Comparison of Neurocognitive Function After Anthracycline-Based Chemotherapy vs Nonanthracycline-Based Chemotherapy

Cognitive effects of chemotherapy: An integrative review

PURPOSE

An estimated 18.1 million new cancer cases (excluding nonmelanoma skin cancers) were diagnosed worldwide in 2020. Despite a rising incidence of cancers worldwide, in developed countries with strong healthcare systems, survival rates are improving as a result of early detection, improved treatments and survivorship care (World Health Organisation (WHO), 2021). Whilst living longer, cancer survivors are often living with side effects of treatment, including chemotherapy related cognitive impairment, often termed "chemobrain".

METHOD

An integrative review of contemporary literature answering the research question how does chemotherapy affect cognitive function? was undertaken utilising three computerised databases CINAHL, Medline and PUBMED, between 2015 and 2021. Data was thematically analysed to identify themes within published literature.

RESULTS

Thematic analysis identified four broad themes within the literature regarding chemotherapy induced cognitive impairment. Identified themes included; cognition as part of a complex scenario, proof of existence and searching for the cause, learning to play the game and timing of cognitive impairment.

CONCLUSIONS

Aggressive treatment with chemotherapy in the adjuvant setting has drastically improved the survival of cancer patients. Subsequent to aggressive treatments, side effects such as cognitive impairment have presented, which may persist in the long term. Despite the exact aetiology of chemotherapy induced cognitive impairment being largely unknown, the consequences of the condition are impacting cancer survivors and their quality of life.

Focal white matter microstructural alteration after anthracycline-based systemic treatment in long-term breast cancer survivors: a structural magnetic resonance imaging study

Understanding the neural correlates of cognitive problems in patients with breast cancer (BC) after systemic treatment have been a topic of increasing investigation. The heterogeneity of the systemic treatment regimens may undermine our ability to identify brain microstructural alterations resulting from any given regimen. We investigated the detrimental effects of the anthracycline-based systemic treatment (AST) regimen (epirubicin and cyclophosphamide + docetaxel + tamoxifen) on brain gray matter (GM) and white matter (WM) microstructural alteration in long-term BC survivors. We performed a battery of neuropsychological tests and structural magnetic resonance imaging (MRI) to 31 long-term BC survivors who had received the AST regimen (AST group) and 43 healthy controls (HC group). Voxel-based morphometry evaluated the whole-brain voxel-wise GM volume, while diffusion tensor imaging technique with tract-based spatial statistics analysis evaluated whole-brain WM microstructural alteration. Partial least squares regression (PLSR) was used to evaluate the relationship between cognitive impairment and brain microstructural alteration in BC survivors. Compared with the HC group, the AST group exhibited a significantly poorer performance in attention, as well as a marginal significantly poorer performance in verbal working memory and executive function. Significantly lower fractional anisotropy (FA), higher radial diffusivity (RD), and lower axial diffusivity (AD) in multiple brain WM regions were showed in AST group compared with the HC group. Overlap of lower FA and higher RD was found in the body of corpus callosum (CC) and bilateral superior corona radiata (SCR), whereas overlap of lower FA and AD was found in the body of CC and right SCR. The PLSR results showed that the WM regions with overlap of lower FA and AD were significantly associated with executive and verbal working memory decline. No significant difference was observed in the GM volume between groups. Our results suggest that microstructural abnormalities of certain vulnerable WM regions in the AST regimen-exposed brain may provide neuroimaging evidence for the identification of brain injury and cognitive impairment induced by specific chemotherapy regimens.

Executive Functioning and Depressive Symptoms After Cancer: The Mediating Role of Coping

OBJECTIVE

Cognitive difficulties are a common complaint among patients with breast cancer and may adversely affect psychological well-being. In particular, problems with executive functioning (EF) may interfere with coping, which is known to influence depressive symptoms. The current study was designed to examine correlations between EF, coping, and depressive symptoms in breast cancer survivors and to longitudinally test the hypothesis that coping mediates the relationship between EF and depressive symptoms.

