL.

textabstractBone mineral density (BMD) Our multi-center study in children treated according to the Dutch Childhood Oncology Group (DCOG)-ALL9 protocol showed a three-years cumulative incidence of fractures of 18%. BMD of ALL patients was lower than of healthy peers. The year after treatment discontinuation BMD recovered, but remained lower than in healthy children. Low BMD at diagnosis, rather than the treatment-related decline, determined fracture risk. These low BMD values were influenced by age, weight and the immunophenotype of the leukemia. Moreover, single nucleotide polymorphisms of the vitamin-D receptor gene and of the folate metabolism (MTHFR 677C>T and MTRR 66A>G) determined the low BMD at diagnosis. Our randomized trial investigating an exercise program to prevent BMD reduction during ALL treatment, demonstrated no beneficial effects on BMD and fracture risk, probably due to non-compliance of such long-term required program. Osteonecrosis Six percent of the ALL patients developed symptomatic osteonecrosis during/ shortly after treatment (DCOG-ALL9 protocol) and older age and female gender were risk factors. That older children with ALL are more prone to develop osteonecrosis may reflect age-related differences in dexamethasone-induced changes in the coagulation system. Finally, current literature provides insufficient evidence to advise any treatment option to reduce the morbidity of osteonecrosis. Prevention of osteonecrosis is feasible by discontinuous, instead of continuous, corticosteroid administration. Conclusion One out of five patients suffer from osteogenic toxicity during/ shortly after the treatment of childhood ALL. The results led to recommendations on screening and treatment of osteogenic toxicity for patients treated according to the DCOG-ALL11 protocol.

Abstract Abstract 1469 Purpose As survival rates for pediatric acute lymphoblastic leukemia (ALL) have significantly improved, awareness of side effects such as skeletal toxicity becomes increasingly important. As BMD decrease over time might be associated with an increased risk of fractures, we performed repeated measurements of BMD in a large nation-wide study and studied the incidence of fractures in these children treated for ALL. Methods Prospectively, serial measurements (at diagnosis, after 32 weeks, after 2 years (at cessation of therapy) and after 3 years (1 year after cessation of therapy)) of bone mineral density of the lumbar spine (BMDLS) were performed in 399 ALL patients using dual energy X-ray absorptiometry (DXA). Using logistic multivariate regression, we evaluated the following putative risk factors for a low BMDLS:age at diagnosis, gender, risk group of ALL treatment, weight and height at diagnosis. Moreover, Kaplan-Meier survival analysis was used to assess the cumulative incidence of fractures in 672 patients treated with the dexamethasone-based DCOG-ALL9 protocol. All reported fractures were symptomatic, and confirmed by X-ray. Cumulative incidences of fractures for different subgroups were compared with the Log-Rank test. Results At diagnosis, mean BMDLS of ALL patients was lower than that of healthy peers (mean BMDLS= −1.10 SDS, P< 0.001), and this remained significant lower during and after treatment (8 months: BMDLS = −1.10 SDS, P< 0.001; 24 months: BMDLS = −1,27 SDS, P< 0.001; 36 months: BMDLS = −0.95 SDS, P< 0.001). Multivariate linear regression analysis showed that after correction for weight, height and gender, treatment according to the HR treatment arm and older age at diagnosis had a significant negative effect on the decline of BMDLS during treatment (high-risk group: b = −0.50, P<0.001 and age at diagnosis: b = −0.15, P<0.001). The cumulative incidence of fractures at 3 years was 17.8%. Cumulative incidences of fractures between risk groups and age groups were not significantly different (NHR 18.8% vs. HR 15.7%, P = 0.18 and <10 years 17.7% vs. ≥10 years 17.6%, P = 0.85). Patients who developed fractures had a lower BMDLS during treatment than those without fractures. Treatment-related bone loss was similar in patients without fractures and patients with fractures (respectively: Δ BMDLS = −0.12 SDS vs. Δ BMDLS= −0.36 SDS; interaction group time, P = 0.295). Conclusion This large prospective study shows that the low value of BMDLS both at diagnosis and during treatment, rather than the treatment-related decline of BMDLS, determines the markedly increased fracture risk of 17.8%. Disclosures: No relevant conflicts of interest to declare.

Searchable abstracts of presentations at key conferences on calcified tissues ISSN 2052-1219 (online)

Introduction: High-dose methotrexate (MTX) is used in the treatment of proliferative diseases such as acute lymphoblastic leukemia. Therapeutic drug monitoring of plasma MTX is important to monitor efficacy and adverse events. The authors aimed to develop a liquid chromatography, electrospray ionization, tandem mass spectrometry (LC-ESI-MS/MS)-based method to determine MTX in plasma for therapeutic drug monitoring and pharmacokinetic studies.Methods: Samples were analyzed using a Waters Acquity UPLC and Quattro Premier XE. A Waters Acquity UPLC BEH C18 column (2.1 mm x 100 mm, 1.7 mu m) was used running an isocratic mobile phase of 21% methanol and 10 mM ammonium bicarbonate. The electrospray was operated in the positive ionization mode monitoring the following mass transitions: m/z 455.2 > 308.2 for MTX and m/z 458.2 > 311.2 for MTXd3. The analysis combined straightforward sample preparation, consisting of dilution and protein precipitation, with a 3-minute run time.Results: The method was linear up to 50 mu M (r(2) > 0.99), and the coefficient of variation was <6% for intraday and <10% for interday precision. Average recovery was 99%. There were no significant matrix effects. The lower limit of quantitation, defined as the lowest concentration at which the coefficient of variation <20% and S/N > 1:10, was 5 nM. Method comparison with the Abbott TDx fluorescent polarization immunoassay (FPIA) showed excellent agreement, and a small but significant negative constant bias was detected (LC-MS/MS = 0.98 x FPIA - 7.3).Conlusions: The authors developed a specific and sensitive stable isotope dilution LC-ESI-MS/MS method to monitor MTX concentrations in plasma within the clinically relevant range. The method can be easily applied in clinical laboratories because it combines straightforward sample pretreatment with LC-MS/MS.

