本研究的首要目的是探讨导管原位癌 (DCIS) 保乳手术 (BCS) 后患同侧浸润性乳腺癌 (iIBC) 的风险趋势。第二个目的是分析 DCIS 分级与 BCS 后发生 iIBC 风险之间的关联。在这项基于人群的回顾性队列研究中，荷兰癌症登记处收集了 1989 年至 2021 年期间诊断为 DCIS 并接受 BCS 的 25,719 名女性的信息。其中 19,034 人接受了辅助放射治疗 (RT)。使用 Kaplan-Meier 分析和 Cox 回归模型。共有 1135 名患者经历了 iIBC。 1989-1998年、1999-2008年和2009-2021年诊断的接受BCS但不进行RT的患者的iIBC的十年累积发病率分别为12.6%、9.0%和5.0%（P<0.001）。对于接受 BCS 和 RT 的患者，这些数字分别为 5.7%、3.7% 和 2.2% (P<0.001)。在多变量分析中，DCIS分级与iIBC的风险无关。自1989年以来，iIBC的风险大幅下降，甚至低于侵袭性对侧乳腺癌的风险。没有发现 DCIS 分级与 iIBC 存在显着关联，这强调需要更强大的预后因素来指导 DCIS 的治疗。© 2024。作者，获得 Springer Nature Limited 的独家许可。

The first aim of this study was to examine trends in the risk of ipsilateral invasive breast cancer (iIBC) after breast-conserving surgery (BCS) of ductal carcinoma in situ (DCIS). A second aim was to analyse the association between DCIS grade and the risk of iIBC following BCS.In this population-based, retrospective cohort study, the Netherlands Cancer Registry collected information on 25,719 women with DCIS diagnosed in the period 1989-2021 who underwent BCS. Of these 19,034 received adjuvant radiotherapy (RT). Kaplan-Meier analyses and Cox regression models were used.A total of 1135 patients experienced iIBC. Ten-year cumulative incidence rates of iIBC for patients diagnosed in the periods 1989-1998, 1999-2008 and 2009-2021 undergoing BCS without RT, were 12.6%, 9.0% and 5.0% (P < 0.001), respectively. For those undergoing BCS with RT these figures were 5.7%, 3.7% and 2.2%, respectively (P < 0.001). In the multivariable analyses, DCIS grade was not associated with the risk of iIBC.Since 1989 the risk of iIBC has decreased substantially and has become even lower than the risk of invasive contralateral breast cancer. No significant association of DCIS grade with iIBC was found, stressing the need for more powerful prognostic factors to guide the treatment of DCIS.© 2024. The Author(s), under exclusive licence to Springer Nature Limited.