Ductal carcinoma in situ (DCIS) represents pre-invasive breast carcinoma. In untreated cases, 25–60% DCIS progress to invasive ductal carcinoma (IDC). The challenge lies in distinguishing between non-progressive and progressive DCIS, often resulting in over- or under-treatment in many cases. With increasing screen-detected DCIS in these years, the nature of DCIS has aroused worldwide attention. A deeper understanding of the biological nature of DCIS and the molecular journey of the DCIS-IDC transition is crucial for more effective clinical management. Here, we reviewed the key signaling pathways in breast cancer that may contribute to DCIS initiation and progression. We also explored the molecular features of DCIS and IDC, shedding light on the progression of DCIS through both inherent changes within tumor cells and alterations in the tumor microenvironment. In addition, valuable research tools utilized in studying DCIS including preclinical models and newer advanced technologies such as single-cell sequencing, spatial transcriptomics and artificial intelligence, have been systematically summarized. Further, we thoroughly discussed the clinical advancements in DCIS and IDC, including prognostic biomarkers and clinical managements, with the aim of facilitating more personalized treatment strategies in the future. Research on DCIS has already yielded significant insights into breast carcinogenesis and will continue to pave the way for practical clinical applications.

导管原位癌（DCIS）代表浸润前乳腺癌。在未经治疗的病例中，25-60% 的 DCIS 会进展为浸润性导管癌 (IDC)。挑战在于区分非进展性和进展性导管原位癌，在许多情况下常常导致治疗过度或治疗不足。近年来，随着屏幕检测DCIS的增多，DCIS的性质引起了全世界的关注。更深入地了解 DCIS 的生物学性质以及 DCIS-IDC 转变的分子历程对于更有效的临床管理至关重要。在这里，我们回顾了乳腺癌中可能导致 DCIS 发生和进展的关键信号通路。我们还探索了 DCIS 和 IDC 的分子特征，通过肿瘤细胞内的固有变化和肿瘤微环境的改变揭示了 DCIS 的进展。此外，系统总结了用于研究DCIS的有价值的研究工具，包括临床前模型和单细胞测序、空间转录组学和人工智能等较新的先进技术。此外，我们还深入讨论了 DCIS 和 IDC 的临床进展，包括预后生物标志物和临床管理，旨在促进未来更加个性化的治疗策略。 DCIS 的研究已经对乳腺癌发生产生了重要的见解，并将继续为实际临床应用铺平道路。