Neurocognitive Function in Adult Cancer Patients

Neuropsychological Evaluation for Oncology

Cognitive dysfunction is common in cancers and their treatments. Factors that can contribute to cognitive dysfunction include direct and indirect effects of cancer, surgery, radiation, systemic therapy, as well as comorbidities, fatigue, and mood disturbance. Using objective, validated measures, a neuropsychological evaluation can provide information regarding patterns of cognitive function. Emphasis of cognitive domains assessed may vary depending on disease and treatment history. Cognitive interventions can minimize the effects of cancer-related cognitive dysfunction on daily life.

Neuropsychological test performance and self-reported cognitive functioning associated with work-related outcomes in occupationally active cancer survivors with cognitive complaints

PURPOSE

To assess cognitive functioning in occupationally active non-central nervous system cancer survivors with cognitive complaints using neuropsychological tests, and to investigate the association between (1) formally assessed cognitive functioning and self-reported work-related outcomes and (2) self-reported cognitive functioning at work and self-reported work-related outcomes.

METHODS

Baseline data of a multicenter, randomized controlled trial (n = 279) were used. Associations between neuropsychological test performance (Amsterdam Cognition Scan) and self-reported cognitive functioning (Cognitive Symptom Checklist-work) with work ability (Work Ability Index) and work functioning (Work Role Functioning Questionnaire) were examined using multivariate linear regression.

RESULTS

Thirty percent of cancer survivors had lower than expected performance on neuropsychological tests. Higher overall neuropsychological test performance was associated with better work ability (Cohen's f2 = 0.014) and physical functioning at work (Cohen's f2 = 0.13). Furthermore, higher motor performance was associated with better work ability (Cohen's f2 = 0.018). In addition, self-reported work-related cognitive complaints were associated with self-reported work-related outcomes (Cohen's f2 = 0.13-0.35).

CONCLUSIONS

The percentage of cancer survivors with lower than expected performance on neuropsychological tests exceeded the percentage expected in a normal population. This neuropsychological test performance was weakly associated with various aspects of work ability and work functioning. Stronger associations were found between self-reported cognitive functioning at work with self-reported work-related outcomes.

IMPLICATIONS FOR CANCER SURVIVORS

A cognitive rehabilitation approach that specifically aims at reducing cognitive symptoms at work could be a valuable part of interventions that aim to improve work-related outcomes. Trial registration The study is registered at ClinicalTrials.gov (NCT03900806) at 03 April 2019 (current status: ongoing), https://clinicaltrials.gov/ct2/show/NCT03900806?term=NCT03900806&draw=2&rank=1.

A common molecular and cellular pathway in developing Alzheimer and cancer

Globally cancer and Alzheimer's disease (AD) are two major diseases and still, there is no clearly defined molecular mechanism. There is an opposite relation between cancer and AD which are the proportion of emerging cancer was importantly slower in AD patients, whereas slow emerging AD in patients with cancer. In cancer, regulation of cell mechanisms is interrupted by an increase in cell survival and proliferation, while on the contrary, AD is related to augmented neuronal death, that may be either produced by or associated with amyloid-β (Aβ) and tau deposition. Stated that the probability that disruption of mechanisms takes part in the regulation of cell survival/death and might be implicated in both diseases. The mechanism of actions such as DNA-methylation, genetic polymorphisms, or another mechanism of actions that induce alteration in the action of drugs with significant roles in resolving the finding to repair and live or die might take part in the pathogenesis of these two ailments. The functions of miRNA, p53, Pin1, the Wnt signaling pathway, PI3 KINASE/Akt/mTOR signaling pathway GRK2 signaling pathway, and the pathophysiological role of oxidative stress are presented in this review as potential candidates which hypothetically describe inverse relations between cancer and AD. Innovative materials almost mutual mechanisms in the aetiology of cancer and AD advocates novel treatment approaches. Among these treatment strategies, the most promising use treatment such as tyrosine kinase inhibitor, nilotinib, protein kinase C, and bexarotene.

Genetic Disruption of System xc-Mediated Glutamate Release from Astrocytes Increases Negative-Outcome Behaviors While Preserving Basic Brain Function in Rat

