The evolving role of adjuvant radiotherapy for elderly women with early-stage breast cancer

Abstract

BACKGROUND Elderly patients with early-stage breast cancer (ESBC) derive a local control benefit from radiotherapy (RT) after lumpectomy, without any apparent effect on overall survival. Therefore, the use of RT is controversial. In the current study, the authors characterized updated trends in RT for elderly patients with estrogen receptor (ER)-positive ESBC. METHODS Patients aged ≥70 years with ER-positive ESBC measuring ≤2 cm after lumpectomy with negative resection margins and known RT details were identified in the National Cancer Data Base. Patients were classified by year of diagnosis and segregated into 3 groups relative to the initial publication and updated presentation of the Cancer and Leukemia Group B (CALGB) 9343 trial. RT use overall, prescription of hypofractionated RT, and use of boost RT were compared between groups using logistic regression analysis, and the influence of clinicopathologic covariates was determined with multivariable logistic regression analysis. RESULTS A total of 122,796 elderly patients with ER-positive ESBC who were diagnosed between 1998 and 2011 were identified. Overall, 84,649 patients (68.9%) received adjuvant RT, with a decline observed between successive cohorts (71.3% in the pre-initial publication cohort, 69.5% in the pre-update cohort, and 64.7% in the post-update cohort; P