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

Blood IL-1α and IL-6 predict specific breast cancer-induced increases in hippocampal pro-inflammatory cytokines in mice

Neuroinflammation is a key factor in cognitive and behavioral changes seen in patients with non-CNS cancers, and cytokine levels in the blood are often used as a proxy for brain inflammation. However, this approach has yielded inconsistent results, and a common inflammatory signature remains elusive. To explore whether a blood-to-brain inflammatory signature exists across breast cancer types, we assessed cytokine and glial protein responses in the hippocampus, prefrontal cortex (PFC), and their relationship to serum cytokines in mice bearing three different mammary cancers (n = 40). While cytokine profiles in both serum and brain varied by cancer type, IL-1β and IL-4 were consistently altered across brain regions. In some cases, elevated serum IL-1α and IL-6 correlated with increased hippocampal IL-6. These findings support the use of blood cytokines to identify cancer patients at risk for cognitive and psychiatric comorbidities. However, our data also suggest that relying solely on serum cytokines may lead to under-diagnosis, as some mice exhibited brain cytokine elevations without changes in serum levels. This underscores the need for a broader range of inflammatory markers in blood to better identify at-risk patients. Brain region-specific differences in the cytokine response to mammary cancer highlighted the hippocampus as more vulnerable to cancer-induced inflammation than the PFC. We observed region-specific glial cell reactivity, however, only astrocyte and oligodendrocyte markers were correlated with cytokine changes within the hippocampus. Elevated serum IL-1α and IL-6 were correlated with reduced cortical astrocyte reactivity, suggesting that these cytokines can inform glial cell-specific changes in this region.

Physical activity and cognition: longitudinal findings from the Thinking and Living with Cancer Study

BACKGROUND

Physical activity can improve cognition; however, little is known regarding the relationships between longitudinal objectively measured physical activity, cognition, and inflammation in older breast cancer survivors.

METHODS

Older (aged 60 years and older) breast cancer survivors (n = 216) and frequency-matched noncancer control participants (n = 216) were assessed at baseline (presystemic therapy for survivors) and annually for up to 5 years. Assessments included hip-worn actigraphs worn for 7 days, neuropsychological tests, the Functional Assessment of Cancer Therapy-Cognitive Function perceived cognitive impairment subscale, and circulating levels of C-reactive protein and interleukin-6. Data were analyzed using linear mixed-effect, random-effect contemporaneous fluctuation, and multilevel mediation models, considering covariates; a P value less than .05 (2-sided) was considered statistically significant.

RESULTS

Survivors had fewer minutes of moderate-to-vigorous physical activity than controls at 36-, 48-, and 60-month time points (P < .03). Fewer survivors met aerobic physical activity guidelines at 36 months than control participants (17.7% vs 33.0%, P = .030). When guidelines were met (vs not), Functional Assessment of Cancer Therapy-Cognitive Function perceived cognitive impairment scores were 2.1 (1.0) (P = .034) points higher. Higher moderate-to-vigorous physical activity and meeting aerobic guidelines were not related to objective neuropsychological performance. Moderate-to-vigorous physical activity was inversely associated with C-reactive protein and interleukin-6 (P < .001), but inflammation did not mediate physical activity effects on perceived cognition.

CONCLUSIONS

Older breast cancer survivors were less physically active than older noncancer controls, especially farther from baseline. Meeting aerobic guidelines was associated with better perceived cognition in survivors. Survivorship care should consider physical activity monitoring and referral to rehabilitation and supervised exercise programs to promote physical activity and improve recovery in older survivors.

Deranged cytokine levels are linked to cancer-related cognitive impairment in lymphoma patients receiving R-CHOP chemotherapy

