{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,11]],"date-time":"2026-07-11T03:15:53Z","timestamp":1783739753224,"version":"3.55.0"},"reference-count":34,"publisher":"Oxford University Press (OUP)","issue":"5","license":[{"start":{"date-parts":[[2026,1,30]],"date-time":"2026-01-30T00:00:00Z","timestamp":1769731200000},"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 Fund","award":["29-A-3"],"award-info":[{"award-number":["29-A-3"]}]},{"name":"National Cancer Center Research and Development Fund","award":["2020-J-3"],"award-info":[{"award-number":["2020-J-3"]}]},{"name":"National Cancer Center Research and Development Fund","award":["2023-J-03"],"award-info":[{"award-number":["2023-J-03"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2026,5,7]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>Oligometastasis is a concept that refers to the condition between localized cancer and widespread distant metastases; however, a consensus on the definition has yet to be reached. Metastasis-directed therapy (MDT) has recently been established to incorporate local therapy, such as radiotherapy and surgery, for distant metastases. Previous trials have proposed the possibility of long-term survival with the administration of MDT for patients with oligometastases. However, the efficacy and safety of MDT have not been sufficiently validated. We are conducting this clinical trial to confirm the superiority of MDT combined with subtype-specific systemic drug therapy over systemic drug therapy alone in patients with oligometastatic breast cancer. Here, \u201coligometastases\u201d are defined as tumors with a maximum diameter\u00a0\u2264\u00a03\u00a0cm and total number\u00a0\u2264\u00a03. The primary endpoint is overall survival. We intend to enroll 340 patients from 62 institutions over a 3-year period. This trial has been registered in the Japan Registry of Clinical Trials (jRCTs031230439).<\/jats:p>","DOI":"10.1093\/jjco\/hyag019","type":"journal-article","created":{"date-parts":[[2026,1,20]],"date-time":"2026-01-20T12:26:23Z","timestamp":1768911983000},"page":"659-665","source":"Crossref","is-referenced-by-count":1,"title":["A randomized controlled trial of metastasis-directed therapy for oligometastases in breast cancer: OLIGAMI trial (JCOG2110)"],"prefix":"10.1093","volume":"56","author":[{"ORCID":"https:\/\/orcid.org\/0009-0005-5100-3863","authenticated-orcid":false,"given":"Keita","family":"Sasaki","sequence":"first","affiliation":[{"name":"National Cancer Center Hospital, Japan Clinical Oncology Group Data Center\/Operations Office , 5-1-1 Tsukiji, Chuo-ku, Tokyo, 104-0045 ,","place":["Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8709-4972","authenticated-orcid":false,"given":"Toshiyuki","family":"Ishiba","sequence":"additional","affiliation":[{"name":"Department of Breast Surgery, Institute of Science Tokyo Hospital , 1-5-45 Yushima, Bunkyo-ku, 113-8519, Tokyo ,","place":["Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5873-4822","authenticated-orcid":false,"given":"Ikuno","family":"Nishibuchi","sequence":"additional","affiliation":[{"name":"Department of Radiation Oncology, Graduate School of Biomedical and Health Sciences, Hiroshima University , 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8551 ,","place":["Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Fumikata","family":"Hara","sequence":"additional","affiliation":[{"name":"Department of Breast Oncology, Aichi Cancer Center , 1-1 Kanokoden, Chikusa-ku, Nagoya, Aichi, 464-8681 ,","place":["Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yuta","family":"Sekino","sequence":"additional","affiliation":[{"name":"National Cancer Center Hospital, Japan Clinical Oncology Group Data Center\/Operations Office , 5-1-1 Tsukiji, Chuo-ku, Tokyo, 104-0045 ,","place":["Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ryunosuke","family":"Machida","sequence":"additional","affiliation":[{"name":"National Cancer Center Hospital, Japan Clinical Oncology Group Data Center\/Operations Office , 5-1-1 Tsukiji, Chuo-ku, Tokyo, 104-0045 ,","place":["Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Taro","family":"Shibata","sequence":"additional","affiliation":[{"name":"National Cancer Center Hospital, Japan Clinical Oncology Group Data Center\/Operations Office , 5-1-1 Tsukiji, Chuo-ku, Tokyo, 104-0045 ,","place":["Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8472-9821","authenticated-orcid":false,"given":"Daisuke","family":"Kawahara","sequence":"additional","affiliation":[{"name":"Department of Radiation Oncology, Graduate School of Biomedical and Health Sciences, Hiroshima University , 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8551 ,","place":["Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yasuaki","family":"Sagara","sequence":"additional","affiliation":[{"name":"Department of Breast Surgical Oncology, Hakuaikai Social Corporation, Sagara Hospital , 3-31 Matsubara-cho, Kagoshima-shi, Kagoshima, 892-0833 ,","place":["Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8490-9064","authenticated-orcid":false,"given":"Yoichi","family":"Naito","sequence":"additional","affiliation":[{"name":"Department of General Internal Medicine, National Cancer Center Hospital East , 6-5-1 Kashiwanoha, Kashiwa-shi, Chiba, 277-8577 ,","place":["Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kaori","family":"Terata","sequence":"additional","affiliation":[{"name":"Department of Breast and Endocrine Surgery, Akita University Hospital , 1-1-1 Hondo, Akita-shi, Akita, 010-8543 ,","place":["Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8064-648X","authenticated-orcid":false,"given":"Yukinori","family":"Ozaki","sequence":"additional","affiliation":[{"name":"Department of Breast Medical Oncology, Cancer Institute Hospital Japanese Foundation for Cancer Research , 3-8-31 Ariake, Koto-ku, Tokyo, 135-8550 ,","place":["Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2557-8170","authenticated-orcid":false,"given":"Akihiko","family":"Shimomura","sequence":"additional","affiliation":[{"name":"Department of Medical Oncology, National Center for Global Health and Medicine , 1-21-1 Toyama, Shinjuku-ku, Tokyo, 162-8655 ,","place":["Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Takehiko","family":"Sakai","sequence":"additional","affiliation":[{"name":"Department of Surgical Oncology, Cancer Institute Hospital of Japanese Foundation for Cancer Research , 3-8-31 Ariake, Koto-ku, Tokyo, 135-8550 ,","place":["Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9393-9655","authenticated-orcid":false,"given":"Hideo","family":"Shigematsu","sequence":"additional","affiliation":[{"name":"Department of Surgical Oncology, Research Institute for Radiation Biology and Medicine, Hiroshima University , 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8553 ,","place":["Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4600-9428","authenticated-orcid":false,"given":"Kazuki","family":"Sudo","sequence":"additional","affiliation":[{"name":"Department of Breast and Medical Oncology, National Cancer Center Hospital , 5-1-1 Tsukiji, Chuo-ku, Tokyo, 104-0045 ,","place":["Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kazuki","family":"Nozawa","sequence":"additional","affiliation":[{"name":"Department of Advanced Clinical Research and Development, Nagoya City University Graduate School of Medical Sciences , 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya, Aichi, 467-8601 ,","place":["Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Michio","family":"Yoshimura","sequence":"additional","affiliation":[{"name":"Department of Radiation Oncology and Image-Applied Therapy, Graduate School of Medicine, Kyoto University , 54 Shogoin-Kawahara-cho, Sakyo-ku, Kyoto, 606-8507 ,","place":["Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Naoto","family":"Shikama","sequence":"additional","affiliation":[{"name":"Department of Radiation Oncology, Juntendo University Graduate School of Medicine , 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421 ,","place":["Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8135-8746","authenticated-orcid":false,"given":"Takashi","family":"Mizowaki","sequence":"additional","affiliation":[{"name":"Department