Longitudinal assessment of chemotherapy-induced structural changes in cerebral white matter and its correlation with impaired cognitive functioning

Neuroinflammation and Its Association with Cognition, Neuronal Markers and Peripheral Inflammation after Chemotherapy for Breast Cancer

Simple Summary

Up to 70% of chemotherapy-treated patients experience problems with memory and concentration, potentially caused by direct and indirect neurotoxicity, such as (neuro-)inflammatory processes. Can neuroinflammation changes be detected in chemotherapy-treated patients with breast cancer using translocator protein [¹⁸F]DPA714 simultaneous positron emission tomographic- and magnetic resonance imaging? Moreover, what is the association with clinical biomarkers? In a study including 19 chemotherapy-treated breast cancer patients, 18 chemotherapy-naïve and 37 healthy controls, we found significant relative glial overexpression in parietal and occipital brain regions in chemotherapy-treated patients compared to controls, which were associated with cognitive abnormalities and markers of neuronal survival. Shortly after ending chemotherapy, changes in brain neuroinflammation seem to occur, possibly contributing to the cognitive decline seen in breast cancer patients. Additionally, blood levels of an axonal damage marker were 20-fold higher in chemotherapy-treated patients, providing evidence for its use as a biomarker to assess neurotoxic effects of anticancer chemotherapies.

Abstract

To uncover mechanisms underlying chemotherapy-induced cognitive impairment in breast cancer, we studied new biomarkers of neuroinflammation and neuronal survival. This cohort study included 74 women (47 ± 10 years) from 22 October 2017 until 20 August 2020. Nineteen chemotherapy-treated and 18 chemotherapy-naïve patients with breast cancer were assessed one month after the completion of surgery and/or chemotherapy, and 37 healthy controls were included. Assessments included neuropsychological testing, questionnaires, blood sampling for 17 inflammatory and two neuronal survival markers (neurofilament light-chain (NfL), and brain-derived neurotrophic factor (BDNF) and PET-MR neuroimaging. To investigate neuroinflammation, translocator protein (TSPO) [¹⁸F]DPA714-PET-MR was acquired for 15 participants per group, and evaluated by volume of distribution normalized to the cerebellum. Chemotherapy-treated patients showed higher TSPO expression, indicative for neuroinflammation, in the occipital and parietal lobe when compared to healthy controls or chemotherapy-naïve patients. After partial-volume correction, differences with healthy controls persisted (p_FWE < 0.05). Additionally, compared to healthy- or chemotherapy-naïve controls, cognitive impairment (17–22%) and altered levels in blood markers (F ≥ 3.7, p ≤ 0.031) were found in chemotherapy-treated patients. NfL, an axonal damage marker, was particularly sensitive in differentiating groups (F = 105, p = 4.2 × 10 ⁻²¹), with levels 20-fold higher in chemotherapy-treated patients. Lastly, in chemotherapy-treated patients alone, higher local TSPO expression was associated with worse cognitive performance, higher blood levels of BDNF/NfL, and decreased fiber cross-section in the corpus callosum (p_FWE < 0.05). These findings suggest that increased neuroinflammation is associated with chemotherapy-related cognitive impairment in breast cancer. Additionally, NfL could be a useful biomarker to assess neurotoxic effects of anticancer chemotherapies.

Patients-centered SurvivorShIp care plan after Cancer treatments based on Big Data and Artificial Intelligence technologies (PERSIST): a multicenter study protocol to evaluate efficacy of digital tools supporting cancer survivors

BACKGROUND

It is encouraging to see a substantial increase in individuals surviving cancer. Even more so since most of them will have a positive effect on society by returning to work. However, many cancer survivors have unmet needs, especially when it comes to improving their quality of life (QoL). Only few survivors are able to meet all of the recommendations regarding well-being and there is a body of evidence that cancer survivors' needs often remain neglected from health policy and national cancer control plans. This increases the impact of inequalities in cancer care and adds a dangerous component to it. The inequalities affect the individual survivor, their career, along with their relatives and society as a whole. The current study will evaluate the impact of the use of big data analytics and artificial intelligence on the self-efficacy of participants following intervention supported by digital tools. The secondary endpoints include evaluation of the impact of patient trajectories (from retrospective data) and patient gathered health data on prediction and improved intervention against possible secondary disease or negative outcomes (e.g. late toxicities, fatal events).

