Relationship of systemic cytokine concentrations to cognitive function over two years in women with early stage breast cancer

Inflammation at diagnosis and cognitive impairment two years later in breast cancer patients from the Canto-Cog study

BACKGROUND

Inflammation could be related to cancer-related cognitive impairment (CRCI) and might be used as a predictive marker of long-term CRCI. We evaluated associations between inflammatory markers assessed at diagnosis of breast cancer and CRCI two years afterwards.

METHODS

Newly diagnosed stage I-III patients with breast cancer from the French CANTO-Cog (Cognitive sub-study of CANTO, NCT01993498) were included at diagnosis (baseline). Serum inflammatory markers (IL-2, IL-4, IL-6, IL-8, IL-10, TNFα, CRP) were assessed at baseline. Outcomes at year 2 post-baseline included overall cognitive impairment (≥ 2 impaired domains) and the following domains: episodic memory, working memory, attention, processing speed, and executive functions. Multivariable logistic regression models evaluated associations between markers and outcomes, controlling for age, education, and baseline cognitive impairment.

RESULTS

Among 200 patients, the mean age was 54 ± 11 years, with 127 (64%) receiving chemotherapy. Fifty-three (27%) patients had overall cognitive impairment at both timepoints. Overall cognitive impairment at year 2 was associated with high (> 3 mg/L) baseline CRP (OR = 2.84, 95%CI: 1.06-7.64, p = 0.037). In addition, associations were found between high CRP and processing speed impairment (OR = 2.47, 95%CI:1.05-5.87, p = 0.039), and between high IL-6 and episodic memory impairment (OR = 5.50, 95%CI:1.43-36.6, p = 0.010).

CONCLUSIONS

In this cohort, high levels of CRP and IL-6 assessed at diagnosis were associated with overall CRCI, processing speed and episodic memory impairments two years later. These findings suggest a potential inflammatory basis for long-term CRCI. CRP may represent an easily measurable marker in clinical settings and be potentially used to screen patients at greater risk of persistent CRCI.

Chemotherapy-induced gut microbiome disruption, inflammation, and cognitive decline in female patients with breast cancer

Chemotherapy is notorious for causing behavioral side effects (e.g., cognitive decline). Notably, the gut microbiome has recently been reported to communicate with the brain to affect behavior, including cognition. Thus, the aim of this clinical longitudinal observational study was to determine whether chemotherapy-induced disruption of the gut microbial community structure relates to cognitive decline and circulating inflammatory signals. Fecal samples, blood, and cognitive measures were collected from 77 patients with breast cancer before, during, and after chemotherapy. Chemotherapy altered the gut microbiome community structure and increased circulating TNF-α. Both the chemotherapy-induced changes in microbial relative abundance and decreased microbial diversity were related to elevated circulating pro-inflammatory cytokines TNF-α and IL-6. Participants reported subjective cognitive decline during chemotherapy, which was not related to changes in the gut microbiome or inflammatory markers. In contrast, a decrease in overall objective cognition was related to a decrease in microbial diversity, independent of circulating cytokines. Stratification of subjects, via a reliable change index based on 4 objective cognitive tests, identified objective cognitive decline in 35% of the subjects. Based on a differential microbial abundance analysis, those characterized by cognitive decline had unique taxonomic shifts (Faecalibacterium, Bacteroides, Fusicatenibacter, Erysipelotrichaceae UCG-003, and Subdoligranulum) over chemotherapy treatment compared to those without cognitive decline. Taken together, gut microbiome change was associated with cognitive decline during chemotherapy, independent of chemotherapy-induced inflammation. These results suggest that microbiome-related strategies may be useful for predicting and preventing behavioral side effects of chemotherapy.

Systemic Biological Mechanisms of Neurocognitive Dysfunction in Long-Term Survivors of Childhood Hodgkin Lymphoma

PURPOSE

Hodgkin lymphoma (HL) survivors experience neurocognitive impairment despite receiving no central nervous system-directed therapy, though little is known about the underlying mechanisms.

EXPERIMENTAL DESIGN

HL survivors (n = 197) and age-, sex- and race/ethnicity frequency-matched community controls (n = 199) underwent standardized neurocognitive testing, and serum collection. Luminex multiplex or ELISA assays measured markers of inflammation and oxidative stress. Linear regression models compared biomarker concentrations between survivors and controls and with neurocognitive outcomes, adjusting for age, sex, race, body mass index, anti-inflammatory medication, and recent infections.

RESULTS

HL survivors [mean (SD) current age 36 (8) years, 22 (8) years after diagnosis] demonstrated higher concentrations of interleukin-6 (IL6), high-sensitivity c-reactive protein (hs-CRP), oxidized low-density lipoprotein, and glutathione peroxidase (GPx), compared with controls (P's < 0.001). Among survivors, higher concentrations of IL6 were associated with worse visuomotor processing speed (P = 0.046). hs-CRP ≥3 mg/L was associated with worse attention, processing speed, memory, and executive function (P's < 0.05). Higher concentrations of malondialdehyde were associated with worse focused attention and visual processing speed (P's < 0.05). Homocysteine was associated with worse short-term recall (P = 0.008). None of these associations were statistically significant among controls. Among survivors, hs-CRP partially mediated associations between cardiovascular or endocrine conditions and visual processing speed, whereas IL6 partially mediated associations between pulmonary conditions and visuomotor processing speed.

CONCLUSIONS

Neurocognitive function in long-term survivors of HL appears to be associated with inflammation and oxidative stress, both representing potential targets for future intervention trials.

Effects of mammary cancer and chemotherapy on neuroimmunological markers and memory function in a preclinical mouse model

Treatment modalities for breast cancer, including cyclophosphamide chemotherapy, have been associated with the development of cognitive decline (CRCD), which is characterized by impairments in memory, concentration, attention, and executive functions. We and others have identified a link between inflammation and decreased cognitive performance in patients with breast cancer receiving chemotherapy. In order to better understand the inflammation-associated molecular changes within the brain related to tumor alone or in combination with chemotherapy, we orthotopically implanted mouse mammary tumors (E0771) into female C57BL/6 mice and administered clinically relevant doses of cyclophosphamide and doxorubicin intravenously at weekly intervals for four weeks. We measured serum cytokines and markers of neuroinflammation at 48 h and up to one month post-treatment and tested memory using a reward-based delayed spatial alternation paradigm. We found that breast tumors and chemotherapy altered systemic inflammation and neuroinflammation. We further found that the presence of tumor and chemotherapy led to a decline in memory over time at the longest delay, when memory was the most taxed, compared to shorter delay times. These findings in a clinically relevant mouse model shed light on possible biomarkers for CRCD and add to the growing evidence that anti-inflammatory strategies have the potential to mitigate cancer- or treatment-related side effects.

Inflammation-related proteins as biomarkers of treatment-related behavioral symptoms: A longitudinal study of breast cancer patients and age-matched controls

Background

Behavioral symptoms in breast cancer (BC) survivors have been attributed to cancer treatment and resulting inflammation. However, studies linking behavioral symptoms to BC treatment have observed patients only after some treatment. Our prospective study with pre-treatment baseline investigates post-treatment changes in inflammation-related biomarkers and whether those changes correlate with changes in symptoms.

Methods

Participants were postmenopausal women, newly-diagnosed with stage 0-3 BC before any treatment (n = 173 "patients"), and age-matched women without cancer (n = 77 "controls"), who were assessed on plasma markers [soluble tumor necrosis factor receptor type 2 (sTNF-RII), interleukin (IL)-6, IL-1 receptor antagonist (IL-1RA), C-reactive protein (CRP)]) and symptoms (Physical Functioning, Pain, Attention/concentration, Perceived Cognitive Problems, Fatigue, Sleep Insufficiency, Depression). Participants were assessed again 1 month, 1 year, and 2 years after completing primary treatment or similar interval in controls. Generalized linear mixed models tested 4 treatments (surgery alone or with chemotherapy, radiation, or both) for association with change per marker. Joint models tested change per marker for association with change per symptom. Models considered demographic, socioeconomic, and clinical covariates. False Discovery Rate method controlled risk of error from multiple hypotheses.

Results

At one month post-completion of treatment, sTNF-RII and IL-6 were elevated by all BC treatments, as were IL-1RA and CRP after surgery alone (all, p < 0.05). By 1 year, markers' average values returned to baseline. Throughout 2-year follow-up, increase-from-baseline in sTNF-RII, IL-1RA, and IL-6 coincided with worsened Physical Functioning, and increase-from-baseline in sTNF-RII coincided with increased Pain (all, p < 0.01). These biomarker-symptom associations (excepting IL-6) were exclusive to patients. No other symptoms worsened, and baseline Fatigue and Depression improved in all participants.

Conclusions

BC treatment, even surgery, is associated with transient elevation in inflammatory markers. In patients post-treatment, increase-from-baseline in sTNF-RII accompanies increased Pain and decreased Physical Functioning, suggesting that sTNF-RII merits development as a clinical biomarker in BC patients.

Cancer-related cognitive impairment in racial and ethnic minority groups: a scoping review

PURPOSE

Disparities in cognitive function among racial and ethnic groups have been reported in non-cancer conditions, but cancer-related cognitive impairment (CRCI) in racial and ethnic minority groups is poorly understood. We aimed to synthesize and characterize the available literature about CRCI in racial and ethnic minority populations.

METHODS

We conducted a scoping review in the PubMed, PsycInfo, and Cumulative Index to Nursing and Allied Health Literature databases. Articles were included if they were published in English or Spanish, reported cognitive functioning in adults diagnosed with cancer, and characterized the race or ethnicity of the participants. Literature reviews, commentaries, letters to the editor, and gray literature were excluded.

