Household net worth is a major and overlooked factor in adherence to hormonal therapy among breast cancer patients and partially explains racial disparities in quality of care. The findings suggest that physicians, health insurers, and policy makers need to pay more attention to this economic variable to ensure that breast cancer patients receive this potentially life-saving treatment. The study was published recently in the online issue of Journal of Clinical Oncology.

“We know that oral hormonal therapy can reduce the recurrence of hormone receptor–positive breast cancer by 50 percent. Yet up to 10 percent of patients discontinue therapy annually, and only about half finish the recommended five-year course of therapy. Thus, it’s imperative that we understand what is preventing women from taking their medications and what we can do to improve adherence,” said lead author Dawn Hershman, MD, MS, associate professor of medicine at the College of Physicians and Surgeons and associate professor of epidemiology at the Mailman School of Public Health, Columbia University Medical Center. Dr. Hershman is also leader of the Breast Cancer Program at the Herbert Irving Comprehensive Cancer Center at NewYork-Presbyterian/Columbia University Medical Center.

Several studies have shown that disparities in income contribute to disparities in health care among racial and ethnic groups, but no one had specifically analyzed the effect of household net worth on quality of care in breast cancer patients. To study this association, the CUMC team collected prescription and financial data on 2,473 women ages 50 and older with early-stage breast cancer who had been prescribed aromatase inhibitors (the most common type of hormone therapy) between 2007 and 2011. Net worth was divided into three categories: low ($250,000 or less), moderate ($250,000 to $750,000), and high ($750,000 or more).

The researchers found that financial factors, such as income and net worth, were directly associated with adherence to hormonal therapy. They also found that black race was associated with decreased adherence. However, when the researchers controlled for net worth, there was no racial difference in adherence in the moderate and high net worth groups.

“This suggests that income may be an inadequate assessment of financial resources,” said Dr. Hershman. “This is particularly true for the elderly, for whom net worth seems to be a more accurate measure of socioeconomic differences in use of health care services.”

The effect of low net worth on quality of care is likely to grow worse as more costly therapies are used to treat cancer. The average monthly cost of generic aromatase inhibitors is $150, while the average monthly cost of oral biologics ranges from $5,000 to $8,000.

Medication non-adherence is a major issue throughout the health care system, according to the researchers. One recent study estimated that the annual cost of non-adherence to all types of medication is $289 billion, or 13 percent of total U.S. health expenditures.

“It’s important that physicians ask patients whether they are able to pay for their medications,” said Dr. Hershman. “Many patients aren’t comfortable raising this issue and just discontinue therapy if they can’t afford it. By engaging patients in conversation, we may be able to come up with a solution, perhaps by finding less expensive alternatives or by asking pharmaceutical companies to assist patients with co-payments.”