Black women more likely to skip breast cancer treatment

Black women with hormone receptor-positive breast cancer appeared 2.5 times more likely than white women to be nonadherent to their endocrine therapy treatment, according to a retrospective cohort study.

“Nationally, breast cancer mortality is 41.5% higher among black women compared with white women, despite a historically lower incidence rate,” Stephanie B. Wheeler, PhD, MPH, associate professor of health policy and management at University of North Carolina Chapel Hill, and colleagues wrote. “Although breast cancer in black women is characterized by higher estrogen receptor negativity, higher grade and histological differences, studies suggest that black women have worse prognoses regardless of subtype and biologic profile of disease. In fact, the largest racial disparity in outcomes occurs within the biologically similar hormone receptor-positive, HER-2-negative subtypes, suggesting that treatment differences and other nonbiological factors may explain these racial differences.”

Wheeler and colleagues used data from the Carolina Breast Cancer Study to assess treatment adherence 2 years after diagnosis among 1,280 women aged 20 to 74 years with hormone receptor-positive breast cancer.

Overall, 43.2% of participants self-identified as black.

Researchers defined nonadherence based on responses to two survey items, including patients who reported not taking endocrine therapy as prescribed and patients who reported missing more than two pills in the past 2 weeks.

Black women appeared more likely than white women to report nonadherence to treatment (13.7% vs. 5.2%; P < .001). Self-reported treatment discontinuation was slightly lower among black women than white women (10% vs. 10.7%).

After adjusting for clinical factors, black race appeared significantly associated with treatment nonadherence (OR = 2.72; 95% CI, 1.75-4.24).

The association remained significant with further adjustment for socioeconomic factors (OR = 2.44; 95% CI, 1.5-3.97).

Compared with white women, black women more often reported:

forgetting to take endocrine therapy when traveling away from home (26.2% vs. 19.5%; P < .001);

having a hard or very hard time sticking to their endocrine therapy treatment plan (27.5% vs. 14%; P < .001);

trouble remembering to take their endocrine therapy pills (27.2% vs. 13.2%; P < .001);

missing pills due to cost (17.1% vs. 6.7%; P <.001);

severe side effects that led to skipping endocrine therapy pills (25% vs. 16.3%; P < .001); and

believing that their recurrence risk would not change if they stopped endocrine therapy (20.7% vs. 9.1%; P < .001).

Researchers also observed underuse of endocrine therapy among younger women (P = .003), women insured by Medicaid (P < .001) and women with annual incomes of less than $50,000 (P = .03).

“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,” Wheeler said in a press release. “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.” – by Cassie Homer

Disclosures: The authors report no relevant financial disclosures.