{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,21]],"date-time":"2026-09-21T21:43:41Z","timestamp":1790027021043,"version":"4.0.1"},"reference-count":35,"publisher":"Public Library of Science (PLoS)","issue":"3","license":[{"start":{"date-parts":[[2026,3,5]],"date-time":"2026-03-05T00:00:00Z","timestamp":1772668800000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100006313","name":"Barncancerfonden","doi-asserted-by":"publisher","award":["PR2021-0056"],"award-info":[{"award-number":["PR2021-0056"]}],"id":[{"id":"10.13039\/501100006313","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100004359","name":"Vetenskapsr\u00c3\u00a5det","doi-asserted-by":"publisher","award":["2022-06312"],"award-info":[{"award-number":["2022-06312"]}],"id":[{"id":"10.13039\/501100004359","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["www.plosmedicine.org"],"crossmark-restriction":false},"short-container-title":["PLoS Med"],"abstract":"<jats:sec id=\"sec001\">\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>The COVID-19 pandemic raised concerns about diagnostic delays and treatment disruptions in childhood cancer, potentially threatening survival. We assessed childhood cancer incidence and survival in Sweden, where only few restrictions were implemented, during the pandemic period.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec id=\"sec002\">\n                    <jats:title>Methods and findings<\/jats:title>\n                    <jats:p>\n                      We conducted a nationwide, register-based cohort study including all children and adolescents (0\u201319 years) with a new cancer diagnosis, defined according to the International Classification of Childhood Cancer, Third Edition (ICCC-3), reported to the Swedish National Cancer Register during 2015\u20132022 (\n                      <jats:italic>N<\/jats:italic>\n                      \u2009=\u20093,333; 2,069 pre-pandemic and 1,264 during the pandemic). We compared quarter-specific age-standardized incidence rates (ASR) per 1,000,000 (overall and by diagnostic group) during 2020\u20132022 to the 2015\u20132019 average. Overall survival at 3, 6, and 12 months post-diagnosis was calculated using the Kaplan\u2013Meier estimator, and mortality at the same intervals was assessed with logistic regression, adjusted for age at diagnosis, sex, and maternal education.\n                    <\/jats:p>\n                    <jats:p>\n                      Overall incidence rates remained largely stable during the pandemic (ASR\n                      <jats:sub>2015\u20132019<\/jats:sub>\n                      : 179.5; 95% CI [172.9,186.1], ASR\n                      <jats:sub>2020<\/jats:sub>\n                      : 174.7; 95% CI [160.5,189.0], ASR\n                      <jats:sub>2021<\/jats:sub>\n                      : 176.5; 95% CI [161.6,191.5], ASR\n                      <jats:sub>2022<\/jats:sub>\n                      : 181.2; 95% CI [166.3,196.2]), but diagnostic groups showed differing tendencies. Acute lymphoblastic leukemia (ALL) declined from February 2020, followed by a rebound in 2021. Acute myeloid leukemia (AML) declined throughout 2020\u20132022 without evidence of a rebound. Lymphomas declined in mid-2020 before returning to pre-pandemic levels. Central nervous system (CNS) tumors transiently increased in 2020. Overall 1-year survival was 94.8% (95% CI [93.9,95.8]) in the pre-pandemic period and 95.9% (95% CI [94.8,97.0]) during the pandemic. No increase in 6-month or 1-year mortality was observed; if anything, point estimates suggested lower 1-year mortality for ALL (aOR = 0.37; 95% CI [0.08,1.21];\n                      <jats:italic>p<\/jats:italic>\n                      \u2009=\u20090.14) and CNS tumors (aOR = 0.61; 95% CI [0.31,1.14];\n                      <jats:italic>p<\/jats:italic>\n                      \u2009=\u20090.13). The main limitation of this study was statistical uncertainty for certain diagnostic groups due to small case numbers.