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Foss-Skiftesvik J, Li S, Rosenbaum A, Hagen CM, Stoltze UK, Ljungqvist S, Hjalmars U, Schmiegelow K, Morimoto L, de Smith AJ, Mathiasen R, Metayer C, Hougaard D, Melin B, Walsh KM, Bybjerg-Grauholm J, Dahlin AM, Wiemels JL. Multi-ancestry genome-wide association study of 4069 children with glioma identifies 9p21.3 risk locus. Neuro Oncol 2023; 25:1709-1720. [PMID: 36810956 PMCID: PMC10484172 DOI: 10.1093/neuonc/noad042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Indexed: 02/24/2023] Open
Abstract
BACKGROUND Although recent sequencing studies have revealed that 10% of childhood gliomas are caused by rare germline mutations, the role of common variants is undetermined and no genome-wide significant risk loci for pediatric central nervous system tumors have been identified to date. METHODS Meta-analysis of 3 population-based genome-wide association studies comprising 4069 children with glioma and 8778 controls of multiple genetic ancestries. Replication was performed in a separate case-control cohort. Quantitative trait loci analyses and a transcriptome-wide association study were conducted to assess possible links with brain tissue expression across 18 628 genes. RESULTS Common variants in CDKN2B-AS1 at 9p21.3 were significantly associated with astrocytoma, the most common subtype of glioma in children (rs573687, P-value of 6.974e-10, OR 1.273, 95% CI 1.179-1.374). The association was driven by low-grade astrocytoma (P-value of 3.815e-9) and exhibited unidirectional effects across all 6 genetic ancestries. For glioma overall, the association approached genome-wide significance (rs3731239, P-value of 5.411e-8), while no significant association was observed for high-grade tumors. Predicted decreased brain tissue expression of CDKN2B was significantly associated with astrocytoma (P-value of 8.090e-8). CONCLUSIONS In this population-based genome-wide association study meta-analysis, we identify and replicate 9p21.3 (CDKN2B-AS1) as a risk locus for childhood astrocytoma, thereby establishing the first genome-wide significant evidence of common variant predisposition in pediatric neuro-oncology. We furthermore provide a functional basis for the association by showing a possible link to decreased brain tissue CDKN2B expression and substantiate that genetic susceptibility differs between low- and high-grade astrocytoma.
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Affiliation(s)
- Jon Foss-Skiftesvik
- Department of Neurosurgery, Rigshospitalet University Hospital, Copenhagen, Denmark
- Department of Pediatrics and Adolescent Medicine, Rigshospitalet University Hospital, Copenhagen, Denmark
- Section for Neonatal Genetics, Statens Serum Institute, Copenhagen, Denmark
| | - Shaobo Li
- Center for Genetic Epidemiology, Department of Population and Public Health Sciences, University of Southern California, Los Angeles, California, USA
| | - Adam Rosenbaum
- Department of Radiation Sciences, Oncology, Umeå University, Umeå, Sweden
| | | | - Ulrik Kristoffer Stoltze
- Department of Pediatrics and Adolescent Medicine, Rigshospitalet University Hospital, Copenhagen, Denmark
- Department of Clinical Genetics, Rigshospitalet University Hospital, Copenhagen, Denmark
| | - Sally Ljungqvist
- Department of Radiation Sciences, Oncology, Umeå University, Umeå, Sweden
| | - Ulf Hjalmars
- Department of Radiation Sciences, Oncology, Umeå University, Umeå, Sweden
| | - Kjeld Schmiegelow
- Department of Pediatrics and Adolescent Medicine, Rigshospitalet University Hospital, Copenhagen, Denmark
| | - Libby Morimoto
- Center for Personalized Medicine, Children’s Hospital of Los Angeles, Los Angeles, California, USA
| | - Adam J de Smith
- Center for Genetic Epidemiology, Department of Population and Public Health Sciences, University of Southern California, Los Angeles, California, USA
| | - René Mathiasen
- Department of Pediatrics and Adolescent Medicine, Rigshospitalet University Hospital, Copenhagen, Denmark
| | - Catherine Metayer
- School of Public Health, University of California, Berkeley, Berkeley, California, USA
| | - David Hougaard
- Section for Neonatal Genetics, Statens Serum Institute, Copenhagen, Denmark
| | - Beatrice Melin
- Department of Radiation Sciences, Oncology, Umeå University, Umeå, Sweden
| | - Kyle M Walsh
