Patients who develop ductal carcinoma or carcinoma of the breast generally require operative treatment of their disease process in conjunction with chemotherapy and/or radiation therapy. Ductal carcinoma in situ (DCIS) is a non-invasive process that most commonly presents as microcalcifications on screening mammography, and accordingly the incidence has increased substantially from the time that screening mammography became widespread. The rates at which DCIS progresses to an invasive process vary, but it is associated with an elevated risk of developing carcinoma and, accordingly, surgical treatment is the current standard of care. Diagnosis is made by an image-guided biopsy in which a core of tissue is interpreted by a histopathologist. DCIS represents a heterogeneous group of pathologic subtypes, with comedo-type necrosis representing cellular features that are associated with aggressive behavior and higher risk of progression to invasive cancer.

While standard treatment of DCIS formerly was mastectomy secondary to a high incidence of multicentric disease, current care for patients with DCIS largely allows for breast conservation techniques in appropriately selected patients. The Van Nuys Prognostic Index (VNPI) looks at three statistically significant predictors of local recurrence: tumor size, margin width, and pathologic classification. Patients who have increased predictors of recurrence undergo lumpectomy followed by radiation treatment rather than mastectomy, while patients with a low VNPI can undergo lumpectomy alone. Of note, a margin less than 1 cm is an independent predictor of recurrence and, accordingly, re-resection rather than radiation treatment is recommended. Although the recommendation for evaluation of the axilla with sentinel node biopsy in patients with DCIS is controversial, those patients with diffuse DCIS or pathologically aggressive features are generally considered appropriate candidates for sentinel lymph node biopsy. Additional adjuvant treatment with tamoxifen, an anti-estrogen drug, should also be considered on an individual basis as it has been shown to reduce both ipsilateral and contralateral breast cancer events.