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec id=\"sec003\">\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>Overall childhood cancer incidence and survival in Sweden showed no major changes during the COVID-19 pandemic. Fluctuations in diagnostic-group-specific incidence may reflect delayed diagnoses or shifts in disease triggers; however, the timing of the ALL decline and the lack of AML rebound challenge this interpretation. Stable or improved survival suggests that any disruptions were not associated with poorer survival up to 1 year after diagnosis.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1371\/journal.pmed.1004934","type":"journal-article","created":{"date-parts":[[2026,3,5]],"date-time":"2026-03-05T18:21:29Z","timestamp":1772734889000},"page":"e1004934","update-policy":"https:\/\/doi.org\/10.1371\/journal.pmed.corrections_policy","source":"Crossref","is-referenced-by-count":1,"title":["Childhood cancer in Sweden during the COVID-19 pandemic: Temporal patterns in incidence and survival in a nationwide register-based cohort study"],"prefix":"10.1371","volume":"23","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-3907-4360","authenticated-orcid":true,"given":"Christina-Evmorfia","family":"Kampitsi","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2985-3301","authenticated-orcid":true,"given":"Javier","family":"Louro","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5195-8065","authenticated-orcid":true,"given":"Hanna","family":"Mogensen","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Friederike","family":"Erdmann","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9304-6144","authenticated-orcid":true,"given":"Kleopatra","family":"Georgantzi","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7637-1949","authenticated-orcid":true,"given":"Mats","family":"Heyman","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5500-9606","authenticated-orcid":true,"given":"P\u00e4ivi","family":"L\u00e4hteenm\u00e4ki","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Anna","family":"Nilsson","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5101-0060","authenticated-orcid":true,"given":"Maria","family":"Feychting","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5210-7219","authenticated-orcid":true,"given":"Giorgio","family":"Tettamanti","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"340","published-online":{"date-parts":[[2026,3,5]]},"reference":[{"key":"pmed.1004934.ref001","unstructured":"International Agency for Research on Cancer, World Health Organization. World Cancer Report 2020; 2020."},{"issue":"12","key":"pmed.1004934.ref002","doi-asserted-by":"crossref","first-page":"1525","DOI":"10.1016\/S1470-2045(22)00637-4","article-title":"Long-term survival and cure fraction estimates for childhood cancer in Europe (EUROCARE-6): results from a population-based study","volume":"23","author":"L Botta","year":"2022","journal-title":"Lancet Oncol"},{"key":"pmed.1004934.ref003","doi-asserted-by":"crossref","first-page":"1187","DOI":"10.3332\/ecancer.2021.1187","article-title":"The threat of the COVID-19 pandemic on reversing global life-saving gains in the survival of childhood cancer: a call for collaborative action from SIOP, IPSO, PROS, WCC, CCI, St Jude Global, UICC and WHPCA","volume":"15","author":"K Pritchard-Jones","year":"2021","journal-title":"Ecancermedicalscience"},{"issue":"2","key":"pmed.1004934.ref004","doi-asserted-by":"crossref","first-page":"208","DOI":"10.1093\/jnci\/djad205","article-title":"Cancer and COVID-19: US cancer incidence rates during the first year of the pandemic","volume":"116","author":"N Howlader","year":"2024","journal-title":"J Natl Cancer Inst"},{"issue":"5","key":"pmed.1004934.ref005","doi-asserted-by":"crossref","first-page":"658","DOI":"10.1080\/0284186X.2021.2024879","article-title":"Drop in cancer diagnosis during the COVID-19 pandemic in Denmark: assessment of impact during 2020","volume":"61","author":"CW Skovlund","year":"2022","journal-title":"Acta Oncol"},{"issue":"1","key":"pmed.1004934.ref006","doi-asserted-by":"crossref","first-page":"427","DOI":"10.1186\/s12887-020-02303-6","article-title":"COVID-19 related reduction in pediatric emergency healthcare utilization\u2014a concerning trend","volume":"20","author":"C Dopfer","year":"2020","journal-title":"BMC Pediatr"},{"issue":"7","key":"pmed.1004934.ref007","doi-asserted-by":"crossref","first-page":"2271","DOI":"10.1007\/s00431-021-04015-0","article-title":"The