- Division of Neuro-Epidemiology, Department of Neurosurgery, Duke University, Durham, North Carolina, USA
| | | | - Anna M Dahlin
- Department of Radiation Sciences, Oncology, Umeå University, Umeå, Sweden
| | - Joseph L Wiemels
- Center for Genetic Epidemiology, Department of Population and Public Health Sciences, University of Southern California, Los Angeles, California, USA
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Dahlin AM, Wibom C, Andersson U, Bybjerg-Grauholm J, Deltour I, Hougaard DM, Scheurer ME, Lau CC, McKean-Cowdin R, Kennedy RJ, Hung LT, Yee J, Margol AS, Barrington-Trimis J, Gauderman WJ, Feychting M, Schüz J, Röösli M, Kjaerheim K, Januszkiewicz-Lewandowska D, Fichna M, Nowak J, Searles Nielsen S, Asgharzadeh S, Mirabello L, Hjalmars U, Melin B. A genome-wide association study on medulloblastoma. J Neurooncol 2020; 147:309-315. [PMID: 32056145 PMCID: PMC7136185 DOI: 10.1007/s11060-020-03424-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Accepted: 02/03/2020] [Indexed: 12/21/2022]
Abstract
INTRODUCTION Medulloblastoma is a malignant embryonal tumor of the cerebellum that occurs predominantly in children. To find germline genetic variants associated with medulloblastoma risk, we conducted a genome-wide association study (GWAS) including 244 medulloblastoma cases and 247 control subjects from Sweden and Denmark. METHODS Genotyping was performed using Illumina BeadChips, and untyped variants were imputed using IMPUTE2. RESULTS Fifty-nine variants in 11 loci were associated with increased medulloblastoma risk (p < 1 × 10-5), but none were statistically significant after adjusting for multiple testing (p < 5 × 10-8). Thirteen of these variants were genotyped, whereas 46 were imputed. Genotyped variants were further investigated in a validation study comprising 249 medulloblastoma cases and 629 control subjects. In the validation study, rs78021424 (18p11.23, PTPRM) was associated with medulloblastoma risk with OR in the same direction as in the discovery cohort (ORT = 1.59, pvalidation = 0.02). We also selected seven medulloblastoma predisposition genes for investigation using a candidate gene approach: APC, BRCA2, PALB2, PTCH1, SUFU, TP53, and GPR161. The strongest evidence for association was found for rs201458864 (PALB2, ORT = 3.76, p = 3.2 × 10-4) and rs79036813 (PTCH1, ORA = 0.42, p = 2.6 × 10-3). CONCLUSION The results of this study, including a novel potential medulloblastoma risk loci at 18p11.23, are suggestive but need further validation in independent cohorts.
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Affiliation(s)
- Anna M Dahlin
- Department of Radiation Sciences, Oncology, Umeå University, Umeå, Sweden
| | - Carl Wibom
- Department of Radiation Sciences, Oncology, Umeå University, Umeå, Sweden
| | - Ulrika Andersson
- Department of Radiation Sciences, Oncology, Umeå University, Umeå, Sweden
| | - Jonas Bybjerg-Grauholm
- Danish Center for Neonatal Screening, Department for Congenital Disorders, Statens Serum Institut, Copenhagen, Denmark
| | - Isabelle Deltour
- Section of Environment and Radiation, International Agency for Research on Cancer, Lyon, France
- Unit of Statistics, Bioinformatics and Registry, Danish Cancer Society Research Center, Copenhagen, Denmark
| | - David M Hougaard
- Danish Center for Neonatal Screening, Department for Congenital Disorders, Statens Serum Institut, Copenhagen, Denmark
| | - Michael E Scheurer
- Department of Pediatrics, Section of Hematology-Oncology, Texas Children's Cancer Center, Baylor College of Medicine, Houston, TX, USA
| | - Ching C Lau
- Department of Pediatrics, Section of Hematology-Oncology, Texas Children's Cancer Center, Baylor College of Medicine, Houston, TX, USA
| | - Roberta McKean-Cowdin
- Department of Preventive Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Rebekah J Kennedy
- Children's Center for Cancer and Blood Diseases, Children's Hospital Los Angeles, Los Angeles, CA, USA
| | - Long T Hung
- Department of Pediatrics, Section of Hematology-Oncology, Children's Hospital Los Angeles and The Saban Research Institute, Keck School of Medicine of University of Southern California, Los Angeles, CA, USA
| | - Janis Yee
- Department of Pediatrics, Section of Hematology-Oncology, Children's Hospital Los Angeles and The Saban Research Institute, Keck School of Medicine of University of Southern California, Los Angeles, CA, USA