Cancer-related cognitive impairment (CRCI) is a significant issue commonly observed following chemotherapy treatment. The study aimed to investigate the changes in cognitive function and their association with IL-6, IL-1β, and IL-10 levels before and after R-CHOP chemotherapy over six cycles. Seventy chemotherapy naïve, newly diagnosed lymphoma patients were enrolled. Cognitive functions and inflammatory cytokines were assessed at baseline (TP1), after 3rd cycle (TP2), and after 6th cycle (TP3). Patients, with mean age of 44.17 ± 13.67 years, showed significantly increased levels of IL-6 and IL-1β and decreased IL-10 levels over time (p < .001). On the Montreal Cognitive Assessment (MoCA), scores of domains such as executive functioning (p = .002), attention (p < .001), language (p < .001), recall (p = .005), and orientation (p < .001) significantly decreased post six cycles of R-CHOP chemotherapy. Correlation analysis at TP2 indicated a positive association between elevated IL-6 levels with a decrease in MoCA scores indicating a decline in cognitive function (ρ = 0.68, p < .001). At TP3, no association of MoCA scores with IL-6 and IL-1β was observed. Decreased IL-10 levels showed a weak association with decreased MoCA scores at TP2 and TP3 (ρ = 0.2, p = .09; for TP3, ρ = 0.16, p = .17), but this was not significant. In summary, the findings of the present study highlight significant cognitive decline and changes in inflammatory cytokine levels following six cycles of R-CHOP. Objective cognitive assessments may be done to detect CRCI in patients treated with R-CHOP.

Changes in S100 calcium-binding protein β (S100β) and cognitive function from pre- to post-chemotherapy among women with breast cancer

Many patients with cancer experience cancer-related cognitive decline (CRCD). Previous studies have shown that elevated S100β, a calcium-binding protein commonly found in glial cells, can exhibit neurotoxic effects, including disruption of the blood-brain barrier (BBB). We studied changes in S100β levels in patients with breast cancer receiving chemotherapy, and the relationship to changes in cognitive function. A total of 505 women with breast cancer (mean (sd) age; 53.4 (53.6)) and 336 age-matched controls without cancer (52.8 (10.3)) were included from a nationwide study as part of the National Cancer Institute Community Oncology Research Program (NCORP). Both groups provided blood samples and completed neurocognitive assessments within 7 days before the patients with breast cancer received their first chemotherapy dose (pre-chemotherapy; T1) and within 1 month of their last chemotherapy administration (post-chemotherapy; T2). Utilizing a linear mixed model, multivariate linear regressions, and Spearman rank correlations (rs), we investigated longitudinal changes in serum S100β concentrations and their relationships to changes in neurocognitive outcomes over time. We observed an increase in S100β for patients with breast cancer (p = 0.002), but not for controls without cancer over time (p = 0.683). Additionally, we identified subtle relationships between increases in serum S100β and worsening in cognitive performance on the Backward Counting test (rs = 0.11, p = 0.041) and self-reported FACT-Cog Perceived Cognitive Abilities (rs = -0.10, p = 0.025). Regression analyses adjusted for age, race, body-mass index (BMI), education, menopausal status, anxiety, and depression revealed a trend remained for the relationship of S100β with Backward Counting. In conclusion, we found that patients with breast cancer experience a significant increase in concentration of serum S100β over the course of chemotherapy. This increase is correlated with worsening in some neurocognitive outcomes from pre-to post-chemotherapy, with trending results remaining following adjustment for covariates.

Nanotechnology Approaches for Prevention and Treatment of Chemotherapy-Induced Neurotoxicity, Neuropathy, and Cardiomyopathy in Breast and Ovarian Cancer Survivors

Nanotechnology has emerged as a promising approach for the targeted delivery of therapeutic agents while improving their efficacy and safety. As a result, nanomaterial development for the selective targeting of cancers, with the possibility of treating off-target, detrimental sequelae caused by chemotherapy, is an important area of research. Breast and ovarian cancer are among the most common cancer types in women, and chemotherapy is an essential treatment modality for these diseases. However, chemotherapy-induced neurotoxicity, neuropathy, and cardiomyopathy are common side effects that can affect breast and ovarian cancer survivors quality of life. Therefore, there is an urgent need to develop effective prevention and treatment strategies for these adverse effects. Nanoparticles (NPs) have extreme potential for enhancing therapeutic efficacy but require continued research to elucidate beneficial interventions for women cancer survivors. In short, nanotechnology-based approaches have emerged as promising strategies for preventing and treating chemotherapy-induced neurotoxicity, neuropathy, and cardiomyopathy. NP-based drug delivery systems and therapeutics have shown potential for reducing the side effects of chemotherapeutics while improving drug efficacy. In this article, the latest nanotechnology approaches and their potential for the prevention and treatment of chemotherapy-induced neurotoxicity, neuropathy, and cardiomyopathy in breast and ovarian cancer survivors are discussed.