impact of lockdown on pediatric ED visits and hospital admissions during the COVID19 pandemic: a multicenter analysis and review of the literature","volume":"180","author":"MD Kruizinga","year":"2021","journal-title":"Eur J Pediatr"},{"issue":"11","key":"pmed.1004934.ref008","doi-asserted-by":"crossref","DOI":"10.1002\/pbc.31976","article-title":"Pediatric and young adult cancer incidence in the United States during the COVID-19 pandemic","volume":"72","author":"DA Siegel","year":"2025","journal-title":"Pediatr Blood Cancer"},{"issue":"10","key":"pmed.1004934.ref009","doi-asserted-by":"crossref","DOI":"10.1002\/pbc.28640","article-title":"A collateral effect of the COVID-19 pandemic: delayed diagnosis in pediatric solid tumors","volume":"67","author":"S Chiaravalli","year":"2020","journal-title":"Pediatr Blood Cancer"},{"issue":"9","key":"pmed.1004934.ref010","article-title":"Delayed cancer diagnoses and high mortality in children during the COVID-19 pandemic","volume":"67","author":"Y-Y Ding","year":"2020","journal-title":"Pediatr Blood Cancer"},{"issue":"2","key":"pmed.1004934.ref011","doi-asserted-by":"crossref","first-page":"596","DOI":"10.1111\/apa.15576","article-title":"Observed reduction in the diagnosis of acute lymphoblastic leukaemia in children during the COVID-19 pandemic","volume":"110","author":"KB Jarvis","year":"2021","journal-title":"Acta Paediatr"},{"issue":"4","key":"pmed.1004934.ref012","doi-asserted-by":"crossref","DOI":"10.1002\/pbc.28777","article-title":"Pediatric cancer registration fluctuation in Greece due to COVID-19 pandemic and changes in health care delivery","volume":"68","author":"M Kourti","year":"2021","journal-title":"Pediatr Blood Cancer"},{"key":"pmed.1004934.ref013","doi-asserted-by":"crossref","first-page":"100240","DOI":"10.1016\/j.ejcped.2025.100240","article-title":"Impact of COVID-19 pandemic on childhood cancer incidence and stage in France\u2014a national registry-based study","volume":"5","author":"M G\u00e9dor","year":"2025","journal-title":"EJC Paediatric Oncol"},{"key":"pmed.1004934.ref014","doi-asserted-by":"crossref","first-page":"100188","DOI":"10.1016\/j.lanepe.2021.100188","article-title":"Impact of the COVID-19 pandemic on incidence, time of diagnosis and delivery of healthcare among paediatric oncology patients in Germany in 2020: evidence from the German Childhood Cancer Registry and a qualitative survey","volume":"9","author":"F Erdmann","year":"2021","journal-title":"Lancet Reg Health Eur"},{"key":"pmed.1004934.ref015","doi-asserted-by":"crossref","first-page":"100398","DOI":"10.1016\/j.lanepe.2022.100398","article-title":"Temporal changes of the incidence of childhood cancer in Germany during the COVID-19 pandemic: updated analyses from the German Childhood Cancer Registry","volume":"17","author":"F Erdmann","year":"2022","journal-title":"Lancet Reg Health Eur"},{"issue":"8","key":"pmed.1004934.ref016","doi-asserted-by":"crossref","first-page":"471","DOI":"10.1038\/s41568-018-0015-6","article-title":"A causal mechanism for childhood acute lymphoblastic leukaemia","volume":"18","author":"M Greaves","year":"2018","journal-title":"Nat Rev Cancer"},{"issue":"7","key":"pmed.1004934.ref017","doi-asserted-by":"crossref","first-page":"1353","DOI":"10.1038\/sj.leu.2404729","article-title":"Impact of SARS on development of childhood acute lymphoblastic leukaemia","volume":"21","author":"CK Li","year":"2007","journal-title":"Leukemia"},{"key":"pmed.1004934.ref018","doi-asserted-by":"crossref","first-page":"101733","DOI":"10.1016\/j.canep.2020.101733","article-title":"Childhood cancer: survival, treatment modalities, late effects and improvements over time","volume":"71","author":"F Erdmann","year":"2021","journal-title":"Cancer Epidemiol"},{"issue":"8","key":"pmed.1004934.ref019","doi-asserted-by":"crossref","first-page":"1023","DOI":"10.1016\/S1470-2045(20)30388-0","article-title":"The impact of the COVID-19 pandemic on cancer deaths due to delays in diagnosis in England, UK: a national, population-based, modelling study","volume":"21","author":"C Maringe","year":"2020","journal-title":"Lancet Oncol"},{"issue":"12","key":"pmed.1004934.ref020","doi-asserted-by":"crossref","first-page":"2459","DOI":"10.1111\/apa.15582","article-title":"The