Apolipoprotein E genotype and cognitive function in postmenopausal women with early-stage breast cancer

Apolipoprotein E is a prognostic factor for pancreatic cancer and associates with immune infiltration

BACKGROUND

The expression level of apolipoprotein E (APOE) in pancreatic ductal adenocarcinoma (PDAC) and its effect on the prognosis of PDAC patients are not clear. The effect of APOE on the immune status of patients with PDAC has not been elucidated.

METHODS

We obtained pancreatic cancer data from the TCGA and GETx databases. Patients with PDAC who underwent pancreatic surgery at the Second Affiliated Hospital of Jiaxing University between 2012 and 2021 were included. Clinical pathological data were recorded, plasma APOE levels were measured, and tissue samples were collected. A tissue microarray was generated using the collected tissue samples. APOE and CD4 staining was performed to determine immunoreactive scores (IRSs). The expression of APOE in the plasma and tumour tissues of pancreatic cancer patients was analysed and compared. The correlations between plasma APOE levels, tissue APOE levels and clinicopathological characteristics were analysed. Survival prognosis was analysed using Kaplan-Meier survival analysis and Cox multivariate regression analysis. The correlations between APOE expression levels and immune biomarkers and immune cells were further analysed. Single-cell analysis of APOE distribution in various cells was performed on the TISCH website.

RESULTS

APOE was highly expressed in the tumour tissue of pancreatic cancer patients, and high plasma APOE levels were associated with poor prognosis. Females, patients with high-grade disease and patients with pancreatic head carcinoma had high plasma APOE levels. High APOE expression in tumour tissues was associated with good prognosis. Mononuclear macrophages in the pancreatic cancer microenvironment primarily expressed APOE. APOE levels positively correlated with immune biomarkers, such as CD8A, PDCD1, GZMA, CXCL10, and CXCL9, in the tumour microenvironment. APOE promoted CD4 + T cell or dendritic cell infiltration in the tumour microenvironment.

CONCLUSIONS

APOE may affect the occurrence and development of pancreatic cancer by regulating the infiltration of immune cells in the tumour microenvironment.

Impact of Apolipoprotein E Genotype on Neurocognitive Function in Patients With Brain Metastases: An Analysis of NRG Oncology's RTOG 0614

PURPOSE

Whole-brain radiation therapy (WBRT) is a common treatment for brain metastases and is frequently associated with decline in neurocognitive functioning (NCF). The e4 allele of the apolipoprotein E (APOE) gene is associated with increased risk of Alzheimer disease and NCF decline associated with a variety of neurologic diseases and insults. APOE carrier status has not been evaluated as a risk factor for onset time or extent of NCF impairment in patients with brain metastases treated with WBRT.

METHODS AND MATERIALS

NRG/Radiation Therapy Oncology Group 0614 treated adult patients with brain metastases with 37.5 Gy of WBRT (+/- memantine), performed longitudinal NCF testing, and included an optional blood draw for APOE analysis. NCF test results were compared at baseline and over time with mixed-effects models. A cause-specific Cox model for time to NCF failure was performed to assess the effects of treatment arm and APOE carrier status.

RESULTS

APOE results were available for 45% of patients (n = 227/508). NCF did not differ by APOE e4 carrier status at baseline. Mixed-effects modeling showed that APOE e4 carriers had worse memory after WBRT compared with APOE e4 noncarriers (Hopkins Verbal Learning Test-Revised total recall [least square mean difference, 0.63; P = .0074], delayed recognition [least square mean difference, 0.75; P = .023]). However, APOE e4 carrier status was not associated with time to NCF failure (hazard ratio, 0.86; 95% CI, 0.60-1.23; P = .40). Memantine delayed the time to NCF failure, regardless of carrier status (hazard ratio, 0.72; 95% CI, 0.52-1.01; P = .054).

CONCLUSIONS

APOE e4 carriers with brain metastases exhibited greater decline in learning and memory, executive function, and the Clinical Trial Battery Composite score after treatment with WBRT (+/- memantine), without acceleration of onset of difference in time to NCF failure.

Construction and validation of a risk-prediction model for chemotherapy-related cognitive impairment in patients with breast cancer

PURPOSE

To identify risk factors of chemotherapy-related cognitive impairment (CRCI) and construct and validate a visual prediction model of such for patients with breast cancer.

METHODS

A multicenter, descriptive, and cross-sectional design was adopted. Data were collected from ten public tertiary hospitals in China. Cognitive function was assessed by using Functional Assessment of Cancer Therapy-cognitive function. Socio-demographic, clinical, psychological, and physical indicators were also assessed. The logistic prediction model was constructed by fivefold cross-validation. Then, a nomogram was utilized to visualize the prediction model, which was also evaluated via discrimination, calibration, and decision curve analysis.

RESULTS

A total of 71 breast cancer patients had CRCI with a prevalence of 9.58%. This visual prediction model was constructed based on education background, exercise frequency, chemotherapy times, and fatigue and demonstrated good discrimination, with an area under the receiver operating characteristic curve of 0.882. The calibration curve indicated good agreement between experimental and projected values, and the decision curve proved good clinical applicability.

CONCLUSION

Education background, exercise frequency, chemotherapy times, and fatigue were associated with high incidence of CRCI. The prediction model exhibits superior performance and has promise as a useful instrument for assessing the likelihood of CRCI in breast cancer patients.

IMPLICATIONS FOR CANCER SURVIVORS

Our findings could provide breast cancer survivors with risk screening based on CRCI predictors to implement prevention and early intervention, and help patients integrate into society and achieve comprehensive recovery.

The chemotherapeutic agent doxorubicin induces brain senescence, with modulation by APOE genotype

Many cancer patients experience serious cognitive problems related to their treatment, which can greatly affect their quality of life. The molecular mechanisms of this cancer chemotherapy-induced cognitive impairment (CICI) are unknown, thus slowing the development of preventative approaches. We hypothesized that cancer chemotherapies could induce cellular senescence in the brain, creating a pro-inflammatory environment and damaging normal brain communication. We tested this hypothesis using the common chemotherapeutic agent doxorubicin in two independent mouse models. In the first model, we used mice that express tdTomato under the pdkn2a (p16) promoter; p16 is a regulator of cellular senescence, and its upregulation is denoted by the presence of fluorescently tagged cells. Two weeks after exposure to three doses of 5 mg/kg doxorubicin, the number of tdTomato positive cells were increased nearly three-fold in both the cerebral cortex and the hippocampus. tdTomato staining co-localized with neurons, microglia, oligodendrocyte precursor cells, and endothelial cells, but not astrocytes. In the second model, we used APOE knock-in mice, since the APOE4 allele is a risk factor for CICI in humans and mouse models. We isolated RNA from the cerebral cortex of APOE3 and APOE4 mice from one to 21 days after a single dose of 10 mg/kg doxorubicin. Using NanoString analysis of over 700 genes related to neuroinflammation and RT-qPCR analysis of cerebral cortex transcripts, we found two-fold induction of four senescence-related genes at three weeks in the APOE4 mice compared to the APOE3 control mice: p21(cdkn1a), p16, Gadd45a, and Egr1. We conclude that doxorubicin promotes cellular senescence pathways in the brain, supporting the hypothesis that drugs to eliminate senescent cells could be useful in preventing CICI.

