Genetic susceptibility to cognitive decline following craniospinal irradiation for pediatric central nervous system tumors

BACKGROUND

Survivors of pediatric central nervous system (CNS) tumors treated with craniospinal irradiation (CSI) exhibit long-term cognitive difficulties. Goals of this study were to evaluate longitudinal effects of candidate and novel genetic variants on cognitive decline following CSI.

METHODS

Intelligence quotient (IQ), working memory (WM), and processing speed (PS) were longitudinally collected from patients treated with CSI (n = 241). Genotype-by-time interactions were evaluated using mixed-effects linear regression to identify common variants (minor allele frequency > 1%) associated with cognitive performance change. Novel variants associated with cognitive decline (P < 5 × 10-5) in individuals of European ancestry (n = 163) were considered replicated if they demonstrated consistent genotype-by-time interactions (P < .05) in individuals of non-European ancestries (n = 78) and achieved genome-wide statistical significance (P < 5 × 10-8) in a meta-analysis across ancestry groups.

RESULTS

Participants were mostly males (65%) diagnosed with embryonal tumors (98%) at a median age of 8.3 years. Overall, 1150 neurocognitive evaluations were obtained (median = 5, range: 2-10 per participant). One of the five loci previously associated with cognitive outcomes in pediatric CNS tumors survivors demonstrated significant time-dependent IQ declines (PPARA rs6008197, P = .004). Two variants associated with IQ in the general population were associated with declines in IQ after Bonferroni correction (rs9348721, P = 1.7 × 10-5; rs31771, P = 7.8 × 10-4). In genome-wide analyses, we identified novel loci associated with accelerated declines in IQ (rs116595313, meta-P = 9.4 × 10-9), WM (rs17774009, meta-P = 4.2 × 10-9), and PS (rs77467524, meta-P = 1.5 × 10-8; rs17630683, meta-P = 2.0 × 10-8; rs73249323, meta-P = 3.1 × 10-8).

CONCLUSIONS

Inherited genetic variants involved in baseline cognitive functioning and novel susceptibility loci jointly influence the degree of treatment-associated cognitive decline in pediatric CNS tumor survivors.

Germline genetic variants and pediatric rhabdomyosarcoma outcomes: a report from the Children's Oncology Group

BACKGROUND

Relative to other pediatric cancers, survival for rhabdomyosarcoma (RMS) has not improved in recent decades, suggesting the need to enhance risk stratification. Therefore, we conducted a genome-wide association study for event-free survival (EFS) and overall survival (OS) to identify genetic variants associated with outcomes in individuals with RMS.

METHODS

The study included 920 individuals with newly diagnosed RMS who were enrolled in Children's Oncology Group protocols. To assess the association of each single nucleotide polymorphism (SNP) with EFS and OS, we estimated hazard ratios (HRs) and 95% confidence intervals (CIs) using multivariable Cox proportional hazards models, adjusted for clinical covariates. All statistical tests were two sided. We also performed stratified analyses by histological subtype (alveolar and embryonal RMS) and carried out sensitivity analyses of statistically significant SNPs by PAX3/7-FOXO1 fusion status and genetic ancestry group.

RESULTS

We identified that rs17321084 was associated with worse EFS (HR = 2.01, 95% CI = 1.59 to 2.53, P = 5.39 × 10-9) and rs10094840 was associated with worse OS (HR = 1.84, 95% CI = 1.48 to 2.27, P = 2.13 × 10-8). Using publicly available data, we found that rs17321084 lies in a binding region for transcription factors GATA2 and GATA3, and rs10094840 is associated with SPAG1 and RNF19A expression. We also identified that CTNNA3 rs2135732 (HR = 3.75, 95% CI = 2.34 to 5.99, P = 3.54 × 10-8) and MED31 rs74504320 (HR = 3.21, 95% CI = 2.12 to 4.86, P = 3.60 × 10-8) were associated with worse OS among individuals with alveolar RMS.

CONCLUSIONS

We demonstrated that common germline variants are associated with EFS and OS among individuals with RMS. Additional replication and investigation of these SNP effects may further support their consideration in risk stratification protocols.

Exome-wide assessment of isolated biliary atresia: A report from the National Birth Defects Prevention Study using child-parent trios and a case-control design to identify novel rare variants

The etiology of biliary atresia (BA) is unknown, but recent studies suggest a role for rare protein-altering variants (PAVs). Exome sequencing data from the National Birth Defects Prevention Study on 54 child-parent trios, one child-mother duo, and 1513 parents of children with other birth defects were analyzed. Most (91%) cases were isolated BA. We performed (1) a trio-based analysis to identify rare de novo, homozygous, and compound heterozygous PAVs and (2) a case-control analysis using a sequence kernel-based association test to identify genes enriched with rare PAVs. While we replicated previous findings on PKD1L1, our results do not suggest that recurrent de novo PAVs play important roles in BA susceptibility. In fact, our finding in NOTCH2, a disease gene associated with Alagille syndrome, highlights the difficulty in BA diagnosis. Notably, IFRD2 has been implicated in other gastrointestinal conditions and warrants additional study. Overall, our findings strengthen the hypothesis that the etiology of BA is complex.

Epigenetic age acceleration among survivors of pediatric medulloblastoma and primitive neuroectodermal tumor

Survivors of childhood central nervous system (CNS) tumors experience early-onset aging-related phenotypes. DNA methylation (DNAm) age is an emerging epigenetic biomarker of physiologic age and may be predictive of chronic health conditions in long-term survivors. This report describes the course of epigenetic age acceleration using post-diagnosis blood samples (median: 3.9 years post-diagnosis; range: 0.04-15.96) from 83 survivors of pediatric CNS tumors. Epigenetic age acceleration was detected in 72% of patients, with an average difference between chronologic and DNAm age of 2.58 years (95% CI: 1.75-3.41, p < 0.001). Time from diagnosis to sample collection correlated with the magnitude of epigenetic age acceleration.

Ethnic-specific predictors of neurotoxicity among patients with pediatric acute lymphoblastic leukemia after high-dose methotrexate

BACKGROUND

High-dose methotrexate (HD-MTX; 5000 mg/m2 ) is an important component of curative therapy in many treatment regimens for high-risk pediatric acute lymphoblastic leukemia (ALL). However, methotrexate therapy can result in dose-limiting neurotoxicity, which may disproportionately affect Latino children. This study evaluated risk factors for neurotoxicity after HD-MTX in an ethnically diverse population of patients with ALL.

METHODS

The authors retrospectively reviewed the medical records of patients who were diagnosed with ALL and treated with HD-MTX at Texas Children's Cancer Center (2010-2017). Methotrexate neurotoxicity was defined as a neurologic episode (e.g., seizures or stroke-like symptoms) occurring within 21 days of HD-MTX that resulted in methotrexate treatment modifications. Mixed effects multivariable logistic regression was used to estimate the odds ratio (OR) and corresponding 95% confidence interval (CI) for the association between clinical factors and neurotoxicity.

RESULTS

Overall, 351 patients (58.1% Latino) who received 1183 HD-MTX infusions were evaluated. Thirty-five patients (10%) experienced neurotoxicity, 71% of whom were Latino. After adjusting for clinical risk factors, the authors observed that serum creatinine elevations ≥50% of baseline were associated with a three-fold increased odds (OR, 3.32; 95% CI, 0.98-11.21; p = .05) for neurotoxicity compared with creatinine elevation <25%. Notably, predictors of neurotoxicity differed by ethnicity. Specifically, Latino children experienced a nearly six-fold increase in neurotoxicity odds (OR, 5.80; 95% CI, 1.39-24.17; p = .02) with serum creatinine elevation ≥50% compared with creatinine elevation <25%.

CONCLUSIONS

The current findings indicate that serum creatinine elevations ≥50% may be associated with an increased risk for neurotoxicity among Latino children with ALL and may identify potential candidates for therapeutic or supportive care interventions.

Clinical and demographic factors contributing to asparaginase-associated toxicities in children with acute lymphoblastic leukemia

A total of 548 patients (age range: 1-22 years, 60.4% Hispanic, 55.8% male) diagnosed with acute lymphoblastic leukemia were reviewed for pegaspargase-associated hypersensitivity (14.8%), hyperbilirubinemia (9.7%), venous thromboembolism (VTE, 9.7%), and pancreatitis (5.3%). Odds ratios (OR) and 95% confidence intervals (CI) evaluated associations between clinical factors and each toxicity, cumulative number of toxicities, and toxicity clusters identified using k-mode analysis. Most (68.9%) did not experience any toxicity, 24.6% experienced one toxicity, and 6.3% two or more. Age >10 years was associated with hyperbilirubinemia (OR = 3.83; 95% CI: 1.64-8.95), pancreatitis (OR = 3.72; 95% CI: 1.29-10.68), VTE (OR = 4.65; 95% CI: 1.96-11.02), and cumulative toxicity burden (OR = 3.28, 95% CI: 1.97-5.47); high-risk therapy with hypersensitivity (OR 2.25; 95% CI 1.25-4.05); and overweight with cumulative toxicity burden (OR = 1.76, 95% CI: 1.20-2.57). Eight unique toxicity profiles were identified. Older age, overweight, and treatment intensity contribute to pegaspargase-associated toxicities.

Germline Genetic and Treatment-Related Risk Factors for Diabetes Mellitus in Survivors of Childhood Cancer: A Report From the Childhood Cancer Survivor Study and St Jude Lifetime Cohorts

PURPOSE

To characterize germline genetic risk factors of diabetes mellitus among long-term survivors of childhood cancer.

METHODS

Adult survivors of childhood cancer from the Childhood Cancer Survivor Study (CCSS) Original Cohort (n = 5,083; 383 with diabetes) were used to conduct a discovery genome-wide association study. Replication was performed using the CCSS Expansion (n = 2,588; 40 with diabetes) and the St Jude Lifetime (SJLIFE; n = 3,351; 208 with diabetes) cohorts. Risk prediction models, stratified on exposure to abdominal radiation, were calculated using logistic regression including attained age, sex and body mass index, diagnosis, alkylating chemotherapy, age at cancer diagnosis, and a polygenic risk score (PRS) on the basis of 395 diabetes variants from the general population. Area under the receiver operating characteristic curve (AUC) was calculated for models on the basis of traditional risk factors, clinical risk factors, and PRS.

RESULTS

There was a genome-wide significant association of rs55849673-A with diabetes among survivors (odds ratio, 2.9; 95% CI, 2.0 to 4.2; P = 3.7 × 10^-8), which is related to expression of ERCC6L2 in the Genotype-Tissue Expression project. The association of rs55849673-A was observed largely among survivors not exposed to abdominal radiation (odds ratio = 3.5, P = 1.1 × 10^-7) and the frequency of rs55849673-A was consistently higher among diabetic survivors in the CCSS Expansion and SJLIFE cohorts. Risk prediction models including traditional diabetes risk factors, clinical risk factors and PRS had an optimism-corrected AUC of 0.801, with an AUC of 0.751 in survivors treated with abdominal radiation versus 0.813 in survivors who did not receive abdominal radiation.

CONCLUSION

There is evidence for a novel locus of diabetes among survivors not exposed to abdominal radiation. Further refinement and validation of clinic-based risk prediction models for diabetes among long-term survivors of childhood cancer is warranted.