METHODS/DESIGN

The study is designed as a single-case experimental prospective study where each individual serves as its own control group with basal measurements obtained at the recruitment and subsequent measurements performed every 6 months during follow ups. The measurement will involve CASE-cancer, Patient Activation Measure and System Usability Scale. The study will involve 160 survivors (80 survivors of Breast Cancer and 80 survivors of Colorectal Cancer) from four countries, Belgium, Latvia, Slovenia, and Spain. The intervention will be implemented via a digital tool (mHealthApplication), collecting objective biomarkers (vital signs) and subjective biomarkers (PROs) with the support of a (embodied) conversational agent. Additionally, the Clinical Decision Support system (CDSS), including visualization of cohorts and trajectories will enable oncologists to personalize treatment for an efficient care plan and follow-up management.

DISCUSSION

We expect that cancer survivors will significantly increase their self-efficacy following the personalized intervention supported by the m-HealthApplication compared to control measurements at recruitment. We expect to observe improvement in healthy habits, disease self-management and self-perceived QoL. Trial registration ISRCTN97617326. https://doi.org/10.1186/ISRCTN97617326 . Original Registration Date: 26/03/2021.

Patients-centered SurvivorShIp care plan after Cancer treatments based on Big Data and Artificial Intelligence technologies (PERSIST): a multicenter study protocol to evaluate efficacy of digital tools supporting cancer survivors

BACKGROUND

It is encouraging to see a substantial increase in individuals surviving cancer. Even more so since most of them will have a positive effect on society by returning to work. However, many cancer survivors have unmet needs, especially when it comes to improving their quality of life (QoL). Only few survivors are able to meet all of the recommendations regarding well-being and there is a body of evidence that cancer survivors' needs often remain neglected from health policy and national cancer control plans. This increases the impact of inequalities in cancer care and adds a dangerous component to it. The inequalities affect the individual survivor, their career, along with their relatives and society as a whole. The current study will evaluate the impact of the use of big data analytics and artificial intelligence on the self-efficacy of participants following intervention supported by digital tools. The secondary endpoints include evaluation of the impact of patient trajectories (from retrospective data) and patient gathered health data on prediction and improved intervention against possible secondary disease or negative outcomes (e.g. late toxicities, fatal events).

METHODS/DESIGN

The study is designed as a single-case experimental prospective study where each individual serves as its own control group with basal measurements obtained at the recruitment and subsequent measurements performed every 6 months during follow ups. The measurement will involve CASE-cancer, Patient Activation Measure and System Usability Scale. The study will involve 160 survivors (80 survivors of Breast Cancer and 80 survivors of Colorectal Cancer) from four countries, Belgium, Latvia, Slovenia, and Spain. The intervention will be implemented via a digital tool (mHealthApplication), collecting objective biomarkers (vital signs) and subjective biomarkers (PROs) with the support of a (embodied) conversational agent. Additionally, the Clinical Decision Support system (CDSS), including visualization of cohorts and trajectories will enable oncologists to personalize treatment for an efficient care plan and follow-up management.

DISCUSSION

We expect that cancer survivors will significantly increase their self-efficacy following the personalized intervention supported by the m-HealthApplication compared to control measurements at recruitment. We expect to observe improvement in healthy habits, disease self-management and self-perceived QoL. Trial registration ISRCTN97617326. https://doi.org/10.1186/ISRCTN97617326 . Original Registration Date: 26/03/2021.

Elevated Oxidative Stress and DNA Damage in Cortical Neurons of Chemotherapy Patients

The unintended neurologic sequelae of chemotherapy contribute to significant patient morbidity. Chemotherapy-related cognitive impairment (CRCI) is observed in up to 80% of cancer patients treated with chemotherapy and involves multiple cognitive domains including executive functioning. The pathophysiology underlying CRCI and the neurotoxicity of chemotherapy is incompletely understood, but oxidative stress and DNA damage are highly plausible mechanisms based on preclinical data. Unfortunately, validating pathways relevant to CRCI in humans is limited by an absence of relevant neuropathologic studies of patient brain tissue. In the present study, we stained sections of frontal lobe autopsy tissue from cancer patients treated with chemotherapy (n = 15), cancer patients not treated with chemotherapy (n = 10), and patients without history of cancer (n = 10) for markers of oxidative stress (nitrotyrosine, 4-hydroxynonenal) and DNA damage (pH2AX, pATM). Cancer patients treated with chemotherapy had increased staining for markers of oxidative stress and DNA damage in frontal lobe cortical neurons compared to controls. We detected no statistically significant difference in oxidative stress and DNA damage by the duration between last administration of chemotherapy and death. The study highlights the potential relevance of oxidative stress and DNA damage in the pathophysiology of CRCI and the neurotoxicity of chemotherapy.

