Ductal carcinoma in situ (DCIS) is considered the earliest form of breast cancer. In DCIS, abnormal cells multiply and form a growth within a milk duct of your breast. DCIS is noninvasive, meaning it hasn’t spread out of the milk duct to invade other parts of the breast.
DCIS is usually found during mammogram screenings, but it can be difficult to detect. Because of increased screening with mammograms, the rate at which DCIS is diagnosed has increased dramatically in recent years.
While DCIS isn’t life-threatening, it does require treatment to prevent the condition from becoming invasive. Most women with DCIS are effectively treated with breast-conserving surgery and radiation.