RESULTS

Seventy-four articles met the inclusion criteria, but only 33.8% differentiated the CRCI findings by racial or ethnic subgroups. There were associations between cognitive outcomes and the participants' race or ethnicity. Additionally, some studies found that Black and non-white individuals with cancer were more likely to experience CRCI than their white counterparts. Biological, sociocultural, and instrumentation factors were associated with CRCI differences between racial and ethnic groups.

CONCLUSIONS

Our findings indicate that racial and ethnic minoritized individuals  may be disparately affected by CRCI. Future research should use standardized guidelines for measuring and reporting the self-identified racial and ethnic composition of the sample; differentiate CRCI findings by racial and ethnic subgroups; consider the influence of structural racism in health outcomes; and develop strategies to promote the participation of members of racial and ethnic minority groups.

Plasma levels of interleukin-6 mediate neurocognitive performance in older breast cancer survivors: The Thinking and Living With Cancer study

BACKGROUND

Immune activation/inflammation markers (immune markers) were tested to explain differences in neurocognition among older breast cancer survivors versus noncancer controls.

METHODS

Women >60 years old with primary breast cancer (stages 0-III) (n = 400) were assessed before systemic therapy with frequency-matched controls (n = 329) and followed annually to 60 months; blood was collected during annual assessments from 2016 to 2020. Neurocognition was measured by tests of attention, processing speed, and executive function (APE). Plasma levels of interleukin-6 (IL-6), IL-8, IL-10, tumor necrosis factor α (TNF-α), and interferon γ were determined using multiplex testing. Mixed linear models were used to compare results of immune marker levels by survivor/control group by time and by controlling for age, racial/ethnic group, cognitive reserve, and study site. Covariate-adjusted multilevel mediation analyses tested whether survivor/control group effects on cognition were explained by immune markers; secondary analyses examined the impact of additional covariates (e.g., comorbidity and obesity) on mediation effects.

RESULTS

Participants were aged 60-90 years (mean, 67.7 years). Most survivors had stage I (60.9%) estrogen receptor-positive tumors (87.6%). Survivors had significantly higher IL-6 levels than controls before systemic therapy and at 12, 24, and 60 months (p ≤ .001-.014) but there were no differences for other markers. Survivors had lower adjusted APE scores than controls (p < .05). Levels of IL-6, IL-10, and TNF-α were related to APE, with IL-6 explaining part of the relationship between survivor/control group and APE (p = .01). The magnitude of this mediation effect decreased but remained significant (p = .047) after the consideration of additional covariates.

CONCLUSIONS

Older breast cancer survivors had worse long-term neurocognitive performance than controls, and this relationship was explained in part by elevated IL-6.

Mitigating long-term and delayed adverse events associated with cancer treatment: implications for survivorship

Despite the importance of chemotherapy-associated adverse events in oncology practice and the broad range of interventions available to mitigate them, limited systematic efforts have been made to identify, critically appraise and summarize the totality of evidence on the effectiveness of these interventions. Herein, we review the most common long-term (continued beyond treatment) and late or delayed (following treatment) adverse events associated with chemotherapy and other anticancer treatments that pose major threats in terms of survival, quality of life and continuation of optimal therapy. These adverse effects often emerge during and continue beyond the course of therapy or arise among survivors in the months and years following treatment. For each of these adverse effects, we discuss and critically evaluate their underlying biological mechanisms, the most commonly used pharmacological and non-pharmacological treatment strategies, and evidence-based clinical practice guidelines for their appropriate management. Furthermore, we discuss risk factors and validated risk-assessment tools for identifying patients most likely to be harmed by chemotherapy and potentially benefit from effective interventions. Finally, we highlight promising emerging supportive-care opportunities for the ever-increasing number of cancer survivors at continuing risk of adverse treatment effects.

Association of markers of inflammation on attention and neurobehavioral outcomes in survivors of childhood acute lymphoblastic leukemia

Background

Survivors of childhood acute lymphoblastic leukemia (ALL) are at-risk of developing cognitive impairment and neurobehavioral symptoms. Inflammation induced by a compromised health status during cancer survivorship is proposed as a pathophysiological mechanism underlying cognitive impairment in cancer survivors.

Objectives

To evaluate the associations of biomarkers of inflammation with attention and neurobehavioral outcomes in survivors of childhood ALL, and to identify clinical factors associated with biomarkers of inflammation in this cohort.

Methods

We recruited patients who were diagnosed with ALL at ≤ 18 years old and were currently ≥5 years post-cancer diagnosis. The study outcomes were attention (Conners Continuous Performance Test) and self-reported behavioral symptoms (Adult Self-Report [ASR] checklist). Using a commercial screening kit, survivors' plasma (5ml) was assayed for 17 cytokines/chemokine cell-signaling molecules that are associated with neurodegenerative diseases. The final panel of the targeted markers included interleukin (IL)-8, IL-13, interferon-gamma (IFN-γ), monocyte chemoattractant protein-1 (MCP-1), macrophage inflammatory protein-1β, and tumor necrosis factor-α. Biomarker levels were rank-ordered into tertiles based on the sample distribution. Multivariable general linear modeling was used to test for associations between biomarkers and study outcomes in the overall cohort and stratified by gender.

Results

This study included 102 survivors (55.9% males, mean[SD] age 26.2[5.9] years; 19.3[7.1] years post-diagnosis). Survivors within top tertiles of IFN-γ (Estimate =6.74, SE=2.26; P=0.0037) and IL-13 (Estimate =5.10, SE=2.27; P=0.027) demonstrated more inattentiveness. Adjusting for age, gender and treatment, more self-reported thought (Estimate=3.53, SE=1.78; P=0.050) and internalizing problems (Estimate =6.52, SE=2.91; P=0.027) correlated with higher IL-8. Higher levels of IL-13 (RR = 4.58, 95% CI: 1.01-11.10) and TNF-α (RR = 1.44, 95% CI: 1.03-4.07) were observed in survivors had developed chronic health conditions (n=26, 25.5%). The stratified analysis showed that association of IFN-γ with attention was stronger in male survivors than in female survivors.

Conclusion

Inflammation due to cancer-related late effects may potentially be mechanistic mediators of neurobehavioral problems in pediatric ALL survivors. Markers of inflammation can potentially be applied to assess or monitor the effectiveness of interventions, particularly behavioral interventions, in improving cognitive outcomes in survivors. Future work includes understanding the underlying gender-specific pathophysiology behind functional outcomes in the population.

Comparison of serum metabolomics in women with breast Cancer Prior to Chemotherapy and at 1 year: cardiometabolic implications

OBJECTIVE

Early-stage breast cancer (BC) is the second most common malignancy in women, worldwide. Early-detection and treatment advances have led to 5-year survival rates of 90% for early-stage breast cancer. However, the long-term morbidity of breast cancer remains high, with a majority of survivors facing increased risk of cardiometabolic conditions as well as secondary cancers. In particular, African American women with breast cancer experience higher morbidity and mortality than other women. Metabolomics is the comprehensive study of metabolites in biological samples to elucidate the role of monosaccharides, amino acids, and their respective metabolic pathways. Although some studies have found differential metabolites in women with breast cancer compared to normal controls, there has been little study of women with breast cancer across time and the active treatment trajectory. This study examines and compares the serum metabolomic profile of women with BC, prior to initial chemotherapy and at 1 year after inception of chemotherapy.

METHODS

This study examined serum metabolites through a secondary analysis of a longitudinal parent study (EPIGEN) of women diagnosed with early-stage BC. Participants were evaluated across 5 time points: prior to their receipt of chemotherapy (T1), at the time of their 4th chemotherapy treatment (T2), 6 months after the initiation of chemotherapy (T3), one year after the initiation of chemotherapy (T4) and two years after the initiation of chemotherapy (T5). This analysis focused on the metabolomic data from 70 participants from T1 to T4. Using ultra high-pressure liquid chromatography high resolution mass spectrometry (UHPLC-HRMS), we performed Friedman Rank Sum Test followed by Nemenyi post-hoc pairwise tests to identify which metabolite levels differed between time points, focusing on metabolites with a Benjamini-Hochberg false discovery rate (FDR) from the overall Friedman test < 0.05 and then specifically examined the p-values from the T1 vs. T4 pairwise comparison.

RESULTS

The untargeted serum metabolomics yielded a total of 2,395 metabolites identified on the basis of the accurate mass and MS/MS fragmentation, 1,264 of which were significant after Friedman's test (FDR < 0.05). The analysis then focused on the levels of 124 metabolites from the T1 vs. T4 post-hoc comparison that had a combined FDR < 0.05 and fold change (FC) > 2.0. Metabolite set enrichment analysis (MSEA) as part of Metaboanalyst 3.0 was performed to identify pathways that were significantly altered. The known metabolites identified from the functional analysis were used to evaluate the up and down regulated pathways. The 40metabolites from the Functional Analysis were mainly attributed to amino acids (specifically lysine regulation), fatty acids (particularly unsaturated) and steroid hormone synthesis (lysophosphatidic acid).

CONCLUSION

There were multiple significant changes in the serum metabolomic profile of women with breast cancer at one-year post inception of chemotherapy compared to pre-chemotherapy, most notably associated with lysine degradation, branched-chain amino acid synthesis, linoleic acid metabolism, tyrosine metabolism and biosynthesis of unsaturated fatty acids as the top 5 metabolic pathways. Some of these changes could be associated with metabolic perturbations that are consistent with heightened risk of cardiometabolic morbidity. Our results provide new insights into the mechanisms underlying potential heightened cardiovascular health risks in this population.

