{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,19]],"date-time":"2026-10-19T14:13:41Z","timestamp":1792419221806,"version":"4.5.0"},"reference-count":14,"publisher":"BMJ","issue":"12","content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["BMJ Open"],"accepted":{"date-parts":[[2017,12,1]]},"published-print":{"date-parts":[[2017,12]]},"abstract":"<jats:sec>\n                    <jats:title>Objectives<\/jats:title>\n                    <jats:p>There is an ongoing debate on the possible association between infections in early childhood and subsequent cancer risk, but it remains unclear if a hospital admission for infection is associated with risk of childhood cancer diagnosis. We examined if a hospital-based diagnosis of pneumonia was a clinical marker of the three most common childhood cancers.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Design<\/jats:title>\n                    <jats:p>Population-based cohort study.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Setting<\/jats:title>\n                    <jats:p>Denmark, hospital diagnoses, 1994\u20132013.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>Using national health registries, we compared the observed incidence of leukaemia, lymphoma and brain cancer among 83\u2009935 children with a hospital-based pneumonia diagnosis with that expected among children in the general population. We calculated absolute cancer risks and standardised incidence ratios (SIRs) as a measure of relative risk.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>The cancer SIRs were substantially increased during the first 6 months of follow-up; lymphoid leukaemia: 6.2 (95% CI 3.5 to 10.3); myeloid leukaemia: 14.8 (95% CI 6.0 to 30.6); Hodgkin\u2019s lymphoma: 60.8 (95% CI 26.2 to 120), non-Hodgkin\u2019s lymphoma: 15.9 (95% CI 5.2 to 37.2) and brain cancer: 4.4 (95% CI 1.9 to 8.7). The 6-month absolute risks of leukaemia, lymphoma and brain cancer were all low, reaching 0.05% when combined. An increased risk persisted beyond 5 years for non-Hodgkin\u2019s lymphoma and brain cancer. However, the 5-year absolute cancer risk was 0.14%.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>The short-term incidence of leukaemia, lymphoma and brain cancer was higher than expected and persisted beyond 5 years for non-Hodgkin\u2019s lymphoma and brain cancer. However, the absolute cancer risk was low.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1136\/bmjopen-2017-019860","type":"journal-article","created":{"date-parts":[[2017,12,29]],"date-time":"2017-12-29T22:35:58Z","timestamp":1514586958000},"page":"e019860","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":6,"title":["Pneumonia diagnosis in childhood and incidence of leukaemia, lymphoma and brain cancer: a Danish nationwide cohort study"],"prefix":"10.1136","volume":"7","author":[{"given":"Kirstine Kobber\u00f8e","family":"S\u00f8gaard","sequence":"first","affiliation":[{"name":"Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus, Denmark"},{"name":"Department of Clinical Microbiology, Aalborg University Hospital, Aalborg, Denmark"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"D\u00f3ra K\u00f6rmendin\u00e9","family":"Farkas","sequence":"additional","affiliation":[{"name":"Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus, Denmark"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Henrik Toft","family":"S\u00f8rensen","sequence":"additional","affiliation":[{"name":"Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus, Denmark"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"239","published-online":{"date-parts":[[2017,12,29]]},"reference":[{"key":"2025121602152455000_7.12.e019860.1","first-page":"A4285","article-title":"Symptoms and time to diagnosis in children with brain tumours","volume":"58","author":"Klitbo","year":"2011","journal-title":"Dan Med Bull"},{"key":"2025121602152455000_7.12.e019860.2","doi-asserted-by":"publisher","DOI":"10.3399\/bjgp12X654461"},{"key":"2025121602152455000_7.12.e019860.3","doi-asserted-by":"publisher","DOI":"10.1002\/pbc.24286"},{"key":"2025121602152455000_7.12.e019860.4","doi-asserted-by":"crossref","first-page":"1017","DOI":"10.1038\/bjc.2015.53","article-title":"Childhood acute lymphoblastic leukaemia and indicators of early immune stimulation: the Estelle study (SFCE)","volume":"112","author":"Ajrouche","year":"2015","journal-title":"Br J Cancer"},{"key":"2025121602152455000_7.12.e019860.5","doi-asserted-by":"publisher","DOI":"10.1093\/ije\/dys113"},{"key":"2025121602152455000_7.12.e019860.6","first-page":"899","article-title":"Community-acquired pneumonia in infants and children","volume":"70","author":"Ostapchuk","year":"2004","journal-title":"Am Fam Physician"},{"key":"2025121602152455000_7.12.e019860.7","unstructured":"Country Summary. Cancer research UK. 2010. 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