A Prospective Evaluation of Fatigue in Pediatric Brain Tumor Patients Treated With Radiation Therapy

Background: Fatigue is a well-established consequence of cranial radiotherapy in survivors of pediatric brain tumor, but less is known about acute fatigue during radiotherapy treatment. This study aimed to longitudinally evaluate fatigue in newly diagnosed pediatric patients with brain tumors during treatment. Methods: Primary caregivers of pediatric patients with brain tumors completed the proxy-reported Parent Fatigue Scale assessments prior to radiotherapy and weekly during radiotherapy treatment. The association between clinical factors and fatigue at each assessment was evaluated with multiple linear regressions. A comparison of fatigue between radiation modalities was also analyzed. Results: A total of 33 caregivers completed pre-radiation fatigue assessments, with 29 reporting fatigue during radiotherapy. Patients were aged 3 to 16 years (M = 8.32) at diagnosis and diagnosed with medulloblastoma (n = 23), primitive neuroectodermal tumor (n = 2), ependymoma (n = 1), germ cell tumor (n = 1), pineoblastoma (n = 1), atypical teratoid rhabdoid (n = 1), and other unspecific tumors (n = 3). Moderate-to-severe fatigue was reported for the majority of patients (31/33; 94%) during treatment. Craniospinal irradiation dose was the only significant predictor of fatigue (p < .05), but this association was restricted to the first week of therapy and was attenuated by therapy completion. Discussion: Although fatigue is often considered a long-term consequence of cranial radiotherapy, this pilot study demonstrates that moderate-to-severe fatigue is pervasive prior to radiotherapy and persists throughout treatment in pediatric patients with brain tumors, regardless of radiation modality or clinical factors. Additional research is warranted to establish a link between acute and long-term fatigue and develop interventions to mitigate this adverse outcome.

Safety analysis of high-dose methotrexate in pediatric non-Hodgkin lymphomas

High-dose methotrexate (HD-MTX) with rigorous supportive care is essential to the treatment of pediatric non-Hodgkin lymphomas (NHL). We describe the safety and tolerability of HD-MTX in patients with NHL treated at our center. In our cohort of 46 patients, the majority had at least one course of delayed clearance and/or creatinine elevation. Additionally, more than one-third of patients experienced an episode of grade ≥3 mucositis. Creatinine elevations and delayed clearance were independently associated with subsequent grade ≥3 mucositis. We advocate for greater availability of methotrexate monitoring to allow dose escalation of this essential modality around the world.

Longitudinal investigation of suicidal ideation and associated factors during pediatric acute lymphoblastic leukemia chemotherapy

OBJECTIVE

This study describes the prevalence of suicidal ideation (SI) during acute lymphoblastic leukemia (ALL) therapy and investigates the influence of clinical factors and physical symptoms on SI.

METHODS

The Children's Depressive Inventory (CDI-2) was administered to ALL patients (diagnosed 2012-2017) at start of consolidation, delayed intensification (DI), maintenance cycle 1 (MC1), and maintenance cycle 2 (MC2) in a multi-site study. SI was present if patients endorsed the item "I want to kill myself." Logistic regression models evaluated associations between SI and sociodemographic factors; depressive symptoms; and below average, average, and above average symptom clusters identified using latent class analysis of pain, nausea, fatigue, and sleep.

RESULTS

Participants (n = 175) were 51% male, 75% high-/very high-risk disease, with a median age of 11.2 years at diagnosis (range: 7-18 years). Overall, 14.9% of patients (75% under age 12 years) endorsed SI during treatment, including 4% at start of consolidation, 9% at DI, 8% at MC1, and 4% at MC2. Non-Hispanic Other patients were 10.9-times (95% CI: 2.30-53.40) more likely than non-Hispanic Whites to endorse SI (p = 0.003). The frequency of SI was higher in patients experiencing above average (53.3%) compared to below average (4.1%, p = 0.003) symptoms. Depressive symptoms were consistently associated with SI.

CONCLUSIONS

SI during the initial year of childhood ALL was more prevalent in children under the age of 12 years, from ethnic groups not typically associated with increased risk, and who endorsed increased physical and depressive symptoms. Findings highlight the need for improved screening of mental health problems to mitigate symptoms of distress.

Distribution and frequency of tyrosine kinase inhibitor-associated long-term complications in children with chronic myeloid leukemia

BACKGROUND

Tyrosine kinase inhibitors (TKIs) improve outcomes for pediatric malignancies characterized by specific gene rearrangements and mutations; however, little is known about the long-term impact of TKI exposure. Our objective was to assess the incidence and type of late-onset TKI-related toxicities in children with chronic myeloid leukemia (CML).

METHODS

We reviewed medical records from patients diagnosed with CML between 2006 and 2019 at <21 years of age and prescribed one or more TKIs. Patients treated with stem cell transplant were excluded. Outcomes were captured beginning at 1 year after CML diagnosis. Outcome incidence was described overall and stratified by TKI exposure during the data-capture period.

RESULTS

Twenty-two eligible TKI-exposed patients with CML were identified. The median follow-up was 6.0 years (range: 2.2-14.3). All pericardial (n = 3) or pleural (n = 3) effusion outcomes occurred in patients treated with TKIs during the data-capture period. Other outcomes included hypertension (n = 2), ectopy on electrocardiogram (n = 2), and gastrointestinal bleed (n = 1). All outcomes were graded as mild to moderate: some resulted in a temporary discontinuation of TKI, but none led to a change in TKI. No differences were noted in outcome incidence by type of TKI exposure.

CONCLUSIONS

TKIs have substantially improved prognosis for subsets of childhood leukemia, but there are limited long-term data to inform exposure-based risk for late-onset complications and screening. Our results suggest that TKI-exposed survivors may be at risk for long-term outcomes that extend well into survivorship.

Abstract 3633: Disparities in relapse among a large multi-ethnic population of children diagnosed with acute lymphoblastic leukemia (ALL): A report from the Reducing Ethnic Disparities in Acute Leukemia (REDIAL) Consortium

Introduction: While end-induction minimal residual disease (MRD) is the strongest prognostic factor for relapsed ALL, approximately half of all relapses occur in children who are MRD negative. Latino ethnicity is also a risk factor for relapse. To further explore these associations, we conducted an interim analysis of risk factors for relapse in a large multi-ethnic population of children diagnosed with ALL.

Methods: The REDIAL Consortium includes patients diagnosed with ALL at six major pediatric cancer centers in the Southwestern U.S. The study period was 2004 to 2018, and we included individuals who were 1-23 years of age when diagnosed with ALL. Time to relapse was defined as time from ALL diagnosis to the initial relapse event, with individuals censored at date of death, last follow-up, or bone marrow transplant. Demographic and clinical factors evaluated included race/ethnicity (Latino, non-Latino Black, non-Latino White, non-Latino other), sex, age at diagnosis (1-5, 6-10, 11-15, &gt;15 years), ALL immunophenotype (B-cell, T-cell), National Cancer Institute (NCI) risk group, central nervous system involvement, enrollment on a Children’s Oncology Group clinical trial, end-induction disease failure, and end-induction bone marrow flow cytometric MRD. Cox proportional hazards models were used to calculate adjusted hazards ratios (HRs) and 95% confidence intervals (CIs). Analyses were further stratified based on end-induction MRD status (positive ≥0.01%, negative &lt;0.01%).

Results: Overall, there were 1,710 ALL patients with a median age at diagnosis of 5 years (interquartile range: 3-11 years). The majority of patients were Latino (60.1%) and male (56.9%). Of the 379 MRD-positive patients, 74 (19.5%) relapsed, compared to 138 of 1,233 (11.2%) MRD-negative patients (p&lt;0.0001). In adjusted models, factors associated with a greater risk of relapse included MRD positivity (HR=1.72, 95% CI: 1.26-2.36), older age at diagnosis (&gt;15 vs. 1-5 years, HR=1.98, 95% CI: 1.19-3.29), and NCI high-risk group (HR=1.74, 95% CI: 1.20-2.52), while patients enrolled on a clinical trial were less likely to relapse (HR=0.76, 95% CI: 0.57-0.99). Among MRD-positive patients, Latinos were less likely to relapse (HR=0.60, 95% CI: 0.33-0.99) compared to non-Latino Whites, whereas Latinos who were MRD negative were more likely to relapse (HR=1.68, 95% CI: 1.09-2.59).

Conclusion: In a large contemporary multi-ethnic cohort of &gt;1,700 children with ALL, we observed significant disparities in relapse by MRD status, age at diagnosis, NCI risk group, clinical trial enrollment, and race/ethnicity. Notably, nearly 65% of relapse events occurred in MRD-negative patients. Further analyses are ongoing in REDIAL to evaluate the impact of other factors including cytogenetics and novel biomarkers of relapse.

Citation Format: Pagna Sok, Austin L. Brown, Olga A. Taylor, M. Brooke Bernhardt, Juan C. Bernini, Rodrigo A. Erana, Timothy Griffin, Kenneth Heym, Van T. Huynh, Laura Klesse, Kathleen Ludwig, Sandi L. Pruitt, Karen R. Rabin, Michael E. Scheurer, Philip J. Lupo. Disparities in relapse among a large multi-ethnic population of children diagnosed with acute lymphoblastic leukemia (ALL): A report from the Reducing Ethnic Disparities in Acute Leukemia (REDIAL) Consortium [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3633.

Abstract 3636: Ethnic disparities in methotrexate neurotoxicity during pediatric acute lymphoblastic leukemia therapy: A report from the Reducing Ethnic Disparities in Acute Leukemia (REDIAL) Consortium

Introduction: Methotrexate (MTX) is a key component of curative chemotherapy for pediatric acute lymphoblastic leukemia (ALL). However, delivery of MTX is often interrupted by dose-limiting acute neurotoxicity, which manifests as seizures, stroke-like symptoms, or altered mental status. Because incidence and risk factors for MTX neurotoxicity are poorly defined, we evaluated clinical and demographic predictors of MTX neurotoxicity using the multi-ethnic REDIAL Consortium.

Methods: The REDIAL cohort includes pediatric patients diagnosed with ALL at six treatment centers in the southwestern U.S. This interim analysis evaluated 756 patients age 1-21 years diagnosed with B-ALL (2005-2018). Electronic health records were reviewed to determine race/ethnicity (Latino, non-Latino White, non-Latino Black, or Other), body mass index, sex, age, and intravenous (IV) MTX dose. Applying Ponte di Legno criteria, acute MTX neurotoxicity was defined as neurologic episodes occurring &lt;21 days from intrathecal or IV MTX, which resulted in MTX treatment modifications. The proportion of patients who experienced MTX neurotoxicity and corresponding 95% confidence interval (CI) was calculated overall and within the induction, post-induction, and maintenance treatment phases. Multivariable logistic regression was used to estimate adjusted odds ratios (aOR) for the association between clinical factors and MTX neurotoxicity.

Results: The study population was 56.6% Latino, 52.8% male, 41.4% treated with &gt;5g/m2 IV MTX, and diagnosed at a median age of 5 years. Overall, 15.5% (95% CI: 12.9-18.3%) of patients experienced neurotoxic events (n=117), including 1.9% (n=14, 95% CI: 1.0-3.1%) during induction, 13.0% (n=98, 95% CI: 10.7-15.6%) during post-induction, and 0.7% (n=5, 95% CI: 0.2-1.5%) during maintenance therapy. Ethnic differences were not statistically significant during induction or maintenance phases. Compared to non-Latinos, post-induction neurotoxicity was significantly more frequent among Latinos (aOR = 2.87, 95% CI: 1.68-5.10), with disparities observed during consolidation, interim maintenance and delayed intensification phases. Exposure to &gt;5g/m2 IV MTX (aOR = 2.16, 95% CI: 1.08-3.24) and older age at diagnosis (aOR = 1.16, 95% CI: 1.08-1.24) were also associated with a significantly more post-induction neurotoxicity. No factors evaluated were significantly associated with neurotoxicity during induction and maintenance therapy.

Conclusions: MTX neurotoxicity disproportionally affects Latino children during ALL post-induction therapy. Additional work is warranted to identify risk factors for neurotoxicity during induction and maintenance therapy as well as the specific clinical and host biological factors responsible for post-induction ethnic differences in MTX neurotoxicity.

