Autoimmune and Metabolic Diseases and the Risk of Early-Onset Colorectal Cancer, a Nationwide Nested Case-Control Study.

Incidence of early-onset (<50 years) colorectal cancer (EOCRC) is increasing in developed countries. The aim was to investigate autoimmune and metabolic conditions as risk factors for EOCRC. In a nationwide nested case-control study, we included all EOCRC cases in Sweden diagnosed during 2007-2016, together with controls, matched for birth year, sex, and county. Information on exposure of autoimmune or metabolic disease was collected from the National Patient Register and Prescribed Drugs Registry. Hazard ratios (HR) as measures of the association between EOCRC and the exposures were estimated using conditional logistic regression. In total, 2626 EOCRC patients and 15,756 controls were included. A history of metabolic disease nearly doubled the incidence hazard of EOCRC (HR 1.82, 95% CI 1.66-1.99). A sixfold increased incidence hazard of EOCRC (HR 5.98, 95% CI 4.78-7.48) was seen in those with inflammatory bowel disease (IBD), but the risk increment decreased in presence of concomitant metabolic disease (HR 3.65, 95% CI 2.57-5.19). Non-IBD autoimmune disease was not statistically significantly associated with EOCRC. IBD and metabolic disease are risk factors for EOCRC and should be considered in screening guidelines.

Acute central nervous system toxicity during treatment of pediatric acute lymphoblastic leukemia: phenotypes, risk factors and genotypes.

Central nervous system (CNS) toxicity is common at diagnosis and during treatment of pediatric acute lymphoblastic leukemia (ALL). We studied CNS toxicity in 1,464 children aged 1.0-17.9 years, diagnosed with ALL and treated according to the Nordic Society of Pediatric Hematology and Oncology ALL2008 protocol. Genome-wide association studies, and a candidate single-nucleotide polymorphism (SNP; n=19) study were performed in 1,166 patients. Findings were validated in an independent Australian cohort of children with ALL (n=797) in whom two phenotypes were evaluated: diverse CNS toxicities (n=103) and methotrexate-related CNS toxicity (n=48). In total, 135/1,464 (9.2%) patients experienced CNS toxicity for a cumulative incidence of 8.7% (95% confidence interval: 7.31-10.20) at 12 months from diagnosis. Patients aged ≥10 years had a higher risk of CNS toxicity than had younger patients (16.3% vs. 7.4%; P<0.001). The most common CNS toxicities were posterior reversible encephalopathy syndrome (n=52, 43 with seizures), sinus venous thrombosis (n=28, 9 with seizures), and isolated seizures (n=16). The most significant SNP identified by the genome-wide association studies did not reach genomic significance (lowest P-value: 1.11x10-6), but several were annotated in genes regulating neuronal functions. In candidate SNP analysis, ATXN1 rs68082256, related to epilepsy, was associated with seizures in patients <10 years (P=0.01). ATXN1 rs68082256 was validated in the Australian cohort with diverse CNS toxicities (P=0.04). The role of ATXN1 as well as the novel SNP in neurotoxicity in pediatric ALL should be further explored.

Optical Coherence Tomography Identifies Visual Pathway Involvement Earlier than Visual Function Tests in Children with MRI-Verified Optic Pathway Gliomas.

This study investigates whether optical coherence tomography (OCT) could add useful information in the examination of children with optic pathway glioma (OPG) at high risk of developing vision loss. For this purpose, the relationship between ganglion cell-inner plexiform layer (GC-IPL) thickness and visual function, evaluated with tests of visual acuity (VA) and visual field (VF), as well as tumor site according to magnetic resonance imaging (MRI), were examined in a geographically defined group of children with OPG. METHODS: Children aged <18 years with OPG underwent ophthalmic examination including VA, VF (Zeiss HFA perimetry) and OCT imaging (Zeiss Cirrus HD-OCT). RESULTS: Out of 51 patients included, 45 provided 77 eyes with MRI-verified OPG, and 19 patients provided 25 eyes without OPG. Significant correlations were found between GC-IPL, VF and VA (p < 0.001). The GC-IPL pattern loss corresponded in 95% to VF defects and in 92% to MRI findings. CONCLUSIONS: Our study indicates that GC-IPL measures could serve as an early marker of vision-threatening changes related to OPG and as a valuable link between MRI and visual function tests. Thinning of GC-IPL and differences in topography between eyes are strong indicators of and predictive of vision loss related to OPG.

