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 pN 0 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.