Memory recovery in relation to default mode network impairment and neurite density during brain tumor treatment

OBJECTIVE

The aim of this study was to test brain tumor interactions with brain networks, thereby identifying protective features and risk factors for memory recovery after resection.

METHODS

Seventeen patients with diffuse nonenhancing glioma (ages 22-56 years) underwent longitudinal MRI before and after surgery, and during a 12-month recovery period (47 MRI scans in total after exclusion). After each scanning session, a battery of memory tests was performed using a tablet-based screening tool, including free verbal memory, overall verbal memory, episodic memory, orientation, forward digit span, and backward digit span. Using structural MRI and neurite orientation dispersion and density imaging (NODDI) derived from diffusion-weighted images, the authors estimated lesion overlap and neurite density, respectively, with brain networks derived from normative data in healthy participants (somatomotor, dorsal attention, ventral attention, frontoparietal, and default mode network [DMN]). Linear mixed-effect models (LMMs) that regressed out the effect of age, gender, tumor grade, type of treatment, total lesion volume, and total neurite density were used to test the potential longitudinal associations between imaging markers and memory recovery.

RESULTS

Memory recovery was not significantly associated with either the tumor location based on traditional lobe classification or the type of treatment received by patients (i.e., surgery alone or surgery with adjuvant chemoradiotherapy). Nonlocal effects of tumors were evident on neurite density, which was reduced not only within the tumor but also beyond the tumor boundary. In contrast, high preoperative neurite density outside the tumor but within the DMN was associated with better memory recovery (LMM, p value after false discovery rate correction [Pfdr] < 10-3). Furthermore, postoperative and follow-up neurite density within the DMN and frontoparietal network were also associated with memory recovery (LMM, Pfdr = 0.014 and Pfdr = 0.001, respectively). Preoperative tumor and postoperative lesion overlap with the DMN showed a significant negative association with memory recovery (LMM, Pfdr = 0.002 and Pfdr < 10-4, respectively).

CONCLUSIONS

Imaging biomarkers of cognitive recovery and decline can be identified using NODDI and resting-state networks. Brain tumors and their corresponding treatment affecting brain networks that are fundamental for memory functioning such as the DMN can have a major impact on patients' memory recovery.

Measuring decline in white matter integrity after systemic treatment for breast cancer: omitting skeletonization enhances sensitivity

Chemotherapy for non-central nervous system cancers is associated with abnormalities in brain structure and function. Diffusion tensor imaging (DTI) allows for studying in vivo microstructural changes in brain white matter. Tract-based spatial statistics (TBSS) is a widely used processing pipeline in which DTI data are typically normalized to a generic DTI template and then 'skeletonized' to compensate for misregistration effects. However, this approach greatly reduces the overall white matter volume that is subjected to statistical analysis, leading to information loss. Here, we present a re-analysis of longitudinal data previously analyzed with standard TBSS (Menning et al., BIB 2018, 324-334). For our current approach, we constructed a pipeline with an optimized registration method in Advanced Normalization Tools (ANTs) where DTI data are registered to a study-specific, high-resolution T1 template and the skeletonization step is omitted. In a head to head comparison, we show that with our novel approach breast cancer survivors who had received chemotherapy plus or minus endocrine therapy (BC + SYST, n = 26) showed a global decline in overall FA that was not present in breast cancer survivors who did not receive systemic therapy (BC-SYST, n = 23) or women without a cancer diagnosis (no cancer controls, NC, n = 30). With the standard TBSS approach we did not find any group differences. Moreover, voxel-based analysis for our novel pipeline showed a widespread decline in FA in the BC + SYST compared to the NC group. Interestingly, the BC-SYST group also showed a decline in FA compared to the NC group, although in much less voxels. These results were not found with the standard TBSS approach. We demonstrate that a modified processing pipeline makes DTI data more sensitive to detecting changes in white matter integrity in non-CNS cancer patients after treatment, particularly chemotherapy.

