{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,23]],"date-time":"2026-10-23T20:06:38Z","timestamp":1792785998984,"version":"4.5.0"},"reference-count":34,"publisher":"Oxford University Press (OUP)","license":[{"start":{"date-parts":[[2026,7,21]],"date-time":"2026-07-21T00:00:00Z","timestamp":1784592000000},"content-version":"am","delay-in-days":0,"URL":"https:\/\/academic.oup.com\/pages\/standard-publication-reuse-rights"}],"funder":[{"name":"the National Research Foundation of Korea","award":["RS-2025- 00558296"],"award-info":[{"award-number":["RS-2025- 00558296"]}],"id":[{"id":"https:\/\/ror.org\/013aysd81","id-type":"ROR","asserted-by":"crossref"}]},{"name":"the Korean Foundation for Cancer Research 2025","award":["202500000003880"],"award-info":[{"award-number":["202500000003880"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>Although smoking is associated with lower breast density but increased breast cancer risk, its association with longitudinal changes in breast density remains unclear. We sought to examine associations among smoking status, breast density, changes in breast density, and subsequent breast cancer risk.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>We conducted a nationwide, population-based cohort study of 4.7 million cancer-free women aged at least 40\u2009years who had participated in the Korean National Breast Cancer Screening Program from 2009 to 2010. Of these cancer-free women, 4.2 million who had subsequently undergone screening between 2011 and 2016 were included for changes in breast density. Breast density was assessed using Breast Imaging Reporting &amp; Data System categories, and changes were evaluated among women with repeated screenings from 2011 to 2016. Breast cancer incidence was ascertained using medical records from the National Health Insurance Service National Health Information Database until December 31, 2023.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>Former and current smokers had lower odds of dense breasts than did never smokers (odds ratio [OR]\u2009=\u20090.94, 95% CI = 0.92 to 0.95, vs OR = 0.88, 95% CI = 0.87 to 0.89). Longer smoking durations, greater daily cigarette use, and greater pack-years were associated with progressively lower odds of having dense breasts. Smokers showed a reduced likelihood of increased density (OR = 0.95, 95% CI = 0.94 to 0.96) and a higher likelihood of decreased density (OR = 1.07, 95% CI = 1.06 to 1.09), particularly among premenopausal women. Smoking was linked to a higher breast cancer risk, especially among postmenopausal women; adjustments for density and density changes did not alter these associations.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>Smoking was associated with lower baseline breast density and greater density decline but increased breast cancer risk in a dose-dependent manner. These findings suggest that the carcinogenic effects of smoking on breast cancer are independent of breast density or its changes, as measured using 4 broad categories.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1093\/jnci\/djag231","type":"journal-article","created":{"date-parts":[[2026,7,12]],"date-time":"2026-07-12T11:38:16Z","timestamp":1783856296000},"source":"Crossref","is-referenced-by-count":0,"title":["Association between smoking habits and breast density, changes in breast density, and breast cancer in Asian women"],"prefix":"10.1093","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-1902-3184","authenticated-orcid":false,"given":"Boyoung","family":"Park","sequence":"first","affiliation":[{"name":"Department of Preventive Medicine, Hanyang University College of Medicine , Seoul,","place":["Republic of Korea"]},{"name":"Hanyang Institute of Bioscience and Biotechnology, Hanyang University , Seoul,","place":["Republic of Korea"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Junghyun","family":"Yoon","sequence":"additional","affiliation":[{"name":"Department of Preventive Medicine, Hanyang University College of Medicine , Seoul,","place":["Republic of Korea"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7720-4552","authenticated-orcid":false,"given":"Somin","family":"Jeon","sequence":"additional","affiliation":[{"name":"Department