Radiotherapy utilization for patients over age 60 with early stage breast cancer

Abstract Introduction Recent studies have questioned the relative benefit of radiotherapy for older patients with favorable breast cancer given the lack of survival benefit and marginal local control benefit. Despite the 2004 NCCN guidelines advocating for the option of hormonal therapy alone, trends in utilization rates of radiotherapy in this group are not well documented. We analyzed our institutional experience with implementation of the guidelines over time. Material and Methods We identified 564 patients ≥ 60 with favorable breast cancer treated with breast conserving surgery from 2000-2017. Patients met criteria for CALGB 9343, PRIME II, or the very-low risk cohort identified in the Toronto-British Columbia study. Multivariable logistic regression analysis was performed to assess the magnitude of association between omission status, grade and tumor size while controlling for age and year of diagnosis. Results Overall RT omission rates were 17.6% prior to the 2004 NCCN update and 45% after the publication of the 10-year CALGB data in 2013. The overall RT omission rate was 29%. Patients with grade 1-2 histology (OR: 3.2: 95% CI 1.3 to 7.7, P-value=0.01) and tumors Conclusions We observed a slight decrease in the use of radiotherapy over time suggesting a move towards adoption of the NCCN guidelines. There remains a fundamental need to continue to individualize breast cancer care based on risk stratification and make evidenced-based treatment recommendations with equitable use of healthcare resources.