| | - Ashley S Margol
- Department of Pediatrics, Section of Hematology-Oncology, Children's Hospital Los Angeles and The Saban Research Institute, Keck School of Medicine of University of Southern California, Los Angeles, CA, USA
| | - Jessica Barrington-Trimis
- Department of Preventive Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - W James Gauderman
- Department of Preventive Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Maria Feychting
- Unit of Epidemiology, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Joachim Schüz
- Section of Environment and Radiation, International Agency for Research on Cancer, Lyon, France
| | - Martin Röösli
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | | | - Danuta Januszkiewicz-Lewandowska
- Institute of Human Genetics, Polish Academy of Sciences, Poznan, Poland
- Department of Pediatric Oncology, Hematology and Bone Marrow Transplantation, Poznan University of Medical Sciences, Poznan, Poland
| | - Marta Fichna
- Department of Endocrinology, Metabolism and Internal Medicine, Poznan University of Medical Sciences, Poznan, Poland
| | - Jerzy Nowak
- Institute of Human Genetics, Polish Academy of Sciences, Poznan, Poland
| | - Susan Searles Nielsen
- Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
- Department of Neurology, School of Medicine, University of Washington, Seattle, WA, USA
| | - Shahab Asgharzadeh
- Department of Pediatrics, Section of Hematology-Oncology, Children's Hospital Los Angeles and The Saban Research Institute, Keck School of Medicine of University of Southern California, Los Angeles, CA, USA
- Department of Pathology, Saban Research Institute at Children's Hospital Los Angeles, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Lisa Mirabello
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Ulf Hjalmars
- Department of Radiation Sciences, Oncology, Umeå University, Umeå, Sweden
| | - Beatrice Melin
- Department of Radiation Sciences, Oncology, Umeå University, Umeå, Sweden.
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Dahlin AM, Wibom C, Andersson U, Hougaard DM, Bybjerg-Grauholm J, Deltour I, Hultman CM, Kähler AK, Karlsson R, Hjalmars U, Melin B. Genetic Variants in the 9p21.3 Locus Associated with Glioma Risk in Children, Adolescents, and Young Adults: A Case-Control Study. Cancer Epidemiol Biomarkers Prev 2019; 28:1252-1258. [PMID: 31040135 DOI: 10.1158/1055-9965.epi-18-1026] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Revised: 01/07/2019] [Accepted: 04/26/2019] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Genome-wide association studies have identified germline genetic variants in 25 genetic loci that increase the risk of developing glioma in adulthood. It is not known if these variants increase the risk of developing glioma in children and adolescents and young adults (AYA). To date, no studies have performed genome-wide analyses to find novel genetic variants associated with glioma risk in children and AYA. METHODS We investigated the association between 8,831,628 genetic variants and risk of glioma in 854 patients diagnosed up to the age of 29 years and 3,689 controls from Sweden and Denmark. Recruitment of patients and controls was population based. Genotyping was performed using Illumina BeadChips, and untyped variants were imputed with IMPUTE2. We selected 41 established adult glioma risk variants for detailed investigation. RESULTS Three adult glioma risk variants, rs634537, rs2157719, and rs145929329, all mapping to the 9p21.3 (CDKN2B-AS1) locus, were associated with glioma risk in children and AYA. The strongest association was seen for rs634537 (odds ratioG = 1.21; 95% confidence interval = 1.09-1.35; P = 5.8 × 10-4). In genome-wide analysis, an association with risk was suggested for 129 genetic variants (P <1 × 10-5). CONCLUSIONS Carriers of risk alleles in the 9p21.3 locus have an increased risk of glioma throughout life. The results from genome-wide association analyses require validation in independent cohorts. IMPACT Our findings line up with existing evidence that some, although not all, established adult glioma risk variants are associated with risk of glioma in children and AYA. Validation of results from genome-wide analyses may reveal novel susceptibility loci for glioma in children and AYA.