METHODS

Participants included 171 women with early-stage breast cancer assessed at the end of primary treatment with surgery, radiation, and/or chemotherapy and at 6 months, 1 year, and 2 years after treatment follow-ups as part of the Mind-Body Study. Participants completed questionnaires to assess subjective EF, approach and avoidant coping, and depressive symptoms, and neuropsychological testing was conducted to assess objective EF. Bivariate correlations were used to examine associations between EF, coping, and depressive symptoms. Mediation analyses were conducted using a bootstrapping approach (PROCESS).

RESULTS

At 1 year after treatment, objective and subjective EFs were correlated with avoidant coping (r = -0.172 [p = .024] and r = 0.297 [p < .001], respectively). In longitudinal analyses, use of the avoidant strategy behavioral disengagement at 1 year mediated the association between objective (95% bootstrap confidence interval = -0.282 to -0.042) and subjective (95% bootstrap confidence interval = 0.020 to 0.254) EFs at 6 months and depressive symptoms at 2 years.

CONCLUSIONS

This study highlights how problems with EF during survivorship are associated with avoidant coping and depressive symptoms. Thus, these findings identify potential cognitive and affective targets for depression intervention in this population.

Physical fitness and neurocognitive outcomes in adult survivors of childhood acute lymphoblastic leukemia: A report from the St. Jude Lifetime cohort

BACKGROUND

Survivors of childhood acute lymphoblastic leukemia (ALL) are at increased risk for both treatment-related exercise intolerance and neurocognitive deficits. This analysis aimed to identify the association between exercise intolerance and neurocognitive impairments in ALL survivors.

METHODS

Cardiopulmonary exercise testing, results from a 2-hour standardized neuropsychological assessment, and self-report questionnaires were obtained for 341 adult survivors of childhood ALL and 288 controls. Multivariable modeling was used to test associations between oxygen uptake at 85% estimated heart rate (rpkVO₂ ) and neuropsychological test and self-reported questionnaire domains, adjusted for sex, age at diagnosis, cranial radiation, anthracycline, and methotrexate exposure and tobacco smoking status.

RESULTS

Compared with controls, survivors had worse rpkVO₂ and performance on verbal intelligence, focused attention, verbal fluency, working memory, dominant/nondominant motor speed, visual-motor speed, memory span, and reading and math measures (all P < .001). In adjusted models, exercise intolerance was associated with decreases in performance of verbal ability, focused attention, verbal fluency, working memory, dominant motor speed, nondominant motor speed, visual-motor speed, memory span, reading academics, and math academics in survivors.

CONCLUSION

This study demonstrates an association between exercise intolerance and neurocognitive outcomes. Research is needed to determine whether interventions that improve exercise tolerance impact neurocognitive function in ALL survivors.

Longitudinal Trajectory and Characterization of Cancer-Related Cognitive Impairment in a Nationwide Cohort Study

PURPOSE

Cancer-related cognitive impairment (CRCI) is an important clinical problem in patients with breast cancer receiving chemotherapy. Nationwide longitudinal studies are needed to understand the trajectory and severity of CRCI in specific cognitive domains.

PATIENTS AND METHODS

The overall objective of this nationwide, prospective, observational study conducted within the National Cancer Institute Community Clinical Oncology Research Program was to assess trajectories in specific cognitive domains in patients with breast cancer (stage I-IIIC) receiving chemotherapy, from pre- (A1) to postchemotherapy (A2) and from prechemotherapy to 6 months postchemotherapy (A3); controls were assessed at the same time-equivalent points. The primary aim assessed visual memory using the Cambridge Neuropsychological Test Automated Battery Delayed Match to Sample test by longitudinal mixed models including A1, A2, and A3 and adjusting for age, education, race, cognitive reserve score, and baseline anxiety and depressive symptoms. We also assessed trajectories of CRCI in other aspects of memory as well as in attention and executive function with computerized, paper-based, and telephone-based cognitive tests.

