{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,11,27]],"date-time":"2025-11-27T12:08:14Z","timestamp":1764245294781,"version":"3.46.0"},"reference-count":24,"publisher":"MDPI AG","issue":"23","license":[{"start":{"date-parts":[[2025,11,27]],"date-time":"2025-11-27T00:00:00Z","timestamp":1764201600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Cancers"],"abstract":"<jats:p>Background: Postoperative radiation therapy (RT) after lumpectomy reduces the risk of locoregional recurrence in ductal carcinoma in situ (DCIS). However, the potential association between RT and ischemic heart disease (IHD) remains uncertain. This nationwide cohort study evaluated the long-term impact of postoperative RT on IHD risk and overall survival (OS) in women with DCIS using real-world data from the Korean National Health Insurance Service (NHIS). Methods: Women diagnosed with DCIS who underwent breast-conserving surgery between 2003 and 2020 were identified from the NHIS claims database. Patients with invasive breast cancer, age under 20 years, a prior history of IHD, or missing smoking or body mass index (BMI) data were excluded. Multivariable Cox regression was performed to assess the association between postoperative RT, IHD incidence, and OS, adjusting for key cardiovascular risk factors. Results: Among 4633 eligible patients (RT, 2778; no RT, 1855), the median follow-up duration was 86.1 months, and baseline characteristics were well balanced between groups without major differences in cardiovascular risk factors. A total of 126 patients (3.4%) developed IHD, with a 10-year cumulative incidence of 4.7%. Older age, hypertension, and hyperlipidemia were independent risk factors for IHD, whereas postoperative RT was not significantly associated with increased IHD risk (hazard ratio [HR] = 1.07, 95% confidence interval [CI] = 0.77\u20131.48; p = 0.690). The 10-year OS rate was 98.0%, and postoperative RT remained an independent predictor of improved survival (HR = 0.47, 95% CI = 0.28\u20130.79; p = 0.004). Conclusions: Postoperative RT did not increase the long-term risk of IHD but was associated with improved OS in patients with DCIS. These findings provide population-based evidence supporting the cardiac safety and oncologic efficacy of postoperative RT, while recognizing that unmeasured differences in health behavior or medical care utilization could have contributed to the observed survival benefit.<\/jats:p>","DOI":"10.3390\/cancers17233805","type":"journal-article","created":{"date-parts":[[2025,11,27]],"date-time":"2025-11-27T11:50:13Z","timestamp":1764244213000},"page":"3805","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Impact of Postoperative Radiotherapy on the Risk of Ischemic Heart Disease and Survival in Patients with Ductal Carcinoma In Situ: A Nationwide Claims-Based Cohort Study"],"prefix":"10.3390","volume":"17","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-8240-3641","authenticated-orcid":false,"given":"Van Hung","family":"Nguyen","sequence":"first","affiliation":[{"name":"Oncology Center, Hanoi Medical University Hospital, Hanoi 100000, Vietnam"},{"name":"Department of Radiation Oncology, Ajou University School of Medicine, 164 Worldcup-ro, Yeongtong-gu, Suwon 16499, Republic of Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Seung Yeun","family":"Chung","sequence":"additional","affiliation":[{"name":"Department of Radiation Oncology, Ajou University School of Medicine, 164 Worldcup-ro, Yeongtong-gu, Suwon 16499, Republic of Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9066-780X","authenticated-orcid":false,"given":"O Kyu","family":"Noh","sequence":"additional","affiliation":[{"name":"Department of Radiation Oncology, Ajou University School of Medicine, 164 Worldcup-ro, Yeongtong-gu, Suwon 16499, Republic of Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2025,11,27]]},"reference":[{"key":"ref_1","first-page":"135","article-title":"The American Cancer Society\u2019s Facts & Figures: 2020 Edition","volume":"11","author":"Viale","year":"2020","journal-title":"J. Adv. Pract. Oncol."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"912","DOI":"10.2214\/AJR.20.23314","article-title":"Digital Mammography Has Persistently Increased High-Grade and Overall DCIS Detection Without Altering Upgrade Rate","volume":"216","author":"Neal","year":"2021","journal-title":"AJR Am. J. Roentgenol."},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Early Breast Cancer Trialists\u2019 Collaborative Group (EBCTCG), Correa, C., McGale, P., Taylor, C., Wang, Y., Clarke, M., Davies, C., Peto, R., Bijker, N., and Solin, L. (2010). Overview of the randomized trials of radiotherapy in ductal carcinoma in situ of the breast. J. Natl. Cancer Inst. Monogr., 2010, 162\u2013177.","DOI":"10.1093\/jncimonographs\/lgq039"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"478","DOI":"10.1093\/jnci\/djr027","article-title":"Long-term outcomes of invasive ipsilateral breast tumor recurrences after lumpectomy in NSABP B-17 and B-24 randomized clinical trials for DCIS","volume":"103","author":"Wapnir","year":"2011","journal-title":"J. Natl. Cancer Inst."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"4054","DOI":"10.1200\/JCO.2013.49.5077","article-title":"Breast-conserving treatment with or without radiotherapy in ductal carcinoma In Situ: 15-year recurrence rates and outcome after a recurrence, from the EORTC 10853 randomized phase III trial","volume":"31","author":"Donker","year":"2013","journal-title":"J. Clin. Oncol."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"e005633","DOI":"10.1161\/JAHA.117.005633","article-title":"Long-Term Cardiovascular Risk After Radiotherapy in Women With Breast Cancer","volume":"6","author":"Cheng","year":"2017","journal-title":"J. Am. Heart Assoc."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"167","DOI":"10.1016\/j.radonc.2011.06.016","article-title":"Incidence of heart disease in 35,000 women treated with radiotherapy for breast cancer in Denmark and Sweden","volume":"100","author":"McGale","year":"2011","journal-title":"Radiother. Oncol."