Accelerated Partial Breast Irradiation for Low-Risk Hormone-Sensitive Breast Cancer: Trends and Underutilization in the National Cancer Database 2010-2022.

Abstract

Despite growing evidence supporting the use of accelerated partial breast irradiation (APBI) and partial breast irradiation (PBI) for early-stage, low-risk breast cancer, utilization remains limited. This study evaluates trends and geographic variations in APBI/PBI adoption within the National Cancer Database from 2010 to 2022. We used the National Cancer Database to identify patients who underwent margin-negative lumpectomy and radiation from 2010 to 2022 with favorable breast cancer: age ≥50 years, hormone receptor-positive/human epidermal growth factor receptor 2-negative, pathologic T1N0, grade 1-2, and nonlobular histology. Patients were stratified by the type of radiation therapy (APBI or whole breast irradiation [WBI]). The primary outcome was the annual utilization rate of accelerated partial breast irradiation (APBI/PBI) compared with WBI. Overall, 256,549 patients met all eligibility criteria. In this cohort, 31,154 (12.1%) received APBI/PBI. The use of APBI/PBI increased from 7.5% (2010-2017) to 16.2% (2018-2022) (P < .001). In the final year, among the 26,124 patients analyzed, 6100 (23.3%) received any form of APBI/PBI, and 4778 (18.2%) were treated with either 30 Gy/5Fx external beam APBI or brachytherapy. We found a significant rise in APBI/PBI use in patients with low-risk hormone receptor-positive/human epidermal growth factor receptor 2-negative breast cancer. Despite the increasing trend, even in the most recent year, fewer than 1 in 4 potentially eligible patients received APBI/PBI. Among patients treated in 2022, fewer than 1 in 5 patients received 30 Gy/5Fx external beam APBI or brachytherapy, the 2 forms of APBI that possess the combination of similar cancer control outcomes, greater convenience, and less toxicity compared with WBI.