The importance of neuronal glutamate to synaptic transmission throughout the brain illustrates the immense therapeutic potential and safety risks of targeting this system. Astrocytes also release glutamate, the clinical relevance of which is unknown as the range of brain functions reliant on signaling from these cells hasn't been fully established. Here, we investigated system xc- (Sxc), which is a glutamate release mechanism with an in vivo rodent expression pattern that is restricted to astrocytes. As most animals do not express Sxc, we first compared the expression and sequence of the obligatory Sxc subunit xCT among major classes of vertebrate species. We found xCT to be ubiquitously expressed and under significant negative selective pressure. Hence, Sxc likely confers important advantages to vertebrate brain function that may promote biological fitness. Next, we assessed brain function in male genetically modified rats (MSxc) created to eliminate Sxc activity. Unlike other glutamatergic mechanisms, eliminating Sxc activity was not lethal and didn't alter growth patterns, telemetry measures of basic health, locomotor activity, or behaviors reliant on simple learning. However, MSxc rats exhibited deficits in tasks used to assess cognitive behavioral control. In a pavlovian conditioned approach, MSxc rats approached a food-predicted cue more frequently than WT rats, even when this response was punished. In attentional set shifting, MSxc rats displayed cognitive inflexibility because of an increased frequency of perseverative errors. MSxc rats also displayed heightened cocaine-primed drug seeking. Hence, a loss of Sxc-activity appears to weaken control over nonreinforced or negative-outcome behaviors without altering basic brain function.SIGNIFICANCE STATEMENT Glutamate is essential to synaptic activity throughout the brain, which illustrates immense therapeutic potential and risk. Notably, glutamatergic mechanisms are expressed by most types of brain cells. Hence, glutamate likely encodes multiple forms of intercellular signaling. Here, we hypothesized that the selective manipulation of astrocyte to neuron signaling would alter cognition without producing widespread brain impairments. First, we eliminated activity of the astrocytic glutamate release mechanism, Sxc, in rat. This impaired cognitive flexibility and increased expression of perseverative, maladaptive behaviors. Notably, eliminating Sxc activity did not alter metrics of health or noncognitive brain function. These data add to recent evidence that the brain expresses cognition-specific molecular mechanisms that could lead to highly precise, safe medications for impaired cognition.

Cognitive and neuroimaging outcomes in individuals with benign and low-grade brain tumours receiving radiotherapy: a protocol for a prospective cohort study

INTRODUCTION

Radiation-induced cognitive decline (RICD) occurs in 50%-90% of adult patients 6 months post-treatment. In patients with low-grade and benign tumours with long expected survival, this is of paramount importance. Despite advances in radiation therapy (RT) treatment delivery, better understanding of structures important for RICD is necessary to improve cognitive outcomes. We hypothesise that RT may affect network topology and microstructural integrity on MRI prior to any gross anatomical or apparent cognitive changes. In this longitudinal cohort study, we aim to determine the effects of RT on brain structural and functional integrity and cognition.

METHODS AND ANALYSIS

This study will enroll patients with benign and low-grade brain tumours receiving partial brain radiotherapy. Patients will receive either hypofractionated (>2 Gy/fraction) or conventionally fractionated (1.8-2 Gy/fraction) RT. All participants will be followed for 12 months, with MRIs conducted pre-RT and 6-month and 12 month post-RT, along with a battery of neurocognitive tests and questionnaires. The study was initiated in late 2018 and will continue enrolling through 2024 with final follow-ups completing in 2025. The neurocognitive battery assesses visual and verbal memory, attention, executive function, processing speed and emotional cognition. MRI protocols incorporate diffusion tensor imaging and resting state fMRI to assess structural connectivity and functional connectivity, respectively. We will estimate the association between radiation dose, imaging metrics and cognitive outcomes.

ETHICS AND DISSEMINATION

This study has been approved by the Research Subjects Review Board at the University of Rochester (STUDY00001512: Cognitive changes in patients receiving partial brain radiation). All results will be published in peer-reviewed journals and at scientific conferences.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov NCT04390906.

The association of genetic polymorphisms with neuroconnectivity in breast cancer patients

Genetic polymorphisms in select genes, including APOE (apolipoprotein E), COMT (Catechol-O-Methyltransferase), MDR1 (multi-drug resistance 1), BDNF (brain derived neurotrophic factor), and GST (glutathione-S-transferase), have been associated with vulnerability to cognitive impairment. In this study, we evaluated the relationship of these genetic variants to measures of brain health in patients with breast cancer, including neurocognitive testing and functional connectome analysis. Women with breast cancer (n = 83) and female healthy controls (n = 53) were evaluated. They underwent resting-state functional MRI scans and neurocognitive testing. Polymerase chain reaction (PCR) was performed on saliva samples to identify single nucleotide polymorphisms (SNPs) in candidate genes: APOE, COMT, MDR1, BDNF, and GST. Breast cancer patients treated with chemotherapy had slower processing speed (p = 0.04) and poorer reported executive function (p < 0.0001) than healthy controls. Those chemotherapy-treated patients that were APOE e4 carriers had significantly slower processing speed. A greater number of risk-related alleles was associated with poorer connectivity in the regions of the left cuneus and left calcarine. While breast cancer patients that are APOE e4 carriers may have a select vulnerability to processing speed impairments, other risk-related alleles were not found to influence cognitive test performance in this population. Conversely, regions of impaired functional connectivity appeared to be related to risk-related genetic polymorphisms in breast cancer patients. This suggests that a cancer patient’s SNPs in candidate genes may influence the risk of neurotoxicity. Further study evaluating the impact of genotype on biomarkers of brain health in cancer survivors is warranted.