Seizures during treatment of childhood acute lymphoblastic leukemia: A population-based cohort study.

BACKGROUND: Seizures are common in children with acute lymphoblastic leukemia (ALL). As ALL survival rates are improving, the challenge to minimize treatment related side effects and late sequelae rises. Here, we studied the frequency, timing, etiology and risk factors of seizures in ALL patients. METHODS: The study included children aged 1-17.9 years at diagnosis of B-cell-precursor and T cell ALL who were treated according to the Nordic Society of Pediatric Hematology and Oncology (NOPHO) ALL2008 protocol between 2008 and 2015. Detailed patient data were acquired from the NOPHO ALL2008 registry and by review of medical records. RESULTS: Seizures occurred in 81/1464 (5.5%) patients. The cumulative incidence of seizures at one months was 1.7% (95% CI: 1.2-2.5) and at one year 5.3% (95% CI 4.2-6.5%). Patients aged 10-17.9 years, those with T cell immunophenotype, CNS involvement, or high-risk induction with dexamethasone had higher risk for seizures in univariable analyses. Only age remained a risk factor in multivariable analyses (the cumulative incidence of seizures for patients 10-17.9 years old at one year was 9.0% (95% CI: 6.2-12.9)). Of the 81 patients with seizures, 43 had posterior reversible encephalopathy syndrome (PRES), 15 had isolated seizures, nine had sinus venous thrombosis (SVT), three had stroke-like syndrome, and 11 had other neurotoxicities. Epilepsy diagnosis was reported in totally 11 ALL survivors at last follow up. CONCLUSION: Seizures are relatively common in ALL patients and occur most often in patients with PRES, SVT, or as an isolated symptom. Older children have higher risk of seizures.

The Role of TPMT, ITPA, and NUDT15 Variants during Mercaptopurine Treatment of Swedish Pediatric Patients with Acute Lymphoblastic Leukemia.

OBJECTIVE: To evaluate the roles of thiopurine methyltransferase (TPMT), inosine triphosphatase (ITPA), and Nudix hydrolase 15 (NUDT15) in 6-mercaptopurine (6-MP) sensitivity during treatment of pediatric patients with acute lymphoblastic leukemia (ALL). STUDY DESIGN: The study included 102 pediatric patients with ALL subject to the Nordic society Of Paediatric Haematology and Oncology (NOPHO) ALL-2000 and ALL-2008 protocols. Episodes of neutropenia and febrile neutropenia, TPMT sequence variants, as well as 6-MP end doses, were collected retrospectively from medical records. TPMT, ITPA, and NUDT15 sequence variants were analyzed using pyrosequencing. RESULTS: TPMT variants were associated with a reduced risk of neutropenia and febrile neutropenia during the maintenance II period (P = .019 and P < .0001, respectively). In addition, a NUDT15 variant was associated with a lower end dose of 6-MP (P = .0097), but not with neutropenia and febrile neutropenia. ITPA variants were not associated with an increased risk of neutropenia, febrile neutropenia, nor lower end dose of 6-MP. However, when analyzing the entire treatment period, ITPA variants were associated with a decreased risk of febrile neutropenia. CONCLUSIONS: White blood cell count-based dose adjustments are regularly performed for known TPMT- deficient patients and results in a reduced risk of neutropenia and febrile neutropenia. Also in NUDT15-deficient patients dose adjustments are performed as indicated by low end dose of 6-MP. ITPA-deficient patients had a decreased risk of febrile neutropenia when analyzing the entire treatment period. Our data suggest that NUDT15 plays an important role in 6-MP treatment and the results should be confirmed in larger cohorts. Future studies should also follow up whether white blood cell count-based dose adjustments affect the risk of relapse.

