Q: What is ductal carcinoma in situ (DCIS)?
A: The term "breast cancer" comprises a wide variety of lesions with a wide range of malignant potential. Ductal carcinoma in situ (DCIS) is the noninvasive form of breast cancer. Because no invasion is present, the likelihood of spread is minimal. Death due to DCIS is very rare; in fact, the life span of patients with DCIS is the same as those with no diagnosis of cancer.

Before mammography was commonplace, DCIS was considered to be less common. Many patients with DCIS had clinical symptoms, such as a breast lump or bloody nipple discharge.

Today, with more prevalent mammography, DCIS is relatively common. In fact, DCIS represents at least 18 percent of all newly diagnosed breast cancer cases in the United States. Most DCIS lesions currently detected are non palpable (cannot be felt with the fingertips) and are found by mammography.

Q. What is the current standard treatment for DCIS?
A. The treatment for most patients has been mastectomy in the past. Today, most patients with DCIS can be treated with breast-preserving surgery.

The National Surgical Adjuvant Breast & Bowel Project (NSABP) strongly advocates excision (lumpectomy) plus radiation therapy for all patients who elect to preserve their breast. This lowers the risk that the cancer will come back in the breast.  Overall survival is excellent with DCIS and not affected by radiation.

Not all DCIS patients electing breast preservation require postoperative radiation therapy. Some patients may benefit a great deal by the addition of postoperative radiation therapy - others possibly not at all. Research has shown that there are ways to select the patients with DCIS whose benefit from radiation therapy is so small that the side effects far outweigh the benefits.

Q. Who needs radiation therapy?
A. When tumors are high-grade (aggressive) and the margins are close or involved, radiation therapy may reduce the risk of local recurrence by a quantity that justifies its use.

Q. Is chemotherapy part of standard DCIS treatment?
A. There is no role for standard chemotherapy in patients with DCIS. Chemotherapy is a systemic form of treatment impacting the entire body. Since DCIS is noninvasive, cure comes with adequate local treatment. With that said, there may be a role for endocrine therapy in the form of tamoxifen to lower the risk of recurrence in the breast.

Q. What options should women discuss with their surgeons?
A. The surgeon treating the patient should carefully review all treatment options, to include, excision only, excision with radiation therapy, and mastectomy with and without breast reconstruction. Patients with wide margins, 10 mm or more, can be considered for excision alone depending on other characteristics of the DCIS. Patients with intermediate margins 1 to 9 mm should consider either re-excision or radiation therapy. Patients with lesions so large that they require mastectomy should consider a skin-sparing mastectomy with immediate reconstruction.