Adoption of Hypofractionated Whole-Breast Irradiation for Early-Stage Breast Cancer: A National Cancer Data Base Analysis

Abstract

To evaluate the relationship of patient, hospital, and cancer characteristics with the adoption of hypofractionation in a national sample of patients diagnosed with early-stage breast cancer. We performed a retrospective study of breast cancer patients in the National Cancer Data Base from 2004-2011 who were treated with radiation therapy and met eligibility criteria for hypofractionation. We used logistic regression to identify factors associated with receipt of hypofractionation (vs conventional fractionation). We identified 13,271 women (11.7%) and 99,996 women (88.3%) with early-stage breast cancer who were treated with hypofractionation and conventional fractionation, respectively. The use of hypofractionation increased significantly, with 5.4% of patients receiving it in 2004 compared with 22.8% in 2011 (P<.001 for trend). Patients living ≥50 miles from the cancer reporting facility had increased odds of receiving hypofractionation (odds ratio 1.57 [95% confidence interval 1.44-1.72], P<.001). Adoption of hypofractionation was associated with treatment at an academic center (P<.001) and living in an area with high median income (P<.001). Hypofractionation was less likely to be used in patients with high-risk disease, such as increased tumor size (P<.001) or poorly differentiated histologic grade (P<.001). The use of hypofractionation is rising and is associated with increased travel distance and treatment at an academic center. Further adoption of hypofractionation may be tempered by both clinical and nonclinical concerns.