Remote assessment of cognitive dysfunction in hematologic malignancies using web-based neuropsychological testing

BACKGROUND

Cognitive impairment is a frequent adverse effect of cancer and its therapies. As neuropsychological assessment is not often standard of care for patients with non-CNS disease, efficient, practical assessment tools are required to track cognition across the disease course. We examined cognitive functioning using a web-based cognitive testing battery to determine if it could detect differences between patients with cancer and controls.

METHODS

We enrolled 22 patients with multiple myeloma (MM) or non-Hodgkin lymphoma (NHL) and 40 healthy controls (mean age = 56 ± 11 years, 52% male). Participants completed the BrainCheck cognitive testing battery and online versions of select measures from the Patient Reported Outcome Measures Information System (PROMIS) during a video conference. MANOVA was used to compare BrainCheck and PROMIS scores between groups controlling for age and sex. An exploratory linear regression analysis was conducted within the cancer group to determine potential contributors to cognitive functioning.

RESULTS

All participants except for one control completed the online assessment measures without difficulty. Compared to controls, the cancer group demonstrated significantly lower scores in objective and subjective cognitive function, physical functioning, and social role performance and elevated fatigue scores. Corticosteroid treatment, immunotherapy, lower physical functioning, lower income, and older age significantly contributed to lower cognitive function (adjusted R²  = 0.925, F = 19.63, p = 0.002).

CONCLUSION

Remote assessment of cognitive and psychosocial functioning is feasible with patients with cancer following treatments. The BrainCheck cognitive testing battery has the potential to detect differences in cognition between patients with cancer and controls.

Cognitive function and breast cancer molecular subtype before and after chemotherapy

Chemotherapy-related cognitive impairment has been reported in patients with breast cancer and received growing attention due to increased survival rate. However, cognitive outcome according to pathological tumor features, especially human epidermal growth factor receptor (HER2) status, has not been clearly elucidated. Despite its potential link with cognitive status through neuroinflammatory response, existing research is sparse and limited to cross-sectional studies. In this observational cohort study, 52 breast cancer patients received a series of neuropsychological examinations before and after chemotherapy. Patients' performances were compared with normative data, and analyzed with Reliable Change Indices and mixed-model analysis of covariance. Results showed that there was a higher percentage of HER2+ patients than HER2- patients who showed defective attention and processing speed before chemotherapy, and that there were more patients with HER2+ status showing cognitive decline on tests of attention and executive functions following chemotherapy. Group-wise analyses confirmed the foregoing pattern and further revealed that patients with HER2+ status also tended to deteriorate more in verbal memory after chemotherapy. These findings indicate that HER2 overexpression may serve as prognostic factors that help explain the heterogeneous cognitive outcome in breast cancer survivors. Further studies are needed to replicate this finding and delineate the underlying mechanisms.

Construction of a predictive model for cognitive impairment risk in patients with advanced cancer

AIMS

The purpose of this study was to identify risk factors for cognitive impairment in advanced cancer patients and to develop predictive models based on these risk factors.

BACKGROUND

Cancer-related cognitive impairment seriously affects the quality of life of advanced cancer patients. However, neural network models of cognitive impairment in patients with advanced cancer have not yet been identified.

DESIGN

A cross-sectional design was used.

METHODS

This study collected 494 questionnaires between January and June 2022. Statistically significant clinical indicators were selected by univariate analysis, and the artificial neural network model and logistic regression model were used for multivariate analysis. The predicted value of the model was estimated using the area under the subject's working characteristic curve.

RESULT

The artificial neural network and the logistic regression models suggested that cancer course, anxiety and age were the major risk factors for cognitive impairment in advanced cancer patients. All the indexes of artificial neural network model constructed in this study are better than those of the logistic model.

CONCLUSION

The artificial neural network model can better predict the risk factors of cognitive impairment in patients with advanced cancer. Better prediction will enable nurses and other healthcare professionals to provide better targeted and timely support.

Tryptophan and Kynurenine Pathway Metabolites and Psychoneurological Symptoms Among Breast Cancer Survivors

BACKGROUND

Among breast cancer survivors, pain, fatigue, depression, anxiety, and sleep disturbance are common psychoneurological symptoms that cluster together. Inflammation-induced activation of the tryptophan-kynurenine metabolomic pathway may play an important role in these symptoms.

AIMS

This study investigated the relationship between the metabolites involved in the tryptophan-kynurenine pathway and psychoneurological symptoms among breast cancer survivors.

DESIGN

Cross-sectional study.

SETTING

Participants were recruited at the oncology clinic at the University of Illinois Hospital & Health Sciences System.

PARTICIPANTS/SUBJECTS

79 breast cancer survivors after major cancer treatment.

METHODS

We assessed psychoneurological symptoms with the PROMIS-29 and collected metabolites from fasting blood among breast cancer survivors after major cancer treatment, then analyzed four major metabolites involved in the tryptophankynurenine pathway (tryptophan, kynurenine, kynurenic acid, and quinolinic acid). Latent profile analysis identified subgroups based on the five psychoneurological symptoms. Mann-Whitney U tests and multivariable logistic regression compared targeted metabolites between subgroups.

RESULTS

We identified two distinct symptom subgroups (low, 81%; high, 19%). Compared with participants in the low symptom subgroup, patients in the high symptom subgroup had higher BMI (p = .024) and were currently using antidepressants (p = .008). Using multivariable analysis, lower tryptophan levels (p = .019) and higher kynurenine/tryptophan ratio (p = .028) were associated with increased risk of being in the high symptom subgroup after adjusting for BMI and antidepressant status.

CONCLUSION

The tryptophan-kynurenine pathway and impaired tryptophan availability may contribute to the development of psychoneurological symptoms.

Elevated C-Reactive Protein and Subsequent Patient-Reported Cognitive Problems in Older Breast Cancer Survivors: The Thinking and Living With Cancer Study

PURPOSE

To examine longitudinal relationships between levels of C-reactive protein (CRP) and cognition in older breast cancer survivors and noncancer controls.

METHODS

English-speaking women age ≥ 60 years, newly diagnosed with primary breast cancer (stage 0-III), and frequency-matched controls were enrolled from September 2010 to March 2020; women with dementia, neurologic disorders, and other cancers were excluded. Assessments occurred presystemic therapy/enrollment and at annual visits up to 60 months. Cognition was measured using the Functional Assessment of Cancer Therapy-Cognitive Function and neuropsychological testing. Mixed linear effect models tested for survivor-control differences in natural log (ln)-transformed CRP at each visit. Random effect-lagged fluctuation models tested directional effects of ln-CRP on subsequent cognition. All models controlled for age, race, study site, cognitive reserve, obesity, and comorbidities; secondary analyses evaluated if depression or anxiety affected results.

RESULTS

There were 400 survivors and 329 controls with CRP specimens and follow-up data (average age of 67.7 years; range, 60-90 years). The majority of survivors had stage I (60.9%), estrogen receptor-positive (87.6%) tumors. Survivors had significantly higher adjusted mean ln-CRP than controls at baseline and 12-, 24-, and 60-month visits (all P < .05). Higher adjusted ln-CRP predicted lower participant-reported cognition on subsequent visits among survivors, but not controls (P interaction = .008); effects were unchanged by depression or anxiety. Overall, survivors had adjusted Functional Assessment of Cancer Therapy-Cognitive Function scores that were 9.5 and 14.2 points lower than controls at CRP levels of 3.0 and 10.0 mg/L. Survivors had poorer neuropsychological test performance (v controls), with significant interactions with CRP only for the Trails B test.

CONCLUSION

Longitudinal relationships between CRP and cognition in older breast cancer survivors suggest that chronic inflammation may play a role in development of cognitive problems. CRP testing could be clinically useful in survivorship care.

The association of systemic inflammation and cognitive functions of pre-school aged children residing in a Schistosoma haematobium endemic area in Zimbabwe

Background

Cognitive function is negatively impacted by schistosomiasis and might be caused by systemic inflammation which has been hypothesized to be one of the mechanisms driving cognitive decline, This study explored the association of systemic inflammatory biomarkers; interleukin (IL)-10, IL-6, IL-17, transforming growth factor (TGF-β), tumor necrosis factor (TNF-α), C-reactive protein (CRP) and hematological parameters with cognitive performance of preschool-aged children (PSAC) from an Schistosoma haematobium endemic area.

Methods

The Griffith III tool was used to measure the cognitive performance of 136 PSAC. Whole blood and sera were collected and used to quantify levels of IL-10, TNF-α, IL-6, TGF-β, IL-17 A and CRP using the enzyme-linked immunosorbent assay and hematological parameters using the hematology analyzer. Spearman correlation analysis was used to determine the relationship between each inflammatory biomarker and cognitive performance. Multivariate logistic regression analysis was used to determine whether systemic inflammation due to S. haematobium infection affected cognitive performance in PSAC.