Altered proportions of circulating CXCR5+ helper T cells do not dampen influenza vaccine responses in children with rheumatic disease.

Biological therapy options for the treatment of rheumatic disease target molecules that can affect the cross-talk between innate and adaptive immune responses upon vaccination. Influenza vaccination in children with rheumatic disease has been recommended, but there are only sparse data on the quality of vaccine responses from pediatric patients treated with biological therapy. We conducted an influenza vaccine study over 3 consecutive seasons where the antibody response to TIV was evaluated in children with PRD (n = 78), including both non-treated (n = 17) and treated (with methotrexate, TNF-inhibitors with or without methotrexate, or IL-inhibitors, n = 61) children as well as healthy age-matched controls (n = 24). Peripheral B cells, T and NK cell populations, as well as CXCR5+ (follicular) helper T cells (TFH) and chemokines involved in antibody responses were assessed prior to immunization in the same cohort. Data on disease duration, therapy and data on previous influenza vaccinations were retrieved. The proportion of circulating TFH cells were significantly lower in non-treated children with PRD compared to treated patients and healthy controls. The significantly lower proportion of TFH cells was mirrored by a marked significant increase in CXCL13 serum level, the ligand for CXCR5, with higher levels in non-treated children with PRD compared to treated patients and healthy controls. However, the proportion of TFH cells or CXCL13 level at the time of vaccination was not a predictor of the antibody response to TIV in this cohort of children. Children with PRD had an overall similar response to TIV as healthy children. Although not significant, children treated with TNF-inhibitors differed as a few children remained seronegative towards H3N2- and influenza B viruses after immunization. Our data show that children with PRD respond to TIV as healthy children. Furthermore, plasma CXCL13 levels did not correlate to the proportion of TFH cells in blood prior to immunisation, or to antibody responses following immunization.

Posterior reversible encephalopathy syndrome in children with acute lymphoblastic leukemia: Clinical characteristics, risk factors, course, and outcome of disease.

BACKGROUND: Posterior reversible encephalopathy syndrome (PRES) is a distinct entity with incompletely known predisposing factors. The aim of this study is to describe the incidence, risk factors, clinical course, and outcome of PRES in childhood acute lymphoblastic leukemia (ALL). PROCEDURE: Patients aged 1.0 to 17.9 years diagnosed with ALL from July 2008 to December 2015 and treated according to the Nordic Society of Pediatric Hematology and Oncology (NOPHO) ALL2008 protocol were included. Patients with PRES were identified in the prospective NOPHO leukemia toxicity registry, and clinical data were collected from the medical records. RESULTS: The study group included 1378 patients, of whom 52 met the criteria for PRES. The cumulative incidence of PRES at one month was 1.7% (95% CI, 1.1-2.5) and at one year 3.7% (95% CI, 2.9-4.9). Older age (hazard ratios [HR] for each one-year increase in age 1.1; 95% CI, 1.0-1.2, P = 0.001) and T-cell immunophenotype (HR, 2.9; 95% CI, 1.6-5.3, P = 0.0005) were associated with PRES. Central nervous system (CNS) involvement (odds ratios [OR] = 2.8; 95% CI, 1.2-6.5, P = 0.015) was associated with early PRES and high-risk block treatment (HR = 2.63; 95% CI, 1.1-6.4, P = 0.033) with late PRES. At follow-up of the PRES patients, seven patients had epilepsy and seven had neurocognitive difficulties. CONCLUSION: PRES is a neurotoxicity in the treatment of childhood ALL with both acute and long-term morbidity. Older age, T-cell leukemia, CNS involvement and high-risk block treatment are risk factors for PRES.

Low-level expression of SAMHD1 in acute myeloid leukemia (AML) blasts correlates with improved outcome upon consolidation chemotherapy with high-dose cytarabine-based regimens.

