Racial Disparities in Hypofractionated Radiotherapy Breast Cancer Clinical Trials

There is a paucity of data regarding factors affecting enrollment onto radiation oncology clinical trials. The purpose of this study was to determine patients and tumor characteristics that influenced enrollment of breast cancer patients onto hypofractionated breast radiotherapy trials (HBRTs) at a single institution. In this retrospective cohort study, patients enrolled on HBRTs at the Rutgers Cancer Institute of New Jersey (n = 132) were compared with a cohort of breast cancer patients eligible for, but not enrolled onto HBRTs treated during the same time period (n = 132). Charts were retrospectively reviewed to determine patients' demographics, clinico-pathologic factors, and treatment characteristics. Statistical analysis was performed to analyze variables affecting enrollment onto HBRTs between the two groups. Over a 42-month time period, 132 patients treated on HBRTs received 2,475-4,995 cGy over 3 to 15 fractions. When compared with patients treated off trial, there was no statistically significant effect of age, family history, lymph node positivity, tumor grade, estrogen or Her-2 receptor status, use of chemotherapy or hormones, use of brachytherapy, or the site of initial consultation on HBRT enrollment. Non-White women were less likely to enroll in HBRT's when compared with White women (25.7% versus 40.1%, p = 0.0129), though this was found to be a nonsignificant trend when taking stage into consideration on multivariate analysis (OR for lower T-stage: 0.281, p = 0.003, OR 1.839 for white race, p = 0.076). Consistent with previous studies, non-White women were less likely to enroll in HBRTs than White women. However, disease stage accounted for these racial disparities. Further studies must be performed to determine if race is an independent factor determining radiation oncology clinical trial enrollment.