Racial and Ethnic Differences in Long-Term Adverse Radiation Therapy Effects Among Breast Cancer Survivors

Purpose: Breast and skin changes are underrecognized side effects of radiation therapy for breast cancer, which may have long-term implications for quality of life (QOL). Racial and ethnic disparities in breast cancer outcomes, including long-term QOL differences after breast radiation therapy, are poorly understood. Methods and Materials: We conducted a cross-sectional survey study of patients from the Texas Cancer Registry who received diagnoses of stage 0-II breast cancer from 2009 to 2014 and treated with lumpectomy and radiation therapy; 2770 patients were sampled and 631 responded (23%). The BREAST-Q Adverse Effects of Radiation overall score and subindices measured the effect of radiation therapy on breast tissue. Multivariable logistic regression evaluated associations of demographic and treatment characteristics with outcomes. Results: The median age was 57 years (IQR, 48-65), median time from diagnosis to survey response 9 years (IQR, 7-10), and the cohort included 62 Asian American or Pacific Islander (9.8%), 11 American Indian or Alaskan Native (AIAN) (1.7%), 161 Black (25.5%), 144 Hispanic (22.8%), and 253 White (40.1%) patients. Mean BREAST-Q Adverse Effects of Radiation score was worse for AIAN patients (–22.2; 95% CI, –39.9 to –4.6; P = .01), Black patients (–10.8; 95% CI, –16.1 to –5.5; P < .001), and Hispanic patients (–7.8; 95% CI, –13.0 to –2.5; P = .004) compared with White patients, age <50 compared with ≥65 (effect size –8.6; 95% CI, –14.0 to –3.2; P = .002), less than a college education (–5.8; 95% CI, –10.0 to –1.6; P = .01), bra cup size of D/E versus A/B (–5.3; 95% CI, –9.9 to –0.65; P = .03), and current smokers (–11.3; 95% CI, –18.3 to –4.2; P = .002). AIAN, Black, and Hispanic patients reported worse changes in skin pigmentation, telangiectasias, dryness, soreness, and/or irritation compared with White patients. Conclusions: AIAN, Black, and Hispanic patients reported substantially worse long-term breast and skin QOL outcomes after radiation therapy. Additional work is needed to understand these differences and how to alleviate them.