A metaanalysis of studies of the effects of cancer chemotherapy on various domains of cognitive function

Abstract

BACKGROUNDLittle is known about the effects of chemotherapy on cognitive function. The purposes of this metaanalysis were to estimate the effect sizes for the effect of chemotherapy on each domain of cognitive function and to differentiate effect sizes by each method of comparison of effects (i.e., normative data, control group, or baseline data).METHODSSixteen studies that evaluated cognitive function in chemotherapy patients were included in the study. DSTAT metaanalysis software was used to calculate an effect size and confidence intervals for each neuropsychologic test. Tests were assigned to a specific cognitive domain, and an average effect size was determined for each domain.RESULTSOnly one domain of cognitive function (i.e., visual memory) had significant chemotherapy‐induced impairment across all comparison types. However, when the neuropsychologic test scores of chemotherapy patients were compared with normative data, significant effect sizes were found for four domains of cognitive function (i.e., executive function, information processing speed, verbal memory, visual memory). In addition, significant, albeit small, effect sizes were found for language and verbal memory when chemotherapy patients' test scores were compared with test scores of healthy matched controls. All significant averaged effect sizes were in the negative direction, indicating that mean scores on neuropsychologic tests for patients who had received chemotherapy were on average lower than comparison scores.CONCLUSIONData from this metaanalysis supported the hypothesis that chemotherapy can have a negative impact on cognitive function. However, most deficits in this study ranged from small to moderate and were nonsignificant. Cancer 2005. © 2005 American Cancer Society.

Cognitive function during neoadjuvant chemotherapy for breast cancer

“…The results were mixed: Poorer performances were reported among patients who received chemotherapy, 2,3,5,7 although others reported no differences 16,17 ; the latter findings also were supported by a meta-analysis. 21 Two longitudinal studies that provided evidence of chemotherapy effects on cognitive function were limited by their rather small sample sizes (Wefel et 18 did not identify any significant differences in cognitive changes between chemotherapy patients, nonchemotherapy patients, and healthy control individuals. The patients were heterogeneous with regard to the chemotherapy regimens administered, with most patients having received only relatively low-dose combined 5-fluorouracil, epirubicin, and cyclophosphamide treatment.…”

“…[16][17][18] Meta-analyses also consistently have stated that it depends on the study design whether chemotherapy-related cognitive impairment is observed, with more appropriate designs resulting in less clear evidence or no evidence of chemotherapy-induced cognitive impairment. [19][20][21] Currently, we are conducting a multicenter, prospective study entitled Cognitive Impairment in Therapy of Breast Cancer (COGITO). Cognitive function in early breast cancer patients is assessed before the start of neoadjuvant chemotherapy, toward the end of chemotherapy, and 1 year after the baseline assessment.…”

Predictors of Cognitive Decline After Chemotherapy in Breast Cancer Patients

“…These declines in cognitive performance are subtle, with the most commonly affected domains being verbal memory, language, visual memory/ spatial ability and executive functioning (for meta-analyses, see Faletti, Sanfi lippo, Maruff, Weih, & Phillips, 2005 ;Jansen, Miaskowski, Dodd, Dowling, & Kramer, 2005 ;Stewart, Bielajew, Collins, Parkinson, & Tomiak, 2006 ). However, reports of affected domains are variable, with some studies fi nding global diffi culties (e.g., Schagen et al, 1999 ;Scherwath et al, 2006 ;Wieneke & Dienst, 1995 ) and some fi nding K.J.…”

Cognitive function in the acute course of allogeneic hematopoietic stem cell transplantation for hematological malignancies

“…3,13,14 Contradictory results exist concerning the extent of impairments either before, or after chemotherapy. Finding deviations from norms before treatment leads to the discussion of other factors not directly associated with the treatment such as influence of the malignancies themselves or psychological factors (anxiety, treatment-related distress, depression).…”