“Cognitive decline is frequently observed after chemotherapy,” according to Michiel B. de Ruiter, PhD, a research scientist with the Netherlands Cancer Institute in Amsterdam. He specializes in cognitive neuroscience and was the lead author of a study published online Sept. 30, 2021, in the. Dr. de Ruiter and colleagues found that fractional anisotropy may demonstrate a low brain white-matter reserve which could be a risk factor for cognitive decline after chemotherapy for breast cancer treatment.
Cognitive decline after chemotherapy has been reported in 20%-40% of patients with cancer affecting quality of life and daily living skills. Studies have suggested that genetic makeup, advanced age, fatigue, and premorbid intelligence quotient are risk factors for chemotherapy-associated cognitive decline. Changes in the microstructure of brain white matter, known as brain reserve, have been reported after exposure to chemotherapy, but its link to cognitive decline is understudied. Several studies outside of oncology have used MRI to derive fractional anisotropy as a measure for brain reserve.
In the new JCO study, researchers examined fractional anisotropy, as measured by MRI, before chemotherapy. The analysis included 49 patients who underwent neuropsychological tests before treatment with anthracycline-based chemotherapy, then again at 6 months and 2 years after chemotherapy.
The results were compared with those of patients with breast cancer who did not receive systemic therapy and then with a control group consisting of patients without cancer.
A low fractional anisotropy score suggested cognitive decline more than 3 years after receiving chemotherapy treatment. The finding was independent of age, premorbid intelligence quotient, baseline fatigue and baseline cognitive complaints. And, having low premorbid intelligence quotient was an independent risk factor for chemotherapy-associated cognitive decline, which the authors said is in line with previous findings.
Fractional anisotropy did not predict cognitive decline in patients who did not receive systemic therapy, as well as patients in the control group.
The findings could possibly lead to the development a pretreatment assessment to screen for patients who may at risk for cognitive decline, the authors wrote. “Clinically validated assessments of white-matter reserve as assessed with an MRI scan may be part of a pretreatment screening. This could also aid in early identification of cognitive decline after chemotherapy, allowing targeted and early interventions to improve cognitive problems,” such as psychoeducation and cognitive rehabilitation.
No potential conflicts of interest were reported.