A new study in the Journal of the National Cancer Institute finds that black women are more likely to skip hormone therapy treatments, also known as endocrine therapy, for breast cancer.
Endocrine therapy is used to add, block, or remove naturally occurring chemicals like estrogen and progesterone that stimulate some types of breast cancer. Evidence suggests that taking endocrine therapy for up to 10 years reduces the risk of breast cancer recurrence. However, between 15% and 49% of women with the disease never initiate endocrine therapy, and more than half do not take endocrine therapy drugs as recommended.
Nationally, breast cancer mortality is 41.5% higher among black women compared to white women, despite a historically lower incidence rate. Failure to receive appropriate treatment is an important cause of observed racial disparities in breast cancer mortality. Different use of endocrine therapy by race may contribute to breast cancer outcome disparities, but racial differences in treatment are poorly understood.
In this paper, researchers using data from the Carolina Breast Cancer Study investigated 1,280 women who reported being prescribed endocrine therapy; of these, 43% self-identified as black. For black women, overall, 24% reported underuse of endocrine therapy drugs, compared to 16% of white women. Compared to white women, black women more often reported not taking their pills every day as prescribed (14% versus 5%), whereas about 10% of both white and black women reported discontinuing their medication before the recommended time-period. Younger women were more often underusing endocrine therapy drugs, as were those women insured by Medicaid and those making less than $50,000/year.
A statistically significantly higher proportion of black women also reported: forgetting to take their drugs when traveling away from home (26% for black women versus 19% for white women); that sticking to their treatment plan was hard or very hard (27% versus 14%); trouble remembering to take their pills (27% versus 13%); missing pills due to cost (17% versus 7%); and severe side effects that led to skipping their endocrine therapy pills (25% versus 16%).
“This study provides evidence in a large, racially-diverse cohort study that black women with hormone receptor positive breast cancer experience unique barriers to endocrine therapy adherence which may lead to differential cancer outcomes by race, though we also found burdensome adherence barriers among white women,” said lead author Stephanie B Wheeler. “These data are important because they shed light on the modifiable mechanisms through which multifaceted and culturally competent behavioral interventions can help women with breast cancer achieve the best outcomes.”