Citation Format: Austin L. Brown, Rachel D. Harris, Olga A. Taylor, Melanie B. Bernhardt, Juan C. Bernini, Rodrigo A. Erana, Timothy Griffin, Kenneth Heym, Van T. Huynh, Kathleen Ludwig, Avner Meoded, Sandi L. Pruitt, Philip J. Lupo, Karen R. Rabin, Michael E. Scheurer. Ethnic disparities in methotrexate neurotoxicity during pediatric acute lymphoblastic leukemia therapy: A report from the Reducing Ethnic Disparities in Acute Leukemia (REDIAL) Consortium [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3636.

Abstract 683: Identification of common germline variants associated with pediatric rhabdomyosarcoma survival: A report from the Children's Oncology Group (COG)

Background: Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children and has one of the poorest survival rates among pediatric cancers, underscoring the need to identify factors which may be leveraged to improve therapeutic options for these individuals.

Methods: We carried out a genome-wide association study of overall survival (OS) and event-free survival (EFS) in 920 RMS patients from COG protocols and randomly divided them into discovery (n=642) and replication (n=278) cohorts. Genotyping was conducted using the Illumina OmniExpress or Global Screening Array and imputed using the Haplotype Reference Consortium. We used Cox proportional hazards regression to calculate an adjusted hazard ratio (aHR) and P value for each common variant (minor allele frequency [MAF]&gt;5%) for OS and EFS while adjusting for age at diagnosis, tumor stage, histological subtype, and the top five principal components. Analyses were also conducted by histological subtype: embryonal RMS (ERMS, n=544) and alveolar RMS (ARMS, n=268). Finally, we performed a meta-analysis of the results from the discovery and replication cohorts to generate a summary aHR and P value for each single nucleotide polymorphism (SNP).

Results: We identified an intergenic SNP at chr8q21.13 associated with worse RMS EFS across subtypes (aHR=2.08, P=2.80x10-9), which had consistent effects across the discovery (aHR=1.91, P=5.05x10-6) and replication (aHR=2.62, P=7.16x10-5) cohorts. This SNP lies in a region which spans the genomic binding site for GATA2 and GATA3, transcription factors that are recognized to contribute to cancer development. We also identified a significant association between a SNP at chr12q21.1 and worse EFS (aHR=2.04, P=3.35x10-8) with consistent effects across the discovery and replication cohorts. Based on data from the Genotype-Tissue Expression project (GTEx), this SNP is associated with expression of SLCO1B1, a gene which encodes a liver anion transporter linked to RMS treatment-related toxicities. In subtype-specific analyses, we identified a SNP at chr17q21.32 that was significantly associated with worse ARMS OS (129 events; aHR=3.18, P=3.12x10-8; discovery: aHR=3.19, P=6.23x10-4; replication: aHR=3.16, P=1.43x10-3). In GTEx, this SNP is associated with expression and splicing of genes including PITPNM3, KIAA0753, and MED31 across various tissues. No SNPs were significantly associated with ERMS OS or EFS.

Conclusion: In the first GWAS of RMS survival outcomes, we identified two SNPs that were significantly associated with worse EFS across RMS subtypes. Further, we identified a SNP that was associated with OS in ARMS patients, a subtype that is associated with worse outcomes. Additional investigation of the impact of these SNPs may further support their consideration for novel risk stratification protocols.

Citation Format: Bailey A. Martin-Giacalone, Michael E. Scheurer, Javed Khan, Stephen J. Chanock, Shengchao Alfred Li, Meredith Yeager, Deborah A. Marquez-Do, Donald A. Barkauskas, David Hall, Matthew T. McEvoy, Melissa A. Richard, Pagna Sok, Austin L. Brown, Aniko Sabo, Stephen X. Skapek, Douglas S. Hawkins, Rajkumar Venkatramani, Lisa Mirabello, Philip J. Lupo. Identification of common germline variants associated with pediatric rhabdomyosarcoma survival: A report from the Children's Oncology Group (COG) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 683.

Association between fatigue and sleep disturbances during treatment for pediatric acute lymphoblastic leukemia and posttreatment neurocognitive performance

BACKGROUND

Survivors of pediatric acute lymphoblastic leukemia (ALL) are at increased risk of neurocognitive weakness in the areas of attention, executive function, and processing speed. Although fatigue and sleep disturbances are frequent complications of ALL therapy and associated with cognitive functions, the impact of fatigue and sleep profiles during active ALL treatment on posttreatment neurocognitive performance has received limited attention.

METHODS

Pediatric patients (n = 120) with ALL (diagnosed 2011-2016) who completed fatigue and sleep questionnaires at four time points during active treatment were enrolled in a study of neurocognitive performance. Latent class growth analysis identified subgroups of patients with similar sleep and fatigue profiles during treatment. Neurocognitive performance collected >6 months post treatment on 40 participants was compared between latent classes using multivariable linear regression models.

RESULTS

Participants (57.5% male and 79.1% Hispanic or non-Hispanic White) were classified into one of two fatigue and sleep profiles: Class 1 characterized by mild fatigue and sleep disturbances during treatment (50.8%), and Class 2 characterized by higher levels of fatigue and sleep disturbances (49.2%). Posttreatment cognitive performance was in the normal range for most measures, but significantly below normative means for executive function, verbal short-term memory, attention, and distractability measures. Compared to Class 1, Class 2 demonstrated significantly (p < .05) poorer posttreatment neurocognitive performance, particularly in measures of attention.

CONCLUSIONS

Our findings indicate that fatigue and sleep disturbances during the first year of pediatric ALL therapy may impact long-term neurocognitive performance. Sleep and fatigue may be targets for intervention to preserve cognitive functioning in survivors.

An updated assessment of 43,110 patients enrolled in the Childhood Cancer Research Network: A Children's Oncology Group report

BACKGROUND

The Childhood Cancer Research Network (CCRN) was established by the Children's Oncology Group (COG) as a resource for epidemiologic studies of childhood cancer. The objective of this study was to evaluate the representativeness of CCRN and identify factors associated with enrollment.

METHOD

The number of US childhood patients with cancer diagnosed <20 years of age enrolled in CCRN (2008-2015) was compared to expected counts, calculated from Surveillance, Epidemiology, and End Results incidence rates and US Census population estimates. Observed-to-expected ratios and corresponding 95% confidence intervals (CI) were estimated across sex, race, diagnosis age, calendar year, and cancer diagnosis groups. Multivariable linear regression models were generated to evaluate the association between open COG phase 3 therapeutic trials and CCRN enrollment rates.

RESULT

The 43,110 cases enrolled in CCRN represented 36% of the expected childhood cancers diagnosed from 2008 to 2015 (N = 120,118). CCRN enrollment ratios [95% CI] were highest among males (0.38 [95% CI, 0.37-0.38]), non-Hispanics (0.35 [95% CI, 0.35-0.36]), and those diagnosed from 1 to 4 years of age (0.50 [95% CI, 0.50-51]). Enrollment ratios varied by diagnosis group, with leukemia, myeloproliferative diseases, myelodysplastic diseases (0.55 [95% CI, 0.54-0.55]), and renal tumors (0.55 [95% CI, 0.53-0.58]) having the highest enrollment. After adjusting for year of diagnosis and cancer diagnosis, there was a 3.1% [95% CI, 0.6-5.6%] increase in CCRN enrollment during windows of open COG therapeutic trials.

CONCLUSIONS

Despite enrolling only 36% of newly diagnosed cases, CCRN remains a valuable resource for investigators conducting childhood cancer etiology and survivorship research. The results of this study may inform efforts to improve enrollment on current and future COG nontherapeutic registry protocols.

Comparison of hypothyroidism, growth hormone deficiency, and adrenal insufficiency following proton and photon radiotherapy in children with medulloblastoma

BACKGROUND

Endocrine deficiencies are common following Craniospinal irradiation (CSI) in children with brain tumors, but empirical data comparing outcomes following proton (PRT) and photon radiation therapy (XRT) are limited.

METHODS

This retrospective chart review compared the incidence of hypothyroidism, Growth hormone deficiency (GHD), and Adrenal insufficiency (AI) in patients with medulloblastoma treated with XRT and PRT between 1997 and 2016. All patients received CSI and had routine endocrine screening labs to evaluate for thyroid dysfunction, GHD, and AI. We used proportional hazards regression to calculate hazard ratios (HR) and 95% confidence intervals (CI) comparing the development of hypothyroidism, AI, and GHD between radiation modalities, adjusting for age at diagnosis, sex, race/ethnicity, and CSI dose.

RESULTS

We identified 118 patients with medulloblastoma who were followed for a median of 5.6 years from the end of radiotherapy. Thirty-five (31%) patients developed hypothyroidism, 71 (66%) GHD, and 20 (18%) AI. Compared to PRT, XRT was associated with a higher incidence of primary hypothyroidism (28% vs. 6%; HR = 4.61, 95% CI 1.2-17.7, p = 0.03). Central hypothyroidism, GHD, and AI incidence rates were similar between the groups.

CONCLUSIONS

Primary hypothyroidism occurs less often after PRT CSI, compared to XRT CSI. This suggests that the thyroid and pituitary glands receive less radiation after spine and posterior fossa boost RT, respectively, using PRT.

A Role for Genetics in Racial Disparities of Therapy-Related Cardiomyopathy

Cardiomyopathy is a significant source of morbidity and early mortality among survivors of childhood cancer, and may disproportionately affect minorities. However, there have been few studies evaluating these outcomes among racially and ethnically diverse survivor populations. A study by Sapkota and colleagues systematically characterizes disparities in the incidence of treatment-associated cardiomyopathy on the basis of genetic ancestry and investigates genetic variants responsible for this inequality. The noteworthy findings include a disproportionate risk of cardiomyopathy among African-American childhood cancer survivors and the identification of inherited genetic variants, which may confer increased susceptibility to cardiomyopathy among these individuals. Although larger studies are needed to confirm these findings, incorporating this knowledge into clinical risk profiles may help focus attention on patient populations who are particularly vulnerable to adverse cardiovascular outcomes and most likely to benefit from preventive strategies.See related article by Sapkota et al., p. 2556.

Abstract 2349: Comparison of the blood, bone marrow, and cerebrospinal fluid metabolomes in children with acute leukemia

Background: Children with acute leukemia (AL) are at risk for relapse, treatment toxicity, second neoplasms, and death. Understanding host and tumor response to therapy is necessary to achieve high survival rates and minimize adverse effects. Metabolomics, the characterization of small molecules in a biological system, may be useful for monitoring treatment response. In support of this, we previously identified metabolites in bone marrow (BM) plasma associated with end-induction minimal residual disease (MRD) and in cerebrospinal fluid (CSF) associated with fatigue. Because procedures for obtaining BM and CSF are invasive and subject patients to risk, we sought to determine whether the BM and CSF metabolomes of children undergoing therapy for AL were correlated with the blood metabolome.

Methods: Blood plasma, BM, and CSF were collected at the end-induction from 11 patients with newly diagnosed AL treated at Texas Children's Hospital (Houston, TX). Global metabolomic profiling was performed by Metabolon (Durham, NC), using liquid chromatography-tandem mass spectrometry according to published methods. We assessed the number and type (e.g. lipid, amino acid) of metabolites in each sample. For each metabolite identified in ≥2 samples from ≥2 patients, we computed Spearman rank correlation coefficients to estimate the pairwise correlations between blood, BM, and CSF.