Current State of Genomics in Nursing: A Scoping Review of Healthcare Provider Oriented (Clinical and Educational) Outcomes (2012-2022)

In the 20 years since the initial sequencing of the human genome, genomics has become increasingly relevant to nursing. We sought to chart the current state of genomics in nursing by conducting a systematic scoping review of the literature in four databases (2012-2022). The included articles were categorized according to the Cochrane Collaboration outcome domains/sub-domains, and thematic analysis was employed to identify key topical areas to summarize the state of the science. Of 8532 retrieved articles, we identified 232 eligible articles. The articles primarily reported descriptive studies from the United States and other high-income countries (191/232, 82%). More than half (126/232, 54.3%) aligned with the "healthcare provider oriented outcomes" outcome domain. Three times as many articles related to the "knowledge and understanding" sub-domain compared to the "consultation process" subdomain (96 vs. 30). Five key areas of focus were identified, including "nursing practice" (50/126, 40%), "genetic counseling and screening" (29/126, 23%), "specialist nursing" (21/126, 17%), "nurse preparatory education" (17/126, 13%), and "pharmacogenomics" (9/126, 7%). Only 42/126 (33%) articles reported interventional studies. To further integrate genomics into nursing, study findings indicate there is a need to move beyond descriptive work on knowledge and understanding to focus on interventional studies and implementation of genomics into nursing practice.

GSK3β rs3107669 polymorphism implicates chemotherapy-associated retrospective memory deficits in breast cancer survivors

Glycogen synthase kinase-3β (GSK-3β) plays an important role in the development of neurodegenerative diseases. However, the underlying effect of GSK-3β polymorphism on chemobrain in cancer survivors is unclear. This study aimed to evaluate the correlation between GSK-3β polymorphism and chemotherapy-associated retrospective memory deficits in breast cancer survivors. The difference in GSK-3β gene expression between breast cancer patients and healthy controls was confirmed using bioinformatics technology. All participants (197 with breast cancer and 40 healthy controls) underwent prospective and retrospective memory tests, and five single-nucleotide polymorphism loci of GSK-3β (rs3107669, rs1154597, rs334543, rs334558 and rs3755557) were genotyped from peripheral blood. Breast cancer survivors had memory impairment after chemotherapy (P<0.0001). The expression difference of the GSK-3β gene was determined through bioinformation analysis, and a genotype frequency difference of GSK-3β rs3107669 was found between the breast cancer and healthy control groups. GSK-3β rs3107669 was a genetic risk in comparison to the healthy controls (OR=0.382; 95% CI=0.186-0.786; P=0.009). Breast cancer with the GSK-3β rs3107669 (C/A+A/A) genotype was a protective factor for chemobrain (Beta=-0.306; 95% CI=-5.556~-2.145; P<0.0001) from multiple linear regression. The C/A+A/A genotype carrier performed better on the retrospective memory test than the C/C genotype (z=-4.302, P<0.0001). Breast cancer patients with chemotherapy who also carried the GSK-3β rs3107669 (C/C) genotype more easily presented cognitive deficits. The GSK-3β rs3107669 polymorphism was a feasible genetic risk factor for chemotherapy-associated retrospective memory impairments in breast cancer survivors.

Association of fall rate and functional status by APOE genotype in cancer survivors after exercise intervention

PURPOSE/OBJECTIVES

Cancer treatment survivors often report impaired functioning and increased falls. Not all survivors experience the same symptom burden, suggesting individual susceptibilities. APOE genotype is a potential genetic risk factor for cancer treatment related side effects. Lifestyle factors such as physical activity can mitigate the effect of APOE genotype on measures of clinical interest in individuals without a history of cancer. We tested the hypothesis that APOE genotype influences cancer treatment related side effects and symptoms as well as response to exercise intervention.

MATERIALS AND METHODS

Data from a subsample of a study of fall prevention exercise in post-treatment female cancer survivors aged 50-75 years old (https://clinicaltrials.gov NCT01635413) were used to conduct a secondary data analysis. ApoE genotype was determined by serum sampling. Physical functioning, frequency of falls, and symptom burden were assessed using survey instruments.

RESULTS

Data from 126 female cancer survivors a median of 49 months out from cancer diagnosis were analyzed. ApoE4 carriers trended toward a higher fall rate at baseline (p = 0.059), but after exercise intervention had a fall rate lower than E4 non-carriers both immediately after structured intervention (p = 0.013) and after 6 months of follow up (p = 0.002). E2 carriers did not show improved measures of depressive symptoms and self-report disability after exercise intervention. E3 homozygotes showed increased self report physical activity after the 6 month exercise intervention, but E4 and E2 carriers did not.

CONCLUSIONS

APOE genotype may modulate cancer treatment related side effects and symptoms and response to exercise intervention.

Translational Genomic Research: The Association between Genetic Profiles and Cognitive Functioning or Cardiac Function Among Breast Cancer Survivors Completing Chemotherapy

Introduction: Emerging evidence suggests that Chemotherapy (CT) treated breast cancer survivors (BCS) who have "risk variants" in genes may be more susceptible to cognitive impairment (CI) and/or poor cardiac phenotypes. The objective of this preliminary study was to examine whether there is a relationship between genetic variants and objective/subjective cognitive or cardiac phenotypes. Methods and Analysis: BCS were recruited from Moffitt Cancer Center, Morsani College of Medicine, AdventHealth Tampa and Sarasota Memorial Hospital. Genomic DNA were collected at baseline for genotyping analysis. A total of 16 single nucleotide polymorphisms (SNPs) from 14 genes involved in cognitive or cardiac function were evaluated. Three genetic models (additive, dominant, and recessive) were used to test correlation coefficients between genetic variants and objective/subjective measures of cognitive functioning and cardiac outcomes (heart rate, diastolic blood pressure, systolic blood pressure, respiration rate, and oxygen saturation). Results: BCS (207 participants) with a mean age of 56 enrolled in this study. The majority were non-Hispanic white (73.7%), married (63.1%), and received both CT and radiation treatment (77.3%). Three SNPs in genes related to cognitive functioning (rs429358 in APOE, rs1800497 in ANKK1, rs10119 in TOMM40) emerged with the most consistent significant relationship with cognitive outcomes. Among five candidate SNPs related to cardiac functioning, rs8055236 in CDH13 and rs1801133 in MTHER emerged with potential significant relationships with cardiac phenotype. Conclusions: These preliminary results provide initial targets to further examine whether BCS with specific genetic profiles may preferentially benefit from interventions designed to improve cognitive and cardiac functioning following CT.

Mitochondria - Nucleus communication in neurodegenerative disease. Who talks first, who talks louder?

Mitochondria - nuclear coadaptation has been central to eukaryotic evolution. The dynamic dialogue between the two compartments within the context of multiorganellar interactions is critical for maintaining cellular homeostasis and directing the balance survival-death in case of cellular stress. The conceptualisation of mitochondria - nucleus communication has so far been focused on the communication from the mitochondria under stress to the nucleus and the consequent signalling responses, as well as from the nucleus to mitochondria in the context of DNA damage and repair. During ageing processes this dialogue may be better viewed as an integrated bidirectional 'talk' with feedback loops that expand beyond these two organelles depending on physiological cues. Here we explore the current views on mitochondria - nucleus dialogue and its role in maintaining cellular health with a focus on brain cells and neurodegenerative disease. Thus, we detail the transcriptional responses initiated by mitochondrial dysfunction in order to protect itself and the general cellular homeostasis. Additionally, we are reviewing the knowledge of the stress pathways initiated by DNA damage which affect mitochondria homeostasis and we add the information provided by the study of combined mitochondrial and genotoxic damage. Finally, we reflect on how each organelle may take the lead in this dialogue in an ageing context where both compartments undergo accumulation of stress and damage and where, perhaps, even the communications' mechanisms may suffer interruptions.

