In a study of 8,769 women prescribed hormonal therapy for breast cancer, researchers from Columbia University Medical Center in New York and Kaiser Permanente in Northern California found that just under half -- 49% -- completed the recommended course.
Hormonal therapy is routinely prescribed for about 60% of breast cancer patients, that is, those who have tumors fueled by the female sex hormones estrogen and progesterone, said Dr. Dawn Hershman, who led the study. The therapy reduces the risk of cancer recurrence, and patients are advised to take it for at least five years.
“There are a lot of outstanding treatments for breast cancer, but it’s clear that if people don’t get them for as long as they should, they won’t get the full benefits,” said Hershman, an associate professor of medicine and epidemiology at Columbia.
The study, published online Monday in the Journal of Clinical Oncology, used the pharmacy records -- specifically, prescriptions and refill dates for tamoxifen, aromatase inhibitors, or both
-- from multiple Kaiser Permantes in Northern California of women diagnosed with Stage I, II or III hormone-sensitive breast cancer between 1997 and 2007. Other studies had found that breast cancer patients often fail to complete such therapy, but this study was one of the largest, helping to clarify which age groups are most at risk of discontinuing the treatment.
In short, women under the age of 40 were the most likely to give up on the treatment.
“This helps us to see which groups are most likely to be affected and stop treatment, so that we can then focus our efforts on them,” Hershman said.
The hormone treatments’ side effects might be more likely to lower the quality of life for younger women than for older women, researchers speculated. The cost of medication or insurance co-payments and younger women’s more inherent sense of immortality could also lead them to discontinue treatment.
Further, Hershman added, some women may discontinue their medication because, as time goes on, their cancer has “become something of the past and they do not want to be reminded of it.”
The study also found that women over the age of 75 are more likely than women in the middle age group -- between between the ages of 40 and 75 -- to discontinue their treatment early. Researchers said that older women, who may already be burdened with taking pills to treat other ailments, might not feel that continuing hormonal therapy for so long is worth the effort.
Here’s an explainer from WebMD on breast cancer and hormone therapy.
-- Jessie Schiewe
Photo: Many breast cancers are first found with a mammogram. But interpreting the images can be difficult. A dense breast is shown at the left; a fatty breast is on the right.
Credit: National Cancer Institute