Management of Ductal Carcinoma In Situ of the Breast: A Review.

IMPORTANCE Ductal carcinoma in situ (DCIS) of the breast represents a disease process that continues to increase in incidence with treatment paradigms that continue to evolve. Greater access to long-term data from large observational studies addressing the natural history of the disease has contributed to changes in treatment paradigms and put into question traditional management strategies. OBSERVATIONS While recent analyses have suggested that a more conservative approach to the management of DCIS without surgical intervention or radiation therapy may be advisable based on breast cancer mortality data, there is a lack of level 1 or prospective evidence to support the widespread adoption of these approaches. Currently, surgery remains the standard of care for the initial treatment of DCIS. Adjuvant radiation therapy (RT) has consistently demonstrated a reduction in the risk of local recurrence following breast-conserving surgery (BCS), even in "low-risk" populations of patients. Invasive recurrences following BCS are associated with increases in breast cancer mortality. Questions that remain to be answered include (1) what constitutes an acceptable risk of local recurrence, (2) what are the costs associated with managing local recurrences compared with RT given initially after BCS (particularly in light of data supporting shorter courses of RT), and (3) what are the benefits of endocrine therapy on local recurrence, and do they justify the additional toxic effects and potential noncompliance with their long-term administration? CONCLUSIONS AND RELEVANCE Surgery and RT remain standard of care treatment options in the management of DCIS. Future studies are required to identify cohorts of patients in which RT can be safely omitted as well as to evaluate whether short-course RT alone may represent a better option than endocrine therapy with respect to compliance, toxic effects, cost and local control following BCS.