Blood-Based Biomarkers of Cancer-Related Cognitive Impairment in Non-Central Nervous System Cancer: A Scoping Review

This scoping review was designed to synthesize the extant literature on associations between subjective and/or objective measures of cancer-related cognitive impairment (CRCI) and blood-based biomarkers in adults with non-central nervous system cancers. The literature search was done for studies published from the start of each database searched (i.e., MEDLINE, Embase, PsycINFO, Cumulative Index to Nursing and Allied Health Literature, Cochrane Central Register of Controlled Trials, grey literature) through to October 20, 2021. A total of 95 studies are included in this review. Of note, a wide variety of biomarkers were evaluated. Most studies evaluated patients with breast cancer. A variety of cognitive assessment measures were used. The most consistent significant findings were with various subjective and objective measures of CRCI and levels of interleukin-6 and tumor necrosis factor. Overall, biomarker research is in an exploratory phase. However, this review synthesizes findings and proposes directions for future research.

Effects of Endocrine Therapy on Cognitive Function in Patients with Breast Cancer: A Comprehensive Review

Simple Summary

Many persons diagnosed with breast cancer are treated with endocrine therapy and will experience the side effects of endocrine therapy. Cognitive adverse effects of endocrine therapy are increasingly being recognised, and can significantly affect quality of life, adherence and treatment outcome. This review aims to discuss the nature of cognitive dysfunction associated with endocrine therapy, the mechanisms underpinning its development, and evidence-based management strategies.

Abstract

Endocrine therapy forms the backbone of systemic therapy for the majority of persons with early and late-stage breast cancer. However, the side effects can negatively affect quality of life, and impact treatment adherence and overall oncological outcomes. Adverse effects on cognition are common, underreported and challenging to manage. We aim to describe the nature, incidence, risk factors and underlying mechanisms of endocrine therapy-induced cognitive dysfunction. We conducted a comprehensive literature review of the studies reporting on cognitive dysfunction associated with endocrine therapies for breast cancer. We also summarise prevention and treatment strategies, and ongoing research. Given that patients are taking endocrine therapies for longer durations than ever before, it is essential that these side effects are managed pro-actively within a multi-disciplinary team in order to promote adherence to endocrine therapy and improve patients’ quality of life.

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).

Mitochondrial DNA and Alzheimer's disease: a first case-control study of the Tunisian population

BACKGROUND

Alzheimer's disease (AD) is the most common neurodegenerative disorder in humans and presents a major health problem throughout the world. The etiology of AD is complex, and many factors are implicated, including mitochondria. Mitochondrial alteration has been proposed as a possible cause of AD. Therefore, several studies have focused on finding an association between inherited mitochondrial DNA variants and AD onset.

METHODS

In this study, we looked, for the first time, for a potential association between mitochondrial haplogroups or polymorphisms and AD in the Tunisian population. We also evaluated the distribution of the major genetic risk factor for AD, the apolipoprotein E epsilon 4 (APOE ε4), in this population. In total, 159 single-nucleotide polymorphisms (SNPs) of mitochondrial DNA haplogroups were genotyped in 254 individuals (58 patients and 196 controls). An additional genotyping of APOE ε4 was performed.

RESULTS

No significant association between mitochondrial haplogroups and AD was found. However, two individual SNPs, A5656G (p = 0.03821, OR = 10.46) and A13759G (p = 0.03719, OR = 10.78), showed a significant association with AD. APOE 4 was confirmed as a risk factor for AD (p = 0.000014).

CONCLUSION

Our findings may confirm the absence of a relation between mitochondrial haplogroups and AD and support the possible involvement of some inherited variants in the pathogenicity of AD.

Association of APOE4 genotype and treatment with cognitive outcomes in breast cancer survivors over time

This prospective longitudinal study of breast cancer survivors (n = 167) examined the association of apolipoprotein ε4 (APOE ε4) genotype with cognition and interactions with chemotherapy or endocrine therapy up to 6 years after treatment. In general, we found no effects of ε4 across timepoints and treatment exposures; post hoc analysis at 3-6 years suggested a trend towards worse cognition in the domains of attention and learning among ε4 carriers exposed to endocrine therapy. Further study is needed.

Brief relaxation training is associated with long-term endocrine therapy adherence among women with breast cancer: post hoc analysis of a randomized controlled trial

PURPOSE

Despite life-saving potential, many women struggle to adhere to adjuvant endocrine therapy (AET) for their breast cancer (BCa). Prior research has demonstrated that emotional distress is a barrier to AET adherence. We followed women from a trial to test the long-term effects of two 5-week post-surgical group-based stress management interventions, cognitive behavioral therapy (CBT), and relaxation training versus an attention-matched health education control, on AET adherence.

METHODS

We conducted a long-term follow-up (median = 8 years) of women randomized to CBT, relaxation training, or health education after surgery for stage 0-3 BCa. We measured adherence with the Endocrine Therapy Medication Usage Questionnaire (ETMUQ). First, we established factors on the ETMUQ via confirmatory factor analysis. We then used Bayesian structural equation modeling to regress these factors on study arm, controlling for age and treatments received.

RESULTS

Of those who completed long-term follow-up (n = 59, 44.7%), over half (n = 33; 55.9%) reported problems with adherence generally. Women receiving relaxation training (n = 15) had better adherence than those receiving health education (n = 24) on the Forgetfulness/Inconsistency [B(SE) = 0.25(0.14), p = 0.049] and Intentional Nonadherence [B(SE) = 0.31(0.14), p = 0.018] factors of the ETMUQ. Similar results were observed for those receiving relaxation training compared to CBT (n = 20): Forgetfulness/Inconsistency [B(SE) = - 0.47(0.25), p = 0.031]; Intentional Nonadherence [B(SE) = - 0.31(0.15), p = 0.027].

CONCLUSION

Women receiving relaxation training were less likely to (1) forget to take their AET and (2) intentionally miss doses of AET in the long term compared to women receiving health education or CBT. This is evidence for the need of randomized trials that aim to improve adherence by incorporating theoretically based behavioral change techniques.

TRIAL REGISTRATION AND DATES

Trial 2R01-CA-064710 was registered March 26, 2006.

Chemotherapy-related cognitive impairment (CRCI) among early-stage breast cancer survivors in Malaysia

Introduction: Breast cancer survivors frequently develop cognitive impairment following chemotherapy which can significantly hamper their well-being, ability to function independently, and overall quality of life. Evidence of cognitive functioning in breast cancer survivors from lower and middle-income countries remains scarce. We examined the prevalence of cognitive impairment among Malaysian multiethnic early-stage breast cancer survivors one to three years post-chemotherapy.Methods: This cross-sectional study included 160 breast cancer survivors from the University Malaya Medical Center (UMMC). The cognitive assessments used included the Montreal Cognitive Assessment (MoCA-BM), the Rey Auditory and Verbal Learning Test (RAVLT-BM), and the digit span and arithmetic of the Working Memory Index (WMI) of Wechsler Adult Intelligence Scale-IV (WAIS-IV). Data were analyzed using independent sample t-tests and Pearson's correlation.Results: Our breast cancer survivors demonstrated poor performances in MoCA-BM (31.9%) RAVLT-BM, recall (53.8%), and WMI of WAIS-IV (51.3%) with 30.6% of them performed poorly in all three cognitive tests administered. There were no significant mean group differences in cognitive performances between <24 months after chemotherapy and ≥24 months after chemotherapy.Conclusions: A high proportion of breast cancer survivors exhibited poor performances in the cognitive assessments. Cognitive rehabilitation programmes tailored to the needs of these survivors should be incorporated into cancer care management.