Results

Higher levels of TNF-α and IL-6, were correlated with lower performance in the Foundations of Learning domain (r = -0.30; p < 0.001 and r = -0.26; p < 0.001), respectively. Low cognitive performance in the Eye-Hand-Coordination Domain was observed in PSAC with high levels of the following inflammatory biomarkers that showed negative correlations to performance; TNF-α (r = -0.26; p < 0.001), IL-6 (r = -0.29; p < 0.001), IL-10 (r = -0.18; p < 0.04), WBC (r = -0.29; p < 0.001), neutrophils (r = -0.21; p = 0.01) and lymphocytes (r = -0.25; p = 0.003) The General Development Domain correlated with TNF-α (r = -0.28; p < 0.001) and IL-6 (r = -0.30; p < 0.001). TGF-β, L-17A and MXD had no significant correlations to performance in any of the cognitive domains. The overall general development of PSAC was negatively impacted by S. haematobium infections (OR = 7.6; p = 0.008) and (OR = 5.6; p = 0.03) where the PSAC had higher levels of TNF-α and IL-6 respectively.

Conclusion

Systemic inflammation and S. haematobium infections are negatively associated with cognitive function. We recommend the inclusion of PSAC into mass drug treatment programs.

Biobehavioral Implications of Chimeric Antigen Receptor T-cell Therapy: Current State and Future Directions

Chimeric antigen receptor (CAR) T-cell therapy has demonstrated remarkable clinical responses in hematologic malignancies. Recent advances in CAR T-cell therapy have expanded its application into other populations including older patients and those with central nervous system and solid tumors. Although its clinical efficacy has been excellent for some malignancies, CAR T-cell therapy is associated with severe and even life-threatening immune-mediated toxicities, including cytokine release syndrome and neurotoxicity. There is a strong body of scientific evidence highlighting the connection between immune activation and neurocognitive and psychological phenomena. To date, there has been limited investigation into this relationship in the context of immunotherapy. In this review, we present a biobehavioral framework to inform current and future cellular therapy research and contribute to improving the multidimensional outcomes of patients receiving CAR T-cell therapy.

Physical Activity as the Best Supportive Care in Cancer: The Clinician's and the Researcher's Perspectives

Multidisciplinary supportive care, integrating the dimensions of exercise alongside oncological treatments, is now regarded as a new paradigm to improve patient survival and quality of life. Its impact is important on the factors that control tumor development, such as the immune system, inflammation, tissue perfusion, hypoxia, insulin resistance, metabolism, glucocorticoid levels, and cachexia. An increasing amount of research has been published in the last years on the effects of physical activity within the framework of oncology, marking the appearance of a new medical field, commonly known as "exercise oncology". This emerging research field is trying to determine the biological mechanisms by which, aerobic exercise affects the incidence of cancer, the progression and/or the appearance of metastases. We propose an overview of the current state of the art physical exercise interventions in the management of cancer patients, including a pragmatic perspective with tips for routine practice. We then develop the emerging mechanistic views about physical exercise and their potential clinical applications. Moving toward a more personalized, integrated, patient-centered, and multidisciplinary management, by trying to understand the different interactions between the cancer and the host, as well as the impact of the disease and the treatments on the different organs, this seems to be the most promising method to improve the care of cancer patients.

Effects of meditation compared to music listening on biomarkers in breast cancer survivors with cognitive complaints: secondary outcomes of a pilot randomized control trial

CONTEXT

We previously reported positive behavioral effects of both daily mantra meditation and classical music listening interventions in breast cancer survivors with cancer related cognitive complaints.

OBJECTIVE

The objective of this pilot study was to compare the effects of the meditation intervention to a music listening intervention on biomarkers of inflammation and cellular aging (secondary outcomes) in breast cancer survivors.

DESIGN

Randomized control trial, baseline data collection (time 1), post intervention data collection (time 2) SETTING: Community-based, Central Texas PARTICIPANTS: 25 breast cancer survivors (BCS) who were 3 months to 6 years post chemotherapy completion and reported cognitive changes.

INTERVENTION(S)

Kirtan Kriya meditation (KK) or classical music listening (ML), 8 weeks, 12 min a day MAIN OUTCOME: Telomerase activity [TA], c-reactive protein [CRP], soluble IL-2 receptor alpha [sIL-2Rα], soluble IL-4 receptor [sIL-4R], soluble IL-6 receptor [sIL-6R], soluble tumor necrosis factor receptor II [sTNF-RII], VEGF receptor 2 [sVEGF-R2], and VEGF receptor 3 [sVEGF-R3] RESULTS: Repeated measures analysis of variance models were analyzed from time 1 to time 2 by group for each biomarker. A pattern of greater telomerase activity across time in both groups (F (1,15) = 3.98, p = .06, ω2 = 0.04); significant decreases in sIL-4R across time for both groups (F (1,22) = 6.28, p = .02, ω2 = .003); group*time effect was nominally different but not statistically different for sIL-4R (F(1,22) = 3.82, p = .06, ω2 = .001); and a pattern for a group*time effect with ML group showing higher levels of sVEGF-R3 at time 2 (F (1,20) = 2.59, p = .12, ω2 = .009). No significant effects were found for CRP, sIL-2Rα, sIL-6R, sTNF-RII, or sVEGF-R2.

Acute and chronic effects of adjuvant therapy on inflammatory markers in breast cancer patients

Background

Inflammation contributes to poor behavioral, functional, and clinical outcomes in cancer survivors. We examined whether standard cancer treatments—radiation and chemotherapy—led to acute and persistent changes in circulating markers of inflammation in breast cancer patients.

Methods

A total of 192 women diagnosed with early stage breast cancer provided blood samples before and after completion of radiation and/or chemotherapy and at 6-, 12-, and 18-month posttreatment follow-ups. Samples were assayed for circulating inflammatory markers, including tumor necrosis factor-α (TNF-α) and interleukin (IL)–6, downstream markers of their activity (soluble TNF receptor type II [sTNF-RII], C reactive protein), and other inflammatory mediators (IL-8, interferon-γ [IFN-γ]). Analyses evaluated within-group changes in inflammatory markers in 4 treatment groups: no radiation or chemotherapy (n = 39), radiation only (n = 77), chemotherapy only (n = 18), and chemotherapy with radiation (n = 58).

Results

Patients treated with chemotherapy showed statistically significant increases in circulating concentrations of TNF-α, sTNF-RII, IL-6, and IFN-γ from pre- to posttreatment, with parameter estimates in standard deviation units ranging from 0.55 to 1.20. Those who received chemotherapy with radiation also showed statistically significant increases in IL-8 over this period. Statistically significant increases in TNF-α, sTNF-RII, IL-6, IFN-γ, and IL-8 persisted at 6, 12, and 18 months posttreatment among patients treated with chemotherapy and radiation (all P < .05). Patients treated with radiation only showed a statistically significant increase in IL-8 at 18 months posttreatment; no increases in any markers were observed in patients treated with surgery only.

Conclusions

Chemotherapy is associated with acute increases in systemic inflammation that persist for months after treatment completion in patients who also receive radiation therapy. These increases may contribute to common behavioral symptoms and other comorbidities in cancer survivors.

Biobehavioral Implications of Covid-19 for Transplantation and Cellular Therapy Recipients

A growing body of literature has emphasized the importance of biobehavioral processes - defined as the interaction of behavior, psychology, socioenvironmental factors, and biological processes - for clinical outcomes among transplantation and cellular therapy (TCT) patients. TCT recipients are especially vulnerable to distress associated with pandemic conditions and represent a notably immunocompromised group at greater risk for SARS-CoV-2 infection with substantially worse outcomes. The summation of both the immunologic and psychologic vulnerability of TCT patients renders them particularly susceptible to adverse biobehavioral sequelae associated with the Covid-19 pandemic. Stress and adverse psychosocial factors alter neural and endocrine pathways through sympathetic nervous system and hypothalamic-pituitary-adrenal axis signaling that ultimately affect gene regulation in immune cells. Reciprocally, global inflammation and immune dysregulation related to TCT contribute to dysregulation of neuroendocrine and central nervous system function, resulting in the symptom profile of depression, fatigue, sleep disturbance, and cognitive dysfunction. In this article, we draw upon literature on immunology, psychology, neuroscience, hematology and oncology, Covid-19 pathophysiology, and TCT processes to discuss how they may intersect to influence TCT outcomes, with the goal of providing an overview of the significance of biobehavioral factors in understanding the relationship between Covid-19 and TCT, now and for the future. We discuss the roles of depression, anxiety, fatigue, sleep, social isolation and loneliness, and neurocognitive impairment, as well as specific implications for sub-populations of interest, including pediatrics, caregivers, and TCT donors. Finally, we address protective psychological processes that may optimize biobehavioral outcomes affected by Covid-19.

Inflammation, Attention, and Processing Speed in Patients With Breast Cancer Before and After Chemotherapy

BACKGROUND

Inflammation may contribute to cognitive difficulties in patients with breast cancer. We tested 2 hypotheses: inflammation is elevated in patients with breast cancer vs noncancer control participants and inflammation in patients is associated with worse attention and processing speed over the course of chemotherapy.

METHODS

Serum cytokines (interleukin [IL]-4, 6, 8, 10; tumor necrosis factor [TNF]-α) and soluble receptors [sTNFRI, II]) were measured in 519 females with breast cancer before and after chemotherapy and 338 females without cancer serving as control participants. Attention and processing speed were measured by Rapid Visual Processing (RVP), Backward Counting (BCT), and Trail Making-A (TMT-A) tests. Linear regression models examined patient vs control cytokines and receptor levels, adjusting for covariates. Linear regression models also examined relationships between patient cytokines and receptor levels and test performance, adjusting for age, body mass index, anxiety, depression, cognitive reserve, and chemotherapy duration. Statistical tests were 2-sided (α = .05).