Sterile alpha motif and histidine/aspartic acid domain containing protein 1 (SAMHD1) limits the efficacy of cytarabine (ara-C) used in AML by hydrolyzing its active metabolite ara-CTP and thus represents a promising therapeutic target. SAMHD1 has also been implicated in DNA damage repair that may impact DNA damage-inducing therapies such as anthracyclines, during induction therapy. To determine whether SAMHD1 limits ara-C efficacy during induction or consolidation therapy, SAMHD1 protein levels were assessed in two patient cohorts of de novo AML from The University of Texas MD Anderson Cancer Center (USA) and the National University Hospital (Singapore), respectively, using immunohistochemistry and tissue microarrays. SAMHD1 was expressed at a variable level by AML blasts but not in a broad range of normal hematopoietic cells in reactive bone marrows. A sizeable patient subset with low SAMHD1 expression (<25% of positive blasts) was identified, which was significantly associated with longer event-free (EFS) and overall (OS) survival in patients receiving high-dose cytarabine (HDAC) during consolidation. Therefore, evaluation of SAMHD1 expression level in AML blasts at diagnosis, may stratify patient groups for future clinical trials combining HDAC with novel SAMHD1 inhibitors as consolidation therapy.

Comparing osteonecrosis clinical phenotype, timing, and risk factors in children and young adults treated for acute lymphoblastic leukemia.

BACKGROUND: Treatment-related osteonecrosis (ON) is a serious complication of treatment of acute lymphoblastic leukemia (ALL). PROCEDURE: This study included 1,489 patients with ALL, aged 1-45 years, treated according to the Nordic Society of Paediatric Haematology and Oncology ALL2008 protocol, using alternate-week dexamethasone during delayed intensification, with prospective registration of symptomatic ON. We aimed at comparing risk factors, timing, and clinical characteristics of ON in children and young adults. RESULTS: ON was diagnosed in 67 patients, yielding a 5-year cumulative incidence of 6.3%, but 28% in female adolescents. Median age at ALL diagnosis was 12.1 years and 14.9 years for females and males, respectively. At ON diagnosis, 59 patients had bone pain (91%) and 30 (46%) had multiple-joint involvement. The median interval between ALL and ON diagnosis was significantly shorter in children aged 1.0-9.9 years (0.7 years [range: 0.2-2.1]) compared with adolescents (1.8 years [range: 0.3-3.7, P < 0.001]) and adults (2.1 years [range: 0.4-5.3, P = 0.001]). Female sex was a risk factor in adolescent patients (hazard ratio [HR] = 2.1, 95% confidence interval [CI]: 1.1-4.2) but not in children aged 1.1-9.9 years (HR = 2.4, 95% CI: 0.9-6.2, P = 0.08) or adults aged 19-45 years (HR = 1.1, 95% CI: 0.3-4.0). Age above 10 years at ALL diagnosis (odds ratio [OR] = 3.7, P = 0.026) and multiple joints affected at ON diagnosis (OR = 3.4, P = 0.027) were risk factors for developing severe ON. CONCLUSION: We provide a detailed phenotype of patients with ALL with symptomatic ON, including description of risk factors and timing of ON across age groups. This awareness is essential in exploring measures to prevent development of ON.

Treatment-related mortality in relapsed childhood acute lymphoblastic leukemia.

BACKGROUND: Treatment of relapsed childhood acute lymphoblastic leukemia (ALL) is particularly challenging due to the high treatment intensity needed to induce and sustain a second remission. To improve results, it is important to understand how treatment-related toxicity impacts survival. PROCEDURE: In this retrospective population-based study, we described the causes of death and estimated the risk for treatment-related mortality in patients with first relapse of childhood ALL in the Nordic Society of Paediatric Haematology and Oncology ALL-92 and ALL-2000 trials. RESULTS: Among the 483 patients who received relapse treatment with curative intent, we identified 52 patients (10.8%) who died of treatment-related causes. Twelve of these died before achieving second remission and 40 died in second remission. Infections were the cause of death in 38 patients (73.1%), predominantly bacterial infections during the chemotherapy phases of the relapse treatment. Viral infections were more common following hematopoietic stem cell transplantation (HSCT) in second remission. Independent risk factors for treatment-related mortality were as follows: high-risk stratification at relapse (hazard ratio [HR] 2.2; 95% confidence interval [CI] 1.3-3.9; P < 0.01), unfavorable cytogenetic aberrations (HR 3.4; 95% CI 1.3-9.2; P = 0.01), and HSCT (HR 4.64; 95% CI 2.17-9.92; P < 0.001). In contrast to previous findings, we did not observe any statistically significant sex or age differences. Interestingly, none of the 17 patients with Down syndrome died of treatment-related causes. CONCLUSIONS: Fatal treatment complications contribute significantly to the poor overall survival after relapse. Implementation of novel therapies with reduced toxicity and aggressive supportive care management are important to improve survival in relapsed childhood ALL.