All for one, though not one for all: team players in normal tissue radiobiology

PURPOSE

As part of the special issue on 'Women in Science', this review offers a perspective on past and ongoing work in the field of normal (non-cancer) tissue radiation biology, highlighting the work of many of the leading contributors to this field of research. We discuss some of the hypotheses that have guided investigations, with a focus on some of the critical organs considered dose-limiting with respect to radiation therapy, and speculate on where the field needs to go in the future.

CONCLUSIONS

The scope of work that makes up normal tissue radiation biology has and continues to play a pivotal role in the radiation sciences, ensuring the most effective application of radiation in imaging and therapy, as well as contributing to radiation protection efforts. However, despite the proven historical value of preclinical findings, recent decades have seen clinical practice move ahead with altered fractionation scheduling based on empirical observations, with little to no (or even negative) supporting scientific data. Given our current appreciation of the complexity of normal tissue radiation responses and their temporal variability, with tissue- and/or organ-specific mechanisms that include intra-, inter- and extracellular messaging, as well as contributions from systemic compartments, such as the immune system, the need to maintain a positive therapeutic ratio has never been more urgent. Importantly, mitigation and treatment strategies, whether for the clinic, emergency use following accidental or deliberate releases, or reducing occupational risk, will likely require multi-targeted approaches that involve both local and systemic intervention. From our personal perspective as five 'Women in Science', we would like to acknowledge and applaud the role that many female scientists have played in this field. We stand on the shoulders of those who have gone before, some of whom are fellow contributors to this special issue.

The APOE ε4 allele in relation to pre- and postsurgical cognitive functioning of patients with primary brain tumors

BACKGROUND

Recent studies suggest a relationship between the APOE ε4 allele and cognitive outcome in patients treated for malignant brain tumors. Still, longitudinal investigations that include a pretreatment cognitive assessment are lacking and APOE's effects in patients with benign tumors are understudied. This study investigated presurgical cognitive performance and postsurgical change in ε4-carrying and non-carrying patients with glioma and meningioma.

METHODS

Neuropsychological test scores (CNS Vital Signs battery [seven measures], Digit Span Forward/Backward, Letter Fluency test) were obtained as part of a prospective study in which patients with meningioma and glioma underwent cognitive assessment 1 day before (T0, n = 505) and 3 (T3, n = 418) and 12 months after (T12, n = 167) surgery. APOE isoforms were identified retrospectively. ε4 carriers and non-carriers were compared with regard to pretreatment cognitive performance on the group and individual level. Changes in performances over time were compared with longitudinal mixed model analysis in the total sample and the subgroup receiving adjuvant treatment.

RESULTS

Carriers and non-carriers did not differ with regard to pretreatment performance. No significant main effect of ε4 carrier status or interaction between time (T0-T12) and carrier status was found on any of the tests in the whole sample nor in the sample receiving adjuvant treatment.

CONCLUSIONS

This study found no evidence of increased vulnerability for pretreatment cognitive dysfunction or cognitive decline within 1 year after surgery in APOE ε4-carrying meningioma and glioma patients. Investigations that include larger samples at longer-term follow-up are recommended to investigate potential late treatment effects.

A narrative review of risk factors and interventions for cancer-related cognitive impairment

Cancer-related cognitive impairment (CRCI) refers to a series of cognitive impairment symptoms associated with alternations in brain structure and function, caused by a non-central nervous system malignant tumor and its related treatment. CRCI may present as memory loss, impaired concentration, difficulty in multitasking and word retrieval, and reduced comprehension speed. CRCI has become one of the prevalent factors that compromise the quality of life for cancer survivors. Different treatments, including surgery, chemotherapy, radiotherapy, endocrine therapy, and targeted drugs, may contribute to CRCI. Meanwhile, patients’ factors, including emotional challenges and genetic makeup, also contribute to the development of CRCI. The condition can be treated with using stimulants methylphenidate and modafinil, metabolites of nicotine: cotinine, antidepressants of fluoxetine and fluvoxamine, dementia drug of donepezil, and antioxidants ZnSO4, n-acetyl cysteine, propofol, and Chinese herbal of silver leaf medicine. Psychotherapies, including meditation and relaxation, cognitive rehabilitation training, along with physical therapies, including aerobic exercise, resistance training, balance training, yoga, qigong, tai chi electroencephalogram biofeedback, and acupuncture, are also beneficial in alleviating cancer-related cognitive impairment symptoms. In recent years, researchers have focused on factors related to the condition and on the available interventions. However, most research was conducted independently, and no review has yet summarized the latest findings. This review details and discusses the status of related factors and potential treatments for CRCI. We also supply specific recommendations to facilitate future research and integration in this field.

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.

Catechol-O-Methyltransferase Gene Polymorphisms and the Risk of Chemotherapy-Induced Prospective Memory Impairment in Breast Cancer Patients with Varying Tumor Hormonal Receptor Expression

Background

Existing research evidence indicates that breast cancer patients have different degrees of cognitive dysfunction after chemotherapy, and polymorphisms in 3 genes (catechol-O-methyltransferase, COMT; apolipoprotein E, APOE; and brain-derived neurotrophic factor, BDNF) have been associated with cognitive impairment. However, the role of these 3 gene polymorphisms in modulating cognitive impairment in breast cancer survivors with varying hormonal receptor expression is not clear at present.

To explore the effects of genetic polymorphisms in BDNF, APOE, and COMT on the regulation of prospective memory impairments induced by chemotherapy in breast cancer patients with various expression levels of estrogen receptor (ER) and progesterone receptor (PR).

Material/Methods

A total of 232 patients with breast cancer (113 with ER−/PR− and 119 with ER+/PR+) were evaluated before and after chemotherapy for cognitive function, including prospective memory. Following previously published sequencing procedures, we assessed 6 single-nucleotide polymorphisms (SNPs), including BDNF (rs6265), APOE (rs429358, rs7412), and COMT (rs165599, rs4680, rs737865).

Results

The patients showed poorer prospective memory scores after chemotherapy than before chemotherapy. Furthermore, the ER−/PR− group showed poorer event-based prospective memory (EBPM) scores than the ER+/PR+ group (z=−7.831, p<0.01) after chemotherapy. The patients with the COMT rs737865G/G genotype, compared with those with the A/A and A/G genotypes, showed a linear EBPM performance (β=1.499, 95% confidence interval (CI)=1.017~2.211) and were less likely to have memory impairment. In contrast, APOE and BDNF polymorphisms did not influence cognitive performance.

Conclusions

The patterns of hormonal receptor expression may be related to prospective memory impairments induced by chemotherapy in breast cancer patients. Furthermore, the COMT polymorphism (rs737865) was linearly related to the extent of deficits in EBPM and may represent a potential genetic marker of risk for cognitive deficits triggered by chemotherapy in patients with breast cancer.

APOE and metabolic dysfunction in Alzheimer's disease

The strongest genetic risk factor for sporadic Alzheimer's disease (AD) is carriage of the E4 allele of APOE. Metabolic dysfunction also increases risk of dementia and AD. Facing a need for effective therapies and an aging global population, studies aimed at uncovering new therapeutic targets for AD have become critical. Insight into the biology underlying the effects of E4 and metabolic impairment on the brain may lead to novel therapies to reduce AD risk. An understudied hallmark of both AD patients and E4 individuals is a common metabolic impairment-cerebral glucose hypometabolism. This is a robust and replicated finding in humans, and begins decades prior to cognitive decline. Possession of E4 also appears to alter several other aspects of cerebral glucose metabolism, fatty acid metabolism, and management of oxidative stress through the pentose phosphate pathway. A critical knowledge gap in AD is the mechanism by which APOE alters cerebral metabolism and clarification as to its relevance to AD risk. Facing a need for effective therapies, studies aimed at uncovering new therapeutic targets have become critical. One such approach is to gain a better understanding of the metabolic mechanisms that may underlie E4-associated cognitive dysfunction and AD risk.

