Population-based analysis of non-operative management and treatment patterns in older women with estrogen receptor-positive breast cancer

To examine the proportion of older women with ER + HER2- breast cancer receiving non-operative management versus surgery, and to evaluate the use of axillary staging and adjuvant radiation in this population. We queried the SEER database to identify all women aged 70 years or older with stage I–III ER + HER2- invasive breast cancer diagnosed between 2010 and 2016. We evaluated trends in non-operative management, breast surgery, axillary staging, and adjuvant radiation according to age at diagnosis. We identified 57,351 older women with ER + HER2- disease. Overall, 3538 (6.2%) of the cohort underwent non-operative management, 38,452 (67.0%) underwent breast-conserving surgery (BCS), and 15,361 (26.8%) underwent mastectomy. The proportion of patients undergoing non-operative management increased from 2.8% among 70–74-year-old women to 30.1% in those ≥ 90 years old (p