RESULTS

sTNFRI and sTNFRII increased over time in patients relative to controls, whereas IL-4, IL-6, and IL-10 decreased. Prechemotherapy, higher IL-8 associated with worse BCT (β = 0.610, SE = 0.241, P = .01); higher IL-4 (β = -1.098, SE = 0.516, P = .03) and IL-10 (β = -0.835, SE = 0.414, P = .04) associated with better TMT-A. Postchemotherapy, higher IL-8 (β = 0.841, SE = 0.260, P = .001), sTNFRI (β = 6.638, SE = 2.208, P = .003), and sTNFRII (β = 0.913, SE = 0.455, P = .045) associated with worse BCT; higher sTNFRII also associated with worse RVP (β = -1.316, SE = 0.587, P = .03). At prechemotherapy, higher IL-4 predicted RVP improvement over time (β = 0.820, SE = 0.336, P = .02); higher sTNFRI predicted worse BCT over time (β = 5.566, SE = 2.367, P = .02). Longitudinally, increases in IL-4 associated with BCT improvement (β = -0.564, SE = 0.253, P = .03).

CONCLUSIONS

Generally, worse attention and processing speed were associated with higher inflammatory cytokines and receptors and lower anti-inflammatory cytokines in patients; future confirmatory studies are needed.

Relationships between cytokines and cognitive function from pre- to post-chemotherapy in patients with breast cancer

Cancer-related cognitive decline (CRCD) is a clinically important problem and negatively affects daily functioning and quality of life. We conducted a pilot longitudinal study from pre- to post-chemotherapy in patients with breast cancer to assess changes in inflammation and cognition over time, as well as the impact of baseline cytokine level on post-chemotherapy cognitive scores. We found that concentrations of IL-6, MCP-1, sTNFRI, and sTNFRII significantly increased in patients, while IL-1β significantly decreased (p < 0.05). After controlling for covariates, increases in IL-6 and MCP-1 were associated with worse executive function and verbal fluency in patients from pre- to post-chemotherapy (p < 0.05). Higher baseline IL-6 was associated with better performance on executive function and verbal fluency post chemotherapy (p < 0.05). Overall, these results suggest that chemotherapy-associated increases in cytokines/receptors is associated with worse cognitive function. Larger studies are needed to confirm these findings.

Electroacupuncture for Cancer-Related Cognitive Impairment: A Clinical Feasibility Study

BACKGROUND

Cancer-related cognitive impairment (CRCI) is a significant problem for cancer patients, as the number of cancer survivors experiencing cognitive impairments is increasing in the absence of standard treatment. There have been attempts to improve the cognitive function of patients with cancer using acupuncture; however, no studies have been conducted using electroacupuncture. Thus, we designed a preliminary study to investigate the feasibility of a clinical trial using electroacupuncture in CRCI patients.

METHODS

We conducted a single-arm, pilot, clinical trial to investigate the feasibility of a study protocol for further large-scale clinical trials of electroacupuncture in CRCI patients. All participants were treated with electroacupuncture twice a week for 30 minutes at a time, for 8 weeks on acupoints GV20, GV24, EX-HN1, and GB20, HT7, PC6, and KI3. Both subjective and objective outcomes of cognitive function, quality of life (QoL), and psychological factors were measured in all participants at baseline, week 4, 8, and 12. For safety assessment, vital signs, laboratory examinations, and adverse events (AEs) were observed throughout the trial.

RESULTS

A total of 12 participants were enrolled at Daejeon and Dunsan Korean Medicine Hospital of Daejeon University from 21 April 2017 to 31 January 2018. After 8 weeks of treatment, electroacupuncture significantly improved both subjective and objective cognitive outcomes, including the perceived cognitive impairments scale of the Functional Assessment of Cancer Therapy-Cognitive Function, QoL scale of the European Organization for Research and Treatment of Cancer Quality of Life Core Questionnaire-C30, Korean version of Montreal Cognitive Assessment, Boston Naming Test, Seoul Verbal Learning Test, and Rey Complex Figure Test. During the entire trial period, 19 AEs were observed, with no serious AEs. Additionally, it was found that all feasibility outcomes, including recruitment, completion, and adherence rates, achieved successful results as the ratio exceeded 0.8.

CONCLUSION

Our study results revealed that electroacupuncture improved cognitive complaints in cancer patients, and we expect electroacupuncture to be a safe and effective management therapy for CRCI patients. These feasibility trial results will be used as preliminary data for future randomized controlled clinical trials.

TRIAL REGISTRATION NUMBER

Korean Clinical Trial Registry (KCT0002168).

Long-Term Cognitive Dysfunction in Cancer Survivors

Cancer-related cognitive impairment (CRCI) is a frequent side effect experienced by an increasing number of cancer survivors with a significant impact on their quality of life. Different definitions and means of evaluation have been used in available literature; hence the exact incidence of CRCI remains unknown. CRCI can be described as cognitive symptoms reported by cancer patients in self-reported questionnaires or as cognitive changes evaluated by formal neuropsychological tests. Nevertheless, association between cognitive symptoms and objectively assessed cognitive changes is relatively weak or absent. Studies have focused especially on breast cancer patients, but CRCI has been reported in multiple types of cancer, including colorectal, lung, ovarian, prostate, testicular cancer and hematological malignancies. While CRCI has been associated with various treatment modalities, including radiotherapy, chemotherapy, hormone therapy and novel systemic therapies, it has been also detected prior to cancer treatment. Therefore, the effects of cancer itself with or without the psychological distress may be involved in the pathogenesis of CRCI as a result of altered coping mechanisms after cancer diagnosis. The development of CRCI is probably multifactorial and the exact mechanisms are currently not completely understood. Possible risk factors include administered treatment, genetic predisposition, age and psychological factors such as anxiety, depression or fatigue. Multiple mechanisms are suggested to be responsible for CRCI, including direct neurotoxic injury of systemic treatment and radiation while other indirect contributing mechanisms are hypothesized. Chronic neuroinflammation mediated by active innate immune system, DNA-damage or endothelial dysfunction is hypothesized to be a central mechanism of CRCI pathogenesis. There is increasing evidence of potential plasma (e.g., damage associated molecular patterns, inflammatory components, circulating microRNAs, exosomes, short-chain fatty acids, and others), cerebrospinal fluid and radiological biomarkers of cognitive dysfunction in cancer patients. Discovery of biomarkers of cognitive impairment is crucial for early identification of cancer patients at increased risk for the development of CRCI or development of treatment strategies to lower the burden of CRCI on long-term quality of life. This review summarizes current literature on CRCI with a focus on long-term effects of different cancer treatments, possible risk factors, mechanisms and promising biomarkers.

Blood and neuroimaging biomarkers of cognitive sequelae in breast cancer patients throughout chemotherapy: A systematic review

Breast cancer treatment can induce alterations in blood- and neuroimaging-based markers. However, an overview of the predictive value of these markers for cognition is lacking for breast cancer survivors. This systematic review summarized studies of the last decade, using the PubMed database, evaluating blood markers, and the association between blood- or structural neuroimaging markers and cognition across the chemotherapy trajectory for primary breast cancer, following PRISMA guidelines. Forty-four studies were included. Differences were observed in all blood marker categories, from on-therapy until years post-chemotherapy. Associations were found between cognitive functioning and (1) blood markers (mainly inflammation-related) during, shortly-, or years post-chemotherapy and (2) white and gray matter metrics in frontal, temporal and parietal brain regions months up until years post-chemotherapy. Preliminary evidence exists for epigenetic and metabolic changes being associated with cognition, only after chemotherapy. This review demonstrated time-dependent associations between specific blood-based and structural neuroimaging markers with cognitive impairment in patients with breast cancer. Future studies are encouraged to include both neuroimaging- and blood markers (e.g. of neuronal integrity, epigenetics and metabolism) to predict long-term cognitive effects of chemotherapy.

Cancer-related cognitive impairment is associated with perturbations in inflammatory pathways

Cancer-related cognitive impairment (CRCI) is a significant problem for patients receiving chemotherapy. While a growing amount of pre-clinical and clinical evidence suggests that inflammatory mechanisms underlie CRCI, no clinical studies have evaluated for associations between CRCI and changes in gene expression. Therefore, the purpose of this study was to evaluate for differentially expressed genes and perturbed inflammatory pathways across two independent samples of patients with cancer who did and did not report CRCI. The Attentional Function Index (AFI) was the self-report measure used to assess CRCI. AFI scores of <5 and of >7.5 indicate low versus high levels of cognitive function, respectively. Of the 185 patients in Sample 1, 49.2% had an AFI score of <5 and 50.8% had an AFI score of >7.5. Of the 158 patients in Sample 2, 50.6% had an AFI score of <5 and 49.4% had an AFI score of >7.5. Data from 182 patients in Sample 1 were analyzed using RNA-seq. Data from 158 patients in Sample 2 were analyzed using microarray. Twelve KEGG signaling pathways were significantly perturbed between the AFI groups, five of which were signaling pathways related to inflammatory mechanisms (e.g., cytokine-cytokine receptor interaction, tumor necrosis factor signaling). This study is the first to describe perturbations in inflammatory pathways associated with CRCI. Findings highlight the role of cytokines both in terms of cytokine-specific pathways, as well as pathways involved in cytokine production and cytokine activation. These findings have the potential to identify new targets for therapeutics and lead to the development of interventions to improve cognition in patients with cancer.

