Many low-income women breast cancer patients skipping hormonal therapy, lowering their survival rates

May 18 2009

Many low-income women are failing to take the hormonal therapy prescribed as part of their breast cancer treatment, possibly lowering their survival rates, according to a study led by a researcher in the Duke Comprehensive Cancer Center.

"Low-income women with breast cancer have a higher mortality rate than other women with cancer, and we wanted to see what might be causing this," said Gretchen Kimmick, M.D., an oncologist at Duke University Medical Center and lead investigator on the study. "What we found is that many low-income women in North Carolina who might benefit from hormonal therapy are not getting it or are not taking it as prescribed."

Medication that blocks hormones, called hormonal therapy, is a key part of treatment for patients whose breast cancer is hormone receptor-positive. Previous studies have shown that failing to take these drugs is associated with higher mortality rates, Kimmick said.

The researchers looked at a sample of Medicaid-insured women with hormone receptor-positive breast cancer and evaluated their prescription records to see whether they'd picked up the drugs.

"Even though these women had continuous health insurance with low prescription co-pays, we found that only 64 percent of them were filling any prescriptions for hormonal therapy within 12 months after being diagnosed," Kimmick said. The results of the study were published in the May 18, 2009 online edition of the Journal of Clinical Oncology.

Hormonal therapy, along with surgery, radiation and chemotherapy, is a component of standard treatment for women with hormone receptor-positive breast cancer, which is responsive to estrogen. These women are generally prescribed hormone pills for at least five years. The pills block hormone formation and action, helping to prevent the hormone receptor-positive breast cancers from growing. This treatment can keep the cancer from returning and has proven beneficial in reducing recurrence and death from breast cancer, Kimmick said.

"Our study also shows, that in the year following the initial prescription fill, 40 percent of the women were not regularly taking their hormonal therapy," Kimmick said. "Of the women actually taking the pills, 20 percent stopped taking the prescription before the end of the first year. This is alarming since women are even more likely to discontinue use over subsequent years."

The findings point out that these low income women are not consistently getting and using hormonal therapy. Therefore, they are actually receiving less than standard care, Kimmick said.

"From this study, there is no way to know why the women were not taking medication as prescribed," Kimmick said. "From previous studies, reasons have included side effects, such as hot flashes, aches and pains, cost of the medication, and lack of understanding about how important it is," she said.

"The hope is that further research will help us design interventions that will assist these women in taking the hormonal therapy as prescribed," Kimmick said. "If we can improve use of these very effective treatments, we may decrease the breast cancer mortality rate among this population."