Adherence to Endocrine Therapy for Breast Cancer in Black Women and White Women


Key Points

  • Black women were more likely than white women to be nonadherent to endocrine therapy.
  • No difference in likelihood of discontinuation was observed.

In a study reported in the Journal of the National Cancer Institute, Wheeler et al found that black women reported nonadherence to endocrine therapy for breast cancer more often than white women, although no significant difference in discontinuation of treatment was observed.

The study included 1,280 women aged 20 to 74 years with first primary, stage I to III, hormone receptor–positive breast cancer in the phase III Carolina Breast Cancer Study. Of these women, 43.2% self-identified as black. Nonadherence—defined as not taking endocrine therapy every day or missing more than two pills in the past 14 days—and discontinuation were analyzed at 2 years postdiagnosis.

Nonadherence and Discontinuation

Compared with white women, black women more often reported nonadherence (13.7% vs 5.2%) but not discontinuation (10.0% vs 10.7%) and more often reported hot flashes (58% vs 43%); night sweats (43% vs 28%); breast sensitivity (24% vs 16%); joint pain (46% vs 36%); believing that their recurrence risk did not change if they stopped endocrine therapy (21% vs 9%); trouble remembering to take endocrine therapy (27% vs 13%); and cost-related barriers (8.5% vs 2.6%).

On multivariable analysis, black women had a significantly greater risk of nonadherence, but not discontinuation, after adjustment for clinical characteristics (adjusted odds ratio [OR] = 2.72, 95% confidence interval [CI] = 1.75–4.24) and after further adjustment for socioeconomic characteristics (adjusted OR = 2.44, 95% CI = 1.50–3.97).

Among all women, strong predictors of underuse (nonadherence or discontinuation) were the belief that recurrence risk does not change if therapy is not taken as prescribed (adjusted OR = 8.35, 95% CI = 5.34–13.1) and a lack of shared decision-making with the provider (OR = 2.17, 95% CI = 1.45–3.23, for primarily patient decision; OR = 2.20, 95% CI = 1.20–4.01, for no discussion). 

The study authors concluded, “Our results highlight important racial differences in [endocrine therapy] adherence behaviors, perceptions of benefits/harms, and shared decision making that may be targeted with culturally tailored interventions.”

The study was funded by the American Cancer Society, National Cancer Institute, and Susan G. Komen Foundation.

Stephanie B. Wheeler, MPH, PhD, of the Department of Health Policy and Management, University of North Carolina, Chapel Hill, is the corresponding author for the Journal of the National Cancer Institute article.

The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.