of Radiation Oncology and Image-Applied Therapy, Graduate School of Medicine, Kyoto University , 54 Shogoin-Kawahara-cho, Sakyo-ku, Kyoto, 606-8507 ,","place":["Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3202-5512","authenticated-orcid":false,"given":"Tadahiko","family":"Shien","sequence":"additional","affiliation":[{"name":"Department of Breast and Endocrine Surgery, Okayama University Hospital , 2-5-1 Shikata-cho, Kita-ku, Okayama, 700-8558 ,","place":["Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"286","published-online":{"date-parts":[[2026,1,30]]},"reference":[{"key":"2026050701220594500_ref1","author":"Ministry of Health, Labour and Welfare, Japan. Vital Statistics of Japan"},{"key":"2026050701220594500_ref2","doi-asserted-by":"publisher","first-page":"1623","DOI":"10.1016\/j.annonc.2020.09.010","article-title":"5th ESO-ESMO international consensus guidelines for advanced breast cancer (ABC 5)","volume":"31","author":"Cardoso","year":"2020","journal-title":"Ann Oncol"},{"key":"2026050701220594500_ref3","doi-asserted-by":"crossref","first-page":"1134","DOI":"10.1016\/S0140-6736(16)31891-8","article-title":"Breast cancer","volume":"389","author":"Nadia","year":"2017","journal-title":"Lancet"},{"key":"2026050701220594500_ref4","author":"Japanese Association of Clinical Cancer Centers"},{"key":"2026050701220594500_ref5","doi-asserted-by":"publisher","first-page":"153","DOI":"10.1016\/j.ejca.2017.12.012","article-title":"Strategies and technical challenges for imaging oligometastatic disease: recommendations from the European Organisation for Research and Treatment of Cancer imaging group","volume":"91","author":"deSouza","year":"2018","journal-title":"Eur J Cancer"},{"key":"2026050701220594500_ref6","doi-asserted-by":"crossref","first-page":"8","DOI":"10.1200\/JCO.1995.13.1.8","article-title":"Oligometastases","volume":"13","author":"Hellman","year":"1995","journal-title":"J Clin Oncol"},{"key":"2026050701220594500_ref7","doi-asserted-by":"publisher","first-page":"e18","DOI":"10.1016\/S1470-2045(19)30718-1","article-title":"Characterisation and classification of oligometastatic disease: a European Society for Radiotherapy and Oncology and European Organisation for Research and Treatment of Cancer consensus recommendation","volume":"21","author":"Guckenberger","year":"2020","journal-title":"Lancet Oncol"},{"key":"2026050701220594500_ref8","doi-asserted-by":"publisher","first-page":"e28","DOI":"10.1016\/S1470-2045(12)70510-7","article-title":"Stereotactic body radiotherapy for oligometastases","volume":"14","author":"Alison","year":"2013","journal-title":"Lancet Oncol"},{"key":"2026050701220594500_ref9","doi-asserted-by":"publisher","first-page":"2051","DOI":"10.1016\/S0140-6736(18)32487-5","article-title":"Stereotactic ablative radiotherapy versus standard of care palliative treatment in patients with oligometastatic cancers (SABR-COMET): a randomised, phase 2, open-label trial","volume":"393","author":"Palma","year":"2019","journal-title":"Lancet"},{"key":"2026050701220594500_ref10","doi-asserted-by":"publisher","first-page":"2830","DOI":"10.1200\/JCO.20.00818","article-title":"Stereotactic ablative radiotherapy for the comprehensive treatment of oligometastatic cancers: long-term results of the SABR-COMET phase II randomized trial","volume":"38","author":"Palma","year":"2020","journal-title":"J Clin Oncol"},{"key":"2026050701220594500_ref11","doi-asserted-by":"publisher","first-page":"412","DOI":"10.1007\/s12282-023-01436-7","article-title":"Survival advantage of locoregional and systemic therapy in oligometastatic breast cancer: an international retrospective cohort study (OLIGO-BC1)","volume":"30","author":"Imoto","year":"2023","journal-title":"Breast Cancer"},{"key":"2026050701220594500_ref12","doi-asserted-by":"crossref","first-page":"970","DOI":"10.1093\/jjco\/hys120","article-title":"A randomized controlled trial comparing primary tumour resection plus systemic therapy with systemic therapy alone in metastatic breast cancer (PRIM-BC): Japan Clinical Oncology Group Study JCOG1017","volume":"42","author":"Shien","year":"2012","journal-title":"Jpn