Inflammatory Markers, Metabolic Profile, and Psychoneurological Symptoms in Women with Breast Cancer: A Literature Review

Breast cancer is one of the most prevalent cancers in women. The improvement in breast cancer treatment has significantly increased the proportion of survival rate for women with breast cancer. Despite the advancement in breast cancer treatment, a great proportion of survivors suffer from co-occurring psychoneurological symptoms which impact their quality of life. The most frequently reported psychoneurological symptoms among women with breast cancer are depressive symptoms, anxiety, fatigue, sleep disturbances, and pain. These symptoms usually appear as a cluster. Inflammatory activation and serum metabolic alterations have been associated with the etiology of cancer and with various chronic neurocognitive disorders. However, to date, no studies considered the combined effects of inflammatory markers and metabolites in the development of psychoneurological symptoms in women with breast cancer especially those who were treated with chemotherapy. Further clarification of the relationships between the inflammatory markers, serum metabolic alterations, and psychoneurological symptoms in women with breast cancer should be pursued.

Four decades of chemotherapy-induced cognitive dysfunction: comprehensive review of clinical, animal and in vitro studies, and insights of key initiating events

Cognitive dysfunction has been one of the most reported and studied adverse effects of cancer treatment, but, for many years, it was overlooked by the medical community. Nevertheless, the medical and scientific communities have now recognized that the cognitive deficits caused by chemotherapy have a strong impact on the morbidity of cancer treated patients. In fact, chemotherapy-induced cognitive dysfunction or 'chemobrain'  (also named also chemofog) is at present a well-recognized effect of chemotherapy that could affect up to 78% of treated patients. Nonetheless, its underlying neurotoxic mechanism is still not fully elucidated. Therefore, this work aimed to provide a comprehensive review using PubMed as a database to assess the studies published on the field and, therefore, highlight the clinical manifestations of chemobrain and the putative neurotoxicity mechanisms.In the last two decades, a great number of papers was published on the topic, mainly with clinical observations. Chemotherapy-treated patients showed that the cognitive domains most often impaired were verbal memory, psychomotor function, visual memory, visuospatial and verbal learning, memory function and attention. Chemotherapy alters the brain's metabolism, white and grey matter and functional connectivity of brain areas. Several mechanisms have been proposed to cause chemobrain but increase of proinflammatory cytokines with oxidative stress seem more relevant, not excluding the action on neurotransmission and cellular death or impaired hippocampal neurogenesis. The interplay between these mechanisms and susceptible factors makes the clinical management of chemobrain even more difficult. New studies, mainly referring to the underlying mechanisms of chemobrain and protective measures, are important in the future, as it is expected that chemobrain will have more clinical impact in the coming years, since the number of cancer survivors is steadily increasing.

Tumour brain: Pretreatment cognitive and affective disorders caused by peripheral cancers

People that develop extracranial cancers often display co-morbid neurological disorders, such as anxiety, depression and cognitive impairment, even before commencement of chemotherapy. This suggests bidirectional crosstalk between non-CNS tumours and the brain, which can regulate peripheral tumour growth. However, the reciprocal neurological effects of tumour progression on brain homeostasis are not well understood. Here, we review brain regions involved in regulating peripheral tumour development and how they, in turn, are adversely affected by advancing tumour burden. Tumour-induced activation of the immune system, blood-brain barrier breakdown and chronic neuroinflammation can lead to circadian rhythm dysfunction, sleep disturbances, aberrant glucocorticoid production, decreased hippocampal neurogenesis and dysregulation of neural network activity, resulting in depression and memory impairments. Given that cancer-related cognitive impairment diminishes patient quality of life, reduces adherence to chemotherapy and worsens cancer prognosis, it is essential that more research is focused at understanding how peripheral tumours affect brain homeostasis.

Effect of Baduanjin exercise intervention on cognitive function and quality of life in women with breast cancer receiving chemotherapy: study protocol of a randomized controlled trial

BACKGROUND

More than 50% cognitive impairment was reported by cancer patients before and after medical treatment. However, there are no effective interventions to manage the cognitive problem in women with breast cancer. This pilot study was designed to evaluate the protective effect of Baduanjin exercise on cognitive function and cancer-related symptoms in women with early-stage breast cancer undergoing chemotherapy.

METHOD

A single-blinded, randomized control trial was designed. The trial will recruit 70 patients with early-stage breast cancer scheduled to receive chemotherapy from Shanghai in China. All participants will be randomly assigned to (1:1) the supervised Baduanjin group (5 times/week, 30 min each time) or the wait-list control group for 3 months. The effect of Baduanjin exercise intervention will be evaluated by outcome measures including subjective and objective cognitive function, symptoms (fatigue, depression, and anxiety), and health-related quality of life at pre-intervention (T0), 8 weeks (T1), and 12 weeks (T2). The PCI score in the FACT-Cog as the primary cognitive outcome will be reported descriptively, while effect sizes and 95% confidence intervals (CIs) will be calculated. The collected data will be analyzed by using an intention-to-treat principle and linear mixed-effects modeling.

DISCUSSION

This is the first randomized clinical trial to investigate whether Baduanjin exercise will have a positive role in improving cognitive function in women with breast cancer receiving chemotherapy. If possible, Baduanjin exercise will be a potential non-pharmacological intervention to manage cognitive dysfunction and promote survivorship care among breast cancer survivors.

TRIAL REGISTRATION

Chinese Clinical Trial Registry (ChiCTR) ChiCTR2000033152 . Registered on 22 May 2020.

Biobehavioral Research and Hematopoietic Stem Cell Transplantation: Expert Review from the Biobehavioral Research Special Interest Group of the American Society for Transplantation and Cellular Therapy

Hematopoietic stem cell transplantation (HCT) is a potentially curative treatment for many hematologic conditions. Despite advances in conditioning and supportive measures, however, there remain significant comorbidities that threaten survivorship. Adverse effects of stress-related biobehavioral processes-defined here as the interactions of behavioral, psychological, and socioenvironmental factors with biology-impact immune recovery and function and are particularly salient in the HCT context, given the importance of immune reconstitution for improved survivorship. However, biobehavioral processes have been underinvestigated in this vulnerable group compared with other cancer populations. Here the Biobehavioral Research Special Interest Group (SIG) of the American Society for Transplantation and Cellular Therapy provides an expert review to inform research directions explicating the biological correlates of behavioral symptoms and evaluate the impact of these on HCT outcomes. The goal of this expert review is to provide a foundation for advancing science that effectively integrates behavioral and biological processes to optimize quality of life and improve clinical outcomes for HCT recipients.

The Promise of Nutrient-Derived Bioactive Compounds and Dietary Components to Ameliorate Symptoms of Chemotherapy-Related Cognitive Impairment in Breast Cancer Survivors

OPINION STATEMENT

One of the most burdensome symptoms reported by breast cancer patients is chemotherapy-related neurocognitive impairment. It is estimated that of the 11 million cancer survivors in the USA, 22% of them are breast cancer patients. The National Cancer Institute classified chemotherapy-related cognitive impairment (CRCI) as one of the most debilitating sequelae of cancer therapy, limiting this patient population from recommencing their lives prior to the diagnosis of breast cancer. Currently, there are no strategies that are established to prevent, mitigate, or treat CRCI. In addition to surviving cancer, quality of life is critical to cancer survivors. Based on the multiple and complex biological and psychosocial etiology, the varying manifestation and extent of cognitive decline documented in breast cancer survivors, possibly attributed to varying combinations of chemotherapy and dose and duration of therapy, multimodal interventions combining promising nutrient-derived bioactive compounds with antioxidant and anti-inflammatory properties, in addition to structured cognitive training and exercise regimens, can work synergistically to reduce inflammation and oxidative stress with significant improvement in cognitive function resulting in improvements in quality of life of breast cancer survivors.

Effects of Cancer, Chemotherapy, and Cytokines on Subjective and Objective Cognitive Functioning Among Patients with Breast Cancer

Simple Summary

Although cognitive impairments have been complained about in patients with breast cancer who underwent chemotherapy, recent research has described possible neurocognitive decline prior to the start of chemotherapy and suggested that inflammatory cytokines may also have been involved. However, inconsistencies have been found in correlations of cognitive impairments with cancer, chemotherapy, and peridiagnostic cytokine levels. This cross-sectional study aimed to examine associations of cognitive functions and levels of cytokines in patients with newly- diagnosed breast cancer before chemotherapy, those that were 3 to 9 months after completing chemotherapy, and non-cancer controls, adjusting for baseline intelligence quotient, mood, and fatigue. We found that the performance in semantic association of verbal fluency in patients post chemotherapy might be affected by the status of cancer, IL-13, and anxiety. Our results indicated that verbal fluency and anxiety may be important when considering relevant psychosocial managements or prophylactic interventions for cognitive preservation associated with regulations in cytokines.

Abstract

Background: We aimed to investigate the associations of breast cancer (BC) and cancer-related chemotherapies with cytokine levels, and cognitive function. Methods: We evaluated subjective and objective cognitive function in BC patients before chemotherapy and 3~9 months after the completion of chemotherapy. Healthy volunteers without cancer were also compared as control group. Interleukins (IL) 2, 4, 5, 6, 10, 12p70, 13, 17A, 1β, IFNγ, and TNFα were measured. Associations of cancer status, chemotherapy and cytokine levels with subjective and objective cognitive impairments were analyzed using a regression model, adjusting for covariates, including IQ and psychological distress. Results: After adjustment, poorer performance in semantic verbal fluency was found in the post-chemotherapy subgroup compared to controls (p = 0.011, η² = 0.070); whereas pre-chemotherapy patients scored higher in subjective cognitive perception. Higher IL-13 was associated with lower semantic verbal fluency in the post-chemotherapy subgroup. Higher IL-10 was associated with better perceived cognitive abilities in the pre-chemotherapy and control groups; while IL-5 and IL-13 were associated with lower perceived cognitive abilities in pre-chemotherapy and control groups. Our findings from mediation analysis further suggest that verbal fluency might be affected by cancer status, although mediated by anxiety. Conclusions: Our findings suggest that verbal fluency might be affected by cancer status, although mediated by anxiety. Different cytokines and their interactions may have different roles of neuroinflammation or neuroprotection that need further research.