of Preventive Medicine, Hanyang University College of Medicine , Seoul,","place":["Republic of Korea"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2954-4792","authenticated-orcid":false,"given":"Thi Huyen Trang","family":"Nguyen","sequence":"additional","affiliation":[{"name":"Department of Preventive Medicine, Hanyang University College of Medicine , Seoul,","place":["Republic of Korea"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8534-2127","authenticated-orcid":false,"given":"Yoonyoung","family":"Jang","sequence":"additional","affiliation":[{"name":"Center for Cohort Studies, Total Healthcare Center, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine , Seoul,","place":["Republic of Korea"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"286","published-online":{"date-parts":[[2026,7,21]]},"reference":[{"key":"2026092206155613500_djag231-B1","doi-asserted-by":"publisher","first-page":"62","DOI":"10.1016\/j.breast.2022.09.007","article-title":"Mammographic breast density and the risk of breast cancer: a systematic review and meta-analysis","volume":"66","author":"Bodewes","year":"2022","journal-title":"Breast"},{"key":"2026092206155613500_djag231-B2","doi-asserted-by":"publisher","first-page":"407","DOI":"10.1097\/cej.0000000000000878","article-title":"Associations between breast cancer risk factors and mammographic breast density in a large cross-section of Korean women","volume":"33","author":"Kim","year":"2024","journal-title":"Eur J Cancer Prev"},{"key":"2026092206155613500_djag231-B3","doi-asserted-by":"publisher","first-page":"53","DOI":"10.4103\/jrms.jrms_962_21","article-title":"The epidemiologic factors associated with breast density: a review","volume":"27","author":"Ye","year":"2022","journal-title":"J Res Med Sci"},{"key":"2026092206155613500_djag231-B4","doi-asserted-by":"publisher","first-page":"pkaa010","DOI":"10.1093\/jncics\/pkaa010","article-title":"Determinants of mammographic breast density by race among a large screening population","volume":"4","author":"Moore","year":"2020","journal-title":"JNCI Cancer Spectr"},{"key":"2026092206155613500_djag231-B5","doi-asserted-by":"publisher","first-page":"e36905","DOI":"10.1097\/md.0000000000036905","article-title":"Breast cancer: a review of risk factors and diagnosis","volume":"103","author":"Obeagu","year":"2024","journal-title":"Medicine (Baltimore)"},{"key":"2026092206155613500_djag231-B6","doi-asserted-by":"publisher","first-page":"1356014","DOI":"10.3389\/fonc.2024.1356014","article-title":"A contemporary review of breast cancer risk factors and the role of artificial intelligence","volume":"14","author":"Nicolis","year":"2024","journal-title":"Front Oncol"},{"key":"2026092206155613500_djag231-B7","doi-asserted-by":"publisher","first-page":"511","DOI":"10.1097\/cej.0000000000000310","article-title":"Adiposity, breast density, and breast cancer risk: epidemiological and biological considerations","volume":"26","author":"Soguel","year":"2017","journal-title":"Eur J Cancer Prev"},{"key":"2026092206155613500_djag231-B8","doi-asserted-by":"publisher","DOI":"10.3390\/cancers13194805","article-title":"Mammographic density changes over time and breast cancer risk: a systematic review and meta-analysis","volume":"13","author":"Mokhtary","year":"2021","journal-title":"Cancers (Basel)"},{"key":"2026092206155613500_djag231-B9","doi-asserted-by":"publisher","first-page":"2674","DOI":"10.1002\/ijc.33455","article-title":"Association between changes in mammographic density category and the risk of breast cancer: a nationwide cohort study in East-Asian women","volume":"148","author":"Kim","year":"2021","journal-title":"Int J Cancer"},{"key":"2026092206155613500_djag231-B10","doi-asserted-by":"publisher","first-page":"e079575","DOI":"10.1136\/bmj-2024-079575","article-title":"Trajectories of breast density change over time and subsequent breast cancer risk: longitudinal study","volume":"387","author":"Park","year":"2024","journal-title":"BMJ"},{"key":"2026092206155613500_djag231-B11","doi-asserted-by":"publisher","first-page":"166","DOI":"10.1186\/s13058-024-01917-3","article-title":"Longitudinal history of mammographic breast density and breast cancer risk by familial