Cortical thinning and altered functional brain coherence in survivors of childhood sarcoma

High-dose chemotherapy is increasingly evidenced to be neurotoxic and result in long-term neurocognitive sequelae. However, research investigating grey matter alterations in childhood cancer patients remains limited. As childhood sarcoma patients receive high-dose chemotherapy, we aimed to investigate cortical brain alterations in adult survivors. We analyzed high-resolution structural (T1-weighted) MRI and resting-state functional MRI (rsfMRI), to derive structural and functional cortical information in survivors of childhood sarcoma, treated with high-dose intravenous chemotherapy (n = 33). These scans were compared to age- and gender- matched controls (n = 34). Cortical volume and thickness were investigated using voxel-based morphometry and vertex-wise surface-based morphometry. Brain regions showing significant group differences in volume or thickness were implemented as seeds of interest to estimate their resting state co-activity with other areas (i.e. functional coherence). We explored whether structural measures were associated with potential risk factors, such as age at diagnosis, and cumulative doses of chemotherapeutic agents (methotrexate, ifosfamide). Finally, we investigated the link between functional regional strength, neurocognitive assessments and daily life complaints. In patients relative to controls we observed lower grey matter volumes in cerebellar and frontal areas, as well as frontal cortical thinning. Cerebellar volume and orbitofrontal thickness appeared dose- and age-related, respectively. Cortical thickness of the parahippocampal area appeared lower, only if the group comparison was not adjusted for depression. This region specifically showed lower functional coherence, which was associated with lower processing speed. This study suggests cortical thinning as well as decreased functional coherence in survivors of childhood sarcoma, which could be important for both long-term attentional functioning and emotional distress in daily life. Frontal areas might be specifically vulnerable during adolescence.

Cognitive complications of cancer and cancer-related treatments - Novel paradigms

As advances in diagnostics and therapeutic strategies in oncology have increased the number of cancer survivors, the investigation of the mechanisms associated with long-term cognitive complications of cancer treatment has become an important topic of interest. The neurotoxic effects of chemotherapeutic agents have been described in pre-clinical and clinical research. In vitro and rodent studies have identified some underlying mechanisms contributing to chemotherapy-induced neurotoxicity and cognitive impairment for various chemotherapy drugs and other cancer treatments. However, investigation of the direct biological effects of cancer and other potential contributing factors in the pathogenesis of cancer-related cognitive impairment (CRCI) has only recently come into focus. This review will highlight evidence from pre-clinical tumor-bearing rodent models suggesting that cancer influences the cognitive and behavioral changes reported in human cancer populations through direct or indirect pathways that alter the normal neuroinflammatory responses, induce structural brain deficits, and decrease neurogenesis. We reflect on human clinical cancer research indicating that cognitive and behavioral changes precede cancer treatment in some malignancies. We also highlight implications for future areas of CRCI research based on novel findings on the interplay between cancer, chemotherapy, inflammation, tau pathology, and dysregulation of the microbiota-gut-brain axis.

Structural Neuroimaging Findings Related to Adult Non-CNS Cancer and Treatment: Review, Integration, and Implications for Treatment of Cognitive Dysfunction

Cancer- and treatment-related cognitive dysfunction (CRCD) is a common challenge faced by patients diagnosed with non-central nervous system (CNS) cancer. It has become increasingly recognized that multiple factors likely play a role in these symptoms, including the cancer disease process, systemic treatments (e.g., chemotherapy and endocrine therapies), and risk factors that may predispose an individual to both cancer and cognitive dysfunction. As the field has evolved, advanced neuroimaging techniques have been applied to better understand the neural correlates of CRCD. This review focuses on structural neuroimaging findings related to CRCD in adult non-CNS cancer populations, including examination of gray matter volume/density and white matter integrity differences between cancer patients and comparison groups, as well as emerging findings regarding structural network abnormalities. Overall, this literature has demonstrated consistent findings of reduced gray matter volume/density and white matter integrity in cancer patients relative to comparison groups. These are most prominent in individuals treated with chemotherapy, though alterations have also been noted in those treated with anti-estrogen and androgen-deprivation therapies. Alterations in gray and white matter structural network connectivity have also been identified. These structural abnormalities have been observed most prominently in frontal and temporal brain regions, and have been shown to correlate with subjective and objective cognitive function, as well as with physiological and clinical variables, helping to inform understanding of CRCD mechanisms. To date, however, structural neuroimaging techniques have not been utilized in systematic studies of potential CRCD treatments, suggesting a potentially fruitful avenue for future research.

Psychological Aspects to Consider in Breast Cancer Diagnosis and Treatment

PURPOSE OF REVIEW

Breast cancer (BC) is the most common cancer diagnosed in women in the West World. Coping with cancer is cause of extreme stress for patients and their family. The purpose of this review is to evaluate possible approaches to follow to control those situations that can impact on quality of life (QoL) and compliance to treatments.

