SAN FRANCISCO—Two studies presented at the ASCO Breast Cancer Symposium 2013 focused on studying cognitive function in women with early-stage breast cancer, focusing on the relationship between perceived and measurable cognitive decline, and factors that may help to predict cognitive decline.
According to background information of the study, patients undergoing adjuvant treatment of breast cancer frequently complain of cognitive decline; however, there are little data to show correlations between perceived cognitive declines reported by the patient and measurable evidence of cognitive problems. In addition, more guidance is needed to help physicians identify factors that might predict cognitive decline.
To examine both, the researchers led by Hope S. Rugo, MD, of the UCSF Helen Diller Family Comprehensive Cancer Center and Lara Heflin, PhD, of New Mexico Highlands University, conducted a prospective trial looking at 81 women assigned to treatment with chemotherapy (n = 14), chemotherapy followed by hormone therapy (n = 33), hormone therapy alone (n = 22), or no treatment (n = 12). All women were aged 35 to 80 years and had no prior history of major psychiatric illness, serious head injury, neurologic disease, drug or alcohol abuse, or significant medical illness.
In addition to disease treatment, patients also underwent a series of objective and subjective cognitive tests at baseline and follow-up. Follow-up tests were conducted 1 month after chemotherapy or 5 months after hormone therapy, at 9 months and at 18 months. Brain MRI, PET and serum estradiol were also conducted at baseline and follow-up.
At each follow-up test, about 25% of patients showed a decline in cognitive function compared to the prior time point. More than half of patients showed a decline at multiple time points, primarily in tests measuring executive function and verbal memory.
Using a univariate conditional logistic regression, the researchers found that cognitive decline occurred more frequently among patients assigned to chemotherapy followed by hormone therapy (OR = 3.15; P = .008), or to hormone therapy overall (OR = 4.95; P = .004). On multivariate analysis, hormone therapy was significantly associated with predicting decline at any point (OR = 7.69; P = .002). No association was found between cognitive decline and serum estradiol, menopausal status, or chemotherapy alone.
When comparing patient-reported outcomes with measurable outcomes the researchers found that certain patient-reported outcomes were related to actual deficits in cognitive function.
Specifically, at 9 months follow-up, the researchers found that depression and fatigue, and a decline in letter fluency predicted poorer overall perceived cognitive function among patients. In addition, a decline in verbal memory predicted perceived memory deficits, even after the researchers controlled for depression and fatigue.
In a discussion of the posters, Julia White, MD, of the Ohio State University, praised both studies for having strong methodology and design.
“While the relationship between chemotherapy and neurocognitive changes is increasingly well described, cognitive changes associated with hormone therapy for breast cancer has proven to be somewhat complex,” Dr. White said. “Chemotherapy can confound this, there are different reports of different outcomes for SERM vs AI, and menopausal status, prior oophorectomy, and hormone replacement therapy all can impact neurocognitive changes in women.”
According to Dr. White, the results of these two studies emphasis the importance of regularly screening patients with cancer for distress, which has often been called the sixth vital sign of cancer care.