Favorable Cosmesis and Local Control for Single-Lumen and Multilumen Applicators for Accelerated Partial Breast Irradiation for Early-Stage Breast Cancer

Abstract

The current standard for early-stage breast cancer is whole-breast irradiation. However, more patients are now being offered Accelerated Partial Breast Irradiation (APBI). This study was undertaken to assess/report our institution’s experience with this modality of treatment. We are comparing clinical outcomes in 55 [39 multi-lumen (ML) and 16 single-lumen (SL)] patients treated with APBI devices. Fifty-eight consecutive patients with early-stage (Tis, T1, or T2) breast cancer were treated between September 2006 and April 2012. 3 patients were excluded for having prior ipsilateral breast cancer. All patients were surgically treated with lumpectomies and APBI; chemotherapy and hormone therapy were administered when appropriate. Patients in both cohorts were treated with 3400 cGy in 10 fractions of 340 cGy in 5 business days. Statistical analysis was performed by use of the Log-Rank and Wilcoxon tests. Overall survival was determined by the Kaplan-Meier method. All patients (n = 55) presented with a median age of 67 years. A majority of patients (56%) were of Asian descent, followed by White (27%), Hispanic (13%), and Black (4%). Due to regional ethnic distribution in the South Bay Area we observed an increased percentage of Asian patients in our study. Patients initially presented as: 21 Tis (38%), 30 T1 (55%), and 4 T2 (7%). Of the 55 patients, only 2 patients experienced a recurrence: 1 patient locally (1.8%) and 1 patient regionally (1.8%). The patient that recurred regionally recurred in the axilla (which was not treated). Overall, there was a not a statistically significant difference between ML and SL cohorts for local and regional control. In addition, no significant difference of reported cosmetic outcomes was observed in either cohort. 67% of patients reported excellent cosmetic outcome in the ML cohort and 69% reported an excellent cosmetic outcome in the SL cohort. At last follow-up all 55 patients had no evidence of disease. The median follow-up time was 35.3 months with an overall 5-year survival of 98%. APBI is a viable treatment option in early-stage breast cancer as the local control and cosmesis are favorable. At the outset of this study, we anticipated a difference in the SL versus the ML cohorts. There was no significant difference between the local control rate, regional control rate, and cosmesis of SL versus ML devices. However, due to our small cohort of SL devices, a further investigation is needed to validate the efficacy of SL devices versus ML devices.