RECENT FINDINGS

Anxiety, distress, depression, and posttraumatic stress disorder are the most frequent psychological disorders in BC patients. Cognitive disorders and sexual dysfunction can also be important in affecting QoL both in younger and older patients. Younger and older patients show different characteristics of these disorders and different strategies of managing them. Several psychotherapeutic and supportive approaches have proven effective in managing psychological disorders in BC patients. Every BC patient should be supported with these techniques during her entire oncological history, in order to increase QoL and compliance to treatments.

Primary central nervous system lymphoma: a narrative review of ongoing clinical trials and goals for future studies

Primary central nervous system lymphoma (PCNSL) is a rare disease of the brain, spine, cerebrospinal fluid (CSF) and/or vitreoretinal space. PCNSL is chemo and radiosensitive but relapse is common even years after initial treatment. Outside of consensus regarding the use of high-dose methotrexate (HD-MTX) for first line treatment, there is little uniformity in the management of newly diagnosed or relapsed PCNSL. The lack of consensus is driven by a paucity of randomized trials in this disease. Prospective studies are troubled by low enrollment, the lack of a standard induction regimen, and a varied approach to consolidation strategies. Moreover, the PCNSL patient population is heterogeneous and includes a high proportion of elderly or frail patients and consists of patients manifesting disease in varied compartments of the central nervous system (CNS). As a result, current treatment strategies vary widely and are often dictated by physician and institutional preference or regional practice. This review provides an overview of recently completed and ongoing therapeutic studies for patients with newly diagnosed and recurrent or refractory PCNSL. It discusses the existing evidence behind common approaches to induction and consolidation or maintenance regimens as well as the recent data regarding management of recurrent disease. Finally, it highlights the complexity of trial design in this disease and provides a framework for the design of future studies, which are needed to identify patient populations likely to benefit from specific induction, consolidation, or maintenance therapies.

Cerebrospinal Fluid Biomarkers in Childhood Leukemias

Involvement of the central nervous system (CNS) in childhood leukemias remains a major cause of treatment failures. Analysis of the cerebrospinal fluid constitutes the most important diagnostic pillar in the detection of CNS leukemia and relies primarily on cytological and flow-cytometry studies. With increasing survival rates, it has become clear that treatments for pediatric leukemias pose a toll on the developing brain, as they may cause acute toxicities and persistent neurocognitive deficits. Preclinical research has demonstrated that established and newer therapies can injure and even destroy neuronal and glial cells in the brain. Both passive and active cell death forms can result from DNA damage, oxidative stress, cytokine release, and acceleration of cell aging. In addition, chemotherapy agents may impair neurogenesis as well as the function, formation, and plasticity of synapses. Clinical studies show that neurocognitive toxicity of chemotherapy is greatest in younger children. This raises concerns that, in addition to injury, chemotherapy may also disrupt crucial developmental events resulting in impairment of the formation and efficiency of neuronal networks. This review presents an overview of studies demonstrating that cerebrospinal fluid biomarkers can be utilized in tracing both CNS disease and neurotoxicity of administered treatments in childhood leukemias.

Chemotherapy-Induced Brain Effects in Small-Cell Lung Cancer Patients: A Multimodal MRI Study

The golden standard of treating Small Cell Lung Cancer (SCLC) entails application of platinum-based chemotherapy, is often accompanied by Prophylactic Cranial Irradiation (PCI), which have been linked to neurotoxic side-effects in cognitive functions. The related existing neuroimaging research mainly focuses on the effect of PCI treatment in life quality and expectancy, while little is known regarding the distinct adverse effects of chemotherapy. In this context, a multimodal MRI analysis based on structural and functional brain data is proposed in order to evaluate chemotherapy-specific effects on SCLC patients. Data from 20 patients (after chemotherapy and before PCI) and 14 healthy controls who underwent structural MRI, DTI and resting state fMRI were selected in this study. From a structural aspect, the proposed analysis included volumetry and thickness measurements on structural MRI data for assessing gray matter dissimilarities, as well as deterministic tractography and Tract-Based Spatial Statistics (TBSS) on DTI data, aiming to investigate potential white matter abnormalities. Functional data were also processed on the basis of connectivity analysis, evaluating brain network parameters to identify potential manifestation of functional inconsistencies. By comparing patients to healthy controls, the obtained results revealed statistically significant differences, with the patients' brains presenting reduced volumetry/thickness and fractional anisotropy values, accompanied by prominent differences in functional connectivity measurements. All above mentioned findings were observed in patients that underwent chemotherapy.