Results: Patients were predominantly male (N=7) and Latino (N=9). Ten were diagnosed with B-cell acute lymphoblastic leukemia and one with mixed phenotype acute leukemia. Among 670 metabolites detected in ≥2 blood and BM plasma samples, 370 (58%) demonstrated moderate to strong correlations (Spearman's rho ≥0.5) and 317 (47%) were significant at p&lt;0.05. Among 340 metabolites detected in ≥2 blood and CSF samples, 135 (40%) demonstrated moderate to strong correlations and 96 (28%) were significant at p&lt;0.05. Among 318 metabolites detected in ≥2 BM plasma and CSF samples, 88 (28%) demonstrated moderate to strong correlations and 66 (21%) were significant at p&lt;0.05. We observed generally moderate to strong correlations between BM and blood for 19 metabolites we previously reported were associated with MRD (median rho 0.51, interquartile range 0.24-0.69). We observed a strong positive correlation between CSF and blood for one of three metabolites we previously reported were associated with fatigue (dimethylglycine, rho=0.7, p=0.02), and a moderate inverse correlation for a second (gamma-glutamylglutamine, rho=-0.51, p=012).

Conclusions: There is substantial correlation between the blood and BM plasma metabolomes at end-induction among children with ALL, including metabolites putatively associated with early treatment response. Correlations between CSF and blood or BM plasma are weaker, implying that the CSF metabolome is distinct. The blood plasma metabolome may approximate the BM but not CSF metabolome in children with ALL.

Citation Format: Jeremy M. Schraw, J.P. Woodhouse, Melanie B. Bernhardt, Olga A. Taylor, Terzah M. Horton, Michael E. Scheurer, Mehmet F. Okcu, Karen R. Rabin, Philip J. Lupo, Austin L. Brown. Comparison of the blood, bone marrow, and cerebrospinal fluid metabolomes in children with acute leukemia [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2349.

Abstract 3032: A pilot study of epigenetic age acceleration and neurocognitive outcomes among survivors of pediatric medulloblastoma

Background: Medulloblastoma is the most common malignant brain tumor diagnosed in children. Treatments for medulloblastoma are associated with neurocognitive impairment; however, there is little known about the biological factors which influence variability in neurocognitive outcomes. There is emerging evidence that epigenetic age acceleration (EAA) – the difference between DNA methylation-based predicted age and chronological age – is associated with chronic health conditions among pediatric cancer survivors. Therefore, we sought to evaluate the association between EAA and neurocognitive outcomes in pediatric medulloblastoma survivors.

Methods: Neurocognitive tests were obtained between 2003 and 2012 from &gt;1-year survivors of pediatric medulloblastoma (n=49). Assessments included the following: Full Scale Intelligence Quotient (FSIQ), Working Memory Index (WMI), and Processing Speed Index (PSI). Whole blood samples were obtained, and DNA was extracted for genome-wide DNA methylation using the Illumina HumanMethylation450K chip. DNA methylation age was calculated using the Horvath DNA Methylation Age Calculator. Associations were assessed using linear regression models with statistical significance defined at p&lt;0.05.

Results: Patients were predominantly male (n=36, 73.5%), non-Hispanic White (n=34, 69%) and diagnosed at a mean age of 7.5 years. Patients received intensity-modulated radiation (n=39, 80%) or proton beam radiation (n=10, 20%). The mean FSIQ was 82.2 (95% CI: 76.9-87.6), WMI was 82.2 (95% CI: 76.2-88.2), and PSI was 79.5 (95% CI: 73.5-85.6) a median of 3.03 years (range: 1.0 – 15.2 years) post-radiotherapy. On average, the DNA methylation age of participants was significantly higher than their chronologic age at the time of sample collection (mean difference = 2.4 years; 95% CI: 1.2-3.5; p &lt;0.01). Time from diagnosis to sample collection was significantly (p &lt;0.01) associated with a larger deviation between DNA methylation and chronologic age. While not significantly associated with poorer neurocognitive performance on FSIQ or PSI in unadjusted models, EAA was associated with poorer WMI (beta coefficient = -1.99, p = 0.03), which was slightly attenuated after accounting for age at radiation therapy, radiation modality, dose, and time post-radiation (beta coefficient = -1.24, p = 0.15).

Conclusions: In this pilot study of pediatric medulloblastoma survivors, we report that the biologic age assessed by DNA methylation profiles often exceeds the chronologic age of survivors. We also identified suggestive associations between EAA and the degree of neurocognitive impairment in survivors of medulloblastoma. These findings highlight the potential utility of evaluating measures of biological aging to better understand variability in neurocognitive performance in larger, longitudinal cohorts of patients with pediatric medulloblastoma.

Citation Format: Kevin O. Wilhelm, Philip J. Lupo, Kimberly P. Raghubar, Lisa S. Kahalley, Murali Chintagumpala, Mehmet F. Ocku, Michael E. Scheurer, Austin L. Brown. A pilot study of epigenetic age acceleration and neurocognitive outcomes among survivors of pediatric medulloblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 3032.

Genetic and treatment risks for diabetes mellitus (DM) in survivors of childhood cancer: A report from the Childhood Cancer Survivor Study (CCSS) and St. Jude Lifetime (SJLIFE) cohorts

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Background: Childhood cancer survivors face increased risk for DM, a polygenic trait also attributable to cancer treatment exposures, particularly abdominal radiation. We aimed to characterize the role of genetic and treatment risk factors for DM among two large cohorts of childhood cancer survivors. Methods: We performed a nested case-control genome-wide association study for DM managed with oral medications in the original CCSS cohort (diagnosed 1970-1986). Logistic regression was conducted in the total sample (N = 5083) and stratified by 1) European ancestry (EA) and 2) abdominal radiation. Replication of suggestive variants (P < 1×10-7) using Fisher’s exact test was performed in independent cohorts: i) CCSS expansion diagnosed 1987-1999 (N = 2588) and ii) SJLIFE diagnosed 1962-2012 (N = 2182). To evaluate the effect of cancer treatment on the background genetic predisposition to DM, we estimated standardized effect sizes (Z’) among EA survivors in each abdominal radiation group for 398 index variants from the largest population-based EA DM study. Radiation group Z’ estimates were compared using linear regression. Results: In the original CCSS cohort we identified nine variants associated with DM and provide further support for four linked variants in the ERCC6L2 locus. Among all survivors, the rs55849673-A allele was associated with increased odds for DM among survivors in the original CCSS cohort (minor allele frequency [MAF]-cases = 0.055; MAF-controls = 0.024; adjusted odds ratio [aOR] = 2.9, 95% CI: 2.0-4.2, P = 3.7×10-8). Allele frequencies were consistent in the CCSS expansion (MAF-cases = 0.075; MAF-controls = 0.028; P = 0.07) and SJLIFE (MAF-cases = 0.036; MAF-controls = 0.027; P = 0.5). Additionally, rs55849673-A estimates were consistent among EA survivors and stronger among survivors not treated with abdominal radiation (MAF-cases = 0.052; MAF-controls = 0.021; aOR = 3.6, P = 1.6×10-6). Notably, in the CCSS expansion all rs55849673-A EA carriers who developed DM did not receive abdominal radiation (MAF-cases = 0.1; MAF-controls = 0.026; P = 0.04). More broadly, the Z’ of population-based DM index variants were 78% lower in survivors treated with abdominal radiation than survivors not treated with abdominal radiation (beta = 0.22; P = 0.01), indicating the background genetic risk for DM may be altered by treatment. Conclusions: We provide evidence for a novel locus of DM in childhood cancer survivors. This locus is a regulatory region associated with expression of ERCC6L2, a gene implicated in an East Asian population-based DM study. Taken together, our findings support the overwhelming effect of abdominal radiation on DM risk in childhood cancer survivors, relative to other risk factors, and provide insight on a genetic locus that may be useful for DM risk prediction in the context of cancer treatment.

Ethnic Disparities in Methotrexate Neurotoxicity among Children and Adolescents with Acute Lymphoblastic Leukemia

Purpose of study: To identify factors related to the increased risk of neurotoxicity in children with acute lymphoblastic leukemia (ALL) after treatment with the antifolate agent methotrexate (MTX), a critical component of curative protocols. Methods: We analyzed the incidence of and factors associated with acute MTX neurotoxicity (neurologic episode within 14d of dose that resulted in treatment modification) in a multi-site study of 280 (48% Latino) newly diagnosed (between 2012–2017) patients treated on recent pediatric ALL protocols. We examined the effects of genetic ancestry and single nucleotide variants in a subset of 190 patients with genotype data. Results: MTX neurotoxicity occurred in 22% of Latino compared to 7% of non- Latino patients; a nearly 2.5-fold increased risk after accounting for other clinical and demographic factors. Patients with neurotoxicity received fewer total MTX doses, and their risk for relapse was 2-fold higher than patients who did not experience neurotoxicity. We also found that 42% of our Latino patients who experienced a first neurotoxic event went on to have additional events, compared to only 21% of non-Latino patients. The proportion of genetic variation that co-segregates with Native American ancestry was overrepresented in individuals with MTX-related neurotoxicity (mean = 35%) vs without neurotoxicity (mean = 23%, p = 0.025). In multivariable models accounting for sex, age at diagnosis, and treatment risk group, every 10% increase in the proportion of Native American genetic ancestry was associated with a 16% increase in neurotoxicity incidence (HR = 1.16; 95% CI: 1.02–1.32). Our data also suggest that Latinos are at higher risk for first (OR = 3.51, p = 0.02) and subsequent (OR = 6.10, p = 0.04) neurotoxic events associated with a missense variant in TCF12, which is more common in admixed Latino (23%) compared to European (3%) or African (&lt;1%) populations. Conclusions: MTX neurotoxicity is more common among Latino children and adolescents with ALL, compromises treatment efficacy, and may contribute to disparities in ALL relapse and survival. Our findings to date highlight that differences in inherited genetic variation, which segregate with ancestry, likely contribute to disparities in the incidence of treatment-related neurotoxicity.

Cerebrospinal Fluid Metabolomic Profiles Associated With Fatigue During Treatment for Pediatric Acute Lymphoblastic Leukemia

CONTEXT

Cancer-related fatigue (CRF) is one of the most distressing and persistent symptoms reported during pediatric acute lymphoblastic leukemia (ALL) therapy; however, information on the pathways underlying CRF severity is limited.

OBJECTIVES

We conducted global metabolomics profiling of cerebrospinal fluid (CSF) samples to provide insight into the underlying mechanisms of CRF.

METHODS

Fatigue in pediatric ALL patients (2012-2017) was assessed during postinduction therapy approximately six months after diagnosis. Postinduction CSF was collected from 171 participants, comprising discovery (n = 86) and replication (n = 85) cohorts. We also conducted secondary validation using diagnostic CSF from 48 replication cohort participants. CSF metabolomic profiling was performed using gas chromatography-mass spectrometry (MS) and liquid chromatography-MS/MS. Kendall's rank correlation was used to evaluate associations between metabolite abundance and CRF. False discovery rate was used to account for multiple comparisons.

RESULTS

Participants were 56% males and 59% Hispanic with a mean age at diagnosis of 8.5 years. A total of 274 CSF-derived metabolites were common to the discovery and replication cohorts. Eight metabolites were significantly associated with fatigue in the discovery cohort (P < 0.05), of which three were significant in the replication cohort, including false discovery rate-corrected associations with gamma-glutamylglutamine (P_combined = 6.2E-6) and asparagine (P_combined = 3.5E-4). Notably, the abundance of gamma-glutamylglutamine in diagnostic CSF samples was also significantly associated with fatigue (P = 0.0062).

CONCLUSION

The metabolites identified in our assessment have been implicated in neurotransmitter transportation and glutathione recycling, suggesting that glutamatergic pathways or oxidative stress may contribute to ALL-associated CRF. This information could inform targeted therapies for reducing CRF in at-risk individuals.