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Affiliation(s)
- Anna M Dahlin
- Department of Radiation Sciences, Oncology, Umeå University, Umeå, Sweden.
| | - Carl Wibom
- Department of Radiation Sciences, Oncology, Umeå University, Umeå, Sweden
| | - Ulrika Andersson
- Department of Radiation Sciences, Oncology, Umeå University, Umeå, Sweden
| | - David M Hougaard
- Department of Congenital Disorders, Danish Centre for Neonatal Screening, Statens Serum Institut, Copenhagen, Denmark
| | - Jonas Bybjerg-Grauholm
- Department of Congenital Disorders, Danish Centre for Neonatal Screening, Statens Serum Institut, Copenhagen, Denmark
| | - Isabelle Deltour
- Section of Environment and Radiation, International Agency for Research on Cancer, Lyon, France
- Unit of Statistics, Bioinformatics and Registry, Danish Cancer Society Research Center, Copenhagen, Denmark
| | - Christina M Hultman
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
- Icahn School of Medicine at Mount Sinai, New York, New York
| | - Anna K Kähler
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
| | - Robert Karlsson
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
| | - Ulf Hjalmars
- Department of Radiation Sciences, Oncology, Umeå University, Umeå, Sweden
| | - Beatrice Melin
- Department of Radiation Sciences, Oncology, Umeå University, Umeå, Sweden
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Dahlin AM, Hollegaard MV, Wibom C, Andersson U, Hougaard DM, Deltour I, Hjalmars U, Melin B. CCND2, CTNNB1, DDX3X, GLI2, SMARCA4, MYC, MYCN, PTCH1, TP53, and MLL2 gene variants and risk of childhood medulloblastoma. J Neurooncol 2015; 125:75-8. [PMID: 26290144 PMCID: PMC4592490 DOI: 10.1007/s11060-015-1891-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Accepted: 08/08/2015] [Indexed: 12/30/2022]
Abstract
Recent studies have described a number of genes that are frequently altered in medulloblastoma tumors and that have putative key roles in the development of the disease. We hypothesized that common germline genetic variations in these genes may be associated with medulloblastoma development. Based on recent publications, we selected 10 genes that were frequently altered in medulloblastoma: CCND2, CTNNB1, DDX3X, GLI2, SMARCA4, MYC, MYCN, PTCH1, TP53, and MLL2 (now renamed as KMT2D). Common genetic variants (single nucleotide polymorphisms) annotating these genes (n = 221) were genotyped in germline DNA (neonatal dried blood spot samples) from 243 childhood medulloblastoma cases and 247 control subjects from Sweden and Denmark. Eight genetic variants annotating three genes in the sonic hedgehog signaling pathway; CCND2, PTCH1, and GLI2, were found to be associated with the risk of medulloblastoma (P(combined) < 0.05). The findings were however not statistically significant following correction for multiple testing by the very stringent Bonferroni method. The results do not support our hypothesis that common germline genetic variants in the ten studied genes are associated with the risk of developing medulloblastoma.
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Affiliation(s)
- Anna M Dahlin
- Department of Radiation Sciences, Oncology, Umeå University, Umeå, Sweden.
| | - Mads V Hollegaard
- Department of Congenital Disorders, Danish Centre for Neonatal Screening, Statens Serum Institut, Copenhagen, Denmark
| | - Carl Wibom
- Department of Radiation Sciences, Oncology, Umeå University, Umeå, Sweden
| | - Ulrika Andersson
- Department of Radiation Sciences, Oncology, Umeå University, Umeå, Sweden
| | - David M Hougaard
- Department of Congenital Disorders, Danish Centre for Neonatal Screening, Statens Serum Institut, Copenhagen, Denmark
| | - Isabelle Deltour
- Section of Environment and Radiation, International Agency for Research on Cancer, Lyon, France
- Unit of Statistics, Bioinformatics and Registry, Danish Cancer Society Research Center, Copenhagen, Denmark
| | - Ulf Hjalmars
- Department of Radiation Sciences, Oncology, Umeå University, Umeå, Sweden
| | - Beatrice Melin
- Department of Radiation Sciences, Oncology, Umeå University, Umeå, Sweden
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Granholm M, Hjalmars U. [Propanolol effective treatment for laryngo-tracheal hemangioma]. Lakartidningen 2013; 110:947-948. [PMID: 23745500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Affiliation(s)
- Markus Granholm
- Barn-och ungdomscentrum, Norrlands universitetssjukhus, Umeå.
