Clinical practice guidelines for the care and treatment of breast cancer

Abstract

"he original recommendations. DCIS of the breast is a proliferation of malignantappearing cells of the ducts and terminal lobular units of the breast that have not breached the ductal basement membrane. Since more women are having screening mammography, DCIS is being diagnosed more frequently. In 1996, over 200 000 Canadian women aged 50–69 participated in 7 provincial screening programs. Of the 991 cancers detected, 171 were DCIS (17%, or 0.8 cases per 1000 women screened).2 DCIS can be considered a precursor of invasive breast cancer and, if left untreated, can develop into invasive disease in up to 35% of cases within 10 years."