Purpose: Deintensification 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 hormone therapy (HT) is not trivial, and adherence rates vary. We hypothesized that adjuvant RT alone would produce survival outcomes comparable to those with adjuvant HT alone among elderly patients treated with lumpectomy.
Methods and materials: We searched the National Cancer Database (2010-2014) for healthy women (aged ≥70 years, Charlson/Deyo [CD] score 0-1) with T1N0 hormone-receptor-positive, HER-2-negative breast cancer treated with lumpectomy and adjuvant HT 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 HT alone and 35% received RT only after lumpectomy. On multivariate analysis of the matched cohort, older age (hazard ratio [HR] 1.10; 95% confidence interval [CI] 1.07-1.13; P < .001), CD score 1 (HR 1.92; 95% CI 1.37-2.70; P = .0002), and living in a metropolitan (vs urban) area (HR 3.09; 95% CI 1.43-6.67; P = .004) were associated with inferior overall survival (OS), whereas treatment with HT (vs RT) was not (HR 1.13; 95% CI 0.85-1.49; P = .406). At a median follow-up of 45 months, no difference was found in OS between HT versus RT cohorts (85% and 86%, respectively; P = .44).
Conclusions: For healthy, older women with biologically favorable breast cancer treated with lumpectomy, adjuvant RT or HT 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.
Published by Elsevier Inc.