J Clin Oncol"},{"key":"2026050701220594500_ref13","doi-asserted-by":"publisher","first-page":"625","DOI":"10.1038\/s41416-025-03097-z","article-title":"Primary tumour resection plus systemic therapy versus systemic therapy alone in metastatic breast cancer (JCOG1017, PRIM-BC): a randomised clinical trial","volume":"133","author":"Shien","year":"2025","journal-title":"Br J Cancer"},{"key":"2026050701220594500_ref14","doi-asserted-by":"publisher","first-page":"163","DOI":"10.21037\/hbsn-2024-678","article-title":"Advances in minimally invasive liver surgery: comparing robotic and laparoscopic approaches","volume":"14","author":"Imtiaz","year":"2025","journal-title":"Hepatobiliary Surg Nutr"},{"key":"2026050701220594500_ref15","doi-asserted-by":"publisher","first-page":"957","DOI":"10.1016\/j.ejso.2013.06.016","article-title":"Video-assisted thoracoscopic surgery lobectomy versus open lobectomy in patients with clinical stage I non-small cell lung cancer: a meta-analysis","volume":"39","author":"Chen","year":"2013","journal-title":"Eur J Surg Oncol"},{"key":"2026050701220594500_ref16","doi-asserted-by":"publisher","first-page":"2401","DOI":"10.1111\/1759-7714.15473","article-title":"Video-assisted thoracoscopic surgery versus open thoracotomy for resection of lung metastasis\u2014a meta-analysis of reconstructed time-to-event data","volume":"15","author":"Passos","year":"2024","journal-title":"Thorac Cancer"},{"key":"2026050701220594500_ref17","doi-asserted-by":"publisher","first-page":"1169","DOI":"10.1002\/jso.25702","article-title":"Appraisal of disease-specific benefits of minimally invasive liver surgery (MILS) over open techniques in breast cancer liver metastases","volume":"120","author":"Ratti","year":"2019","journal-title":"J Surg Oncol"},{"key":"2026050701220594500_ref18","doi-asserted-by":"crossref","first-page":"1007","DOI":"10.1200\/JCO.2022.40.16_suppl.1007","article-title":"NRG-BR002: a phase IIR\/III trial of standard of care systemic therapy with or without stereotactic body radiotherapy (SBRT) and\/or surgical resection (SR) for newly oligometastatic breast cancer (NCT02364557)","volume":"40","author":"ASCO","year":"2022","journal-title":"J Clin Oncol"},{"key":"2026050701220594500_ref19","doi-asserted-by":"publisher","first-page":"893","DOI":"10.1093\/jjco\/hyad077","article-title":"Metastasis-directed therapy for oligometastases in breast cancer","volume":"53","author":"Ishiba","year":"2023","journal-title":"Jpn J Clin Oncol"},{"key":"2026050701220594500_ref20","doi-asserted-by":"publisher","first-page":"156","DOI":"10.1097\/PPO.0000000000000436","article-title":"Radiation in the treatment of oligometastatic and oligoprogressive disease: rationale, recent data, and research questions","volume":"26","author":"Zayed","year":"2020","journal-title":"Cancer J"},{"key":"2026050701220594500_ref21","doi-asserted-by":"publisher","first-page":"2109","DOI":"10.1016\/j.jtho.2019.07.025","article-title":"Definition of synchronous oligometastatic non-small cell lung cancer-a consensus report","volume":"14","author":"Dingemans","year":"2019","journal-title":"J Thorac Oncol"},{"key":"2026050701220594500_ref22","doi-asserted-by":"publisher","first-page":"177","DOI":"10.1016\/j.radonc.2017.08.032","article-title":"Radical radiation therapy for oligometastatic breast cancer: results of a prospective phase II trial","volume":"126","author":"Trovo","year":"2018","journal-title":"Radiother Oncol"},{"key":"2026050701220594500_ref23","doi-asserted-by":"publisher","first-page":"45","DOI":"10.1016\/j.radonc.2018.11.022","article-title":"Oligometastatic breast cancer treated with hypofractionated stereotactic radiotherapy: some patients survive longer than a decade","volume":"131","author":"Milano","year":"2019","journal-title":"Radiother Oncol"},{"key":"2026050701220594500_ref24","doi-asserted-by":"publisher","first-page":"55","DOI":"10.1016\/j.breast.2019.10.016","article-title":"Stereotactic ablative body radiotherapy (SABR) for bone-only oligometastatic breast cancer: a prospective clinical