Cancer Chemotherapy Related Cognitive Impairment and the Impact of the Alzheimer's Disease Risk Factor APOE

Cancer related cognitive impairment (CRCI) is a serious impairment to maintaining quality of life in cancer survivors. Cancer chemotherapy contributes to this condition through several potential mechanisms, including damage to the blood brain barrier, increases in oxidative stress and inflammation in the brain, and impaired neurogenesis, each of which lead to neuronal dysfunction. A genetic predisposition to CRCI is the E4 allele of the Apolipoprotein E gene (APOE), which is also the strongest genetic risk factor for Alzheimer's disease. In normal brains, APOE performs essential lipid transport functions. The APOE4 isoform has been linked to altered lipid binding, increased oxidative stress and inflammation, reduced turnover of neural progenitor cells, and impairment of the blood brain barrier. As chemotherapy also affects these processes, the influence of APOE4 on CRCI takes on great significance. This review outlines the main areas where APOE genotype could play a role in CRCI. Potential therapeutics based on APOE biology could mitigate these detrimental cognitive effects for those receiving chemotherapy, emphasizing that the APOE genotype could help in developing personalized cancer treatment regimens.

Internet-based cognitive rehabilitation for WORking Cancer survivors (i-WORC): study protocol of a randomized controlled trial

Background

Cognitive problems are common in non-central nervous system cancer survivors. These problems are perceived as an important contributor to decline in work performance and work ability. Various interventions for cognitive problems have been proposed, but effectiveness regarding work-related outcomes has not yet been established. Effective treatment options to alleviate the adverse influence of cognitive problems on work performance are needed for working cancer survivors. In this paper, we will describe the design of a randomized, controlled, multicenter trial that evaluates the (cost-)effectiveness of an Internet-based cognitive rehabilitation program for occupationally active cancer survivors confronted with cognitive problems.

Methods/ design

A three-armed randomized controlled trial will be conducted, including two intervention groups (i.e., basic and extensive cognitive rehabilitation program) and one waitlist control group. In total, 261 cancer survivors (18–65 years) who have returned to work and who experience cognitive problems will be recruited. Patients with and without cognitive impairment as established in a neuropsychological assessment will be eligible; stratification will take place based on the presence of this cognitive impairment. The extensive intervention arm will contain a comprehensive training program (including psycho-education, fatigue management, and cognitive strategy training) with individual guidance (blended intervention). The basic intervention arm will contain a brief cognitive training program (including psycho-education and fatigue management) without individual guidance. The primary outcome will be accomplishment of an individually defined work-related treatment goal. Secondary outcomes include, among others, subjective cognitive functioning, work functioning, and quality of life. Primary and secondary outcomes will be measured at baseline (T0) and at 12 weeks (T1) and 26 weeks (T2) post-randomization.

Discussion

About 40–50% of the cancer patients worldwide are of working age at time of diagnosis. Many of the occupationally active cancer survivors experience cognitive problems. Both from an individual and a societal perspective, it is important to sustain cancer survivors’ employability. An effective treatment to alleviate the impact of cognitive decline and to improve work ability might help cancer survivors to sustain employability.

Trial registration

ClinicalTrials.gov NCT03900806. Registered on 03 April 2019 (current status: ongoing).

Cancer-related cognitive problems at work: experiences of survivors and professionals

PURPOSE

Cancer-related cognitive problems (cancer-related cognitive problems) in working cancer survivors are found to affect work outcomes. We aimed to generate in-depth information regarding cancer-related cognitive problems in working cancer survivors, strategies used to cope with cancer-related cognitive problems at work, and needs of cancer survivors and professionals regarding cancer-related cognitive problems at work.

METHODS

Five focus groups were formed, amongst which three focus groups with cancer survivors (n = 8, n = 7, and n = 8) and two focus groups with professionals (n = 7, n = 8). Thematic analysis of the transcripts was performed to create concepts.

RESULTS

Both cancer survivors and professionals confirmed that cancer-related cognitive problems, which occurred in several domains of neurocognitive functioning, affect work functioning. Cancer survivors used several strategies (e.g., applying practical adjustments, re-organization of work, and accepting limitations) to cope with cancer-related cognitive problems at work, as did professionals in their attempt at supporting cancer survivors facing these problems. Various needs of cancer survivors (e.g., supportive care options, acknowledgment by others) and professionals (e.g., improvement of expertise, clarity about referral pathways) regarding cancer-related cognitive problems at work were mentioned.

CONCLUSIONS

Due to the growing number of working cancer survivors dealing with cancer-related cognitive problems, it is essential to sustain their employability. Therefore, cognitive rehabilitation interventions should be developed, taking functioning at work into account. Knowledge amongst professionals regarding cancer-related cognitive problems, as well as coordination of care for cancer-related cognitive problems, should be improved. Ensuring professional education regarding cancer-related cognitive problems, within both the healthcare and occupational setting, is of utmost importance.

IMPLICATIONS FOR CANCER SURVIVORS

Support for working cancer survivors who experience cancer-related cognitive problems might increase their employability in the longer term.