PURPOSE:We studied cumulative incidence, risk factors, therapeutic strategies, and outcome of symptomatic osteonecrosis in pediatric patients with acute lymphoblastic leukemia (ALL). PATIENTS AND METHODS:Cumulative incidence of osteonecrosis was assessed prospectively in 694 patients treated with the dexamethasone-based Dutch Child Oncology Group-ALL9 protocol. Osteonecrosis was defined by development of symptoms (National Cancer Institute grade 2 to 4) during treatment or within 1 year after treatment discontinuation, confirmed by magnetic resonance imaging. We evaluated risk factors for osteonecrosis using logistic multivariate regression. To describe outcome, we reviewed clinical and radiologic information after antileukemic treatment 1 year or more after osteonecrosis diagnosis. RESULTS:Cumulative incidence of osteonecrosis at 3 years was 6.1%. After adjustment for treatment center, logistic multivariate regression identified age (odds ratio [OR], 1.47; P < .01) and female sex (OR, 2.23; P = .04) as independent risk factors. Median age at diagnosis of ALL in patients with osteonecrosis was 13.5 years, compared with 4.7 years in those without. In 21 (55%) of 38 patients with osteonecrosis, chemotherapy was adjusted. Seven patients (18%) underwent surgery: five joint-preserving procedures and two total-hip arthroplasties. Clinical follow-up of 35 patients was evaluated; median follow-up was 4.9 years. In 14 patients (40%), symptoms completely resolved; 14 (40%) had symptoms interfering with function but not with activities of daily living (ADLs; grade 2); seven (20%) had symptoms interfering with ADLs (grade 3). In 24 patients, radiologic follow-up was available; in six (25%), lesions improved/disappeared; in 13 (54%), lesions remained stable; five (21%) had progressive lesions. CONCLUSION:Six percent of pediatric patients with ALL developed symptomatic osteonecrosis during or shortly after treatment. Older age and female sex were risk factors. After a median follow-up of 5 years, 60% of patients had persistent symptoms.

Background: This study aims to identify folate-metabolism-related genetic risk factors for low bone mineral density (BMD) during/after pediatric acute lymphoblastic leukemia (ALL) treatment.Patients and methods: We investigated the influence of methylenetetrahydrofolate reductase (MTHFR 677C > T and 1298A > C) and methionine synthase reductase (MTRR 66A > G) single nucleotide polymorphisms (SNPs) on total body BMD (BMDTB) and lumbar spine BMD (BMDLS) in 83 patients. Homocysteine, folate and vitamin 312 were determined. BMD was measured repeatedly using dual-energy X-ray absorptiometry in patients >= 4 years (n = 68).Results: Carriers of the MTHFR 677 T-allele showed a lower baseline BMDTB than non-carriers (-0.38 SDS vs. + 0.55 SDS, p = 0.01) and BMDTB remained lower during/after treatment. MTHFR 677C > T did not influence treatment-related loss of BMDTB (p = 0.39). The MTRR 66 G-allele carriers showed a trend towards a lower BMDTB compared with non-carriers. Combining these two SNPs, patients carrying >= 2 risk alleles had a significantly lower BMDTB (-1.40 SDS) than patients with one (-0.80 SDS) or no risk alleles (-0.31 SDS). Although carriers of the MTHFR 1298A > C had higher homocysteine levels, this SNP was not related to BMDTB. BMDLS of carriers was similar to non-carriers of the investigated SNPs.Conclusions: The MTHFR 677C > T SNP and the MTRR 66A > G SNP were identified as determinants of impaired BMDTB in childhood ALL patients. Crown Copyright (C) 2010 Published by Elsevier Inc. All rights reserved.

Abstract 3578 This icon denotes a clinically relevant abstract

BACKGROUND:Aim of this study was to investigate the long-term endocrine effects of treatment of childhood non-Hodgkin lymphoma (NHL).PATIENTS AND METHODS:A single-center cohort of 84 survivors (22 females) was included in this retrospective study. Median age was 21 years (9-40 years) and time after cessation of therapy 12 years (4-30 years). Height, weight, percentage fat, lean body mass (LBM), bone mineral content (BMC), bone mineral density of total body (BMD(TB)) and bone mineral density of lumbar spine (BMD(LS)) were measured. Thyroid-stimulating hormone (TSH), free thyroxin (fT4), insulin-like growth factor-1 (IGF-1), inhibin B and anti-müllerian hormone (AMH) levels were measured. Results were compared with Dutch controls.RESULTS:Height was lower in survivors [mean standard deviation score (SDS) -0.36, P = 0.002], but further analysis showed that shorter stature was already present at diagnosis (mean SDS -0.28, P = 0.023). Body mass index, percentage fat, BMC, BMD(TB) and BMD(LS) were not different from controls. LBM was lower in survivors (mean SDS -0.47, P = 0.008). TSH, fT4 and IGF-1 were normal in all survivors. Three of 20 adult females had low AMH levels and 23 of 42 adult males had low inhibin B levels.CONCLUSIONS:Twelve years after cessation of treatment, NHL survivors did not develop adiposity, osteoporosis or thyroid disease. Male survivors may be at risk for infertility.