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Sjöström S, Hjalmars U, Juto P, Wadell G, Hallmans G, Tjönneland A, Halkjaer J, Manjer J, Almquist M, Melin BS. Human immunoglobulin G levels of viruses and associated glioma risk. Cancer Causes Control 2011; 22:1259-66. [PMID: 21717196 PMCID: PMC3146711 DOI: 10.1007/s10552-011-9799-3] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2011] [Accepted: 06/10/2011] [Indexed: 01/12/2023]
Abstract
Few consistent etiological factors have been identified for primary brain tumors. Inverse associations to asthma and low levels of varicella-zoster virus, immunoglobulin (Ig) levels in prevalent cases have indicted a role for the immune system in the development of glioma. Because samples from prevalent cases of glioma could be influenced by treatments such as steroids and chemotherapy, we investigated pre-diagnostic samples from three large Scandinavian cohorts. To test the hypothesis that immune response levels to these viruses are associated etiologically with glioma risk, we investigated pre-diagnostic immunoglobulin levels for cytomegalovirus (CMV), varicella-zoster virus (VZV), adenovirus (Ad), and Epstein-Barr virus (EBV) including the nuclear antigen (EBNA1) using plasma samples from 197 cases of adult glioma and 394 controls collected from population-based cohorts in Sweden and Denmark. Low VZV IgG levels were marginally significantly more common in glioma cases than the controls (odds ratio (OR) = 0.68, 95% CI 0.41–1.13) for the fourth compared with the first quartile (p = 0.06 for trend). These results were more prominent when analyzing cases with blood sampling at least 2 years before diagnosis (OR = 0.63, 95% CI 0.37–1.08) (p = 0.03). No association with glioma risk was observed for CMV, EBV, and adenovirus.
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Affiliation(s)
- Sara Sjöström
- Department of Radiation Sciences, Oncology, Umeå University, 90187, Umeå, Sweden.
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Ljungman G, Jakobson A, Behrendtz M, Ek T, Friberg LG, Hjalmars U, Hjorth L, Lindh J, Pal N, Sandstedt B, Österlundh G, Gustafsson G. Incidence and survival analyses in children with solid tumours diagnosed in Sweden between 1983 and 2007. Acta Paediatr 2011; 100:750-7. [PMID: 21158910 DOI: 10.1111/j.1651-2227.2010.02122.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
AIM Solid tumours constitute 40% of childhood malignancies. The Swedish Childhood Cancer Registry is population based and includes all children with cancer reported from the six paediatric oncology centres in Sweden. The aim was to investigate incidence and survival. METHODS We used the new WHO ICCC-3 for reclassification of the patients. Incidence and survival analyses were performed in the study population. RESULTS Two thousand four hundred and eighty-seven children (<15 years) were diagnosed with solid tumours in Sweden between 1983 and 2007. The distribution of diagnoses was similar to that reported in other studies. The annual incidence was 65.3 per million children. The survival rates at 10 years of follow-up have improved significantly when comparing the two time periods, 1983-1995 and 1995-2007 (76 vs. 82%; p < 0.01). CONCLUSIONS The mean annual incidence of solid tumours in children was 65.3/million and has been stable during the study period. Survival rates for solid tumours at 5, 10 and 20 years follow-up were 80, 79 and 76%, respectively.
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Affiliation(s)
- Gustaf Ljungman
- Department of Women's and Children's Health, Uppsala University, Sweden.
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Andersson U, McKean-Cowdin R, Hjalmars U, Malmer B. Genetic variants in association studies--review of strengths and weaknesses in study design and current knowledge of impact on cancer risk. Acta Oncol 2009; 48:948-54. [PMID: 19863254 DOI: 10.1080/02841860903124648] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Sequencing of the human genome has recently been completed and mapping of the complete genomic variation is ongoing. During the last decade there has been a huge expansion of studies of genetic variants, both with respect to association studies of disease risk and for studies of genetic factors of prognosis and treatments response, i.e., pharmacogenomics. The use of genetics to predict a patient's risk of disease or treatment response is one step toward an improved personalised prevention and screening modality for the prevention of cancer and treatment selection. The technology and statistical methods for completing whole genome tagging of variants and genome wide association studies has developed rapidly over the last decade. After identifying the genetic loci with the strongest, statistical associations with disease risk, future studies will need to further characterise the genotype-phenotype relationship to provide a biological basis for prevention and treatment decisions according to genetic profile. This review discusses some of the general issues and problems of study design; we also discuss challenges in conducting valid association studies in rare cancers such as paediatric brain tumours, where there is support for genetic susceptibility but difficulties in assembling large sample sizes. The clinical interpretation and implementation of genetic association studies with respect to disease risk and treatment is not yet well defined and remains an important area of future research.
