Ductal carcinoma in situ (DCIS), in which cancerous cells are confined to the milk ducts of the breast, is the most common form of non-invasive breast cancer. Diagnosed in more than 60,000 women in the U.S. each year, a significant increase over previous decades due to the widespread use of digital mammograms and MRIs, it is nearly always curable. Here, Eric Winer, MD, director of the Breast Oncology Center at the Susan F. Smith Center for Women’s Cancers at Dana-Farber, answers some common questions.
Q: Should DCIS be considered cancer?
It doesn’t matter what we call it. It matters that women have a conversation with their physician about what it is and what a diagnosis of the condition means. DCIS cells are true cancer cells, but they’re located entirely within the milk ducts of the breast.
Q: Is it a life-threatening condition?
A woman’s chance of dying from it is almost zero. The reason it is important is that, if left untreated, it has the potential to become invasive breast cancer.
Q: If I have calcifications in a breast, does that mean I have DCIS?
Most calcifications are not a sign of DCIS. In some cases, however, the appearance of certain calcifications on a mammogram increases the likelihood that DCIS is present.
Q: Do women with DCIS need to be treated?
Because of the risk that it is a forerunner of invasive breast cancer, we recommend treatment.
Q: What are the treatments?
Treatment typically includes surgery, sometimes followed by radiation and/or hormonal therapy. The type of surgery performed is usually a lumpectomy, in which only the abnormal tissue and a layer of surrounding tissue are removed. Sometimes a mastectomy is performed, in which the entire breast is removed. Mastectomy may be recommended if the DCIS is very extensive and the surgeon cannot remove it entirely with a lumpectomy.
Radiation therapy is generally given after a lumpectomy, although there is a great deal of debate over who should and shouldn’t receive radiotherapy after a diagnosis of DCIS. Occasionally, the drug tamoxifen is prescribed to prevent a recurrence.