Adjuvant radiation use in older women with early-stage breast cancer at Johns Hopkins

Purpose: In 2004, The National Comprehensive Cancer Network (NCCN) Guidelines incorporated omission of radiation therapy after breast-conservation surgery in women ≥70 years old with stage I, estrogen receptor-positive breast cancer who plan to receive endocrine therapy. One study demonstrated wide variation in implementing this change across 13 NCCN institutions. We evaluated the practice pattern at our institution.

Methods: We identified women ≥70 years old treated at our institution from 2009 to 2014. We calculated radiation therapy omission rate in those meeting the guidelines. We explored associations between radiation therapy omission, year of diagnosis, and patient characteristics with Wilcoxon rank sum tests and Fisher's exact tests.

Results: A total of 667 women met the inclusion criteria, and 117 (18 %) were candidates for radiation therapy omission. Mean age among the 117 was 76.3 years (Range: 70-95). Overall radiation therapy omission rate was 36.8 %, but varied greatly by year of diagnosis (Range: 7.7-54.5 %). This variation persisted after excluding women who did not receive endocrine therapy (Mean: 39.0 %, Range: 0.0-75.0 %). Factors associated with higher radiation therapy omission rates included older age and not having pathological nodal evaluation. The radiation therapy omission rate did not vary by race, tumor type, grade, or size.

Conclusions: The implementation of the NCCN guideline has not been consistent at our institution. Our data suggest that other tools should be considered to apply the guidelines more consistently. We have implemented a quality improvement protocol that incorporates life expectancy estimate and geriatric assessment in women meeting the NCCN guideline at our institution.