A scoping review evaluating physical and cognitive functional outcomes in cancer survivors treated with chemotherapy: charting progress since the 2018 NCI think tank on cancer and aging phenotypes

PURPOSE

The primary goal of this scoping review was to summarize the literature published after the 2018 National Cancer Institute think tank, "Measuring Aging and Identifying Aging Phenotypes in Cancer Survivors," on physical and cognitive functional outcomes among cancer survivors treated with chemotherapy. We focused on the influence of chemotherapy on aging-related outcomes (i.e., physical functional outcomes, cognitive functional outcomes, and frailty), given the known associations between chemotherapy and biologic mechanisms that affect aging-related physiologic processes.

METHODS

A search was conducted across electronic databases, including PubMed, Scopus, and Web of Science, for manuscripts published between August 2018 and July 2023. Eligible studies: 1) included physical function, cognitive function, and/or frailty as outcomes; 2) included cancer survivors (as either the whole sample or a subgroup); 3) reported on physical or cognitive functional outcomes and/or frailty related to chemotherapy treatment (as either the whole sample or a subgroup); and 4) were observational in study design.

RESULTS

The search yielded 989 potentially relevant articles, of which 65 met the eligibility criteria. Of the 65 studies, 49 were longitudinal, and 16 were cross-sectional; 30 studies (46%) focused on breast cancer, 20 studies (31%) focused on the age group 60 + years, and 17 (26%) focused on childhood cancer survivors. With regards to outcomes, 82% of 23 studies reporting on physical function showed reduced physical function, 74% of 39 studies reporting on cognitive functional outcomes found reduced cognitive function, and 80% of 15 studies reporting on frailty found increasing frailty among cancer survivors treated with chemotherapy over time and/or compared to individuals not treated with chemotherapy. Fourteen studies (22%) evaluated biologic mechanisms and their relationship to aging-related outcomes. Inflammation was consistently associated with worsening physical and cognitive functional outcomes and epigenetic age increases. Further, DNA damage was consistently associated with worse aging-related outcomes.

CONCLUSION

Chemotherapy is associated with reduced physical function, reduced cognitive function, and an increase in frailty in cancer survivors; these associations were demonstrated in longitudinal and cross-sectional studies. Inflammation and epigenetic age acceleration are associated with worse physical and cognitive function; prospective observational studies with multiple time points are needed to confirm these findings.

IMPLICATIONS FOR CANCER SURVIVORS

This scoping review highlights the need for interventions to prevent declines in physical and cognitive function in cancer survivors who have received chemotherapy.

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.

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.

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.

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.

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.

Association of markers of tumor aggressivity and cognition in women with breast cancer before adjuvant treatment: The Thinking and Living with Cancer Study

PURPOSE

Tumor features associated with aggressive cancers may affect cognition prior to systemic therapy. We evaluated associations of cognition prior to adjuvant therapy and tumor aggressivity in older breast cancer patients.

METHODS

Women diagnosed with non-metastatic breast cancer (n = 705) ages 60-98 were enrolled from August 2010-March 2020. Cognition was measured post-surgery, pre-systemic therapy using self-reported (FACT-Cog Perceived Cognitive Impairment [PCI]) and objective tests of attention, processing speed, and executive function (APE domain) and learning and memory [LM domain]. Linear regression tested associations of pre-treatment tumor features and cognition, adjusting for age, race, and study site. HER2 positivity and higher stage (II/III vs. 0/I) were a priori predictors of cognition; in secondary analyses we explored associations of other tumor features and cognitive impairment (i.e., PCI score < 54 or having 2 tests < 1.5 SD or 1 test < 2 SD from the mean APE or LM domain score).

RESULTS

HER2 positivity and the hormone receptor negative/HER2 + molecular subtype were associated with lower adjusted mean self-reported cognition scores and higher impairment rates (p values < .05). Higher stage of disease was associated with lower objective performance in APE. Other tumor features were associated with cognition in unadjusted and adjusted models, including larger tumor size and lower PCI scores (p = 0.02). Tumor features were not related to LM.

CONCLUSIONS

Pre-adjuvant therapy cognition was associated with HER2 positivity and higher stage of disease and other features of aggressive tumors. Additional research is needed to confirm these results and assess potential mechanisms and clinical management strategies.