Extended phenotypes on coral reefs: cryptic phenotypes modulate coral-vermetid interactions

Phenotypic variation can lead to variation in the strength and outcome of species interactions. Variation in phenotypic traits can arise due to plastic responses to environmental stimuli, underlying genetic variation, or both, and may reflect differences in the focal organism or aspects of the extended phenotype (e.g., associated microbes). We used a reciprocal transplant experiment of Porites corals to evaluate the role of plasticity vs. heritable diversity on phenotypic traits and performance of corals that varied in their prior exposure to vermetid gastropods, an organism known to reduce coral growth and survival. We measured a suite of phenotypic traits associated with coral performance, many of which showed a plastic response to vermetid exposure. Vermetids decreased calcification of corals, increased microbial diversity, and shifted microbial composition. Most traits also showed a signature of previous exposure environment that persisted even when exposure was reversed: i.e., under the same conditions, corals naïve to vermetids had slower calcification rates, thicker tissues, higher Symbiodiniaceae densities, and different microbiomes than corals previously exposed to vermetids. We suggest the phenotypic differences are heritable, as reefs with and without vermetids were comprised of two different mitotypes, that revealed high, consistent genetic variation. Vermetids were only found on the fast-growing coral mitotype that was characterized by thin tissue, and that likely had a history of disturbance. As extended phenotypes can have community impacts, we suggest vermetid, in addition to microbes, are part of the extended community phenotype of these corals. Coral genotypes can establish different reef trajectories, with thin-tissue types more prone to disturbance and subsequent colonization by other species, like vermetids, which can further facilitate the degradation of coral reefs. The effects of the extended phenotype of species likely influence heterogeneity across landscapes as well as temporal differences in community composition.

Neighborhood deprivation index is associated with weight status among long-term survivors of childhood acute lymphoblastic leukemia

PURPOSE

Area deprivation index (ADI), a measure of neighborhood socioeconomic disadvantage, has been linked to metabolic outcomes in the general population but has received limited attention in survivors of childhood acute lymphoblastic leukemia (ALL), a population with high rates of overweight and obesity.

METHODS

We retrospectively reviewed heights and weights of ≥ 5 year survivors of pediatric ALL (diagnosed 1990-2013). Residential addresses were geocoded using ArcGIS to assign quartiles of ADI, a composite of 17 measures of poverty, housing, employment, and education, with higher quartiles reflecting greater deprivation. Odds ratios (OR) and 95% confidence intervals (CI) for the association between ADI quartiles and overweight/obesity or obesity alone were calculated with logistic regression.

RESULTS

On average, participants (n = 454, 50.4% male, 45.2% Hispanic) were age 5.5 years at diagnosis and 17.4 years at follow-up. At follow-up, 26.4% were overweight and 24.4% obese. Compared to the lowest ADI quartile, survivors in the highest quartile were more likely to be overweight/obese at follow-up (OR = 2.33, 95% CI: 1.23-4.44) after adjusting for race/ethnicity, sex, age at diagnosis, and age at follow-up. The highest ADI quartile remained significantly associated with obesity (OR = 5.28, 95% CI: 1.79-15.54) after accounting for weight status at diagnosis.

CONCLUSIONS

This study provides novel insights into possible social determinants of health inequalities among survivors of childhood ALL by reporting a significant association between neighborhood deprivation and overweight/obesity.

IMPLICATIONS FOR CANCER SURVIVORS

Survivors of childhood ALL residing in neighborhood with greater socioeconomic disadvantage may be at increased risk of overweight and obesity and candidates for targeted interventions.

Genetic variation in the body mass index of adult survivors of childhood acute lymphoblastic leukemia: A report from the Childhood Cancer Survivor Study and the St. Jude Lifetime Cohort

BACKGROUND

Treatment characteristics such as cranial radiation therapy (CRT) do not fully explain adiposity risk in childhood acute lymphoblastic leukemia (ALL) survivors. This study was aimed at characterizing genetic variation related to adult body mass index (BMI) among survivors of childhood ALL.

METHODS

Genetic associations of BMI among 1458 adult survivors of childhood ALL (median time from diagnosis, 20 years) were analyzed by multiple approaches. A 2-stage genome-wide association study in the Childhood Cancer Survivor Study (CCSS) and the St. Jude Lifetime Cohort Study (SJLIFE) was performed. BMI was a highly polygenic trait in the general population. Within the known loci, the BMI percent variance explained was estimated, and additive interactions (chi-square test) with CRT in the CCSS were evaluated. The role of DNA methylation in CRT interaction was further evaluated in a subsample of ALL survivors.

RESULTS

In a meta-analysis of the CCSS and SJLIFE, 2 novel loci associated with adult BMI among survivors of childhood ALL (LINC00856 rs575792008 and EMR1 rs62123082; P_Meta < 5E-8) were identified. It was estimated that the more than 700 known loci explained 6.2% of the variation in adult BMI in childhood ALL survivors. Within the known loci, significant main effects for 23 loci and statistical interactions with CRT at 9 loci (P < 7.0E-5) were further identified. At 2 CRT-interacting loci, DNA methylation patterns may have differed by age.

CONCLUSIONS

Adult survivors of childhood ALL have genetic heritability for BMI similar to that observed in the general population. This study provides evidence that treatment with CRT can modify the effect of genetic variants on adult BMI in childhood ALL survivors.

Early evidence of pulmonary dysfunction in survivors of childhood Hodgkin lymphoma

Survivors of childhood Hodgkin lymphoma (HL) are at risk for pulmonary late effects, but whether survivors also experience pulmonary dysfunction early off therapy is not well understood. We determined the incidence of pulmonary dysfunction in children/adolescents with HL at entry into survivorship, as well as risk factors related to this outcome. Survivors in clinical remission and with a pulmonary function test (PFT) obtained 2-6 years off therapy were included. Seventy-five of 118 subjects met eligibility criteria (mean age at diagnosis: 13 years, mean time off therapy: 40 months). Survivors of HL had a higher than expected incidence of pulmonary dysfunction at entry into survivorship (40/75 [53%] had an abnormal DLCO and/or a restrictive or obstructive impairment). Evidence for diffusion impairment was associated with female sex (odds ratio [OR] = 3.19, p = .04). Longitudinal follow-up studies are needed to determine if early evidence of pulmonary dysfunction predicts risk for later onset pulmonary outcomes.

β-Cell and renal transplantation options for diabetes

Despite major advances in structured education, insulin delivery and glucose monitoring, diabetes self-management remains an unremitting challenge. Insulin therapy is inextricably linked to risk of dangerous hypoglycaemia and sustained hyperglycaemia remains a leading cause of renal failure. This review sets out to demystify transplantation for diabetes multidisciplinary teams, facilitating consideration and incorporation within holistic overall person-centred management. Deceased and living donor kidney, whole pancreas and isolated islet transplant procedures, indications and potential benefits are described, in addition to outcomes within the integrated UK transplant programme.

Utilization of archived neonatal dried blood spots for genome-wide genotyping

Introduction

Heel pricks are performed on newborns for diagnostic screenings of various pre-symptomatic metabolic and genetic diseases. Excess blood is spotted on Guthrie cards and archived by many states in biobanks for follow-up diagnoses and public health research. However, storage environment may vary across biobanks and across time within biobanks. With increased applications of DNA extracted from spots for genetic studies, identifying factors associated with genotyping success is critical to maximize DNA quality for future studies.

Method

We evaluated 399 blood spots, which were part of a genome-wide association study of childhood leukemia risk in children with Down syndrome, archived at the Michigan Neonatal Biobank between 1992 and 2008. High quality DNA was defined as having post-quality control call rate ≥ 99.0% based on the Illumina GenomeStudio 2.0 GenCall algorithm after processing the samples on the Illumina Infinium Global Screening Array. Bivariate analyses and multivariable logistic regression models were applied to evaluate effects of storage environment and storage duration on DNA genotyping quality.

Results

Both storage environment and duration were associated with sample genotyping call rates (p-values < 0.001). Sample call rates were associated with storage duration independent of storage environment (p-trend = 0.006 for DBS archived in an uncontrolled environment and p-trend = 0.002 in a controlled environment). However, 95% of the total sample had high genotyping quality with a call rate ≥ 95.0%, a standard threshold for acceptable sample quality in many genetic studies.

Conclusion

Blood spot DNA quality was lower in samples archived in uncontrolled storage environments and for samples archived for longer durations. Still, regardless of storage environment or duration, neonatal biobanks including the Michigan Neonatal Biobanks can provide access to large collections of spots with DNA quality acceptable for most genotyping studies.

Inherited genetic susceptibility to acute lymphoblastic leukemia in Down syndrome

Children with Down syndrome (DS) have a 20-fold increased risk of acute lymphoblastic leukemia (ALL) and distinct somatic features, including CRLF2 rearrangement in ∼50% of cases; however, the role of inherited genetic variation in DS-ALL susceptibility is unknown. We report the first genome-wide association study of DS-ALL, comprising a meta-analysis of 4 independent studies, with 542 DS-ALL cases and 1192 DS controls. We identified 4 susceptibility loci at genome-wide significance: rs58923657 near IKZF1 (odds ratio [OR], 2.02; Pmeta = 5.32 × 10-15), rs3731249 in CDKN2A (OR, 3.63; Pmeta = 3.91 × 10-10), rs7090445 in ARID5B (OR, 1.60; Pmeta = 8.44 × 10-9), and rs3781093 in GATA3 (OR, 1.73; Pmeta = 2.89 × 10-8). We performed DS-ALL vs non-DS ALL case-case analyses, comparing risk allele frequencies at these and other established susceptibility loci (BMI1, PIP4K2A, and CEBPE) and found significant association with DS status for CDKN2A (OR, 1.58; Pmeta = 4.1 × 10-4). This association was maintained in separate regression models, both adjusting for and stratifying on CRLF2 overexpression and other molecular subgroups, indicating an increased penetrance of CDKN2A risk alleles in children with DS. Finally, we investigated functional significance of the IKZF1 risk locus, and demonstrated mapping to a B-cell super-enhancer, and risk allele association with decreased enhancer activity and differential protein binding. IKZF1 knockdown resulted in significantly higher proliferation in DS than non-DS lymphoblastoid cell lines. Our findings demonstrate a higher penetrance of the CDKN2A risk locus in DS and serve as a basis for further biological insights into DS-ALL etiology.

Adaptive functioning in pediatric brain tumor survivors: An examination of ethnicity and socioeconomic status

BACKGROUND

Survivors of pediatric brain tumor are at risk for adaptive difficulties. The present study examined adaptive functioning in a multiethnic sample of survivors accounting for socioeconomic status, and whether demographic, diagnostic, and/or treatment-related variables predict adaptive outcomes.

METHOD

Participants included a multiethnic sample of survivors (58 Caucasian, 34 Hispanic, and 22 other non-Caucasian; M age = 14.05 years, SD = 4.33) who were approximately seven years post-treatment. Parents rated adaptive functioning and provided demographic information. Diagnostic and treatment-related information was abstracted from the electronic medical record.

RESULTS

Parent ratings of adaptive functioning were similar across Caucasian, Hispanic, and other non-Caucasian survivors covarying for family income and primary caregiver education, both of which served as proxies for socioeconomic status. All ethnic groups were rated lower than the normative mean in overall adaptive functioning as well as the specific domains of conceptual, social, and practical skills. Demographic, diagnostic, and treatment-related variables were differentially associated with adaptive functioning in survivors of pediatric brain tumor, though socioeconomic status emerged as a strong significant predictor of adaptive functioning domains.

CONCLUSIONS

Adaptive outcomes do not differ as a function of ethnicity after accounting for primary caregiver education and family income. Racial and ethnic minorities may be at increased risk for poorer outcomes given their overrepresentation at lower income levels. Assessing demographic and treatment-related variables early on may be helpful in identifying children likely to develop adaptive difficulties.

Association Between Birth Defects and Cancer Risk Among Children and Adolescents in a Population-Based Assessment of 10 Million Live Births

Importance

Birth defects affect approximately 1 in 33 children. Some birth defects are known to be strongly associated with childhood cancer (eg, trisomy 21 and acute leukemia). However, comprehensive evaluations of childhood cancer risk in those with birth defects have been limited in previous studies by insufficient sample sizes.

Objectives

To identify specific birth defect-childhood cancer (BD-CC) associations and characterize cancer risk in children by increasing number of nonchromosomal birth defects.

Design, Setting, and Participants

This multistate, population-based registry linkage study pooled statewide data on births, birth defects, and cancer from Texas, Arkansas, Michigan, and North Carolina on 10 181 074 children born from January 1, 1992, to December 31, 2013. Children were followed up to 18 years of age for a diagnosis of cancer. Data were retrieved between September 26, 2016, and September 21, 2017, and data analysis was performed from September 2, 2017, to March 21, 2019.

Exposures

Birth defects diagnoses (chromosomal anomalies and nonchromosomal birth defects) recorded by statewide, population-based birth defects registries.

Main Outcomes and Measures

Cancer diagnosis before age 18 years, as recorded in state cancer registries. Cox regression models were used to generate hazard ratios (HRs) and 95% CIs to evaluate BD-CC associations and the association between number of nonchromosomal defects and cancer risk.

Results

Compared with children without any birth defects, children with chromosomal anomalies were 11.6 (95% CI, 10.4-12.9) times more likely to be diagnosed with cancer, whereas children with nonchromosomal birth defects were 2.5 (95% CI, 2.4-2.6) times more likely to be diagnosed with cancer before 18 years of age. An increasing number of nonchromosomal birth defects was associated with a corresponding increase in the risk of cancer. Children with 4 or more major birth defects were 5.9 (95% CI, 5.3-6.4) times more likely to be diagnosed with cancer compared with those without a birth defect. In the analysis of 72 specific BD-CC patterns, 40 HRs were statistically significant (adjusted P < .05) after accounting for multiple comparisons. Cancers most frequently associated with nonchromosomal defects were hepatoblastoma and neuroblastoma.

Conclusions and Relevance

Several significant and novel associations were observed between specific birth defects and cancers. Among children with nonchromosomal birth defects, the number of major birth defects diagnosed was significantly and directly associated with cancer risk. These findings could inform clinical treatment for children with birth defects and may elucidate mechanisms that lead to these complex outcomes.

Abstract 1575: DNA methylation-derived neutrophil-to-lymphocyte ratio and survival among pediatric medulloblastoma patients

Background/Objectives: Medulloblastoma is the most common malignant brain tumor diagnosed in children. Current risk-stratification methods of pediatric medulloblastoma do not fully explain the observed variability in clinical outcomes. Methylation-derived neutrophil-to-lymphocyte ratio (mdNLR) captures immune-specific information and has been identified as a potential prognostic biomarker of outcomes in various cancers, including adult brain tumors. Therefore, we evaluated the association between blood-derived mdNLR and overall survival in a cohort of patients with pediatric medulloblastoma.

Design/Methods: We identified pediatric patients diagnosed and treated for medulloblastoma at Texas Children’s Cancer Center between 1995 and 2015. Peripheral blood DNA methylation was measured using the Infinium Human Methylation 450K Beadchip. Methylation data underwent quality control, including beta-mixture quantile normalization and batch correction. Immune cell proportions (CD4+ T-Cells, CD8+ T-Cells, B-cells, natural killer cells, monocytes, and granulocytes) were estimated using cellular deconvolution methods and used to estimate mdNLR, which was then log-transformed to improve normality. Cox regression models were estimated to evaluate the association between mdNLR and overall survival.

Results: Of the 78 eligible patients include in this analysis, 83% (n=65) were alive at last follow-up (median follow-up=7.8 years). Deceased patients (n=13; median follow-up=2.6 years) had a higher mean mdNLR than patients who were alive at last contact (12.3 vs. 4.0, P = 0.046). Elevated log-transformed mdNLR was associated with an increased risk of death in both unadjusted models (HR=1.68, 95%CI: 1.11-2.55) and models accounting for age, sex, race, and clinical risk group (HR=1.97, 95%CI: 1.12-3.45).

Conclusion: We identified a significant association between peripheral blood mdNLR and survival in pediatric medulloblastoma. As a promising prognostic biomarker of outcomes, mdNLR captures immune-specific information and is a potential avenue of research in settings where cytologic determination of NLR may not be possible. Future work should investigate the relationship between elevated mdNLR and specific pediatric medulloblastoma molecular subtypes.

Citation Format: Vidal M. Arroyo, Philip J. Lupo, Michael E. Scheurer, Surya P. Rednam, Jeffrey C. Murray, M F. Okcu, Murali M. Chintagumpala, Austin L. Brown. DNA methylation-derived neutrophil-to-lymphocyte ratio and survival among pediatric medulloblastoma patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1575.

Abstract 3287: Survival disparities for second primary malignancies diagnosed among childhood cancer survivors: A population-based assessment

Background: Curative therapy places childhood cancer survivors at increased risk of second primary malignancies (SPMs). However, there have been few population-based attempts to characterize differences in outcomes between SPMs in childhood cancer survivors and comparable de novo first primary malignancies (FPMs).

Methods: We extracted clinical and demographic information from childhood cancer survivors who developed SPMs and from individuals with comparable de novo FPMs using the Surveillance, Epidemiology, and End Results (SEER) 1973-2015 database. Hazard ratios (HR) and 95% confidence intervals (CI) were estimated with Cox proportional hazards models comparing overall survival (OS) between individuals with and without a history of childhood cancer. OS was evaluated overall and within specific cancers diagnosed in ≥50 childhood cancer survivors. Models accounted for potential confounders, including sex, race, age, decade of diagnosis, histology, and disease stage.

Results: Compared to individuals with FPMs (n=1,332,203), childhood cancer survivor with a similar SPM as the FPMs (n=1,409) experienced poorer OS (HR=1.86, 95%CI: 1.72-2.02) after accounting for age, sex, race, and decade of diagnosis. Estimated five-year overall survival for SPMs diagnosed in survivors of childhood cancer was 61.7% (95% CI: 58.9-64.4), compared to 77.4% (95% CI: 75.0-79.5) among de novo FPMs propensity score-matched on confounding factors. A history of childhood cancer remained a poor prognostic factor for all specific cancer evaluated, including: breast (HR=2.07, 95%CI: 1.63-2.62), thyroid (HR=3.59, 95%CI: 2.08-6.19), acute myeloid leukemia (HR=2.38, 95%CI:1.87-3.05), brain (HR=2.09, 95%CI:1.72-2.55), melanoma (HR=2.57, 95%CI: 1.55-4.27), bone (HR=1.88, 95%CI:1.37-2.57), and soft tissue sarcoma (HR=2.44, 95%CI: 1.78-3.33). Survival disparities were most pronounced in survivors diagnosed with a childhood cancer before age 10 (HR=2.83, 95%CI: 2.46-3.25), diagnosed with a SPM within 10 years of the childhood cancer (HR=2.61, 95%CI: 2.29-2.99), and exposed to radiotherapy during childhood (HR=2.13, 95%CI: 1.92-2.37).

Conclusion: Compared to individuals without a prior cancer diagnosis, survivors of childhood cancer with a SPM experience inferior outcomes. These survival disparities persist across cancer types, therapeutic exposures, and clinical factors.

Citation Format: Austin L. Brown, Vidal M. Arroyo, Jennifer Agrusa, Michael E. Scheurer, Maria M. Gramatges, Philip J. Lupo. Survival disparities for second primary malignancies diagnosed among childhood cancer survivors: A population-based assessment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3287.

Survival disparities for second primary malignancies diagnosed among childhood cancer survivors: A population-based assessment

BACKGROUND

Curative therapy places childhood cancer survivors at increased risk for second primary malignancies (SPMs). However, there have been few population-based attempts to characterize differences between outcomes of SPMs in childhood cancer survivors and outcomes of first primary malignancies (FPMs).

METHODS

Clinical and demographic information about childhood cancer survivors who developed SPMs and individuals with comparable FPMs was extracted from the Surveillance, Epidemiology, and End Results program. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated with Cox proportional hazards models comparing the overall survival (OS) of individuals with and without a history of childhood cancer. OS was evaluated both overall and for specific cancers diagnosed in 50 or more childhood cancer survivors. Models accounted for potential confounders, including sex, race, age, treatment decade, histology, and disease stage.

RESULTS

Compared with individuals with FPMs (n = 1,332,203), childhood cancer survivors (n = 1409) with an SPM experienced poorer OS (HR, 1.86; 95% CI, 1.72-2.02) after the study had accounted for cancer type, age, sex, race, and decade of diagnosis. A history of childhood cancer remained a poor prognostic factor for all specific cancers evaluated, including breast cancer (HR, 2.07; 95% CI, 1.63-2.62), thyroid cancer (HR, 3.59; 95% CI, 2.08-6.19), acute myeloid leukemia (HR, 2.38; 95% CI, 1.87-3.05), brain cancer (HR, 2.09; 95% CI, 1.72-2.55), melanoma (HR, 2.57; 95% CI, 1.55-4.27), bone cancer (HR, 1.88; 95% CI, 1.37-2.57), and soft-tissue sarcoma (HR, 2.44; 95% CI, 1.78-3.33).

CONCLUSIONS

Compared with individuals without a prior cancer diagnosis, survivors of childhood cancer with an SPM experienced inferior outcomes. Survival disparities were observed for the most frequent SPMs diagnosed in childhood cancer survivors.

Weight trends in a multiethnic cohort of pediatric acute lymphoblastic leukemia survivors: A longitudinal analysis

BACKGROUND

As survival rates for childhood acute lymphoblastic leukemia (ALL) continue to improve, there is growing concern over the chronic health conditions that survivors face. Given that survivors of childhood ALL are at increased risk of cardiovascular complications and obesity, we sought to characterize BMI trends from diagnosis through early survivorship in a multi-ethnic, contemporary cohort of childhood ALL patients and determine if early weight change was predictive of long-term weight status.

METHODS

The study population consisted of ALL patients aged 2-15 years at diagnosis who were treated with chemotherapy alone at Texas Children's Hospital. Each patient had BMI z-scores collected at diagnosis, 30-days post-diagnosis, and annually for five years. Linear regression models were estimated to evaluate the association between: 1) BMI z-score change in the first 30 days and BMI z-scores at five-years post-diagnosis; and 2) BMI z-score change in the first year post-diagnosis and BMI z-scores at five-years post-diagnosis.

RESULTS

This retrospective cohort study included longitudinal data from 121 eligible patients. The mean BMI z-scores for the population increased significantly (p-value<0.001) from baseline (mean = 0.25) to 30 days post-diagnosis (mean = 1.17) before plateauing after one year post-diagnosis (mean = 0.99). Baseline BMI z-scores were statistically significant predictors to five year BMI z-scores (p <0.001). Independent of baseline BMI z-score and other clinical factors, the BMI z-score at one year post-diagnosis was significantly associated with BMI z-score at five-years post-diagnosis (β = 0.63, p <0.001), while BMI z-score at 30 days post-diagnosis was not (β = 0.10, p = 0.23).

CONCLUSION

Our results suggest that weight gain within the first year after diagnosis is more strongly associated with long-term BMI than early weight gain (within 30 days). If confirmed, this information may help identify a window of time during therapy when ALL patients would benefit most from weight management directed interventions.

