Trends in utilization of hypofractionated whole breast irradiation (HF-WBI) in triple negative breast cancer (TNBC): a national cancer database (NCDB) analysis.

PURPOSE: We sought to identify trends over time with respect to the use of hypofractionated whole breast irradiation (HF-WBI) in women with triple negative breast cancer (TNBC) in the national cancer database (NCDB). METHODS: Trends in utilization of HF-WBI in women diagnosed with T1-2N0 TNBC in the NCDB between 2008 and 2013 were analyzed. Case-matched luminal A women were used for comparison. Variables included age, race, year of diagnosis, insurance status, income quartile, receipt of neoadjuvant chemotherapy, and institution (academic vs. community). Chi square, logistic regression, and multivariate analysis was performed. RESULTS: Utilization of HF-WBI among the 53,269 TNBC women identified steadily increased from 4.7% in 2008 to 14.0% in 2013 for women with TNBC compared to luminal A cancer whose utilization increased from 7.3 to 23.3% over the same time frame (p < 0.001). On univariate analysis, HF-WBI was associated with increasing age (p < 0.001), Medicare insurance (p < 0.001), race (p = 0.041), diagnosis after 2011 (p < 0.001), higher income quartile (p < 0.001), and treatment at academic institutions (p < 0.001). On multivariate analysis, age (p < 0.001, OR 1.038 per year), income quartile (p = 0.002, OR 1.061 per increase in quartile), treatment at an academic institution (p < 0.001, OR 1.78) significantly increased use of HF-WBI. CONCLUSIONS: Treatment at an academic center and year of diagnosis were most correlated with increased HF-WBI in T1-2N0 TNBC women in the NCDB from 2008 to 2013, followed by increasing age and income. Only 14% of T1-2N0 TNBC women received HF-WBI in 2013. Focus on increased utilization is needed for non-academic centers, lower income, and younger women.