Computational Modeling of Neuropsychological Test Performance to Disentangle Impaired Cognitive Processes in Cancer Patients

There is a need to better identify impaired cognitive processes to increase our understanding of cognitive dysfunction caused by cancer and cancer treatment and to improve interventions. The Trail Making Test is frequently used for evaluating information-processing speed (part A) and executive function (part B), but interpretation of its outcomes is challenging because performance depends on many cognitive processes. To disentangle processes, we collected high-resolution data from 192 non-central nervous system cancer patients who received systemic therapy and 192 cancer-free control participants and fitted a Shifted-Wald computational model. Results show that cancer patients were more cautious than controls (Cohen d = 0.16). Patients were cognitively slower than controls when the task required task switching (Cohen d = 0.16). Our results support the idea that cancer and cancer treatment accelerate cognitive aging. Our approach allows more precise assessment of cognitive dysfunction in cancer patients and can be extended to other instruments and patient populations.

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.

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

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

Executive functioning in 6 year old children exposed to chemotherapy in utero

BACKGROUND

Cancer treatment during pregnancy imposes a dilemma. Maternal advantage should be weighed against the potential impact of chemotherapy on child development. Recent studies in cancer survivors have shown that exposure to chemotherapeutic agents can have late adverse effects on cognitive functioning and executive functioning (EF). It is still unclear whether these late adverse effects also arise if a child is exposed to chemotherapy in utero.

AIM

To compare the development of executive functioning in 6 year old children prenatally exposed to chemotherapy (study group) and children born to healthy women after an uncomplicated pregnancy (control group).

METHODS AND STUDY DESIGN

In a multicenter cohort study, the outcome on a measure of EF was compared. Study and control children were prospectively examined by means of the Behavior Rating Inventory of Executive Function (BRIEF), a health questionnaire and an intelligence test.

RESULTS

In total 37 study children and 37 matched controls were included. In the study group, 11 children (29.7%) were exposed to chemotherapy alone, 22 children (59.5%) were exposed to chemotherapy and surgery and 4 children (10.8%) were exposed to chemotherapy, surgery and radiotherapy during pregnancy. All outcome scales of the BRIEF were within normal ranges. However, a significant between-group difference in emotional control was found.

CONCLUSION

Overall outcomes of EF were reassuring. However, children prenatally exposed to chemotherapy have weaker emotion regulation skills compared to their matched controls. The results underscore the need for long-term follow-up of these children.

Study of Chemotherapy-Induced Cognitive Impairment in Women with Breast Cancer

Background: Oncology patients experience a large number of symptoms and, those referring to cognitive performance has an ever-increasing importance in clinical practice, due to the increase in survival rates and interest in the patient’s quality of life. The studies reviewed showed that chemotherapy-related cognitive impairment might occur in 15 and 50% of oncology patients. The main objective of this research was to study the impact of chemotherapy on the cognitive function of patients with locoregional breast cancer. Method: Analytical, prospective, longitudinal study using three measures, unifactorial intrasubject design, non-probability, and random selection sampling. The sample comprised women newly diagnosed with locoregional breast cancer in stages I, II, IIIA who received chemotherapy at the University Hospital of Salamanca (Complejo Asistencial Universitario de Salamanca), randomly selected for three years. Semi-structured interviews were conducted, and anxiety and depression (Hospital Anxiety and Depression scale, HAD); quality of life (QLQ-BR23 scale) and the following cognitive variables were assessed—processing speed, attention, memory, and executive functions (subtests of the Wechsler Intelligence Scale and the Trail Making Test). Results: The final sample size included 151 participants; 23 were excluded. A decline in cognitive performance was observed in patients, which did not completely recover two months after chemotherapy was completed. Additionally, worse cognitive performance was observed in patients with anxious or depressive symptoms. There was a negative impact on the quality of life. Conclusion: Chemotherapy had an impact on the cognitive performance of oncology patients in most cognitive domains studied.

Longitudinal investigation of cognitive deficits in breast cancer patients and their gray matter correlates: impact of education level

