Hormone Therapy Adherence in Breast Cancer Linked to Race, Income

Economic factors, including household income, and racial disparities both play a role in the adherence to hormonal therapy in breast cancer patients, according to the results of a new study.

Black women were 24% less likely to adhere to treatment compared with their white counterparts (P < .001). Women of advanced age who had comorbidities and Medicare insurance were also less likely to adhere to their adjuvant hormonal therapy (P < .001).

Women with a medium net worth (between $250,000 and $750,000) had a 33% higher probability of adhering to the long-term therapy compared with those with a low net worth. Those with a high net worth, defined as greater than $750,000, had a 66% higher probability of adhering to treatment compared with those with a low net worth.

Dawn L. Hershman, MD, of the division of hematology and oncology at Columbia University in New York, and colleagues looked at why some breast cancer patients receiving adjuvant hormonal therapy to reduce their risk of recurrence discontinued their treatment. The results of the study were published in the Journal of Clinical Oncology.

While oral adjuvant hormonal therapy results in as much as a 50% reduction in the incidence of recurrence among women with high-risk hormone receptor–positive disease, prior studies showed that about 7% to 10% of patients discontinued therapy every year. Moreover, only about half of patients finished the entire recommended 5-year course of therapy.

In the current study, Hershman and colleagues investigated whether treatment factors and costs of treatment influenced adherence.

“Patients with financial resources-a higher net worth-are more likely to be adherent to hormone therapy, and probably other cancer therapies, as cancer patients often have high out-of-pocket costs,” said Hershman. “Some of the racial disparity in adherence may be due to access because differences in net worth explain a portion of racial disparities in adherence.”

The authors analyzed insurance claims of 10,302 patients, of which 24% (2,473) were nonadherent. Women were followed for up to 2 years. Most of the women were white (79.2%), and 9.2% and 5.8% of the women were black and Hispanic, respectively. Most patients had commercial insurance (95.8%) and medium net worth (48%). About one-third (33%) of the women had a low net worth (less than $250,000), and 19% had a high net worth.

After adjusting for net worth, the odds of adherence for black women were 19% lower than for white women (P = .02).

A total of 71.2% of black patients were adherent compared with 76.6% of white patients. Black patients were less likely to have a high net worth (4.4% vs 20.5% of white women) and more likely to have a higher co-payment (42.5% vs 38.4% of white women).

“It is not surprising that patients who are more financially vulnerable are more likely to discontinue therapy early or delay renewing prescriptions,” stated the authors in their discussion.

In a previous study, switching from a brand name to a generic medication decreased the discontinuation rate. Women in a higher income bracket also had better adherence rates compared with those with lower incomes. Black women have a higher breast cancer mortality rate and often do not receive timely adjuvant treatment compared with their white counterparts.

Because all patients included in the current study received some prescription insurance coverage, the results are not applicable to those patients who have no prescription drug coverage.

These results suggest that economic factors may contribute significantly to disparities in the quality of breast cancer care,” the authors concluded.

“There are many programs to help patients with co-payment assistance. Both foundations and the pharmaceutical companies have programs in place, but patients need to know they exist in order to use them,” Hershman noted. “Healthcare providers need to bring these issues up with patients. Patients may not always feel comfortable telling their physician they cannot afford a medication.”

“Efforts to improve adherence and reduce disparities should focus on patients with low net worth,” said Hershman, who is currently investigating ways to improve adherence to oral cancer therapies.