first eight months of Sweden\u2019s COVID-19 strategy and the key actions and actors that were involved","volume":"109","author":"JF Ludvigsson","year":"2020","journal-title":"Acta Paediatr"},{"issue":"1","key":"pmed.1004934.ref021","doi-asserted-by":"crossref","first-page":"424","DOI":"10.1186\/s13104-021-05839-7","article-title":"Impact of the Covid-19 pandemic on primary care utilization: evidence from Sweden using national register data","volume":"14","author":"B Ekman","year":"2021","journal-title":"BMC Res Notes"},{"issue":"1","key":"pmed.1004934.ref022","doi-asserted-by":"crossref","first-page":"27","DOI":"10.1080\/02841860802247664","article-title":"The completeness of the Swedish Cancer Register: a sample survey for year 1998","volume":"48","author":"L Barlow","year":"2009","journal-title":"Acta Oncol"},{"issue":"7","key":"pmed.1004934.ref023","doi-asserted-by":"crossref","first-page":"1457","DOI":"10.1002\/cncr.20910","article-title":"International classification of childhood cancer, third edition","volume":"103","author":"E Steliarova-Foucher","year":"2005","journal-title":"Cancer"},{"key":"pmed.1004934.ref024","volume-title":"Cancer mortality for selected sites in 24 countries (1950-1957)","author":"M Segi","year":"1960"},{"key":"pmed.1004934.ref025","unstructured":"Statistics Sweden. Population, number by age, sex and year: SCB Statistical database; [cited 2025 June 04]. Available from: https:\/\/www.statistikdatabasen.scb.se\/pxweb\/en\/ssd\/START__BE__BE0101__BE0101A\/BefolkningR1860N\/"},{"key":"pmed.1004934.ref026","volume-title":"Cancer incidence in five continents volume IX","author":"International Agency for Research on Cancer","year":"2007"},{"issue":"1","key":"pmed.1004934.ref027","doi-asserted-by":"crossref","first-page":"118","DOI":"10.1038\/bjc.2015.449","article-title":"Socioeconomic differences in cancer survival among Swedish children","volume":"114","author":"H Mogensen","year":"2016","journal-title":"Br J Cancer"},{"issue":"4","key":"pmed.1004934.ref028","doi-asserted-by":"crossref","first-page":"423","DOI":"10.1007\/s10654-019-00511-8","article-title":"The longitudinal integrated database for health insurance and labour market studies (LISA) and its use in medical research","volume":"34","author":"JF Ludvigsson","year":"2019","journal-title":"Eur J Epidemiol"},{"key":"pmed.1004934.ref029","volume-title":"R: a language and environment for statistical computing","author":"R Core Team","year":"2023"},{"issue":"5","key":"pmed.1004934.ref030","doi-asserted-by":"crossref","first-page":"332","DOI":"10.1016\/S2352-4642(21)00031-6","article-title":"Global effect of the COVID-19 pandemic on paediatric cancer care: a cross-sectional study","volume":"5","author":"D Graetz","year":"2021","journal-title":"Lancet Child Adolesc Health"},{"issue":"7","key":"pmed.1004934.ref031","article-title":"COVID-19 and childhood acute lymphoblastic leukemia","volume":"67","author":"JW Taub","year":"2020","journal-title":"Pediatr Blood Cancer"},{"issue":"12","key":"pmed.1004934.ref032","doi-asserted-by":"crossref","DOI":"10.1002\/pbc.28481","article-title":"COVID-19 and childhood acute lymphoblastic leukemia","volume":"67","author":"M Greaves","year":"2020","journal-title":"Pediatr Blood Cancer"},{"issue":"12","key":"pmed.1004934.ref033","doi-asserted-by":"crossref","first-page":"2908","DOI":"10.1038\/s41375-022-01730-x","article-title":"Temporal changes of the incidence of childhood B-cell precursor acute lymphoblastic leukaemia in Germany during the COVID-19 pandemic","volume":"36","author":"A Borkhardt","year":"2022","journal-title":"Leukemia"},{"issue":"6","key":"pmed.1004934.ref034","doi-asserted-by":"crossref","first-page":"1088","DOI":"10.1111\/apa.15270","article-title":"Systematic review of COVID-19 in children shows milder cases and a better prognosis than adults","volume":"109","author":"JF Ludvigsson","year":"2020","journal-title":"Acta Paediatr"},{"key":"pmed.1004934.ref035","unstructured":"A treatment study protocol for participants 0-45 years with acute lymphoblastic leukaemia: ClinicalTrials.gov; [cited 2025 June 04]. 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