[Chinese expert consensus on the diagnosis and treatment of breast carcinoma in situ].

In situ carcinomas of the breast constitute 15% to 30% of all newly diagnosed breast cancer cases. Although the concept of carcinoma in situ has been proposed for a long time, there is still a great controversy regarding the screening, diagnosis and treatment. This article attempts to reach some consensus on the management of ductal carcinoma in situ and lobular carcinoma in situ and provide references for clinicians in the following aspects: definition and classification, natural history and prognosis, diagnosis, local and systemic treatment for primary carcinoma in situ, recurrence risk and treatment approaches for recurrent cancers.