LAUSR

Background: Adjuvant radiotherapy (RT) following surgery significantly improves breast cancer survival. However, some patients, particularly minorities, develop acute skin toxicities that negatively impact their quality of life (QOL). The traditionally used measure of skin toxicities is clinician-reported outcomes (CROs), but recently there has been an increased interest in incorporating patient-reported outcomes (PROs). Therefore, our objective was to assess RT-related acute skin toxicities CROs and PROs in a large tri-racial/ethnic breast cancer population with 85% minorities. Methods: Patient demographics, treatment-, and clinical characteristics were prospectively collected for breast cancer patients who underwent breast-conserving surgery and planned to receive adjuvant RT from 2008 to 2014. 386 breast cancer patients with complete CROs and PROs were included in the final data analyses. The Common Terminology Criteria for Adverse Events (CTCAE, v. 3.0) was used for CROs and a skin-based QOL questionnaire was used for PROs. Concordance was assessed by calculating percent agreement and Cohen’s Kappa using McNemar’s test for significance. Results: The study population included 56 non-Hispanic whites (NHW), 81 black/African Americans (AA), and 249 Hispanic white (HW) breast cancer patients. Overall, the most commonly reported symptoms among patients were hyperpigmentation (n=179, 46%) and erythema (n=173, 45%). There were significant racial/ethnic differences in 4 patient-reported symptoms: warm to touch (p<0.0001), hyperpigmentation (p<0.0001), flaking (p=0.03), and erythema (p<0.0001). A higher proportion of HW reported these 4 symptoms, warm to touch (29%), hyperpigmentation (54%), flaking (35%), and erythema (52%) compared to NHW and black/AA. There was no significant racial/ethnic difference in CROs. There was a fair level of concordance between PROs and CROs (agreement 61.1%, Kappa coefficient 0.22, p=0.022). Conclusion: Multiple RT-induced skin-related symptoms differed significantly by race/ethnicity. However, CROs did not show racial/ethnic differences. There was a fair but significant agreement between PROs and CROs. A moderate level of concordance between PROs and CROs highlights the difficulty in assessing RT-related skin toxicities without a direct measure for which an improved skin assessment tool should be developed. PROs delineated a broader spectrum in capturing the impact of RT on patients’ QOL, which highlights the importance of integrating PROs in accessing RT-induced skin toxicities, particularly in minorities with worse RT-related skin symptoms that were not captured by CROs. Citation Format: Laura G. Acosta, Cristiane Takita, Isilinha M. Reis, Jean L. Wright, Wei Zhao, Jennifer J. Hu. Patient- and clinician-reported outcomes of radiotherapy-related acute skin toxicities in a tri-racial/ethnic breast cancer population [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3052.