With me or against me: Tumor suppressor and drug resistance activities of SAMHD1.

Sterile alpha motif and histidine/aspartic acid domain-containing protein 1 (SAMHD1) is a (deoxy)guanosine triphosphate (dGTP/GTP)-activated deoxyribonucleoside triphosphate (dNTP) triphosphohydrolase involved in cellular dNTP homoeostasis. Mutations in SAMHD1 have been associated with the hyperinflammatory disease Aicardi-Goutières syndrome (AGS). SAMHD1 also limits cells' permissiveness to infection with diverse viruses, including human immunodeficiency virus (HIV-1), and controls endogenous retroviruses. Increasing evidence supports the role of SAMHD1 as a tumor suppressor. However, SAMHD1 also can act as a resistance factor to nucleoside-based chemotherapies by hydrolyzing their active triphosphate metabolites, thereby reducing response of various malignancies to these anticancer drugs. Hence, informed cancer therapies must take into account the ambiguous properties of SAMHD1 as both an inhibitor of uncontrolled proliferation and a resistance factor limiting the efficacy of anticancer treatments. Here, we provide evidence that SAMHD1 is a double-edged sword for patients with acute myelogenous leukemia (AML). Our time-dependent analyses of The Cancer Genome Atlas (TCGA) AML cohort indicate that high expression of SAMHD1, even though it critically limits the efficacy of high-dose ara-C therapy, might be associated with more favorable disease progression.

Targeting SAMHD1 with the Vpx protein to improve cytarabine therapy for hematological malignancies.

The cytostatic deoxycytidine analog cytarabine (ara-C) is the most active agent available against acute myelogenous leukemia (AML). Together with anthracyclines, ara-C forms the backbone of AML treatment for children and adults. In AML, both the cytotoxicity of ara-C in vitro and the clinical response to ara-C therapy are correlated with the ability of AML blasts to accumulate the active metabolite ara-C triphosphate (ara-CTP), which causes DNA damage through perturbation of DNA synthesis. Differences in expression levels of known transporters or metabolic enzymes relevant to ara-C only partially account for patient-specific differential ara-CTP accumulation in AML blasts and response to ara-C treatment. Here we demonstrate that the deoxynucleoside triphosphate (dNTP) triphosphohydrolase SAM domain and HD domain 1 (SAMHD1) promotes the detoxification of intracellular ara-CTP pools. Recombinant SAMHD1 exhibited ara-CTPase activity in vitro, and cells in which SAMHD1 expression was transiently reduced by treatment with the simian immunodeficiency virus (SIV) protein Vpx were dramatically more sensitive to ara-C-induced cytotoxicity. CRISPR-Cas9-mediated disruption of the gene encoding SAMHD1 sensitized cells to ara-C, and this sensitivity could be abrogated by ectopic expression of wild-type (WT), but not dNTPase-deficient, SAMHD1. Mouse models of AML lacking SAMHD1 were hypersensitive to ara-C, and treatment ex vivo with Vpx sensitized primary patient-derived AML blasts to ara-C. Finally, we identified SAMHD1 as a risk factor in cohorts of both pediatric and adult patients with de novo AML who received ara-C treatment. Thus, SAMHD1 expression levels dictate patient sensitivity to ara-C, providing proof-of-concept that the targeting of SAMHD1 by Vpx could be an attractive therapeutic strategy for potentiating ara-C efficacy in hematological malignancies.