Radiation Therapy for Breast Cancer: American Society of Breast Surgeons Responds to San Antonio Breast Cancer Symposium Data

n a study presented on 12/7/2011 at the San Antonio Breast Cancer Symposium (“Partial Breast Brachytherapy is Associated With Inferior Effectiveness and Increased Toxicity Compared to Whole Breast Irradiation in Older Patients”), physicians from the MD Anderson Cancer Center compared the 5-year results of accelerated partial breast irradiation (APBI) to whole-breast irradiation (WBI) in patients undergoing breast-conserving therapy. They observed higher rates of mastectomy (4% vs.2.2%) and of treatment-related complications in the APBI patients, differences which are statistically significant but small in absolute terms. The study comprises more than 130,000 patients' Medicare claims data, but is retrospective and therefore cannot assure that the ABPI and the WBI patients were comparable in all other ways. In addition, because this is a claims database, it cannot be concluded that the additional mastectomies were necessarily performed because of a recurrence of cancer.

The American Society of Breast Surgeons (ASBrS) maintains a registry of 1440 patients treated by APBI with the MammosSite® balloon catheter device through 2004, and in numerous publications has observed 1) a 5-year local recurrence rate of <5%, comparable to that of whole-breast radiation therapy, 2) a low rate of other complications, and 3) good or excellent cosmesis in approximately 90% of patients. Several single-institution randomized and nonrandomized studies using another technique of APBI, multiple interstitial catheters, also report rates of local recurrence comparable to WBI. source: PR Web