risk, menopausal status, and initial mammographic density level in a high risk cohort: a nested case\u2013control study","volume":"26","author":"Tehranifar","year":"2024","journal-title":"Breast Cancer Res"},{"key":"2026092206155613500_djag231-B12","doi-asserted-by":"publisher","first-page":"135","DOI":"10.1007\/s10549-011-1414-5","article-title":"Alcohol, tobacco, and mammographic density: a population-based study","volume":"129","author":"Cabanes","year":"2011","journal-title":"Breast Cancer Res Treat"},{"key":"2026092206155613500_djag231-B13","doi-asserted-by":"publisher","first-page":"1039","DOI":"10.1158\/1055-9965.Epi-19-0348","article-title":"Alcohol and tobacco use in relation to mammographic density in 23,456 women","volume":"29","author":"McBride","year":"2020","journal-title":"Cancer Epidemiol Biomarkers Prev"},{"key":"2026092206155613500_djag231-B14","doi-asserted-by":"publisher","first-page":"271","DOI":"10.1007\/s10552-015-0704-3","article-title":"Cigarette smoking and mammographic density in the Danish diet, cancer and health cohort","volume":"27","author":"Jacobsen","year":"2016","journal-title":"Cancer Causes Control"},{"key":"2026092206155613500_djag231-B15","doi-asserted-by":"publisher","first-page":"301","DOI":"10.1007\/s10552-009-9462-4","article-title":"Active, but not passive cigarette smoking was inversely associated with mammographic density","volume":"21","author":"Butler","year":"2010","journal-title":"Cancer Causes Control"},{"key":"2026092206155613500_djag231-B16","doi-asserted-by":"publisher","first-page":"R73","DOI":"10.1186\/bcr1782","article-title":"Different measures of smoking exposure and mammographic density in postmenopausal Norwegian women: a cross-sectional study","volume":"9","author":"Bremnes","year":"2007","journal-title":"Breast Cancer Research"},{"key":"2026092206155613500_djag231-B17","doi-asserted-by":"publisher","first-page":"1335645","DOI":"10.3389\/fonc.2024.1335645","article-title":"Cigarette smoking and mammographic breast density in post-menopausal women from the EPIC Florence cohort","volume":"14","author":"Bendinelli","year":"2024","journal-title":"Front Oncol"},{"key":"2026092206155613500_djag231-B18","doi-asserted-by":"publisher","first-page":"1764","DOI":"10.3346\/jkms.2017.32.11.1764","article-title":"Using the national health information database of the national health insurance service in Korea for monitoring mortality and life expectancy at national and local levels","volume":"32","author":"Bahk","year":"2017","journal-title":"J Korean Med Sci"},{"key":"2026092206155613500_djag231-B19","doi-asserted-by":"publisher","first-page":"e2025031","DOI":"10.4178\/epih.e2025031","article-title":"Socioeconomic inequality in organized and opportunistic screening for breast cancer: results from the Korean National Cancer Screening Survey, 2009-2021","volume":"47","author":"Ha","year":"2025","journal-title":"Epidemiol Health."},{"key":"2026092206155613500_djag231-B20","doi-asserted-by":"publisher","first-page":"330","DOI":"10.4143\/crt.2020.263","article-title":"Trends in cancer screening rates among Korean men and women: results of the Korean national cancer screening survey, 2004\u20132018","volume":"53","author":"Hong","year":"2021","journal-title":"Cancer Res Treat"},{"key":"2026092206155613500_djag231-B21","doi-asserted-by":"publisher","first-page":"352","DOI":"10.4143\/crt.2021.044","article-title":"Validation of cancer diagnosis based on the national health insurance service database versus the national cancer registry database in Korea","volume":"54","author":"Yang","year":"2022","journal-title":"Cancer Res Treat"},{"key":"2026092206155613500_djag231-B22","doi-asserted-by":"publisher","first-page":"491","DOI":"10.1530\/eje.1.01867","article-title":"Smoking and hormones in health and endocrine disorders","volume":"152","author":"Kapoor","year":"2005","journal-title":"Eur J Endocrinol"},{"key":"2026092206155613500_djag231-B23","first-page":"105","article-title":"The effects of smoking on estradiol metabolism","volume":"56","author":"Tansavatdi","year":"2004","journal-title":"Minerva Ginecol"},{"key":"2026092206155613500_djag231-B24","doi-asserted-by":"publisher","first-page":"pkz004","DOI":"10.1093\/jncics\/pkz004","article-title":"Determinants