Cancer-related cognitive impairment: an update on state of the art, detection, and management strategies in cancer survivors

BACKGROUND

Advances in diagnostic and therapeutic strategies in oncology have significantly increased the chance of survival of cancer patients, even those with metastatic disease. However, cancer-related cognitive impairment (CRCI) is frequently reported in patients treated for non-central nervous system cancers, particularly during and after chemotherapy.

DESIGN

This review provides an update of the state of the art based on PubMed searches between 2012 and March 2019 on 'cognition', 'cancer', 'antineoplastic agents' or 'chemotherapy'. It includes the most recent clinical, imaging and pre-clinical data and reports management strategies of CRCI.

RESULTS

Evidence obtained primarily from studies on breast cancer patients highlight memory, processing speed, attention and executive functions as the most cognitive domains impaired post-chemotherapy. Recent investigations established that other cancer treatments, such as hormone therapies and targeted therapies, can also induce cognitive deficits. Knowledge regarding predisposing factors, biological markers or brain functions associated with CRCI has improved. Factors such as age and genetic polymorphisms of apolipoprotein E, catechol-O-methyltransferase and BDNF may predispose individuals to a higher risk of cognitive impairment. Poor performance on neuropsychological tests were associated with volume reduction in grey matter, less connectivity and activation after chemotherapy. In animals, hippocampus-based memory and executive functions, mediated by the frontal lobes, were shown to be particularly susceptible to the effects of chemotherapy. It involves altered neurogenesis, mitochondrial dysfunction or brain cytokine response. An important next step is to identify strategies for managing cognitive difficulties, with primary studies to assess cognitive training and physical exercise regimens.

CONCLUSIONS

CRCI is not limited to chemotherapy. A multidisciplinary approach has improved our knowledge of the complex mechanisms involved. Nowadays, studies evaluating cognitive rehabilitation programmes are encouraged to help patients cope with cognitive difficulties and improve quality of life during and after cancer.

Cognitive impairment after cytotoxic chemotherapy

Background

Neurotoxicity is a frequent side effect of cytotoxic chemotherapy and affects a large number of patients. Despite the high medical need, few research efforts have addressed the impact of cytotoxic agents on cognition (ie, postchemotherapy cognitive impairment; PCCI). One unsolved question is whether individual cytotoxic drugs have differential effects on cognition. We thus examine the current state of research regarding PCCI. Neurological symptoms after targeted therapies and immunotherapies are not part of this review.

Methods

A literature search was conducted in the PubMed database, and 1215 articles were reviewed for predefined inclusion and exclusion criteria. Thirty articles were included in the systematic review.

Results

Twenty-five of the included studies report significant cognitive impairment. Of these, 21 studies investigated patients with breast cancer. Patients mainly received combinations of 5-fluorouracil, epirubicin, cyclophosphamide, doxorubicin, and taxanes (FEC/FEC-T). Five studies found no significant cognitive impairment in chemotherapy patients. Of these, 2 studies investigated patients with colon cancer receiving 5-fluorouracil and oxaliplatin (FOLFOX). Independent risk factors for PCCI were patient age, mood alterations, cognitive reserve, and the presence of apolipoprotein E e4 alleles.

Conclusions

There is evidence that certain chemotherapy regimens cause PCCI more frequently than others as evidenced by 21 out of 23 studies in breast cancer patients (mainly FEC-T), whereas 2 out of 3 studies with colon cancer patients (FOLFOX) did not observe significant changes. Further studies are needed defining patient cohorts by treatment protocol in addition to cancer type to elucidate the effects of individual cytotoxic drugs on cognitive functions.

Long-term leukoencephalopathy and neurocognitive functioning in childhood sarcoma patients treated with high-dose intravenous chemotherapy

PURPOSE

Knowledge is limited regarding the prevalence and persistence of chemotherapy-induced leukoencephalopathy in childhood sarcoma patients. This study explored the presence, clinical relevance, and potential risk factors of leukoencephalopathy in childhood bone and soft tissue sarcoma survivors, treated with intravenous chemotherapy.

METHODS

We acquired cross-sectional neurocognitive data in adult survivors (n = 34) (median age at diagnosis [AaD] = 13.32 years, age range = 16-35 years) and healthy age-matched controls (n = 34). Additionally, magnetic resonance imaging included T2-weighted FLAIR (leukoencephalopathy Fazekas rating), multiexponential T2 relaxation (MET2), and multishell diffusion MRI to estimate myelin integrity-related metrics and fluid movement restrictions. Finally, chemotherapy subgroups (methotrexate, alkylating agents, or combination), AaD, and Apoε and MTHFRC677T polymorphisms were explored as potential risk factors for leukoencephalopathy.

RESULTS

At the group level, quality of life, working memory, processing speed, and visual memory were significantly lower in patients compared to controls. Furthermore, long-term leukoencephalopathy was observed in 27.2% of the childhood sarcoma survivors, which was related to attentional processing speed. Lesions were related to diffusion-derived, but not to myelin-sensitive metrics. A significant interaction effect between AaD and chemotherapy group demonstrated more lesions in case of high-dose methotrexate (HD-MTX) (F = 3.434, P = .047). However, patients treated with alkylating agents (without HD-MTX) also showed lesions in younger patients. Genetic predictors were nonsignificant.

CONCLUSION AND IMPLICATION

This study suggests long-term leukoencephalopathy with possibly underlying changes in vasculature, inflammation, or axonal injury, but not necessarily long-term demyelination. Such lesions could affect processing speed, and as such long-term daily life functioning of these patients.

Translational genomic research: the role of genetic polymorphisms in MBSR program among breast cancer survivors (MBSR[BC])

Genetic variations of breast cancer survivors (BCS) may contribute to level of residual symptoms, such as depression, stress, fatigue, and cognitive impairment. The objective of this study was to investigate whether particular single-nucleotide polymorphisms (SNPs) moderated symptom improvement resulting from the Mindfulness-Based Stress Reduction for Breast Cancer (MBSR[BC]) program. An overarching goal of personalized medicine is to identify individuals as risk for disease and tailor interventions based on genetic profiles of patients with diseases including cancer. BCS were recruited from Moffitt Cancer Center and University of South Florida's Breast Health Program and were randomized to either the 6-week MBSR(BC) program (n = 92) or Usual Care (n = 93). Measures of symptoms, demographic, and clinical history data were attained at baseline, 6 weeks, and 12 weeks. A total of 10 SNPs from eight genes known to be related to these symptoms were studied using genomic DNA extracted from blood. Our results were examined for effect sizes, consistency, and statistical significance (p < .05). Three SNPs (rs4680 in COMT, rs6314 in HTR2A, and rs429358 in APOE) emerged as having the strongest (though relatively weak) and most consistent effects in moderating the impact of the MBSR program on symptom outcomes. Although effects were generally weak, with only one effect withstanding multiple comparisons correction for statistical significance, this translational behavioral research may help start the identification of genetic profiles that moderate the impact of MBSR(BC). The ultimate goal of this study is the development of personalized treatment programs tailored to the genetic profile of each patient.

