Ductal carcinoma in situ (DCIS) is a non-invasive breast cancer. In DCIS, abnormal cells are contained in the milk ducts. It is called “in situ” (which means "in place") because the cells have not left the milk ducts to invade nearby breast tissue. DCIS is also called intraductal (within the milk ducts) carcinoma. You may also hear the terms “pre-invasive” or “pre-cancerous” to describe DCIS.
DCIS is non-invasive, but without treatment, the abnormal cells could turn into invasive cancer over time. Left untreated, about 20 to 30 percent of low grade DCIS will progress to invasive breast cancer . Higher grade DCIS may be more likely to turn into invasive cancer if left untreated.
At this time, health care providers cannot predict which cases of DCIS will progress to invasive breast cancer and which will not. Because DCIS might turn into invasive breast cancer, almost every case of DCIS is treated.
Surgery (with or without radiation therapy) is recommended for the treatment of all DCIS. Prognosis is usually excellent.
Learn more about DCIS and risk of invasive breast cancer.
Treatment guidelines for DCIS
Although the exact treatment for DCIS varies from person to person, guidelines help ensure quality care. These guidelines are based on the latest research and the consensus of experts. The American Society of Clinical Oncology (ASCO) and National Comprehensive Care Network (NCCN) are two respected organizations that regularly update and post their guidelines online. The National Cancer Institute (NCI) also has overviews of treatment options.
*Please note, the information provided within Komen Perspectives articles is only current as of the date of posting. Therefore, some information may be out of date at this time.