Understanding the Profile of Cancer-Related Cognitive Impairments: A Critique of Meta-Analyses

Abstract

A large body of evidence indicates that cancer survivors who have undergone chemotherapy have cognitive impairments. Substantial disagreement exists regarding which cognitive domains are impaired in this population. We suggest that is in part due to inconsistency in how neuropsychological tests are assigned to cognitive domains. The purpose of this paper is to critically analyze the meta-analytic literature on cancer-related cognitive impairments (CRCI) to quantify this inconsistency. We identified all neuropsychological tests reported in seven meta-analyses of the CRCI literature. Although effect sizes were generally negative (indicating impairment), every domain was declared to be impaired in at least one meta-analysis and unimpaired in at least one other meta-analysis. We plotted summary effect sizes from all the meta-analyses and quantified disagreement by computing the observed and ideal distributions of the one-way χ2 statistic. The actual χ2 distributions were noticeably more peaked and shifted to the left than the ideal distributions, indicating substantial disagreement among the meta-analyses in how neuropsychological tests were categorized to domains. A better understanding of the profile of impairments in CRCI is essential for developing effective remediation methods. To accomplish this goal, the research field needs to promote better agreement on how to measure specific cognitive functions.

How do we measure attention? Using factor analysis to establish construct validity of neuropsychological tests

“…However, the downside is that it is very difficult to pin down which cognitive faculties are affected (Jaeger, 2018). For research purposes, this construct validity problem is a major limitation (McFall, 2005;McFall & Townsend, 1998), and poses a general challenge to integrating neuropsychological research with cognitive neuroscience (Horowitz et al, 2019).…”

“…However, this difference score is rarely reported in the scientific literature Treviño et al Cogn. Research (2021) 6:51 (e.g., in the cancer-related cognitive impairment field, see Horowitz et al, 2019).…”

“…The goal of this paper is to begin to address this problem, using factor analysis tools to map the relationships. Specifically, we will address the attention domain, which was the most frequently assessed cognitive domain in our survey of cancer-related cognitive impairment studies (Horowitz et al, 2019 ).…”

“…This means that it is often difficult to know exactly what cognitive faculties are being measured by a given test (Kessels, 2019 ; Schmidt et al, 1994 ). The Digit Symbol Coding test, for example, is a widely used neuropsychological test that is variously held to measure attention, psychomotor speed, working memory, processing speed, and executive function (Horowitz et al, 2019 ). In the clinical setting, this lack of specificity can be an advantage.…”

Protective Effects of APOE ε2 Genotype on Cognition in Older Breast Cancer Survivors: The Thinking and Living With Cancer Study

“…First, we examined models that excluded participants with ε3/ε4 and ε4/ε4 genotypes to confirm that the presence of any ε4 allele did not confound results ( 13 ). Next, because cognitive declines can be subtle ( 38 ), we modeled the effects of ε2 on individual neuropsychological test scores and self-reported cognition. The APOE ε2 genotype has been associated with type III hyperlipoproteinemia, which may increase risk for heart disease and adversely affect cognition ( 39 ), so we tested the effects of cardiovascular-related comorbidities in lieu of baseline deficit accumulation.…”