Older breast cancer survivors who have certain aging-related phenotypes and genotypes may be at increased risk for cognitive decline, especially after treatment with chemotherapy, according to study results.
“[Results of this study] are good news for the majority of patients with breast cancer who worry about potential long-lasting cognitive effects of treatment,” Jeanne Mandelblatt, MD, MPH, professor of oncology at Georgetown Lombardi Comprehensive Cancer Center, said in a press release. “Our study suggests that for most older patients with breast cancer, chemotherapy and hormonal treatments do not have major adverse effects on cognitive function, at least as measured by our current tests.”
Mandelblatt and colleagues sought to evaluate the effects of treatment and aging on longitudinal cognitive function among 344 survivors (mean age, 68.1 years) of newly diagnosed nonmetastatic breast cancer compared with 347 controls (mean age, 67.8 years) without cancer.
Researchers collected data during presystemic treatment and control enrollment, and also through biospecimen collection at 1-year and 2-year follow-up. Patients also completed surveys, self-reported Functional Assessment of Cancer Therapy-Cognitive Function, and underwent neuropsychological tests that measured attention, processing speed and executive function, and learning and memory.
Survivors and controls were well educated, had similar baseline cognitive scores, and did not have dementia or neurologic disease.
Results showed women treated with chemotherapy scored worse (P = .05) on neuropsychological tests that measured attention, processing speed and executive function.
In addition, women who initiated hormonal therapy had lower learning and memory scores at 1-year follow-up (P = .03).
Group-by-time differences varied by status of apolipoprotein E (APOE4) gene — a risk factor for Alzheimer disease that may also be associated with cancer-related cognitive decline.
Breast cancer survivors who were positive for the APOE4 gene and received hormonal therapy had lower adjusted learning and memory scores at 1-year follow-up (three-way interaction, P = .03).
Although the three-way group-by-time-by-APOE4 interaction for attention, processing speed and executive function scores was not signicant, 2-year scores were signicantly lower for survivors who were APOE4 positive and exposed to chemotherapy compared with controls who were APOE4 positive (–0.4 vs. 0.01; P < .05).
Baseline scores on all cognitive measures decreased with increasing age (P < .001), and frailty appeared associated with baseline attention, processing speed and executive function and self-reported decline (P < .001).
“In this study, patients who were more likely to have cognitive issues were a small group who have one or two copies of the APOE4 gene, but the data are inconclusive and we are examining this more thoroughly,” Mandelblatt said in the release. – by Jennifer Southall
Disclosures: Mandelblatt reports no relevant financial disclosures. Please see the study for all other authors’ relevant financial disclosures.