Trajectories of Cognitive Function and Associated Phenotypic and Genotypic Factors in Breast Cancer

OBJECTIVES

This study identified women with unique trajectories of executive function, concentration, and visual working memory before and during adjuvant therapy for breast cancer, and examined phenotypic and genotypic predictors associated with subgroups.

SAMPLE & SETTING

399 postmenopausal women, of whom 288 were women with early-stage breast cancer and 111 were women without breast cancer, matched on age and years of education to the women with breast cancer, and all at an urban cancer center.

METHODS & VARIABLES

A repeated-measures design was used; assessments occurred before adjuvant therapy and every six months post-therapy initiation. Group-based trajectory modeling determined subgroups. Multinomial logistic regression identified phenotypic and genotypic characteristics.

RESULTS

Three executive function and concentration trajectory subgroups were identified.

IMPLICATIONS FOR NURSING

Advancing age, greater pretherapy fatigue, and poorer pretherapy cognitive function are associated with the low subgroups. DNA repair and oxidative stress mechanisms may be involved in the cognitive changes that women experience.

Genetic risk factors for cancer-related cognitive impairment: a systematic review

Background: Cancer-related cognitive impairment (CRCI) is a commonly reported complaint among non-CNS cancer patients. Even subtle CRCI may have detrimental effects on quality of life and identifying patients at increased risk for CRCI to improve survivorship care is important. In the present paper, we systematically reviewed available studies of possible genetic risk factors for developing CRCI. Methods: Keyword-based systematic searches were undertaken on 24 July 2018 in PubMed, Web of Science, The Cochrane Library, and CINAHL. Three authors independently evaluated full-texts of identified papers and excluded studies with registration of reasons. Seventeen studies reporting results from 14 independent samples were included for review. Two authors independently quality assessed the included studies. The review was preregistered with PROSPERO (CRD42018107689). Results: Ten studies investigated apolipoprotein E (APOE), with four studies reporting that carrying at least one risk allele (APOE4 (ε4)) was associated with CRCI, while six studies found no association. The remaining identified genetic risk variants associated with CRCI located in: COMT, four DNA repair genes, five oxidative stress genes, 22 genes related to breast cancer phenotype, and GNB3. No associations were found between CRCI and genes coding for interleukin-6 (IL6), tumor necrosis factor alpha (TNF), interleukin 1 beta (IL1B), and brain-derived neurotropic factor (BDNF). With the exception of APOE, the genetic risk factors had only been investigated in one or two studies each. Conclusions: Overall, the available evidence of possible genetic risk factors for CRCI is limited. While some research suggests a role for the ε4 allele, the literature is generally inconsistent, and the currently available evidence does not allow clear-cut conclusions regarding the role of genetic factors in the development of CRCI. Larger genetic studies and studies investigating additional genetic variants are needed to uncover genetic risk factors for CRCI.

Pretreatment Psychoneurological Symptoms and Their Association With Longitudinal Cognitive Function and Quality of Life in Older Breast Cancer Survivors

CONTEXT

Symptoms affect quality of life (QOL), functional status, and cognitive function in cancer survivors, but older survivors are understudied.

OBJECTIVES

The objectives of this study were to identify prototypical presystemic therapy psychoneurological symptom clusters among older breast cancer survivors and determine whether these symptom clusters predicted cognition and QOL over time.

METHODS

Women with newly diagnosed nonmetastatic breast cancer (n = 319) and matched noncancer controls (n = 347) aged 60+ years completed questionnaires and neuropsychological tests before systemic therapy and 12 and 24 months later. Latent class analysis identified clusters of survivors based on their pretherapy depression, anxiety, fatigue, sleep disturbance, and pain. Linear mixed-effects models examined changes in objective cognition, perceived cognition, and functional status (Instrumental Activities of Daily Living disability, functional well-being, and breast cancer-specific QOL) by group, controlling for covariates.

RESULTS

Nearly one-fifth of older survivors were classified as having high pretherapy symptoms (n = 51; 16%); the remainder had low symptoms (n = 268; 84%); both groups improved over time on all outcomes. However, compared to the low symptom group and controls, survivors with high symptoms had lower baseline objective cognition and lower perceived cognition at baseline and 24 months, lower functional well-being at baseline and 12 months, greater Instrumental Activities of Daily Living disability at baseline, and lower breast cancer-specific QOL at all time points (all P < 0.05).

CONCLUSION

Nearly one-fifth of older breast cancer survivors had high psychoneurological symptoms at diagnosis, which predicted clinically meaningful decrements in perceived cognition and function in the first 24 months after diagnosis. Pretreatment psychoneurological symptom clusters could identify survivors for monitoring or intervention.

Replication and Meta-analysis of the Association between BDNF Val66Met Polymorphism and Cognitive Impairment in Patients Receiving Chemotherapy

Cancer-related cognitive impairment (CRCI) adversely affects cancer patients. We had previously demonstrated that the BDNF Val66Met genetic polymorphism is associated with lower odds of subjective CRCI in the multitasking and verbal ability domains among breast cancer patients receiving chemotherapy. To further assess our previous findings, we evaluated the association of BDNF Val66Met polymorphism with subjective and objective CRCI in a temporally separate cohort of patients and pooled findings from both the original (n = 145) and current (n = 193) cohorts in a meta-analysis. Subjective CRCI was assessed using FACT-Cog. Objective CRCI was evaluated using computerized neuropsychological tests. Genotyping was carried out using Sanger sequencing. The association of BDNF Val66Met genotypes and CRCI was examined with logistic regression. A fixed-effect meta-analysis was conducted using the inverse variance method. In the meta-analysis (n = 338), significantly lower odds of CRCI were associated with Met allele carriers based on the global FACT-Cog score (OR = 0.52, 95% CI 0.29–0.94). Furthermore, Met allele carriers were at lower odds of developing impairment in the domains of memory (OR = 0.34, 95% CI: 0.17–0.70), multitasking (OR = 0.33, 95% CI: 0.18–0.59), and verbal ability (OR = 0.46, 95% CI: 0.24–0.88). Consistent with the previous study, lower odds of subjective CRCI among patients with the BDNF Met allele was observed after adjusting for potential confounders in the multitasking (OR = 0.30, 95% CI: 0.14–0.67) domain. In conclusion, carriers of the BDNF Met allele were protected against global subjective CRCI, particularly in the domains of memory, multitasking, and verbal ability. Our findings further contribute to the understanding of CRCI pathophysiology.

Systematic review of genetic polymorphisms associated with psychoneurological symptoms in breast cancer survivors

PURPOSE

Psychoneurological (PN) symptoms, such as anxiety, cognitive impairment, depression, fatigue, sleep disturbances, and pain, are highly prevalent in breast cancer patients undergoing cancer treatment. Emerging evidence suggests that genetic polymorphisms may contribute to differential symptom susceptibility. We aimed to systematically review associations between genetic polymorphisms and PN symptoms during or after cancer treatment for early-stage breast cancer.

METHODS

Twenty-six eligible articles published until October 2017 were identified in PubMed, PsycINFO, Web of Science, and additional records. Information on study characteristics, genetic polymorphisms, and PN symptoms was extracted. Study quality was evaluated by the STrengthening the REporting of Genetic Association (STREGA) guideline. Genes included in the analysis were categorized by biological pathways based on the Reactome database.

RESULTS

A total of 54 single nucleotide polymorphisms and haplotypes that are significantly associated with PN symptoms were identified; half of them were associated with increased severity of PN symptoms, while the other half contributed to the decrease of PN symptoms. Pain has the known highest number of associated genetic polymorphisms reported, followed by fatigue, cognitive impairment, depressive symptoms, sleep disturbances, and anxiety. The majority of genetic polymorphisms were involved in immune system and neuronal system pathways. Most studies were unsuccessful in meeting the STREGA guideline, which requires transparent reporting of methods and results.

