Dr. Vicini on Partial Breast Irradiation Versus Whole Breast Irradiation in Women With Early-Stage Breast Cancer

Frank A. Vicini, MD, radiation oncologist, 21st Century Oncology of Michigan, compares the use of partial breast irradiation (PBI) with that of whole breast irradiation (WBI) in women with early-stage breast cancer at the 2018 San Antonio Breast Cancer Symposium.

Primary results of the NSABP B-39/RTOG 0413 trial were presented at the symposium, in which 4216 women who had received a lumpectomy with 0 to 3 positive axillary nodes were randomized to treatment with WBI or PBI. Of these patients, 25% had ductal carcinoma in situ, 65% had stage I disease, and 10% had stage II disease. Additionally, 81% of patients were hormone receptor—positive and 61% were postmenopausal.

Ipsilateral breast tumor recurrence (IBTR) occurred in 90 women and 71 women who received PBI and WBI, respectively. The percentage of patients who were IBTR-free at 10 years was 95.2% in those who received PBI and 95.9% in those who were given WBI. The difference in the 10-year relapse-free interval was 1.5%, demonstrating statistical significance. Although the trial could not declare equivalence in controlling local in-breast tumor recurrence, Vicini says there are subsets of patients for whom PBI may be appropriate.