Relationship between cytokines and brain-derived neurotrophic factor (BDNF) in trajectories of cancer-related cognitive impairment

Cytokines facilitate the peripheral immune and cerebral response, through their ability to modulate the expression of brain derived neurotrophic factor (BDNF). Cytokines and BDNF are implicated in cancer-related cognitive impairment (CRCI), but their relationship has not been clearly defined for this condition. The aim of this study was to evaluate the associations of cytokines and BDNF among early stage breast cancer (ESBC) patients with different CRCI trajectories. This was a multicenter longitudinal study involving 136 ESBC patients. CRCI was assessed using the FACT-Cog (V3) questionnaire. Plasma cytokines and BDNF levels were quantified at three time points throughout chemotherapy. The associations between cytokines and BDNF were analyzed using linear mixed models, with interaction terms for CRCI status. All cytokines analyzed showed inverse associations with BDNF levels. There was a significant interaction between IL-6 and the persistent impairment trajectory, which would impact on BDNF levels (p = 0.026). The inverse associations with BDNF were more pronounced for IFN-γ, IL-1β, IL-4, IL-8, and GM-CSF in patients with persistent CRCI. The coefficient values for IL-2, IL-4, and TNF-α also indicate that there was a greater magnitude of decrease in BDNF level for every unit of cytokine increase in patients with acute and persistent CRCI, compared to patients without CRCI. The differential associations between cytokines and BDNF may be indicative of probable susceptibility to the elevation of cytokines. Further research is required to elucidate the specific associations of cytokines and BDNF, along with their contributions to acute and persistent CRCI.

Effects of an Exercise and Nutritional Intervention on Circulating Biomarkers and Metabolomic Profiling During Adjuvant Treatment for Localized Breast Cancer: Results From the PASAPAS Feasibility Randomized Controlled Trial

Purpose:

Exercise has been shown to improve physical and psychological conditions during cancer therapy, but mechanisms remain poorly understood. The purpose of the present study was to report the results of cancer-related biomarkers and metabolomics outcomes from the PASAPAS feasibility study.

Methods:

In the PASAPAS randomized controlled trial, 61 women beginning adjuvant chemotherapy for localized breast cancer were randomized in a 6-month program of weekly aerobic exercises associated with nutritional counseling versus usual care with nutritional counseling. In the present analysis of 58 women for whom blood samples were available, first, circulating levels of biomarkers (ie, insulin, insulin-like growth factor 1, estradiol, adiponectin, leptin, interleukin-6, and tumor necrosis factor α) were measured at baseline and 6-month follow-up. Changes in biomarkers were compared between exercisers (n = 40) and controls (n = 18) using mixed-effect models. Second, serum metabolites were studied using an untargeted ¹H nuclear magnetic resonance spectroscopy, and orthogonal partial least squares analyses were performed to discriminate exercisers and controls at baseline and at 6 months.

Results:

Over the 6-month intervention, no statistically significant differences were observed between exercisers and controls regarding changes in biomarkers and metabolomic profiles.

Conclusion:

The present analysis of the PASAPAS feasibility trial did not reveal any improvement in circulating biomarkers nor identified metabolic signatures in exercisers versus controls during adjuvant breast cancer treatment. Larger studies preferably in women with poor physical activity level to avoid ceiling effect, testing different doses and types of exercise on additional biological pathways, could allow to clarify the mechanisms mediating beneficial effects of physical exercise during cancer treatment.

Trial registration:

ClinicalTrials.gov Identifier: NCT01331772. Registered 8 April 2011, https://clinicaltrials.gov/ct2/show/NCT01331772?term=pasapas&rank=1

Inflammation Mediates Exercise Effects on Fatigue in Patients with Breast Cancer

PURPOSE

The randomized controlled OptiTrain trial showed beneficial effects on fatigue after a 16-wk exercise intervention in patients with breast cancer undergoing adjuvant chemotherapy. We hypothesize that exercise alters systemic inflammation and that this partially mediates the beneficial effects of exercise on fatigue.

METHODS

Two hundred and forty women scheduled for chemotherapy were randomized to 16 wk of resistance and high-intensity interval training (RT-HIIT), moderate-intensity aerobic and high-intensity interval training (AT-HIIT), or usual care (UC). In the current mechanistic analyses, we included all participants with >60% attendance and a random selection of controls (RT-HIIT = 30, AT-HIIT = 27, UC = 29). Fatigue (Piper Fatigue Scale) and 92 markers (e.g., interleukin-6 [IL-6] and tumor necrosis factor α [TNF-α]) were assessed at baseline and postintervention. Mediation analyses were conducted to explore whether changes in inflammation markers mediated the effect of exercise on fatigue.

RESULTS

Overall, chemotherapy led to an increase in inflammation. The increases in IL-6 (pleiotropic cytokine) and CD8a (T-cell surface glycoprotein) were however significantly less pronounced after RT-HIIT compared with UC (-0.47, 95% confidence interval = -0.87 to -0.07, and -0.28, 95% confidence interval = -0.57 to 0.004, respectively). Changes in IL-6 and CD8a significantly mediated the exercise effects on both general and physical fatigue by 32.0% and 27.7%, and 31.2% and 26.4%, respectively. No significant between-group differences in inflammatory markers at 16 wk were found between AT-HIIT and UC.

CONCLUSIONS

This study is the first showing that supervised RT-HIIT partially counteracted the increase in inflammation during chemotherapy, i.e., IL-6 and soluble CD8a, which resulted in lower fatigue levels postintervention. Exercise, including both resistance and high-intensity aerobic training, might be put forward as an effective treatment to reduce chemotherapy-induced inflammation and subsequent fatigue.

Prevalence of cognitive impairment and change in patients with breast cancer: A systematic review of longitudinal studies

OBJECTIVE

Patients with breast cancer face cognitive impairment that affects their quality of life; partially attributable to treatment. Our aim was to detail the prevalence and change of cognitive impairment during the course of treatment. We also investigated the effect of therapy (chemotherapy [CT]) vs. radiotherapy and/or endocrine therapy vs. healthy controls).

METHODS

This article reviews longitudinal cohort studies published to date in Medline and Embase that (i) assess cognition before and after therapy, (ii) report prevalence cognitive impairment or change, and (iii) use standardized and valid neuropsychological tests. We used the original authors' criteria for cognitive impairment.

RESULTS

The title and abstract of 891 articles were screened, resulting in the identification of 90 potentially relevant articles while applying the eligibility criteria. After full-text examination, 17 studies were included. Prevalence of cognitive impairment range from 25% before therapy, through 24% after therapy to 21% at maximal 1-year follow-up (FU). Compared to their pretreatment cognitive functioning, 24% of patients decline after treatment and 24% at 1-year FU. Some studies also reported cognitive improvement showing that 15% and 31% of patients improve, respectively. In general, patients undergoing CT have a higher chance of cognitive impairment and decline than no-CT patients and healthy controls.

CONCLUSIONS

This study shows that one out of four breast cancer patients shows cognitive impairment prior to treatment administration CT and a significant number of patients decline during the course of disease, suggesting that cognitive impairment is not exclusively related to CT and/or no-CT therapies. This study shows that assessment of cognitive functioning, ideally over time, is crucial and may help the implementation of personalized rehabilitation pathways.

Intestinal Dysbiosis and Development of Cardiometabolic Disorders in Childhood Cancer Survivors: A Critical Review

Significance: Survivors of pediatric cancers have a high risk of developing side effects after the end of their treatments. Many potential factors have been associated with the onset of cardiometabolic disorders (CMD), including cancer disease itself, chemotherapy, hormonal treatment, radiotherapy, and genetics. However, the precise etiology and underlying mechanisms of these long-term complications are poorly understood. Recent Advances: Greater awareness is currently paid to the role of microbiota in the emergence of cancers and modulation of cancer therapies in both children and adults. Alterations in the composition and diversity of intestinal microbiota can clearly influence tumor development and progression as well as immune responses and clinical output. As dysbiosis is closely linked to the development of host metabolic diseases, including obesity, metabolic syndrome, type 2 diabetes, and non-alcoholic fatty liver disease, it may increase the risk of CMD in cancer populations. Critical Issues: Only limited studies targeting the profile of intestinal dysbiosis before and after cancer treatment have been conducted. Further, the exact contribution of intestinal dysbiosis to the development of CMD in cancer survivors is poorly appreciated. This review intends to clarify the influence of gut microbiota on CMD in childhood cancer survivors, elucidate the potential mechanisms, and evaluate the latest research on the interplay between diet/food supplement, microbiota, and cancer-related CMD. Future Directions: The implication of intestinal dysbiosis in late metabolic complications of childhood cancer survivors should be clarified. Intervention strategies could be developed to reduce the risk of survivors to CMD. Antioxid. Redox Signal. 34, 223-251.

Trajectories of Cognitive Function Prior to Cancer Diagnosis: A Population-Based Study

BACKGROUND

An emerging body of research suggests that noncentral nervous system cancer may negatively impact the brain apart from effects of cancer treatment. However, studies assessing cognitive function in newly diagnosed cancer patients cannot exclude selection bias and psychological effects of cancer diagnosis. To overcome these limitations, we investigated trajectories of cognitive function of patients before cancer diagnosis.

