Lumpectomy plus Hormone or Radiation Therapy Alone for Women Aged 70 Years or Older with Hormone Receptor–Positive Early Stage Breast Cancer in the Modern Era: An Analysis of the National Cancer Database

Abstract Background De-intensification of adjuvant therapy is being considered for older women with early-stage, biologically-favorable breast cancer. Although radiation therapy (RT) can be omitted in some cases, toxicity from endocrine therapy (ET) is not trivial, and adherence rates vary. We hypothesized that adjuvant RT alone would produce comparable survival outcomes as adjuvant ET alone among elderly patients treated with lumpectomy. Methods We searched the National Cancer Database (2010–2014) for healthy women (≥70 years, Charlson/Deyo (CD) score 0-1) with T1N0 hormone-receptor–positive, HER-2-negative breast cancer treated with lumpectomy and adjuvant ET or RT. Propensity scores were used to match patients for analysis. Results We identified 2995 patients (median age, 78 years), most (81%) with a CD score of 0, clinical stage IA (77%), of whom 65% received ET alone and 35% RT only after lumpectomy. On multivariate analysis of the matched cohort, older age (HR 1.10 (95% CI 1.07-1.13), P Conclusions For healthy, older women with biologically favorable breast cancer treated with lumpectomy, adjuvant RT or ET is associated with equivalent 5-year OS rates. A randomized controlled trial is warranted to explore these adjuvant monotherapy options in elderly patients with hormone receptor-positive breast cancer.