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Affiliation(s)
- U Hjalmars
- Department of Paediatrics Ostersunds Hospital Ostersund, Sweden
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Abstract
The Knox method, as well as other tests for space-time interaction, are biased when there are geographical population shifts, i.e., when there are different percent population growths in different regions. In this paper, the size of the population shift bias is investigated for the Knox test, and it is shown that it can be a considerable problem. A Monte Carlo method for constructing unbiased space-time interaction tests is then presented and illustrated on the Knox test as well as for a combined Knox test. Practical implications are discussed in terms of the interpretation of past results and the design of future studies.
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Affiliation(s)
- M Kulldorff
- Biometry Branch, DCP, National Cancer Institute, Bethesda, Maryland 20892-7354, USA.
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Hjalmars U, Kulldorff M, Wahlqvist Y, Lannering B. Increased incidence rates but no space-time clustering of childhood astrocytoma in Sweden, 1973-1992: a population-based study of pediatric brain tumors. Cancer 1999; 85:2077-90. [PMID: 10223251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
BACKGROUND Incidence patterns, trends, and spatial and/or temporal clustering of childhood brain tumors were analyzed in the population-based national cancer registry of Sweden. METHODS Temporal trends were analyzed by a logistic regression procedure in which the average annual percentages of change in incidence rates and the corresponding 95% confidence intervals (CIs) were calculated. Spatial and/or temporal clustering were investigated by using a geographic information system and analyzed with a modified version of the Knox test and a spatial scan statistic. RESULTS Primary brain tumors in 1223 children ages 0-15 years were registered during 1973-1992. In 80% of cases, the tumor was classified as malignant. Conclusive histopathology was classified in 1142 cases. The age-adjusted incidence rate for all subtypes of brain tumors was 35.9 cases per million children, and for malignant brain tumors 28.6. A statistically significant increasing temporal trend was observed for the group of malignant brain tumors as a whole (P=0.0001) and the astrocytoma subgroup (P=0.0001). The annual average increases were 2.6% (95% CI=1.5-3.8) and 3.0%, respectively (95% CI=1.6-4.4). The increase in astrocytoma cases was significantly larger for girls than for boys (P=0.021) and was most striking for girls ages 6-15 years, with an annual average increase of 4.7%. Rates had not increased for the primitive neuroectodermal tumor (PNET)/medulloblastoma or ependymoma subgroups. The geographic distribution of astrocytoma cases was homogenous. No statistically significant space-time interaction or local clusters in space and/or time were found for astrocytomas only or when astrocytomas were grouped with PNETs/medulloblastomas and ependymomas. CONCLUSIONS The results show statistically increased incidence rates of childhood astroglial tumors, predominantly for girls, in Sweden during the period 1973-1992, but no clustering in space or time.
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Affiliation(s)
- U Hjalmars
- Department of Pediatrics, Ostersunds Hospital, Ostersund, Sweden
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14
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Abstract
A population-based sample of acute childhood leukaemia cases in Sweden 1973-94 was analysed by a geographical information system (GIS) for spatial leukaemia distribution in relation to population density. The annual incidence rate for acute lymphoblastic leukaemia (ALL) was 3.6, and for acute non-lymphoblastic leukaemia (ANLL) 0.7, cases per 100,000 children. Incidence rates in population centres, constituting 1.3% of Sweden's land area and approximately 80% of the population, compared with the rest of Sweden showed a statistically significant excess of ALL [odds ratio (OR) 1.68; 95% confidence interval (CI) 1.44-1.95], but not ANLL (OR 1.13; 95% CI 0.98-1.32). An increasing trend, however not statistically significant, was found for ALL incidence with both increasing population density in parishes and increasing degree of urbanity in municipalities. These findings support the theories that some environmental factors associated with high population density, such as infectious agents, may be of aetiological importance for childhood acute lymphoblastic leukaemia.