RESULTS

In total, 580 patients with breast cancer (mean age, 53.4 years) and 363 controls (mean age, 52.6 years) were assessed. On the Delayed Match to Sample test, the longitudinal mixed model results revealed a significant group-by-time effect ( P < .005); patients declined over time from prechemotherapy (A1) to 6 months postchemotherapy (A3; P = .005), but controls did not change ( P = .426). The group difference between patients and controls was also significant, revealing declines in patients but not controls ( P = .017). Several other models of computerized, standard, and telephone tests indicated significantly worse performance by patients compared with controls from pre- to postchemotherapy and from prechemotherapy to 6 months postchemotherapy.

CONCLUSION

This nationwide study showed CRCI in patients with breast cancer affects multiple cognitive domains for at least 6 months postchemotherapy.

Evaluating cognitive complaints in breast cancer survivors with the FACT-Cog and quantitative electroencephalography

PURPOSE

Targeted methods for evaluating cognitive dysfunction in breast cancer survivors are needed to effectively address this important survivorship issue. To address this need, we examined the validity of a self-report instrument (The functional assessment of cancer therapy: cognitive function; FACT-Cog) regarding correspondence with neuropsychological performance versus depression and evaluated neurophysiological biomarkers of cognition and depressed mood in a sample of breast cancer survivors several years from diagnosis.

METHODS

This is a cross-sectional study sample from the prospective observational Mind Body Study. Recruited participants were breast cancer survivors at least 3 years from cancer diagnosis who were part of a longitudinal cohort, and were without current psychiatric disorder or history of a neurological or cognitive disorder at baseline (after completion of primary cancer treatment). Exploratory analysis of the FACT-Cog and quantitative electroencephalography (qEEG) were conducted, with respect to their association with neuropsychological domain scores and depressive symptoms as measured by the Beck Depression Inventory, 2nd edition (BDI-II).

RESULTS

Self-reported cognitive abilities and the impact of cognitive dysfunction on quality of life were associated with memory function in addition to depressive symptoms in our sample of breast cancer survivors. qEEG measures exhibit differential patterns of association with neuropsychological performance and mood.

CONCLUSIONS

Our findings indicate that perceived cognitive abilities and the impact of cognitive difficulties on quality of life are valid indicators of objective cognitive function, independent of depressive symptoms. Neurophysiological correlates of cognitive function and depressive symptoms represent promising biomarkers of these behavioral difficulties in survivorship.

Cognitive impairment in the first year after breast cancer diagnosis: A prospective cohort study

OBJECTIVES

The objective of this study was to assess the relation between cancer treatments and incident cognitive impairment in breast cancer patients, taking into account the levels of anxiety before treatment.

MATERIALS AND METHODS

We conducted a prospective cohort study with 418 newly diagnosed breast cancer patients with no cognitive impairment, defined as values at least 1.5 standard deviations below age- and education-adjusted cut-offs in the Montreal Cognitive Assessment (MoCA), at baseline. The Hospital Anxiety and Depression Scale and MoCA were used for evaluations before treatment and at 1-year after diagnosis. We used Poisson regressions to compute adjusted relative risks (RR) and corresponding 95% confidence intervals (95%CI) to identify predictors of cognitive impairment.

RESULTS

The median (Percentile 25, Percentile 75) MoCA score before treatment was 24 (21, 26). A total of 8.1% (95%CI: 5.8, 11.2) of the patients presented incident cognitive impairment during the follow-up. There was a statistically significant interaction between anxiety at baseline and the effect of chemotherapy on the incidence of cognitive impairment (P for interaction = 0.028). There was a significantly increased risk of incident cognitive impairment among patients with no anxiety prior to treatment with schemes including doxorubicin and cyclophosphamide (adjusted RR = 4.22, 95%CI: 1.22, 14.65).

CONCLUSION

There was a statistically significant association between chemotherapy and cognitive impairment, but only among women with no anxiety at baseline.