Impact of race, ethnicity, and socioeconomic factors on receipt of radiation after breast conservation surgery: analysis of the national cancer database.

Introduction: Many eligible women with invasive breast cancer do not receive recommended adjuvant radiation (RT), despite its role in local control and overall survival. We examined trends in RT use over 10 years, and the impact of sociodemographic factors on the receipt of standard-of-care RT, using the National Cancer Database (NCDB).

Materials/methods: Women under age 70 with invasive breast cancer who underwent BCS from 2004 to 2014 were analyzed. Receipt of RT was evaluated in the whole cohort and by time period to identify temporal trends. Multiple logistic regression models were used to assess associations between factors such as race, insurance status, ethnicity, and receipt of RT.

Results: A total of 501,733 patients met eligibility criteria. The percentage of patients undergoing adjuvant RT increased from 86.7% in 2004 to 92.4% in 2012, and then decreased in 2013 and 2014 to 88.9%. On univariate analysis, patients of white race were significantly more likely to receive RT compared with patients of black race (90.4% vs 86.9%, p < 0.0001), as were non-Hispanic women compared to Hispanic patients (90.2% vs. 85.3%, p < 0.0001). On multivariate analysis, race, ethnicity, insurance status, education level, and age remained significantly associated with receipt of RT. On temporal analysis, gaps remained stable, with no significant improvements over time.

Conclusions: This analysis suggests a recent decline in guideline-concordant receipt of RT in women under 70, and persistent disparities in the use of RT after BCS by race, ethnicity, and socioeconomic factors. These findings raise concern for a recent detrimental change in patterns of care delivery.