Ductal carcinoma in situ of the breast is a heterogeneous group of lesions with diverse malignant potential.
Most new cases are nonpalpable and discovered mammographically.
Treatment is controversial and ranges from excision only, to excision with radiation therapy, to mastectomy. Nonrandomized single facility series suggest that age, family history, nuclear grade, comedonecrosis, tumor size and margin width are all important factors in predicting local recurrence and that one or more of these factors could be used to select subgroups of patients who do not benefit sufficiently from radiation therapy to merit its use. Genetic changes routinely precede morphologic evidence of malignant transformation. Lessons learned from ongoing basic science research will help us to identify those DCIS lesions that are unlikely to progress and to prevent progression in the rest.