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"473","DOI":"10.1016\/j.ijrobp.2020.12.053","article-title":"Risk of Cardiac Disease in Patients With Breast Cancer: Impact of Patient-Specific Factors and Individual Heart Dose From Three-Dimensional Radiation Therapy Planning","volume":"110","author":"Chung","year":"2021","journal-title":"Int. J. Radiat. Oncol. Biol. Phys."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"987","DOI":"10.1056\/NEJMoa1209825","article-title":"Risk of ischemic heart disease in women after radiotherapy for breast cancer","volume":"368","author":"Darby","year":"2013","journal-title":"N. Engl. J. Med."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"106","DOI":"10.1016\/j.radonc.2021.01.010","article-title":"Risk of coronary artery disease after adjuvant radiotherapy in 29,662 early breast cancer patients: A population-based Danish Breast Cancer Group study","volume":"157","author":"Milo","year":"2021","journal-title":"Radiother. Oncol."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"95","DOI":"10.1007\/s10549-018-4803-1","article-title":"Risk of ischemic heart disease after radiotherapy for ductal carcinoma in situ","volume":"171","author":"Wadsten","year":"2018","journal-title":"Breast Cancer Res. Treat."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"dju156","DOI":"10.1093\/jnci\/dju156","article-title":"Cardiovascular morbidity and mortality after treatment for ductal carcinoma in situ of the breast","volume":"106","author":"Boekel","year":"2014","journal-title":"J. Natl. Cancer Inst."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"470","DOI":"10.1111\/j.1524-4741.2011.01122.x","article-title":"Cardiac morbidity and mortality in women with ductal carcinoma in situ of the breast treated with breast conservation therapy","volume":"17","author":"Park","year":"2011","journal-title":"Breast J."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"e111","DOI":"10.3346\/jkms.2025.40.e111","article-title":"Leveraging National Health Insurance Service Data for Public Health Research in Korea: Structure, Applications, and Future Directions","volume":"40","author":"Lim","year":"2025","journal-title":"J. Korean Med. Sci."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"3571","DOI":"10.21873\/anticanres.16535","article-title":"Recent Postoperative Radiotherapy for Left-sided Breast Cancer Does Not Increase Mortality of Heart Disease in Asians or Pacific Islanders: SEER Database Analysis","volume":"43","author":"Jingu","year":"2023","journal-title":"Anticancer. Res."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"112","DOI":"10.1515\/raon-2018-0008","article-title":"Voluntary Deep Inspiration Breath-hold Reduces the Heart Dose Without Compromising the Target Volume Coverage During Radiotherapy for Left-sided Breast Cancer","volume":"52","author":"Caparrotti","year":"2018","journal-title":"Radiol. Oncol."},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Lu, Y., Ma, Y., Yang, D., Li, Y., Yuan, W., Tang, F., Xu, L., Zhou, L., Lin, H., and Li, B. (2023). Cardiorespiratory dose comparison among six radiotherapy regimens for patients with left-sided breast cancer. Sci. Rep., 13.","DOI":"10.1038\/s41598-023-40577-9"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"3122","DOI":"10.1161\/01.CIR.0000133187.74800.B9","article-title":"Cardiovascular complications of cancer therapy: Diagnosis, pathogenesis, and management","volume":"109","author":"Yeh","year":"2004","journal-title":"Circulation"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"249","DOI":"10.3857\/roj.2019.00577","article-title":"Recent trends in intensity-modulated radiation therapy use in Korea","volume":"37","author":"Huh","year":"2019","journal-title":"Radiat. Oncol. J."},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Prunaretty, J., Bourgier, C., Gourgou, S., Lemanski, C., Azria, D., and Fenoglietto, P. (2022). Different meaning of the mean heart dose between 3D-CRT and IMRT for breast cancer radiotherapy. Front. Oncol., 12.","DOI":"10.3389\/fonc.2022.1066915"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"365","DOI":"10.1093\/jnci\/djk064","article-title":"Long-term risk of cardiovascular disease in 10-year survivors of breast cancer","volume":"99","author":"Hooning","year":"2007","journal-title":"J. Natl. Cancer Inst."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"117","DOI":"10.3390\/epidemiologia4020012","article-title":"Screening and Surveillance Bias in Cancer","volume":"4","author":"Tancredi","year":"2023","journal-title":"Epidemiologia"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"105","DOI":"10.1007\/s10549-019-05372-z","article-title":"Survival benefit of postoperative radiotherapy for ductal carcinoma in situ after breast-conserving surgery: A Korean population-based cohort study","volume":"178","author":"Kim","year":"2019","journal-title":"Breast Cancer Res. Treat."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"972","DOI":"10.1001\/jama.2024.26698","article-title":"Active Monitoring With or Without Endocrine Therapy for Low-Risk Ductal Carcinoma In Situ: The COMET Randomized Clinical Trial","volume":"333","author":"Hwang","year":"2024","journal-title":"JAMA"}],"container-title":["Cancers"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-6694\/17\/23\/3805\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,11,27]],"date-time":"2025-11-27T12:04:45Z","timestamp":1764245085000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-6694\/17\/23\/3805"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,11,27]]},"references-count":24,"journal-issue":{"issue":"23","published-online":{"date-parts":[[2025,12]]}},"alternative-id":["cancers17233805"],"URL":"https:\/\/doi.org\/10.3390\/cancers17233805","relation":{},"ISSN":["2072-6694"],"issn-type":[{"value":"2072-6694","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,11,27]]}}}