DCIS is a localized, early-stage breast cancer in the milk passages (ducts) of the breast. In DCIS, the cancer has not grown into the surrounding breast tissue. “In situ” means “in place,” describing a cancer that has not spread out of the area of the body where it originally developed. Thus, DCIS remains in the ducts and has not spread to the fatty breast tissue, the lymph nodes, or any other part of the body. It is the most common type of in situ breast carcinoma.

DCIS cancer may be present in one or more of the ducts of the breast. It cannot usually be felt as a breast lump or other breast change, and is usually discovered on a mammogram. More women are learning that they have this condition because more are participating in mammographic breast screening.

A small number of women with DCIS may have symptoms such as a breast lump or fluid discharge from the nipple.

Breast cancer specialists grade DCIS as low, intermediate, or high, depending on the degree of abnormality of the cells. The higher the grade, the greater the risk that the DCIS will progress to an invasive cancer; however, the cure rate for DCIS is close to 100 percent when this cancer is treated properly.

DCIS deserves full and careful attention. The patient should take the time to learn about all of the treatment options available and work with the breast care team to determine the most appropriate course of care.

Care: Your physician will want to treat DCIS to prevent it from developing into an invasive breast cancer. The treatment may involve local excision of the cancer-lumpectomy, mastectomy, radiation therapy, or hormonal therapy.