of mammographic density change","volume":"3","author":"Azam","year":"2019","journal-title":"JNCI Cancer Spectr"},{"key":"2026092206155613500_djag231-B25","doi-asserted-by":"publisher","first-page":"548","DOI":"10.1093\/oncolo\/oyac084","article-title":"Association between lifestyle changes, mammographic breast density, and breast cancer","volume":"27","author":"Lester","year":"2022","journal-title":"Oncologist"},{"key":"2026092206155613500_djag231-B26","doi-asserted-by":"publisher","first-page":"2794603","DOI":"10.1155\/2023\/2794603","article-title":"Factors associated with longitudinal changes in mammographic density in a multiethnic breast screening cohort of postmenopausal women","volume":"2023","author":"Park","year":"2023","journal-title":"Breast J"},{"key":"2026092206155613500_djag231-B27","doi-asserted-by":"publisher","first-page":"1313","DOI":"10.1038\/bjc.1996.536","article-title":"Cigarette smoking and urinary oestrogen excretion in premenopausal and post-menopausal women","volume":"74","author":"Key","year":"1996","journal-title":"Br J Cancer."},{"key":"2026092206155613500_djag231-B28","doi-asserted-by":"publisher","first-page":"1285","DOI":"10.1289\/ehp.7899","article-title":"Cigarette smoking and effects on hormone function in premenopausal women","volume":"113","author":"Windham","year":"2005","journal-title":"Environ Health Perspect"},{"key":"2026092206155613500_djag231-B29","doi-asserted-by":"publisher","first-page":"905","DOI":"10.1007\/s12282-025-01715-5","article-title":"Meta-analysis of smoking and breast cancer risk: by age of smoking initiation","volume":"32","author":"Peng","year":"2025","journal-title":"Breast Cancer"},{"key":"2026092206155613500_djag231-B30","doi-asserted-by":"publisher","first-page":"640","DOI":"10.2188\/jea.JE20220206","article-title":"Dose-response relationships between cigarette smoking and breast cancer risk: a systematic review and meta-analysis","volume":"33","author":"Scala","year":"2023","journal-title":"J Epidemiol"},{"key":"2026092206155613500_djag231-B31","doi-asserted-by":"publisher","first-page":"1273","DOI":"10.1158\/1055-9965.Epi-24-0005","article-title":"Systematic review and meta-analysis of lifestyle and reproductive factors associated with risk of breast cancer in Asian women","volume":"33","author":"Ang","year":"2024","journal-title":"Cancer Epidemiol Biomarkers Prev"},{"key":"2026092206155613500_djag231-B32","doi-asserted-by":"publisher","first-page":"15","DOI":"10.1186\/s13058-024-01766-0","article-title":"Differential patterns of reproductive and lifestyle risk factors for breast cancer according to birth cohorts among women in China, Japan and Korea","volume":"26","author":"Nabila","year":"2024","journal-title":"Breast Cancer Research"},{"key":"2026092206155613500_djag231-B33","doi-asserted-by":"publisher","first-page":"894","DOI":"10.1016\/j.amepre.2022.07.001","article-title":"Longitudinal changes in smoking habits in women and subsequent risk of cancer","volume":"63","author":"Tran","year":"2022","journal-title":"Am J Prev Med"},{"key":"2026092206155613500_djag231-B34","volume-title":"Epidemiology: Beyond the Basics","author":"Szklo","year":"2014"}],"container-title":["JNCI: Journal of the National Cancer Institute"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/academic.oup.com\/jnci\/advance-article-pdf\/doi\/10.1093\/jnci\/djag231\/69696686\/djag231.pdf","content-type":"application\/pdf","content-version":"am","intended-application":"syndication"},{"URL":"https:\/\/academic.oup.com\/jnci\/advance-article-pdf\/doi\/10.1093\/jnci\/djag231\/69696686\/djag231.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,9,22]],"date-time":"2026-09-22T10:16:36Z","timestamp":1790072196000},"score":1,"resource":{"primary":{"URL":"https:\/\/academic.oup.com\/jnci\/advance-article\/doi\/10.1093\/jnci\/djag231\/8739203"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,7,21]]},"references-count":34,"URL":"https:\/\/doi.org\/10.1093\/jnci\/djag231","relation":{},"ISSN":["0027-8874","1460-2105"],"issn-type":[{"value":"0027-8874","type":"print"},{"value":"1460-2105","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,7,21]]},"article-number":"djag231"}}