Is there racial bias in the application of hypofractionated adjuvant radiotherapy for breast cancer that increases the burden of care in African American women within the UPMC system?

Purpose: Compared to Caucasian women, African American women in the United States are 39% more likely to die from breast cancer. National disparities in the application of shorter course of radiotherapy have been noted in African American women, with potential for improvement in breast cancer specific survival through improved access to care. This project aims to examine if racial bias exists in the application of hypofractionated radiotherapy (HFRT) within the UPMC Hillman Cancer Center network. We hypothesize that the national trends of underutilization of shorter courses of radiotherapy in African American women also exist in our network. If this disparity exists in our network, we hope to identify barriers to the application of HFRT in African American women, in hopes of improving access to care, and narrowing the racial gap in breast cancer outcomes.

Methodology: Deidentified data for 2678 women with early-stage node negative breast cancer treated across the UPMC network from 2020-2023 was collected and organized. Data collected included patient age, race, tumor stage, tumor grade, tumor receptor status, oncotype, neoadjuvant chemotherapy use, and prescribed treatment including radiation dose and fractionation. Chi-squared analysis was used to test for correlation between these factors and prescribing HFRT. IBM SPSS Statistics, version 27 (IBM Corp., Armonk, NY) was used to perform all statistical analyses.

Results: Of the 2678 patients analyzed, 162 patients (6%) were African American. Most patients were pT1 (78.2%), ER positive (88.5%), and HER2 negative (97.9%). Neoadjuvant chemotherapy was used in 8.5% of patients. Conventional fractionation was prescribed in 117 (4.4%) patients while HFRT was prescribed in 2567 (95.6%) patients. Significant correlation was seen with prescribed fractionation and age (p=0.023) as well as neoadjuvant chemotherapy use (p=0.002), with less HFRT use for patients younger than 50 and for those who received neoadjuvant chemotherapy. No significant correlation was seen with race (p=0.456) or other analyzed factors including tumor stage, receptor status, or oncotype.

Conclusions: No significant correlation was seen with race and HFRT use for women with early-stage breast cancer treated with adjuvant radiation in our network, possibly due to the horizontal delivery platform of the UPMC network design and use of clinical pathways to standardize care across the UPMC system. A significant correlation was seen with less HFRT use for patients younger than 50 as well as for patients who received neoadjuvant chemotherapy.

References: