Study Finds Cognitive Impairment Before Chemotherapy

PHOENIX—Between 17.5% and 29.8% of 57 nonmetastatic breast cancer patients had cognitive impairment prior to starting chemotherapy in an ongoing study exploring the effects of chemotherapy on cognitive functioning among breast cancer patients. The prevalence of impairment depended on which of three common definitions was applied to the patients’ scores on a battery of neuropsychological tests, said Janhavi Desai, MA, of the Center on Outcomes, Research and Education (CORE), Evanston Northwestern Health Care, Evanston, Illinois. Ms. Desai presented the results at a poster at the Second Annual Conference of the American Psychosocial Oncology Society (APOS abstract P2-6). "In order to better understand the effects of chemotherapy on cognition, a consensus-driven definition of impairment is needed," she said.

The study population comprised 55 women and 2 men; 43 had stage II disease; the rest were stage I, III, or unknown; 25 women were premenopausal.

Ten patients (17.5%) were impaired based on a standard that defined impairment as 1.5 or more standard deviations (SDs) below the norm on one or more tests, or 2 or more SDs on a single test in the battery. When impairment was defined as 1 or more SDs below the age-adjusted mean on three or more neuropsychological measures, 13 patients (22.8%) met the criterion. The third definition—scores in the lowest quartile for four or more neuropsychological domains—classified 17 patients (29.8%) as cognitively impaired. Five patients (8.8%) met the definition for cognitive impairment by all three standards.

While deficits were recorded in many domains, the most common were in visual-spatial skills, immediate memory, and executive functioning.

A growing number of studies have linked cognitive impairment to chemotherapy, but few have looked at the patients’ cognitive performance prior to treatment, said Ms. Desai, the project coordinator. "We don’t know if this impairment was there before chemotherapy, occurred after chemotherapy, or was exacerbated by chemotherapy," she told ONI. Further, she said, previous studies have not used a consistent standard for defining impairment.

The investigators plan to continue the study, adding more patients and tracking cognitive functioning during and after chemotherapy. For more information about the trial, please contact principal investigator Lynne Wagner, PhD, at LWagner@northwestern.edu.