CONCLUSIONS

This review provides comprehensive evidence of genetic polymorphisms underlying PN symptoms, which may pave the way for the development of personalized therapeutics targeting these symptoms. More well-designed genome-wide association studies are required to validate and replicate these findings.

Exploratory Study of Associations Between DNA Repair and Oxidative Stress Gene Polymorphisms and Cognitive Problems Reported by Postmenopausal Women With and Without Breast Cancer

PURPOSE

Women with breast cancer report varying frequencies of cognitive problems during adjuvant systemic therapy. This variability suggests latent subgroups. Therefore, we identified latent subgroups of self-reported cognitive problems among postmenopausal women with and without breast cancer. We explored associations between membership in these subgroups and (a) demographic, clinical, and symptom characteristics and (b) variations in candidate gene polymorphisms.

METHODS

We evaluated frequency of cognitive problems using the Patient Assessment of Own Functioning Inventory. Growth mixture modeling identified latent subgroups over 18 months of adjuvant systemic therapy and at matched time points for women without cancer ( N = 331). We evaluated for differences among subgroups in demographic, clinical, and symptom characteristics and in 41 single nucleotide polymorphisms in 10 candidate genes involved in DNA repair and oxidative stress pathways ( n = 199). We modeled associations between genotypes and subgroup membership using multinomial logistic regression.

RESULTS

We identified three latent subgroups: more frequent, persistent, and almost never. Receipt of chemotherapy plus anastrozole, depressive symptoms, and baseline neuropathic symptoms increased the odds of belonging to the more frequent subgroup. Anxiety and depressive symptoms increased the odds of belonging to the persistent subgroup. With covariates controlled for, carrying the ERCC5 rs873601 G minor allele increased the odds of reporting more frequent cognitive problems.

CONCLUSIONS

Chemotherapy plus anastrozole, depressive symptoms, and presence of neuropathic symptoms may predict more frequent cognitive problems during systemic therapy that later resolve. Mood dysregulation before therapy may predict persistent cognitive problems during therapy. ERCC5 genotype may influence frequency of cognitive problems after controlling for these risk factors.

Cognitive Effects of Cancer and Cancer Treatments

As the population of cancer survivors has grown into the millions, there has been increasing emphasis on understanding how the late effects of treatment affect survivors' ability to return to work/school, their capacity to function and live independently, and their overall quality of life. This review focuses on cognitive change associated with cancer and cancer treatments. Research in this area has progressed from a pharmacotoxicology perspective to a view of the cognitive change as a complex interaction of aspects of the treatment, vulnerability factors that increase risk for posttreatment cognitive decline, cancer biology, and the biology of aging. Methodological advances include the development of (a) measurement approaches that assess more fine-grained subcomponents of cognition based on cognitive neuroscience and (b) advanced statistical approaches. Conceptual issues that arise from this multidimensional perspective are described in relation to future directions, understanding of mechanisms, and development of innovative interventions.

Probability of Alzheimer's disease in breast cancer survivors based on gray-matter structural network efficiency

Introduction

Breast cancer chemotherapy is associated with accelerated aging and potentially increased risk for Alzheimer's disease (AD).

Methods

We calculated the probability of AD diagnosis from brain network and demographic and genetic data obtained from 47 female AD converters and 47 matched healthy controls. We then applied this algorithm to data from 78 breast cancer survivors.

Results

The classifier discriminated between AD and healthy controls with 86% accuracy (P < .0001). Chemotherapy-treated breast cancer survivors demonstrated significantly higher probability of AD compared to healthy controls (P < .0001) and chemotherapy-naïve survivors (P = .007), even after stratifying for apolipoprotein e4 genotype. Chemotherapy-naïve survivors also showed higher AD probability compared to healthy controls (P = .014).

Discussion

Chemotherapy-treated breast cancer survivors who have a particular profile of brain structure may have a higher risk for AD, especially those who are older and have lower cognitive reserve.

CNS side effects of immune checkpoint inhibitors: preclinical models, genetics and multimodality therapy

Following cancer treatment, patients often report behavioral and cognitive changes. Novel cancer immunotherapeutics have the potential to produce sustained cancer survivorship, meaning patients will live longer with the side effects of treatment. Given the role of inflammatory pathways in mediating behavioral and cognitive impairments seen in cancer, we aim in this review to discuss emerging evidence for the contribution of immune checkpoint blockade to exacerbate these CNS effects. We discuss ongoing studies regarding the ability of immune checkpoint inhibitors to reach the brain and how treatment responses to checkpoint inhibitors may be modulated by genetic factors. We further consider the use of preclinical tumor-models to study the role of tumor status in CNS effects of immune checkpoint inhibitors and multimodality therapy.

An exploratory study of host polymorphisms in genes that clinically characterize breast cancer tumors and pretreatment cognitive performance in breast cancer survivors

PURPOSE

Inspired by the hypothesis that heterogeneity in the biology of breast cancers at the cellular level may account for cognitive dysfunction symptom variability in survivors, the current study explored relationships between host single-nucleotide polymorphisms (SNPs) in 25 breast cancer-related candidate genes (AURKA, BAG1, BCL2, BIRC5, CCNB1, CD68, CENPA, CMC2, CTSL2, DIAPH3, ERBB2, ESR1, GRB7, GSTM1, MELK, MKI67, MMP11, MYBL2, NDC80, ORC6, PGR, RACGAP1, RFC4, RRM2, and SCUBE2), identified from clinically relevant prognostic multigene-expression profiles for breast cancer, and pretreatment cognitive performance.

PATIENTS AND METHODS

The sample (n=220) was comprised of 138 postmenopausal women newly diagnosed with early stage breast cancer and 82 postmenopausal age- and education-matched healthy controls without breast cancer. Cognitive performance was assessed after primary surgery but prior to initiation of adjuvant chemotherapy and/or hormonal therapy using a comprehensive battery of neuropsychological tests encompassing eight cognitive function composite domains: attention, concentration, executive function, mental flexibility, psychomotor speed, verbal memory, visual memory, and visual working memory. In total, 131 SNPs were included in the analysis. Standard and robust multiple linear regression modeling was used to examine relationships between each domain and the presence or absence of one or more minor alleles for each SNP. Genetic risk/protection scores (GRSs) were calculated for each domain to evaluate the collective effect of possession of multiple risk/protective alleles.

RESULTS

With the exception of CMC2, MMP11, and RACGAP1, significant (P<0.05) SNP main effect and/or SNP by future prescribed treatment group interactions were observed for every gene between at least one domain and one or more SNPs. All GRSs were found to be significantly (P<0.001) associated with each respective domain score.

CONCLUSION

Associations between host SNPs and computed GRSs and variability in pretreatment cognitive function performance support the study hypothesis, and warrant further investigations to identify biomarkers for breast cancer-related cognitive dysfunction.

