{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,25]],"date-time":"2026-06-25T23:06:12Z","timestamp":1782428772421,"version":"3.54.5"},"reference-count":19,"publisher":"Springer Science and Business Media LLC","issue":"1","license":[{"start":{"date-parts":[[2021,4,17]],"date-time":"2021-04-17T00:00:00Z","timestamp":1618617600000},"content-version":"tdm","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"},{"start":{"date-parts":[[2021,4,17]],"date-time":"2021-04-17T00:00:00Z","timestamp":1618617600000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001826","name":"ZonMw","doi-asserted-by":"publisher","award":["10430022010014"],"award-info":[{"award-number":["10430022010014"]}],"id":[{"id":"10.13039\/501100001826","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["link.springer.com"],"crossmark-restriction":false},"short-container-title":["J Hematol Oncol"],"published-print":{"date-parts":[[2021,12]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:sec>\n                <jats:title>Background<\/jats:title>\n                <jats:p>The onset of the COVID-19 pandemic forced the Dutch national screening program to a halt and increased the burden on health care services, necessitating the introduction of specific breast cancer treatment recommendations from week 12 of 2020. We aimed to investigate the impact of COVID-19 on the diagnosis, stage and initial treatment of breast cancer.\n<\/jats:p>\n              <\/jats:sec><jats:sec>\n                <jats:title>Methods<\/jats:title>\n                <jats:p>Women included in the Netherlands Cancer Registry and diagnosed during four periods in weeks 2\u201317 of 2020 were compared with reference data from 2018\/2019 (averaged). Weekly incidence was calculated by age group and tumor stage. The number of women receiving initial treatment within 3\u00a0months of diagnosis was calculated by period, initial treatment, age, and stage. Initial treatment, stratified by tumor behavior (ductal carcinoma in situ [DCIS] or invasive), was analyzed by logistic regression and adjusted for age, socioeconomic status, stage, subtype, and region. Factors influencing time to treatment were analyzed by Cox regression.<\/jats:p>\n              <\/jats:sec><jats:sec>\n                <jats:title>Results<\/jats:title>\n                <jats:p>Incidence declined across all age groups and tumor stages (except stage IV) from 2018\/2019 to 2020, particularly for DCIS and stage I disease (<jats:italic>p<\/jats:italic>\u2009&lt;\u20090.05). DCIS was less likely to be treated within 3\u00a0months (odds ratio [OR]<jats:sub>wks2\u20138<\/jats:sub>: 2.04, OR<jats:sub>wks9\u201311<\/jats:sub>: 2.18). Invasive tumors were less likely to be treated initially by mastectomy with immediate reconstruction (OR<jats:sub>wks12\u201313<\/jats:sub>: 0.52) or by breast conserving surgery (OR<jats:sub>wks14\u201317<\/jats:sub>: 0.75). Chemotherapy was less likely for tumors diagnosed in the beginning of the study period (OR<jats:sub>wks9\u201311<\/jats:sub>: 0.59, OR<jats:sub>wks12\u201313<\/jats:sub>: 0.66), but more likely for those diagnosed at the end (OR<jats:sub>wks14\u201317<\/jats:sub>: 1.31). Primary hormonal treatment was more common (OR<jats:sub>wks2\u20138<\/jats:sub>: 1.23, OR<jats:sub>wks9\u201311<\/jats:sub>: 1.92, OR<jats:sub>wks12\u201313<\/jats:sub>: 3.01). Only women diagnosed in weeks 2\u20138 of 2020 experienced treatment delays.<\/jats:p>\n              <\/jats:sec><jats:sec>\n                <jats:title>Conclusion<\/jats:title>\n                <jats:p>The incidence of breast cancer fell in early 2020, and treatment approaches adapted rapidly. Clarification is needed on how this has affected stage migration and outcomes.<\/jats:p>\n              <\/jats:sec>","DOI":"10.1186\/s13045-021-01073-7","type":"journal-article","created":{"date-parts":[[2021,4,17]],"date-time":"2021-04-17T12:02:54Z","timestamp":1618660974000},"update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":78,"title":["Impact of the COVID-19 pandemic on diagnosis, stage, and initial treatment of breast cancer in the Netherlands: a population-based study"],"prefix":"10.1186","volume":"14","author":[{"name":"the NABON COVID-19 Consortium and the COVID and Cancer-NL Consortium","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Anouk H.","family":"Eijkelboom","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Linda","family":"de Munck","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Marie-Jeanne T. F. D.","family":"Vrancken Peeters","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mireille J. M.","family":"Broeders","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Luc J. A.","family":"Strobbe","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Monique E. M. M.","family":"Bos","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Marjanka K.","family":"Schmidt","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Cristina","family":"Guerrero Paez","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Marjolein L.","family":"Smidt","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Maud","family":"Bessems","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Janneke","family":"Verloop","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sabine","family":"Linn","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Marc B. 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Effect of the COVID-19 pandemic on surgical breast cancer care in the Netherlands: a multicenter retrospective cohort study. Clin Breast Cancer. 2020;20(6):454\u201361.","journal-title":"Clin Breast Cancer."},{"issue":"6","key":"1073_CR3","doi-asserted-by":"publisher","first-page":"750","DOI":"10.1016\/S1470-2045(20)30265-5","volume":"21","author":"AG Dinmohamed","year":"2020","unstructured":"Dinmohamed AG, Visser O, Verhoeven RH, et al. Fewer cancer diagnoses during the COVID-19 epidemic in the Netherlands. Lancet Oncol. 2020;21(6):750\u20131.","journal-title":"Lancet Oncol"},{"issue":"30","key":"1073_CR4","first-page":"D5123","volume":"164","author":"YA Civil","year":"2020","unstructured":"Civil YA, van Iersel T, Menke-vandeHouven CW, Barb\u00e9 E, van der Velde S. Prioritering van borstkankerzorg tijdens coronacrisis. 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According to the Central Committee on Research involving Human Subjects (CCMO), this type of observational study does not require approval from an ethics committee in the Netherlands.","order":2,"name":"Ethics","group":{"name":"EthicsHeading","label":"Ethics approval and consent to participate"}},{"value":"Not applicable.","order":3,"name":"Ethics","group":{"name":"EthicsHeading","label":"Consent for publication"}},{"value":"The authors declare that they have no competing interests.","order":4,"name":"Ethics","group":{"name":"EthicsHeading","label":"Competing interests"}}],"article-number":"64"}}