Cognitive deficits are a major complaint in breast cancer patients, even before chemotherapy. Comprehension of the cerebral mechanisms related to cognitive impairment in breast cancer patients remains difficult due to the scarcity of studies investigating both cognitive and anatomical imaging changes. Furthermore, only some of the patients experienced cognitive decline following chemotherapy, yet few studies have identified risk factors for cognitive deficits in these patients. It has been shown that education level could impact cognitive abilities during the recovery phase following chemotherapy. Our main aim was to longitudinally evaluate cognitive and anatomical changes associated with cancer and chemotherapy in breast cancer patients. Our secondary aim was to assess the impact of education level on cognitive performances and gray matter (GM) atrophy in these patients. Twenty patients were included before chemotherapy (T1), 1 month (T2) and 1 year (T3) after chemotherapy. Twenty-seven controls without a history of cancer were assessed at T1 and T3 only. Cluster groups based on education level were defined for both groups and were further compared. Comparison between patients and controls revealed deficits in patients on verbal episodic memory retrieval at T1 and T3 and on executive functions at T3. After chemotherapy, breast cancer patients had GM atrophy that persisted or recovered 1 year after chemotherapy depending on the cortical areas. Increase in GM volumes from T1 to T3 were also found in both groups. At T2, patients with a higher level of education compared to lower level exhibited higher episodic memory retrieval and state anxiety scores, both correlating with cerebellar volume. This higher level of education group exhibited hippocampal atrophy. Our results suggest that, before chemotherapy, cancer-related processes impact cognitive functioning and that this impact seems exacerbated by the effect of chemotherapy on certain brain regions. Increase in GM volumes after chemotherapy were unexpected and warrant further investigations. Higher education level was associated, 1 month after the end of chemotherapy, with greater anxiety and hippocampal atrophy despite a lack of cognitive deficits. These results suggest, for the first time, the occurrence of compensation mechanisms that may be linked to cognitive reserve in relationship to state anxiety. This identification of factors, which may compensate cognitive impairment following chemotherapy, is critical for patient care and quality of life.

Proton therapy for selected low grade glioma patients in the Netherlands

Proton therapy offers an attractive alternative to conventional photon-based radiotherapy in low grade glioma patients, delivering radiotherapy with equivalent efficacy to the tumour with less radiation exposure to the brain. In the Netherlands, patients with favourable prognosis based on tumour and patient characteristics can be offered proton therapy. Radiation-induced neurocognitive function decline is a major concern in these long surviving patients. Although level 1 evidence of superior clinical outcome with proton therapy is lacking, the Dutch National Health Care Institute concluded that there is scientific evidence to assume that proton therapy can have clinical benefit by reducing radiation-induced brain damage. Based on this decision, proton therapy is standard insured care for selected low grade glioma patients. Patients with other intracranial tumours can also qualify for proton therapy, based on the same criteria. In this paper, the evidence and considerations that led to this decision are summarised. Additionally, the eligibility criteria for proton therapy and the steps taken to obtain high-quality data on treatment outcome are discussed.

The impact of cancer and chemotherapy during pregnancy on child neurodevelopment: A multimodal neuroimaging analysis

BACKGROUND

This study applies multimodal MRI to investigate neurodevelopment in nine-year-old children born to cancer-complicated pregnancies.

METHODS

In this cohort study, children born after cancer-complicated pregnancies were recruited alongside 1:1 matched controls regarding age, sex and gestational age at birth (GA). Multimodal MRI was used to investigate whole-brain and subcortical volume, cortical structure (using surface-based morphometry), white matter microstructure (using fixel-based analysis) and functional connectivity (using resting-state blood-oxygen-level-dependant signal correlations). Graph theory probed whole-brain structural and functional organization. For each imaging outcome we conducted two group comparisons: 1) children born after cancer-complicated pregnancies versus matched controls, and 2) the subgroup of children with prenatal chemotherapy exposure versus matched controls. In both models, we used the covariate of GA and the group-by-GA interaction, using false-discovery-rate (FDR) or family-wise-error (FWE) correction for multiple comparisons. Exploratory post-hoc analyses investigated the relation between brain structure/function, neuropsychological outcome and maternal oncological/obstetrical history.

FINDINGS

Forty-two children born after cancer-complicated pregnancies were included in this study, with 30 prenatally exposed to chemotherapy. Brain organization and functional connectivity were not significantly different between groups. Both cancer and chemotherapy in pregnancy, as compared to matched controls, were associated with a lower travel depth, indicating less pronounced gyrification, in the left superior temporal gyrus (pFDR ≤ 006), with post-hoc analysis indicating platinum derivatives during pregnancy as a potential risk factor (p = .028). Both cancer and chemotherapy in pregnancy were related to a lower fibre cross-section (FCS) and lower fibre density and cross-section (FDC) in the posterior corpus callosum and its tapetal fibres, compared to controls. Higher FDC in the chemotherapy subgroup and higher FCS in the whole study group were observed in the anterior thalamic radiations. None of the psycho-behavioural parameters correlated significantly with any of the brain differences in the study group or chemotherapy subgroup.