trial","volume":"49","author":"David","year":"2020","journal-title":"Breast"},{"key":"2026050701220594500_ref25","doi-asserted-by":"crossref","first-page":"335","DOI":"10.1016\/S1010-7940(02)00331-7","article-title":"Results of lung metastasectomy from breast cancer: prognostic criteria on the basis of 467 cases of the International Registry of Lung Metastases","volume":"22","author":"Friedel","year":"2002","journal-title":"Eur J Cardiothorac Surg"},{"key":"2026050701220594500_ref26","doi-asserted-by":"crossref","first-page":"28","DOI":"10.1002\/cncr.11881","article-title":"Uncertain benefit from surgery in patients with lung metastases from breast carcinoma","volume":"100","author":"Planchard","year":"2004","journal-title":"Cancer"},{"key":"2026050701220594500_ref27","doi-asserted-by":"crossref","first-page":"485","DOI":"10.1007\/s10549-007-9747-9","article-title":"Favourable long-term results after surgical removal of lung metastases of breast cancer","volume":"110","author":"Yoshimoto","year":"2008","journal-title":"Breast Cancer Res Treat"},{"key":"2026050701220594500_ref28","doi-asserted-by":"crossref","first-page":"897","DOI":"10.1097\/01.sla.0000246847.02058.1b","article-title":"Is liver resection justified for patients with hepatic metastases from breast cancer?","volume":"244","author":"Adam","year":"2006","journal-title":"Ann Surg"},{"key":"2026050701220594500_ref29","doi-asserted-by":"publisher","first-page":"710","DOI":"10.1016\/j.surg.2011.12.017","article-title":"Resection of liver metastases from breast cancer: estrogen receptor status and response to chemotherapy before metastasectomy define outcome","volume":"151","author":"Abbott","year":"2012","journal-title":"Surgery"},{"key":"2026050701220594500_ref30","doi-asserted-by":"publisher","first-page":"512","DOI":"10.1007\/s12094-019-02155-2","article-title":"Resection of liver metastases from breast cancer: a multicentre analysis","volume":"22","author":"He","year":"2020","journal-title":"Clin Transl Oncol"},{"key":"2026050701220594500_ref31","doi-asserted-by":"publisher","first-page":"1170","DOI":"10.1016\/j.athoracsur.2012.11.043","article-title":"Prolonged overall survival after pulmonary metastasectomy in patients with breast cancer","volume":"95","author":"Meimarakis","year":"2013","journal-title":"Ann Thorac Surg"},{"key":"2026050701220594500_ref32","doi-asserted-by":"publisher","first-page":"700","DOI":"10.1016\/j.hpb.2016.05.014","article-title":"The role of liver-directed surgery in patients with hepatic metastasis from primary breast cancer: a multi-institutional analysis","volume":"18","author":"Margonis","year":"2016","journal-title":"HPB"},{"key":"2026050701220594500_ref33","doi-asserted-by":"crossref","first-page":"163","DOI":"10.2307\/2530299","article-title":"Nomograms for calculating the number of patients needed for a clinical trial with survival as an endpoint","volume":"38","author":"Schoenfeld","year":"1982","journal-title":"Biometrics"},{"key":"2026050701220594500_ref34","doi-asserted-by":"crossref","first-page":"659","DOI":"10.2307\/2336502","article-title":"Discrete sequential boundaries for clinical trials","volume":"70","author":"Lan","year":"1983","journal-title":"Biometrika"}],"container-title":["Japanese Journal of Clinical Oncology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/academic.oup.com\/jjco\/article-pdf\/56\/5\/659\/66640998\/hyag019.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/academic.oup.com\/jjco\/article-pdf\/56\/5\/659\/66640998\/hyag019.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,5,7]],"date-time":"2026-05-07T05:22:15Z","timestamp":1778131335000},"score":1,"resource":{"primary":{"URL":"https:\/\/academic.oup.com\/jjco\/article\/56\/5\/659\/8445438"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,1,30]]},"references-count":34,"journal-issue":{"issue":"5","published-online":{"date-parts":[[2026,1,30]]},"published-print":{"date-parts":[[2026,5,7]]}},"URL":"https:\/\/doi.org\/10.1093\/jjco\/hyag019","relation":{},"ISSN":["1465-3621"],"issn-type":[{"value":"1465-3621","type":"electronic"}],"subject":[],"published-other":{"date-parts":[[2026,5]]},"published":{"date-parts":[[2026,1,30]]}}}