Clinical outcomes using accelerated partial breast irradiation in patients with ductal carcinoma in situ.

BACKGROUND: Limited data exist on the use of accelerated partial breast irradiation (APBI) in patients with ductal carcinoma in situ (DCIS). The purpose of this analysis was to evaluate clinical outcomes after APBI in patients with DCIS. PATIENTS AND METHODS: Between December 2002 and December 2010, 99 patients with DCIS underwent APBI as part of their breast-conserving therapy (BCT). Partial breast irradiation techniques included interstitial brachytherapy, balloon-based brachytherapy, and 3-dimensional conformal radiotherapy (3D-CRT). Clinical outcomes including local recurrence, regional recurrence, disease-free survival (DFS), cause-specific survival, and overall survival (OS) were analyzed.
RESULTS: Mean follow up was 3.0 years, with a mean patient age of 61.8 years. At 5 years, the rates of local recurrence and regional recurrence were 1.4% and 0%, respectively. Overall survival was 94%, whereas cause-specific survival was 100%. No difference was noted in local control for each treatment technique. When comparing rates using the Eastern Cooperative Oncology Group (ECOG) E-5194 trial groupings, the rate of local recurrence in our cohort was 2.0% for patients with grade I/II disease < 2.5 cm and 0% for grade III < 1.0 cm, representing a 50% and 100% decrease, respectively, in local recurrence compared with excision alone.
CONCLUSIONS: Patients with DCIS treated with APBI had excellent clinical outcomes regardless of the APBI technique used. Until the publication of prospective phase III trials, these data confirm previous reports highlighting the efficacy of APBI in the treatment of noninvasive carcinoma of the breast.