Most patients are eligible for an alternative to conventional whole breast irradiation for early-stage breast cancer: A National Cancer Database Analysis.

We evaluated the proportion of patients eligible for alternatives to standard whole breast irradiation (WBI) following breast-conserving surgery using the National Cancer Database (NCDB). Using the 2016 dataset, Stage I-III patients were identified. Eligibility for hypofractionated WBI (HFRT), accelerated partial breast irradiation (APBI) and endocrine therapy (ET-alone) was defined using eligibility from large clinical trials as well as consensus guidelines. For patients with pN0 breast cancer, 20.6% and 37.0% were eligible for ET-alone based on the CALGB 9343/PRIME-II trials, respectively. In terms of HFRT, 72.5% and 50.4% were eligible based on IMPORT LOW/ASTRO HFRT guidelines, respectively. Based on IMPORT LOW/GEC-ESTRO trial/ASTRO guidelines/ABS guidelines/GEC-ESTRO guidelines, 72.5%, 86.1%, 39.0%, 72.5%, 45.7%, respectively, were eligible for APBI. Of those who qualify for HFRT per ASTRO guidelines, approximately 90% were eligible for APBI and 50% for ET-alone. This analysis shows that a large proportion of patients with node-negative breast cancer are eligible for HFRT, APBI and/or ET-alone after breast-conserving surgery.