The role of genetic variation in DGKK on moderate and severe hypospadias

BACKGROUND

Recent genome-wide association studies of hypospadias have implicated the role of genetic variants in or near the diacylglycerol kinase kappa (DGKK) gene. However, these variants are largely identified among samples of mild and moderate hypospadias cases. Therefore, we evaluated previously identified DGKK variants among second- and third-degree hypospadias cases and controls recruited in Arkansas, a state characterized by a high birth prevalence of hypospadias.

METHODS

Second- and third-degree hypospadias non-Hispanic white cases (n = 36 and n = 9, respectively) and controls (n = 45) were recruited at Arkansas Children's Hospital. Preputial tissue was collected on cases and controls between 2013 and 2017. Cases and controls were genotyped using the Illumina Infinium Global Screening Array. We used logistic regression models to assess the association of genotyped and imputed genetic variants mapped to the DGKK region with second- and third-degree hypospadias.

RESULTS

All families self-reported as non-Hispanic white and genetic principal component analyses did not demonstrate evidence of population stratification. Five DGKK variants previously reported as associated with hypospadias were identified in the genotype data. None of the variants were associated with second- or third-degree hypospadias (range of odds ratios = 0.7-0.9, all p > .05).

CONCLUSIONS

In our analyses, genetic variation in DGKK does not play a role in the development of moderate and severe hypospadias. Our findings provide support to the etiologic heterogeneity of hypospadias by all classifications of severity.

Pilot study of DNA methylation-derived neutrophil-to-lymphocyte ratio and survival in pediatric medulloblastoma

INTRODUCTION

Methylation-derived neutrophil-to-lymphocyte ratio (mdNLR) has been identified as a potential prognostic biomarker of outcomes in various cancers. We evaluated the prognostic value of blood-derived mdNLR within a retrospective cohort of pediatric medulloblastoma patients.

MATERIALS AND METHODS

DNA methylation was measured in archival peripheral blood samples collected on 56 pediatric medulloblastoma patients. Hazard ratios (HR) and 95% confidence intervals (CI) for the association between mdNLR and survival were evaluated using Cox proportional hazard models.

RESULTS

Compared to patients who were alive at last follow-up (n = 43), the mean mdNLR value was slightly higher in deceased patients (n = 13) (12.3 vs. 5.2,P =  0.163). Elevated log-transformed mdNLR was suggestively associated with an increased likelihood of death in unadjusted models (HR=1.43, 95%CI: 0.92-2.22) and significantly associated with mortality in adjusted models (HR=1.61, 95%CI: 1.01-2.58).

DISCUSSION

Future work is warranted to investigate the relationship between mdNLR outcomes in specific pediatric medulloblastoma molecular subgroups.

DNA methylation and obesity in survivors of pediatric acute lymphoblastic leukemia: A report from the Childhood Cancer Survivor Study

Because survivors of pediatric acute lymphoblastic leukemia (ALL) are more likely to be obese than unaffected contemporaries, we compared DNA methylation profiles between normal-weight and obese survivors at adiposity-associated CpG sites previously-reported by epigenome-wide association studies (EWAS) of body mass index (BMI) in the general population. We selected 96 ALL survivors from the Childhood Cancer Survivor Study: 48 obese and 48 normal weight. The Illumina HumanMethylation450 BeadChip was used to compare DNA methylation at 211 loci identified in EWAS of BMI in the general population. Thirty-nine loci were associated (false discovery rate <0.05) with obesity among survivors who only received chemotherapy (n = 49). No loci were significantly associated with obesity among CRT-exposed survivors (n = 47). Our results suggest that previously identified BMI-DNA methylation loci are associated with obesity in ALL survivors who were spared CRT, while no loci were significantly associated with obesity in survivors who received CRT.

A Review on Energy, Environmental, and Sustainability Implications of Connected and Automated Vehicles

Connected and automated vehicles (CAVs) are poised to reshape transportation and mobility by replacing humans as the driver and service provider. While the primary stated motivation for vehicle automation is to improve safety and convenience of road mobility, this transformation also provides a valuable opportunity to improve vehicle energy efficiency and reduce emissions in the transportation sector. Progress in vehicle efficiency and functionality, however, does not necessarily translate to net positive environmental outcomes. Here, we examine the interactions between CAV technology and the environment at four levels of increasing complexity: vehicle, transportation system, urban system, and society. We find that environmental impacts come from CAV-facilitated transformations at all four levels, rather than from CAV technology directly. We anticipate net positive environmental impacts at the vehicle, transportation system, and urban system levels, but expect greater vehicle utilization and shifts in travel patterns at the society level to offset some of these benefits. Focusing on the vehicle-level improvements associated with CAV technology is likely to yield excessively optimistic estimates of environmental benefits. Future research and policy efforts should strive to clarify the extent and possible synergetic effects from a systems level to envisage and address concerns regarding the short- and long-term sustainable adoption of CAV technology.

Disparities in Neurotoxicity Risk and Outcomes among Pediatric Acute Lymphoblastic Leukemia Patients

Purpose: Methotrexate chemotherapy can be associated with neurologic complications during therapy and long-term neurologic deficits. This study evaluated demographic and clinical factors associated with incidence of methotrexate neurotoxicity and described the impact of neurotoxicity on acute lymphoblastic leukemia (ALL) therapy in pediatric patients.Experimental Design: Patients were enrolled between 2012 and 2017 from three pediatric cancer treatment centers in the United States. Medical records for suspected cases of methotrexate neurotoxicity, defined as an acute neurologic event following methotrexate therapy, were reviewed. Cox proportional hazards models were used to estimate the association between race/ethnicity and methotrexate neurotoxicity. Multivariable linear regression models compared treatment outcomes between patients with and without methotrexate neurotoxicity.Results: Of the 280 newly diagnosed patients enrolled, 39 patients (13.9%) experienced methotrexate neurotoxicity. Compared with non-Hispanic whites, Hispanic patients experienced the greatest risk of methotrexate neurotoxicity (adjusted HR, 2.43; 95% CI, 1.06-5.58) after accounting for sex, age at diagnosis, BMI Z-score at diagnosis, and ALL risk stratification. Patients who experienced a neurotoxic event received an average of 2.25 fewer doses of intrathecal methotrexate. Six of the 39 cases of neurotoxicity (15.4%) experienced relapse during the study period, compared with 13 of the 241 (2.1%) patients without neurotoxicity (P = 0.0038).Conclusions: Hispanic ethnicity was associated with increased risk of methotrexate neurotoxicity, which was associated with treatment modifications and relapse. Understanding the mechanism and predictors of methotrexate neurotoxicity is important to improving treatment outcomes in pediatric ALL. Clin Cancer Res; 24(20); 5012-7. ©2018 AACR.

Abstract LB-161: A population-based assessment of cancer risk among children with non-chromosomal birth defects in 10 million live births

Purpose: While cancer risk is increased among children with chromosomal birth defects, less is known about associations between specific non-chromosomal structural birth defects and specific childhood cancers. To investigate these, we established a population-based retrospective cohort of &gt;10 million children by pooling statewide registry data from four U.S. states (Texas, Michigan, North Carolina, and Arkansas) for the period 1992-2013.

Methods: Individual level data from birth certificates, birth defects registries, and cancer registries were linked in each state; demographic and diagnostic variables were harmonized; and the data were pooled for the overall analysis. We used Cox proportional hazards models to evaluate associations between 60 birth defects and 31 childhood cancers when there were five or more comorbid cases. A hazard ratio (HR) and 95% confidence interval (CI) was calculated for each birth defect-childhood cancer (BD-CC) pairwise combination, adjusted for maternal age, infant sex, and state. The false discovery rate (FDR) was computed via the Benjamini-Hochberg procedure to account for multiple comparisons.

Results: We identified 517,548 children with non-chromosomal structural birth defects and 14,774 children with cancer. The risk of any cancer was increased among children with any non-chromosomal structural defect compared to children without any birth defect (HR=2.6, 95% CI 2.4-2.7). Of 2,511 potential BD-CC combinations, we tested 606 where there were ≥5 comorbid cases and identified 496 BD-CC associations with significantly elevated HRs at a 5% FDR. No significant inverse associations were identified for any BD-CC combination. Notably, hepatoblastoma, astrocytoma, ependymoma, and extracranial germ cell tumors were each strongly associated with several birth defects. For example, the risk of hepatoblastoma was increased among children with atrial septal defects (HR=12.5, 95% CI 7.9-19.7) and craniosynostosis (HR=15.4, 95% CI 7.6-31.3). Astrocytoma and ependymoma were associated with central nervous system (CNS) defects (HR=6.7, 95% CI 4.6-9.8 and HR=7.4, 95%CI 3.5-15.7, respectively). Elevated risk of extracranial germ cell tumors was observed among children with CNS defects (HR=22.5, 95% CI 10.9-46.4) and obstructive genitourinary defects (HR=32.4, 95% CI 16.2-64.6).

Conclusions: By pooling registry data across four U.S. states, we were able to evaluate specific BD-CC patterns and report several novel associations. Our findings suggest that children with non-chromosomal birth defects have a significantly elevated risk of several childhood cancers. These findings may inform research into the etiologies of childhood cancer, as well as new cancer surveillance protocols for children with non-chromosomal birth defects. This work was supported by the Cancer Prevention Research Institute of Texas.

Citation Format: Jeremy M. Schraw, Tania A. Desrosiers, Wendy N. Nembhard, Glenn Copeland, Robert E. Meyer, Austin L. Brown, Tiffany M. Chambers, Heather E. Danysh, Saumya Sisoudiya, Chunqiao Luo, Amir Mian, Michael E. Scheurer, Sharon E. Plon, Philip J. Lupo. A population-based assessment of cancer risk among children with non-chromosomal birth defects in 10 million live births [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr LB-161.

Abstract 2967: Ethnic-specific risk of neurotoxocity and its impact on treatment outcomes among pediatric patients receiving acute lymphoblastic leukemia therapy

Purpose: Because of the increasing awareness that Hispanics diagnosed with acute lymphoblastic leukemia (ALL) often experience worse outcomes, we sought to evaluate the risk of methotrexate (MTX)-related neurotoxicity (NT) by ethnic group and evaluate its effects on treatment outcomes in a multi-institutional prospective cohort of pediatric patients (2-17 years old).

Methods: Patients with ALL were prospectively recruited from 3 pediatric cancer centers in the United States for the period 2012-2017 and systematically followed for the development of treatment-related symptoms and toxicities. For this analysis, suspected NT cases were defined as patients with a neurologic event following intrathecal (IT) and/or intravenous (IV) MTX that led to a change in subsequent MTX therapy. Cumulative incidence of MTX NT was calculated by ethnic group. Multivariable linear regression models were generated to compare treatment differences between patients with and without MTX NT. The frequency of all-cause and central nervous system (CNS) relapse was compared between patients with and without MTX NT using the log-rank test and Cox regression models.

Results: Of the 280 patients enrolled, 39 (13.9%) experienced MTX NT (median follow-up = 22.6 months; range: 1.3 - 55.6 months). Cumulative incidence of MTX NT was 21.8% among Hispanic patients compared to 7.0% among non-Hispanic patients (p &lt;0.001). After adjusting for relevant clinical characteristics, Hispanic patients were 2.74 times more likely to develop MTX NT compared to non-Hispanic white patients (95% CI: 1.21-6.19). Patients who experienced MTX NT received an average of 2.25 fewer doses of IT MTX (95% CI: 1.73-2.77), independent of treatment risk group, sex, or age. Six cases of MTX NT (15.4%) experienced all-cause relapse during the study period, compared to 13 (2.1%) patients without MTX NT (log-rank p = 0.0038). Similarly, CNS relapse was more frequent among patients with MTX NT (10.3%) than patients without NT (2.1%; log-rank p = 0.0014). In univariate Cox regression models, MTX NT was significantly associated with CNS relapse (HR: 3.80, 95% CI: 1.44-10.02), a trend which remained after individually accounting for treatment risk arm (HR: 2.92, 95% CI: 1.07-7.95), MRD status at day 29 (HR: 3.49, 95% CI: 1.32-9.24), race and ethnicity (HR: 3.15, 95% CI: 1.13-8.79), age at diagnosis (HR: 2.56, 95% CI: 0.91-7.21), and sex (HR: 3.82, 95% CI: 1.44-10.10).

