The diagnosis and management of ductal carcinoma in-situ of the breast.

Abstract

The widespread utilization of screening mammography has produced a shift in the stage of breast cancer at diagnosis in the US: Currently, 12% to 15% of newly diagnosed breast cancer cases annually are ductal carcinoma in-situ (DCIS). The diagnosis is made, in at least 90% of patients, with mammography. Only about 10% of patients will have a palpable mass. The accurate characterization and visualization of calcifications typically requires magnification of mammographic imaging. The morphology of the calcifications is generally considered to be the most important factor in differentiating benign from malignant formations. Round and uniform shapes are more likely to be benign, while linear and heterogeneous morphologies are associated with DCIS. Following a complete mammographic work-up, most suspicious lesions are potential candidates for a stereotactic core needle biopsy. Ten percent to 50% of patients initially diagnosed with atypical ductal hyperplasia by needle biopsy have subsequently been surgically diagnosed with cancer near the biopsy site. Due to this relatively high incidence of co-existent carcinoma, a needle biopsy diagnosis of atypical ductal hyperplasia necessitates subsequent surgical excision. The most important change in our thinking about DCIS was from a monolithic view, conceiving of DCIS as a single disease highly likely to invade if left untreated, to the realization that DCIS represents a non-obligate precursor with a variable risk of progression, depending on a combination of factors, such as histology, lesion, size, and margin status. In discussing treatment options, patients should understand that local recurrence following total mastectomy is rare and that this is the procedure of choice for disease that cannot be adequately encompassed with a breast-conserving approach. If the patient and her surgeon are in agreement about proceeding with a breast-conserving approach, there needs to be a clear understanding of the incidence and implications of local recurrence. In all such discussions with newly diagnosed patients, however, it is essential to emphasize the excellent prognosis with this disease, irrespective of the surgical approach.