METHODS

Between 1989 and 2013, a total of 2059 participants from the population-based Rotterdam Study were diagnosed with noncentral nervous system cancer. Cognitive assessments were performed every 3 to 5 years using a neuropsychological battery. The general cognitive factor was composed of individual cognitive tests to assess global cognition. Using linear mixed models, we compared change in cognitive function of cancer case patients before diagnosis with cognitive change of age-matched cancer-free control subjects (1:2). In addition, we performed sensitivity analyses by discarding assessments of control subjects 5 years before the end of follow-up to exclude effects from potential undiagnosed cancer. All statistical tests were two-sided.

RESULTS

The Word Learning Test immediate recall declined faster among case patients than among control subjects (-0.05, 95% confidence interval = -0.09 to -0.01 vs 0.01, 95% confidence interval = -0.01 to 0.03; P for difference = .003). However, this difference was not statistically significant in sensitivity analyses. Furthermore, no statistically significant differences were observed in change of other individual cognitive tests and of the general cognitive factor.

CONCLUSIONS

In this study, we evaluated cognitive function in a large group of cancer patients prior to diagnosis, thereby excluding the psychological impact of cancer diagnosis and biased patient selection. In contrast to previous studies shortly after cancer diagnosis, we found no difference in change of cognitive function between cancer patients and control subjects.

Brain structure prior to non-central nervous system cancer diagnosis: A population-based cohort study

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In a population-based setting we studied brain structure before cancer diagnosis.

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Brain structure was not altered before non-CNS cancer diagnosis.

•

The effect of cancer on the brain before clinical manifestation is not supported.

Purpose

Many studies have shown that patients with non-central nervous system (CNS) cancer can have brain abnormalities, such as reduced gray matter volume and cerebral microbleeds. These abnormalities can sometimes be present even before start of treatment, suggesting a potential detrimental effect of non-CNS cancer itself on the brain. In these previous studies, psychological factors associated with a cancer diagnosis and selection bias may have influenced results. To overcome these limitations, we investigated brain structure with magnetic resonance imaging (MRI) prior to cancer diagnosis.

Patients and methods

Between 2005 and 2014, 4,622 participants from the prospective population-based Rotterdam Study who were free of cancer, dementia, and stroke, underwent brain MRI and were subsequently followed for incident cancer until January 1st, 2015. We investigated the association between brain MRI measurements, including cerebral small vessel disease, volumes of global brain tissue, lobes, and subcortical structures, and global white matter microstructure, and the risk of non-CNS cancer using Cox proportional hazards models. Age was used as time scale. Models were corrected for e.g. sex, intracranial volume, educational level, body mass index, hypertension, diabetes mellitus, smoking status, alcohol use, and depression sum-score.

Results

During a median (interquartile range) follow-up of 7.0 years (4.9–8.1), 353 participants were diagnosed with non-CNS cancer. Results indicated that persons who develop cancer do not have more brain abnormalities before clinical manifestation of the disease than persons who remain free of cancer. The largest effect estimates were found for the relation between presence of lacunar infarcts and the risk of cancer (hazard ratio [HR] 95% confidence interval [CI] = 1.39 [0.97–1.98]) and for total brain volume (HR [95%CI] per standard deviation increase in total brain volume = 0.76 [0.55–1.04]).

Conclusion

We did not observe associations between small vessel disease, brain tissue volumes, and global white matter microstructure, and subsequent cancer risk in an unselected population. These findings deviate from previous studies indicating brain abnormalities among patients shortly after cancer diagnosis.

Biomarkers of cardiometabolic complications in survivors of childhood acute lymphoblastic leukemia

Survivors of childhood acute lymphoblastic leukemia (cALL) are at higher risk of developing cardiometabolic complications. We aimed at exploring the associations between biomarkers of inflammation, oxidative stress, endothelial function, endotoxemia and cardiometabolic risk factors. We conducted a cross-sectional analysis in 246 cALL survivors (mean age, 22.1 ± 6.3 years; mean time since diagnosis, 15.5 ± 5.2 years) and evaluated the associations using a series of logistic regressions. Using structural equation models, we also tested if the relationship between endotoxemia and cardiometabolic complications was mediated by the latent (unobserved) variable inflammation inferred from the observed biomarkers CRP, TNF-α and IL-6. High leptin-adiponectin ratio was associated with obesity [adjusted OR = 15.7; 95% CI (6.2–39.7)], insulin resistance [20.6 (5.2–82.1)] and the metabolic syndrome [11.2 (2.6–48.7)]. Higher levels of plasminogen activator inhibitor-1 and tumor necrosis factor-α were associated with obesity [3.37 (1.6–7.1) and 2.34 (1.3–4.2), respectively] whereas high C-reactive protein levels were associated with insulin resistance [3.3 (1.6–6.8)], dyslipidemia [2.6 (1.4–4.9)] and MetS [6.5 (2.4–17.9)]. Our analyses provided evidence for a directional relationship between lipopolysaccharide binding protein, related to metabolic endotoxemia, inflammation and cardiometabolic outcomes. Identification of biomarkers and biological mechanisms could open new avenues for prevention strategies to minimize the long-term sequelae, improve follow-up and optimize the quality of life of this high-risk population.

Serum Tumor Necrosis Factor-Alpha Levels Correlate with Cognitive Function Scales Scores in Multiple Sclerosis Patients

BACKGROUND

Cognitive dysfunction is an important feature and source of disability for patients with multiple sclerosis (MS). The correlation of cognitive function scales' scores and serum levels of the proinflammatory cytokine tumor necrosis factor-alpha (TNF-α) in MS is not well established. We aim to investigate the correlation of TNF-α serum levels with cognitive function as measured by multiple cognitive scales in patients with MS.

METHODS

Eligible sequential MS patients attending neurology clinics between October 2018 and June 2019 at King Abdulla University Hospital (KAUH) in Jordan were included. Demographic data were collected from all participants. Motor disability was measured using the Expanded Disability Status Score (EDSS), the Functional System Score (FSS), as well as the Patient Determined Disease Steps (PDDS). The Brief International Cognitive Assessment for Multiple Sclerosis (BICAMS) and the Montreal Cognitive Assessment (MOCA) were used to evaluate the cognitive status. TNF-α serum levels were measured for each patient. Correlations of TNF-α levels with cognitive function scales' scores and motor disability scores were statistically analyzed.

RESULTS

A total of 88 MS patients were included in the study. The mean age (± SD) was 35.78 (± 10.30) years, and 72.7% were females. The majority of patients (82) had relapsing multiple sclerosis (RMS). Serum TNF-α levels were significantly correlated with scores of motor disability scales in the whole patient cohort (EDSS: Pearson correlation coefficient r = 0.230, p=0.031; FSS: r = 0.260, p=0.022; and PDDS: r = 0.261, p=0.014) and in females, but not in males. In the whole cohort, the correlation between TNF-α and EDSS score was also statistically significant (r = 0.216, p=0.047) after adjustment for confounding factors including age, disease duration, and type of MS. Likewise, Serum TNF-α levels were correlated with the scores of cognitive function scales in the whole patient cohort (BICAMS: r = -0.328, p=0.002; and MOCA: r = -0.256, p=0.016). After adjusting for age, gender, education, type of MS, and EDSS score, cognitive performance was still negatively correlated with TNF-α levels (p<0.05).

CONCLUSION

Our findings confirm the presence of a significant correlation between TNF-α levels and different cognitive scales' scores in MS patients.

Measurement, outcomes and interventions of cognitive function after breast cancer treatment: A narrative review

Cancer-related cognitive impairment (CRCI) is a common complaint in breast cancer patients, especially related to chemotherapy. It is characterized as cognitive disorders in areas of memory, attention and executive function, which can negatively affect patients' quality of life and their ability to work. While various assessment methods of CRCI cause highly diverse results in CRCI-related studies. Currently, it is not clear how cerebral structure and function change in breast cancer patients and underlying mechanisms of developing CRCI are still undefined. Intervention research is limited. This article reviews the results of CRCI-related studies and research progress and discusses the advantages and limits of various methods. Besides, the mechanisms and intervention strategies are reviewed.

Exercise May Affect Metabolism in Cancer-Related Cognitive Impairment

Cancer-related cognitive impairment (CRCI) is a significant comorbidity for cancer patients and survivors. Physical activity (PA) has been found to be a strong gene modulator that can induce structural and functional changes in the brain. PA and exercise reduce the risk of cancer development and progression and has been shown to help in overcoming post-treatment syndromes. Exercise plays a role in controlling cancer progression through direct effects on cancer metabolism. In this review, we highlight several priorities for improving studies on CRCI in patients and its underlying potential metabolic mechanisms.

Distinct cytokine profiles across trajectories of self-perceived cognitive impairment among early-stage breast cancer survivors

The aim of the current study is to identify distinct cytokine profiles in relation to self-perceived cognitive trajectories. In our study cohort (n = 128), early-stage breast cancer patients were categorized into no impairment reported, acute, delayed, persistent and intermittent cognitive decline respectively. Pro-inflammatory cytokines were elevated compared to baseline; with TNF-α implicated in the acute cognitive trajectory while IL-6 and IL-8 were involved in the persistent cognitive trajectory. Our findings help to further our understanding of cytokine profiles implicated in cancer-related cognitive impairment (CRCI) and support the use of cytokine levels as biomarkers of cognitive decline over time.