Is Accelerated Partial Breast Irradiation Appropriate Adjuvant Therapy for Patients with Ductal Carcinoma In-Situ?

Abstract

Introduction: Accelerated partial breast irradiation (APBI) using high-dose rate (HDR) balloon catheter breast brachytherapy following wide segmental resection of the breast has been shown to be equivalent to whole breast irradiation (WB-XRT) in the treatment of stage-I breast carcinoma. Because the majority of all breast cancers recur in the same quadrant as the original tumor, the advantages of this treatment compared with WB-XRT include concentration of radiation in the area where cancer is most likely to recur, shorter treatment duration, and greater patient acceptance. This study examined the rate of local/regional recurrence in patients diagnosed with stage-0 breast cancer, specifically ductal carcinoma in-situ (DCIS), following wide segmental resection of the breast and treatment with APBI using HDR balloon catheter breast brachytherapy.Methods: An IRB-approved, single-institution, retrospective chart review was conducted identifying 40 patients diagnosed with stage-0 breast cancer between March, 2004 and April, 2008 who were treated with wide segmental resection of the breast followed by APBI using HDR MammoSite™ balloon catheter breast brachytherapy. Outcome measures included rates of same-quadrant recurrence, ipsilateral second-primary occurrence, and regional recurrence.Results: Patient age ranged from 44 to 89 years (median = 69 years) with a median follow-up of 40 months (range: 16 to 60 months). All 40 patients had DCIS. One patient of 40 (2.5%) had DCIS with an additional focus of lobular carcinoma in-situ. 29 of 40 patients (72.5%) were estrogen receptor (ER) positive. Of these 29 patients, 17 were also progesterone receptor (PR) positive. One patient (2.5%) at 38 months experienced a local recurrence of DCIS with micro-invasion and a synchronous focus of invasive ductal carcinoma in a separate quadrant. This was subsequently treated with total mastectomy, sentinel lymph node mapping, and axillary lymph node dissection. No other patients experienced local-regional recurrence or ipsilateral primary breast cancer occurrence.Conclusion: Patients with DCIS can be effectively treated with APBI/HDR balloon catheter breast brachytherapy following wide segmental breast resection. The rate of local-regional recurrence was 2.5% at a median follow-up time of 40 months. This is consistent with that of patients with DCIS treated with wide segmental breast resection followed by WB-XRT. Long-term follow-up will be required to assure these rates remain favorable. Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2116.