According to current guidelines of the National Comprehensive Cancer Network (NCCN, version 6.2024), it is recommended to consider the omission of radiotherapy after BCS if adjuvant endocrine therapy is planned and patients meet the following criteria: age ≥ 70 years, HR+, HER2-negative, cN0, pT1 and age ≥65 years, HR+, HER2-negative, pN0, tumor ≤ 3 cm in diameter [28]. The gene discussed is ERBB2; the disease is neoplasm.