Conclusion: We identified an increased risk of relapse, specifically in the CNS, among ALL patients following MTX NT, which was not fully explained by other clinical risk factors. Further, incidence of NT was higher among Hispanic patients in our clincs. This is particularly interesting given that Hispanic patients typically present with more favorable disease characterstics, yet often experience worse treatment outcomes.

Citation Format: Michael E. Scheurer, Olga A. Taylor, Austin L. Brown, Julienne Brackett, ZoAnne E. Dreyer, Ida (Ki) Moore, Pauline Mitby, Mary C. Hooke, Philip J. Lupo, Marilyn J. Hockenberry. Ethnic-specific risk of neurotoxocity and its impact on treatment outcomes among pediatric patients receiving acute lymphoblastic leukemia therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2967.

Abstract 222: Genome-wide association study of acute lymphoblastic leukemia in children with Down syndrome

Purpose: Children with Down syndrome (DS) have a 20-fold increased risk of acute lymphoblastic leukemia (ALL) compared to children without DS. While genome-wide association studies (GWAS) have identified several susceptibility loci in childhood ALL, studies of ALL in children with DS are lacking. Therefore, we conducted the first GWAS of DS-ALL.

Methods: We analyzed independent cohorts of: 1) 226 newly diagnosed DS-ALL cases from Children's Oncology Group (COG) ALL trials (2000-2013) and 436 DS controls from the National Down Syndrome Project (NDSP), 2) 124 additional COG ALL cases (2011-2015) and 336 additional NDSP DS controls, 3) 20 DS-ALL cases and 275 DS controls from Michigan neonatal bloodspots, and 4) 157 DS-ALL cases and 145 DS controls largely from neonatal bloodspots from California and Washington. Genotyping was performed with Affymetrix or Illumina single nucleotide polymorphism (SNP) arrays. STRUCTURE software was used to define European (372 cases, 1,056 controls), Hispanic (140 cases, 136 controls), and African (15 cases, 62 controls) genetic ancestry. After genome-wide imputation and quality control, ancestry- and cohort-specific associations were evaluated at &gt;6,000,000 autosomal SNPs with minor allele frequency ≥1%. Associations were meta-analyzed across cohort and ancestry groups, assuming additive allelic effects.

Results: Genome-wide significant (p&lt;5x10-8) association signals were identified for known ALL susceptibility loci, including rs58923657 near IKZF1 (Odds Ratio [OR]=2.02, p=5.32x10-15), CDKN2A missense mutation rs3731249 (OR=3.63, p=3.91x10-10), rs3781093 near GATA3 (OR=1.73, p=2.89x10-8), and rs7090445 near ARID5B (OR=1.57, p=2.93x10-8). A novel potential risk locus was identified at chromosome 20q11.21 (rs78019519, OR=3.17, p=5.11x10-7) with consistent effects observed across each cohort and ancestry group. This SNP is in the promoter region of the oncogene TPX2 and is also associated with expression of HM13 in whole blood in the Genotype-Tissue Expression (GTEx) Portal.

Conclusion: We confirmed that known ALL susceptibility loci in children without DS, including IKZF1, CDKN2A, GATA3, PIP4K2A and ARID5B, also confer risk of ALL in children with DS, with CDKN2A showing the largest effect size. We also identified a potentially novel locus associated with ALL susceptibility in DS at chromosome 20q11.21. Additional investigation of these loci is ongoing and may advance our understanding of DS-ALL etiology and biology.

Citation Format: Austin L. Brown, Adam J. de Smith, Michael E. Scheurer, Noah A. Kallsen, Shanna A. Peyton, Gareth E. Davies, Erik A. Ehli, Michael E. Zwick, Naomi Winick, Kelly Maloney, Anne L. Angiolillo, Reuven Schore, MIchael M. Burke, Wanda L. Salzer, Nyla A. Heerema, Andrew J. Carroll, Michael J. Borowitz, Brent L. Wood, William L. Carroll, Elizabeth A. Raetz, Elanor Feingold, Stephanie L. Sherman, Wenjian Yang, Meenakshi Devidas, Kyle Walsh, Andrew T. DeWan, Maria S. Pombo-de-Oliveira, Jeffrey W. Taub, Daniel Sinnett, Jasmine Healy, Jillian M. Birch, Lisa F. Barcellos, Helen Hansen, Ivan Smirnov, Charles G. Mullighan, Stephen P. Hunger, Ching-Hon Pui, Mignon Loh, Joe L. Wiemels, Xiaomei Ma, Catherine Metayer, Beth A. Mueller, Mary V. Relling, Jun J. Yang, Philip J. Lupo, Karen R. Rabin. Genome-wide association study of acute lymphoblastic leukemia in children with Down syndrome [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 222.

DNA methylation of a novel PAK4 locus influences ototoxicity susceptibility following cisplatin and radiation therapy for pediatric embryonal tumors

Background

Ototoxicity is a common adverse side effect of platinum chemotherapy and cranial radiation therapy; however, individual susceptibility is highly variable. Therefore, our objective was to conduct an epigenome-wide association study to identify differentially methylated cytosine-phosphate-guanine (CpG) sites associated with ototoxicity susceptibility among cisplatin-treated pediatric patients with embryonal tumors.

Methods

Samples were collected for a discovery cohort (n = 62) and a replication cohort (n = 18) of medulloblastoma and primitive neuroectodermal tumor patients. Posttreatment audiograms were evaluated using the International Society of Paediatric Oncology (SIOP) Boston Ototoxicity Scale. Genome-wide associations between CpG methylation and ototoxicity were examined using multiple linear regression, controlling for demographic and treatment factors.

Results

The mean cumulative dose of cisplatin was 330 mg/m2 and the mean time from end of therapy to the last available audiogram was 6.9 years. In the discovery analysis of 435233 CpG sites, 6 sites were associated with ototoxicity grade (P < 5 × 10-5) after adjusting for confounders. Differential methylation at the top CpG site identified in the discovery cohort (cg14010619, PAK4 gene) was replicated (P = 0.029) and reached genome-wide significance (P = 2.73 × 10-8) in a combined analysis. These findings were robust to a sensitivity analysis evaluating other potential confounders.

Conclusions

We identified and replicated a novel CpG methylation loci (cg14010619) associated with ototoxicity severity. Methylation at cg14010619 may modify PAK4 activity, which has been implicated in cisplatin resistance in malignant cell lines.

Aerobic method for the synthesis of nearly size-monodisperse bismuth nanoparticles from a redox non-innocent precursor

Herein, we report an aerobic synthesis method to produce bismuth nanoparticles (Bi NPs) with average diameters in the range 40-80 nm using commercially available bismuth triiodide (BiI₃) as the starting material; the method uses only readily available chemicals and conventional laboratory equipment. Furthermore, size data from replicates of the synthesis under standard reaction conditions indicate that this method is highly reproducible in achieving Bi NP populations with low standard deviations in the mean diameters. We also investigated the mechanism of the reaction, which we determined results from the reduction of a soluble alkylammonium iodobismuthate precursor species formed in situ. Under appropriate concentration conditions of iodobismuthate anion, we demonstrate that burst nucleation of Bi NPs results from reduction of Bi³⁺ by the coordinated, redox non-innocent iodide ligands when a threshold temperature is exceeded. Finally, we demonstrate phase transfer and silica coating of the Bi NPs, which results in stable aqueous colloids with retention of size, morphology, and colloidal stability. The resultant, high atomic number, hydrophilic Bi NPs prepared using this synthesis method have potential for application in emerging x-ray contrast and x-ray therapeutic applications.

Genome-wide discovery of novel susceptibility loci for treatment-associated hypothyroidism among survivors of pediatric medulloblastoma

10571

Background: Pediatric medulloblastoma patients exposed to craniospinal radiation (CSI) are at high risk of developing endocrinopathies, including hypothyroidism. We sought to evaluate the role of genetic variation on hypothyroidism susceptibility among survivors of pediatric medullobastoma. Methods: Records from 61 medulloblastoma survivors treated at Texas Children’s Hospital between 1997 and 2013 were reviewed. All patients completed baseline and yearly follow-up thyroid assessments. Genome-wide genotyping was performed on Illumina HumanOmni1 and HumanOmni2.5 BeadChip single nucleotide polymorphism (SNP) arrays. Following standard quality control measures and exclusion of rare variants (minor allele frequency [MAF] < 5%), 572,562 autosomal SNPs were included in our analyses. The association between each SNP and hypothyroidism was tested using Fisher’s exact test and logistic regression, assuming additive allelic effects. Results: A total of 25 patients (41%) developed hypothyroidism with median follow-up of 8.3 years from diagnosis (range: 1.8-17.2 years). Primary hypothyroidism was identified in 9 (36%) cases, while the remaining 16 (64%) developed central hypothyroidism. Hypothyroidism was detected in 13 of 40 (33%) individuals exposed to < 30 Gy CSI and 12 of 21 (57%) individuals exposed to ≥30 Gy CSI (p = 0.06). Genome-wide association analysis identified several risk loci, including 3 variants associated with hypothyroidism (p-value < 1x10-5) at chromosome 2q11.2 ( NPAS2 gene). The top overall SNP (MAF = 27.5%, p-value = 6.5x10-7) remained strongly associated with hypothyroidism after accounting for possible confounders, including CSI dose, CSI type (proton/photon), age, sex, and genetic ancestry. Conclusions: Our findings suggest susceptibility to treatment-related hypothyroidism is strongly influenced by common genetic variation in NPAS2. The NPAS2 gene, a central component of the circadian rhythm network, is a transcriptional activator and regulator of DNA damage response and DNA repair genes.

Evaluation of maternal and perinatal characteristics on childhood lymphoma risk: A population-based case-control study

BACKGROUND

Lymphoma is one of the most common pediatric malignancies; however, there are few well-established risk factors. Therefore, we investigated if maternal and perinatal characteristics influenced the risk of childhood lymphoma.

PROCEDURE

Information on cases (n = 374) diagnosed with lymphoma and born in Texas for the period 1995-2011 was obtained from the Texas Cancer Registry. Birth certificate controls were randomly selected at a ratio of 10 controls per 1 case for the same period of 1995-2011. Unconditional logistic regression was used to generate unadjusted (OR) and adjusted odds ratios (aOR) and 95% confidence intervals (CI) for the following histologic subtypes: Hodgkin (HL), Burkitt (BL), and non-BL non-HLs (non-BL NHLs).

RESULTS

Overall, our findings indicate specific maternal and perinatal characteristics influence childhood lymphoma risk. Mexico-born mothers were more likely to have offspring who developed BL compared to mothers born in the United States (U.S.; aOR: 2.15; 95% CI: 1.06-4.36). Further, mothers who resided at time of delivery in a county on the U.S.-Mexico border were more likely to give birth to offspring who developed non-BL NHL (aOR: 1.72; 95% CI: 1.11-2.67) compared to mothers not living on the U.S.-Mexico border at time of infant birth. Last, infants born large-for-gestational-age experienced a twofold increase in BL risk (aOR: 2.00; 95% CI: 1.10-3.65).

CONCLUSIONS

In this population-based assessment, we confirmed previously reported risk predictors of childhood lymphoma, including sex of infant, while highlighting novel risk factors that warrant assessment in future studies.