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Affiliation(s)
- U Hjalmars
- Department of Pediatrics, Ostersunds Hospital, Sweden
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Abstract
The study of disease clustering is becoming increasingly common in the field of medical epidemiology. There is great public concern and numerous reports on perceived clusters of various diseases, and with cancers, and especially leukaemia, being the most commonly studied. We present a population based study on acute childhood leukaemia in Sweden 1973-1993, illustrating the possibility of a system for full-scale spatial epidemiological study design. The aim of the study is to test a large set of childhood leukaemia cases for the presence of geographical clusters. Necessary prerequisites, in the form of extensive population and disease data, a tool for geographical spatial analysis and a proper statistical method were fulfilled. No significant clusters were found.
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Affiliation(s)
- U Hjalmars
- Department of Paediatrics, Ostersund Central Hospital, Ostersund, Sweden
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Waller LA, Turnbull BW, Gustafsson G, Hjalmars U, Andersson B. Detection and assessment of clusters of disease: an application to nuclear power plant facilities and childhood leukaemia in Sweden. Stat Med 1995; 14:3-16. [PMID: 7701156 DOI: 10.1002/sim.4780140103] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
We review some recent statistical methods for examining geographic patterns of disease incidence for the presence of clusters. General methods search for clusters throughout the study area and then assess the statistical significance of any clusters detected. Focused methods check for elevated incidence rates close to prespecified locations of putative sources of hazard. We apply the methods to leukaemia incidence data for children aged 0-15 years in Sweden (1980-1990), particularly in reference to locations of nuclear power facilities. Unlike some other studies, notably in the United Kingdom, we do not find any significant clusters.
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Affiliation(s)
- L A Waller
- Division of Biostatistics, University of Minnesota, Minneapolis 55455-0392
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Hjalmars U, Kulldorff M, Gustafsson G. Risk of acute childhood leukaemia in Sweden after the Chernobyl reactor accident. Swedish Child Leukaemia Group. BMJ 1994; 309:154-7. [PMID: 8044093 PMCID: PMC2540704 DOI: 10.1136/bmj.309.6948.154] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
OBJECTIVE To evaluate the risk of acute childhood leukaemia in areas of Sweden contaminated after the Chernobyl reactor accident in April 1986. DESIGN Population based study of childhood leukaemia diagnosed during 1980-92. SETTING Coordinates for places of residence of all 1.6 million children aged 0-15 years; aerial mapped areas of Sweden heavily contaminated after the Chernobyl accident. SUBJECTS 888 children aged 0-15 years with acute leukaemia diagnosed in Sweden during 1980-92, identified with place of birth and residence at diagnosis. MAIN OUTCOME MEASURES Risk of leukaemia in areas contaminated after the Chernobyl accident compared with the rest of Sweden and in the same areas before the accident. RESULTS During six and a half years of follow up after the accident the odds ratio for acute leukaemia was 0.9 (95% confidence interval 0.6 to 1.4) in highly contaminated areas (> or = 10 kBq/m2) compared with the same areas before the accident. For the subgroup acute lymphoblastic leukaemia in children aged under 5 years at diagnosis the odds ratio was 1.5 (0.8 to 2.6). For all cases diagnosed after May 1986 in highly contaminated areas compared with areas of low contamination the odds ratio was 0.9 (0.7 to 1.3). For acute lymphoblastic leukaemia in children aged under 5 years at diagnosis the odds ratio was 1.2 (0.8 to 1.9) in highly contaminated areas compared with areas of low contamination. Dose-response analysis showed no correlation between the degree of contamination and the incidence of childhood leukaemia. CONCLUSION There has been no significant increase in the incidence of acute childhood leukaemia in areas of Sweden contaminated after the Chernobyl reactor accident.
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Affiliation(s)
- U Hjalmars
- Department of Paediatrics, Central Hospital, Ostersund, Sweden
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Hjalmars U, Wålinder O, Mårtensson A, Karlsson A, Venge P. [Hypovolemic shock with edema/hemoconcentration caused by periodic leakage of plasma proteins]. Lakartidningen 1985; 82:2971-3. [PMID: 4046682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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