The COMT (rs165599) gene polymorphism contributes to chemotherapy-induced cognitive impairment in breast cancer patients

The present study aimed to investigate the effect of genetic polymorphisms of catechol-O-methyl transferase (COMT), apolipoprotein E (APOE), and brain derived neurotrophic factor (BDNF) on the modulation of the chemotherapy-induced cognitive impairment (CICI) in breast cancer patients. Eighty triple negative breast cancer (TNBC) and 165 non-triple negative breast cancer (NTNBC) patients were selected, and subjected to a number of neuropsychological tests, including memory questionnaires, before and after chemotherapy. Six single-nucleotide polymorphisms (SNPs), including COMT (rs165599, rs4680, rs737865), APOE (rs429358, rs7412), and BDNF (rs6265), were evaluated. The scores of breast cancer patients after chemotherapy were poorer in comparison to those before chemotherapy (t = -5.317, z = -3.372, respectively, P < 0.01), and the scores of TNBC patients were poorer than those of NTNBC patients were after chemotherapy (t = -5.997, z = -5.284, respectively, P < 0.01). Patients with the COMT (rs165599) genotype had a significantly lower chance of developing cognitive decline than the patients with the G/G genotype, and this was linear with the retrospective memory (RM) questionnaires (β = -1.441, CI (95%) = -2.781~-0.101). However, there was no significant difference between the memory scores of APOE (rs429358, rs7412) and BDNF (rs6265) carriers before or after chemotherapy. This study suggests that CICI in TNBC patients was more prominent than that in NTNBC patients after chemotherapy, and the COMT (rs165599) polymorphism was linear to the retrospective memory (RM) questionnaires, and may be a potential genetic marker for increased vulnerability to CICI in TNBC patients.

Cognitive Impairment in a Subset of Breast Cancer Patients After Systemic Therapy-Results From a Longitudinal Study

CONTEXT

Studies indicate adverse effects of breast cancer (BC) and cancer treatment on cognitive function.

OBJECTIVES

To investigate the effects of systemic treatment on cognitive performance in BC patients.

METHODS

Participants were BC patients scheduled to receive systemic treatment (BC + SYST; n = 31), or no systemic treatment (BC; n = 24) and no-cancer (NC) controls (n = 33). Neuropsychological examinations were used to study cognitive performance on 18 tests grouped into eight cognitive domains, before adjuvant treatment (T1) and six months after chemotherapy (T2), or at similar intervals. We also assessed health-related quality of life, anxiety and depression, mood, stress, and cognitive problems. Analysis of variance was used to assess group differences of cognitive performance and multivariate normative comparison to classify impairment, comparing scores of each participant against the distribution of the scores of NC controls.

RESULTS

Of BC + SYST, 16% were cognitively impaired at T2, compared to 4% in BC and 6% in NC. Although not significant, we observed moderate effect sizes for worse performance in the BC + SYST group compared to NC (Flanker congruent [effect size {ES} = 0.44] and stimulus incongruent [ES = 0.44]) and compared to BC (Controlled Oral Word Association Test [ES = 0.47], digit span [ES = 0.41], and Hopkins Verbal Learning Test immediate [ES = 0.71] and delayed recall [ES = 0.65]). Cognitively impaired patients had a significantly lower estimated premorbid intelligence, worse physical and social functioning, and more distress at T2 compared to unimpaired patients.

CONCLUSION

Our findings indicate that cognitive impairment after systemic treatment occurs in a subset of BC patients. The predictive value of demographic and psychosocial factors in cognitive impairment should be further investigated in a larger sample of impaired patients.

Neurocognitive functioning and genetic variation in patients with primary brain tumours

Impairment of neurocognitive functioning is a common result of cerebral neoplasms and treatment, although there is substantial heterogeneity in the pattern and severity of neurocognitive dysfunction across individuals and tumour types. The effects of many clinical and patient characteristics on neurocognitive functioning have been documented, but little research has been devoted to understanding the effect of genetic variation on neurocognitive outcomes in patients with brain tumours. This Review highlights preliminary evidence that suggests an association between various genes and risk of adverse neurocognitive outcomes in patients with brain tumours. Studies include genes specific to neuronal function, and those associated with more systemic cellular regulation. Related scientific literature in other disease populations is briefly discussed to indicate additional candidate genes. We consider methodological issues central to the study of neurocognitive functioning and genetic associations for patients with brain tumours, and emphasise the need for future research integrating novel investigative techniques.

Cognitive Function in Patients With Colorectal Cancer Who Do and Do Not Receive Chemotherapy: A Prospective, Longitudinal, Controlled Study

PURPOSE

Cognitive dysfunction is reported in people with cancer. Therefore, we evaluated longitudinal changes in cognitive function and underlying mechanisms in people with colorectal cancer (CRC) and healthy controls (HCs).

PATIENTS AND METHODS

Participants completed cognitive assessments and questionnaires reporting cognitive symptoms, fatigue, quality of life, and anxiety/depression at baseline (before chemotherapy, if given) and 6, 12, and 24 months. Blood tests included cytokines, clotting factors, apolipoprotein E genotype, and sex hormones. Primary end point was overall cognitive function measured by the Global Deficit Score at 12 months.

RESULTS

We recruited 289 patients with localized CRC (173 received chemotherapy; median age, 59 years; 63% male), 73 patients with limited metastatic/recurrent CRC, and 72 HCs. Cognitive impairment was more frequent in patients with localized CRC than HCs at baseline (43% v 15%, respectively; P < .001) and 12 months (46% v 13%, respectively; P < .001), with no significant effect of chemotherapy. Attention/working memory, verbal learning/memory, and complex processing speed were most affected. Cognitive impairment was similar in patients with localized and metastatic CRC. Cytokine levels were elevated in patients with CRC compared with HCs. There was no association between overall cognitive function and fatigue, quality of life, anxiety/depression, or any blood test. Cognitive symptoms at 12 months were reported in 25% of patients with localized CRC versus 17% of HCs (P = .19). More participants who received chemotherapy had cognitive symptoms at 6 months (32%) versus those who did not (16%; P = .007), with no significant difference at 12 months (29% v 21%, respectively; P = .19). Objective cognitive function was only weakly associated with cognitive symptoms.

CONCLUSION

Patients with CRC had substantially more cognitive impairment at every assessment than HCs, with no significant added effect of chemotherapy. Mechanisms of cognitive impairment remain unknown.

Course and Predictors of Cognitive Function in Patients With Prostate Cancer Receiving Androgen-Deprivation Therapy: A Controlled Comparison

PURPOSE

Men receiving androgen-deprivation therapy (ADT) for prostate cancer may be at risk for cognitive impairment; however, evidence is mixed in the existing literature. Our study examined the impact of ADT on impaired cognitive performance and explored potential demographic and genetic predictors of impaired performance.

PATIENTS AND METHODS

Patients with prostate cancer were assessed before or within 21 days of starting ADT (n = 58) and 6 and 12 months later. Age- and education-matched patients with prostate cancer treated with prostatectomy only (n = 84) and men without prostate cancer (n = 88) were assessed at similar intervals. Participants provided baseline blood samples for genotyping. Mean-level cognitive performance was compared using mixed models; cognitive impairment was compared using generalized estimating equations.

RESULTS

ADT recipients demonstrated higher rates of impaired cognitive performance over time relative to all controls (P = .01). Groups did not differ at baseline (P > .05); however, ADT recipients were more likely to demonstrate impaired performance within 6 and 12 months (P for both comparisons < .05). Baseline age, cognitive reserve, depressive symptoms, fatigue, and hot flash interference did not moderate the impact of ADT on impaired cognitive performance (P for all comparisons ≥ .09). In exploratory genetic analyses, GNB3 single-nucleotide polymorphism rs1047776 was associated with increased rates of impaired performance over time in the ADT group (P < .001).

CONCLUSION

Men treated with ADT were more likely to demonstrate impaired cognitive performance within 6 months after starting ADT relative to matched controls and to continue to do so within 12 months after starting ADT. If confirmed, findings may have implications for patient education regarding the risks and benefits of ADT.