{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,9]],"date-time":"2026-09-09T16:13:51Z","timestamp":1788970431788,"version":"build-2803163510"},"reference-count":18,"publisher":"Oxford University Press (OUP)","issue":"9","license":[{"start":{"date-parts":[[2026,5,31]],"date-time":"2026-05-31T00:00:00Z","timestamp":1780185600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/academic.oup.com\/pages\/standard-publication-reuse-rights"}],"funder":[{"name":"National Cancer Center Research and Development Funds","award":["31-A-14, 2022-A-15"],"award-info":[{"award-number":["31-A-14, 2022-A-15"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2026,9,9]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>Ewing sarcoma arises at both skeletal (SES) and extraskeletal (EES) sites; however, whether the anatomical origin influences outcomes in current practice remains uncertain. This study compared clinical characteristics, treatment, and survival rates of patients with SES and EES in a large nationwide Japanese cohort.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>We analyzed patients diagnosed with Ewing\u2019s sarcoma between 2016 and 2019 in Japan, classified as having SES or EES, using a population-based cancer registry. Demographics, stage, treatment, hospital characteristics, and overall survival (OAS) were evaluated using chi-square tests, Kaplan\u2013Meier estimates, and log-rank analyses.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>We identified 505 patients with ES: 211 with SES and 294 with EES. Patients with EES were significantly older than those with SES (P\u00a0&amp;lt;\u00a0.001). Chemotherapy (97.7% vs. 74.9%, P\u00a0&amp;lt;\u00a0.001) and radiotherapy (36.6% vs. 27.1%, P\u00a0=\u00a0.024) were administered more frequently in the SES group. Three-year OAS rate was 62.3%, 73.5% for SES, and 54.7% for EES, with significantly worse survival in EES group (P\u00a0&amp;lt;\u00a0.001). Favorable prognostic factors included younger age, localized stage, surgery, chemotherapy, treatment at certified institutions, higher hospital volume, and female sex among patients with EES.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>In this nationwide cohort, EES presented at older ages, received less chemotherapy, and demonstrated inferior survival compared to SES, despite a similar stage distribution. Patient background, hospital type, and volume influenced the outcomes. These findings underscore the need for equitable multimodal therapy delivery, particularly for patients with EES.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1093\/jjco\/hyag086","type":"journal-article","created":{"date-parts":[[2026,5,8]],"date-time":"2026-05-08T11:43:36Z","timestamp":1778240616000},"page":"1044-1051","source":"Crossref","is-referenced-by-count":0,"title":["Distinct epidemiology and treatment outcomes between skeletal and extraskeletal Ewing sarcoma in Japan: a population-based study"],"prefix":"10.1093","volume":"56","author":[{"given":"Yu","family":"Toda","sequence":"first","affiliation":[{"name":"Department of Musculoskeletal Oncology, National Cancer Center Hospital , 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045 ,","place":["Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6956-3117","authenticated-orcid":false,"given":"Koichi","family":"Ogura","sequence":"additional","affiliation":[{"name":"Department of Musculoskeletal Oncology, National Cancer Center Hospital , 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045 ,","place":["Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6560-7503","authenticated-orcid":false,"given":"Chigusa","family":"Morizane","sequence":"additional","affiliation":[{"name":"Department of Hepatobiliary and Pancreatic Oncology, National Cancer Center Hospital , 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045 ,","place":["Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tomoyuki","family":"Satake","sequence":"additional","affiliation":[{"name":"Department of Hepatobiliary and Pancreatic Oncology, National Cancer Center Hospital East , 6-5-1 Kashiwanoha, Kashiwa-shi, Chiba 277-8577 ,","place":["Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2024-514X","authenticated-orcid":false,"given":"Shintaro","family":"Iwata","sequence":"additional","affiliation":[{"name":"Department of Musculoskeletal Oncology, National Cancer Center Hospital , 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045 ,","place":["Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5751-473X","authenticated-orcid":false,"given":"Eisuke","family":"Kobayashi","sequence":"additional","affiliation":[{"name":"Department of Musculoskeletal Oncology, National Cancer Center Hospital , 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045 ,","place":["Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4330-7822","authenticated-orcid":false,"given":"Toshiyuki","family":"Takemori","sequence":"additional","affiliation":[{"name":"Department of Musculoskeletal Oncology, National Cancer Center Hospital , 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045 ,","place":["Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4642-5448","authenticated-orcid":false,"given":"Hiroya","family":"Kondo","sequence":"additional","affiliation":[{"name":"Department of Musculoskeletal Oncology, National Cancer Center Hospital , 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045 ,","place":["Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shudai","family":"Muramatsu","sequence":"additional","affiliation":[{"name":"Department of Musculoskeletal Oncology, National Cancer Center Hospital , 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045 ,","place":["Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Takahiro","family":"Higashi","sequence":"additional","affiliation":[{"name":"Department of Public Health and Health Policy, The University of Tokyo , 7-3-1 Hongo, Bunkyo-Ku, Tokyo 113-0033 ,","place":["Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2116-586X","authenticated-orcid":false,"given":"Akira","family":"Kawai","sequence":"additional","affiliation":[{"name":"Department of Musculoskeletal Oncology, National Cancer Center Hospital , 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045 ,","place":["Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"286","published-online":{"date-parts":[[2026,5,31]]},"reference":[{"key":"2026090910425842900_ref1","volume-title":"WHO classification of tumours editorial board. 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