INTERPRETATION

Prenatal exposure to maternal cancer and its treatment might affect local grey and white matter structure, but not functional connectivity or global organization. While platinum-based therapy was identified as a potential risk factor, this was not the case for chemotherapy in general.

FUNDING

This project has received funding from the European Union's Horizon 2020 research and innovation program (European Research council, grant no 647,047), the Foundation against cancer (Stichting tegen kanker, grant no. 2014-152) and the Research Foundation Flanders (FWO, grants no. 11B9919N, 12ZV420N).

Differentiation of groups of patients with cognitive complaints at breast cancer diagnosis: Results from a sub-study of the French CANTO cohort

OBJECTIVE

Cognitive complaints are more frequent in women with breast cancer (BC) than in healthy controls and can be present before any treatment. Findings regarding contributive factors remain inconsistent. This study aimed to identify different groups of patients with cognitive complaints at BC diagnosis and to determine whether these different groups were associated with demographic, medical, or psychological characteristics.

METHODS

Cognitive complaints were assessed in a subset of 264 women from the French multicenter prospective CANTO cohort, at baseline before any treatment. Clustering analyzes were performed using the six-cognitive dimension Costa's scoring of the FACT-Cog V3. Univariable analyses were used to study how cognitive function (standardized neuropsychological tests, ICCTF), anxiety, depression, fatigue, and quality of life (HADS, FA12, QLQ-C30) were associated with specific cognitive complaints groups.

RESULTS

Results included 263 women (54±11 years), newly diagnosed with BC (69% stages I-III). Four distinct groups emerged, ranged from "no complaints" (22.8%), "low complaints" (55.1), "mixed complaints" (14.5%), to "consistent complaints" (7.6%). No significant differences were found in terms of demographic and medical factors between the four groups. However, the groups with higher proportions of patients with complaints were found to have more impairment in executive function, higher scores of anxiety, depressive symptoms, and fatigue, and lower quality of life, than the groups with lower proportions of cognitive complaints.

CONCLUSION

Using complete cognitive assessment prior to BC treatment, we identified four distinct cognitive complaints groups with specific characteristics. This work provides valuable clinical basis to further investigations for a better understanding of cognitive complaints and their associates.

Longitudinal exploration of cancer-related cognitive impairment in patients with newly diagnosed aggressive lymphoma: protocol for a feasibility study

INTRODUCTION

Cancer-related cognitive impairment (CRCI) is a distressing and disabling side-effect of cancer treatments affecting up to 75% of patients. For some patients, their cognitive impairment may be transient, but for a subgroup, these symptoms can be long-standing and have a major impact on the quality of life. This paper describes the protocol for a study: (1) to assess the feasibility of collecting longitudinal data on cognition via self-report, neuropsychological testing, peripheral markers of inflammation and neuroimaging and (2) to explore and describe patterns of cancer-related cognitive impairment over the course of treatment and recovery in patients with newly diagnosed, aggressive lymphoma undergoing standard therapy with curative intent.

METHODS AND ANALYSIS

This is a prospective, longitudinal, feasibility study in which 30 newly diagnosed, treatment-naive patients with aggressive lymphoma will be recruited over a 12-month period. Patients will complete comprehensive assessments at three time points: baseline (time 1, pre-treatment) and two post-baseline follow-up assessments (time 2, mid-treatment and time 3, 6-8 weeks post-treatment completion). All patients will be assessed for self-reported cognitive difficulties and objective cognitive function using Stroop Colour and Word, Trail Making Test Part A and B, Hopkins Verbal Learning Test-Revised, Controlled Oral Word Association and Digit Span. Blood cell-based inflammatory markers and neuroimaging including a positron emission tomography (PET) with 18F-labelled fluoro-2-deoxyglucose (18F-FDG) and CT (18F-FDG-PET/CT) and a MRI will explore potential inflammatory and neuroanatomical or functional mechanisms and biomarkers related to CRCI. The primary intent of analysis will be to assess the feasibility of collecting longitudinal data on cognition using subjective reports and objective tasks from patients during treatment and recovery for lymphoma. These data will inform the design of a larger-scale investigation into the patterns of cognitive change over the course of treatment and recovery, adding to an underexplored area of cancer survivorship research.

ETHICS AND DISSEMINATION

Ethical approval has been granted by Austin Health Human Rights Ethics Committee (HREC) in Victoria Australia. Peer reviewed publications and conference presentations will report the findings of this novel study.

TRIAL REGISTRATION NUMBER

Australian New Zealand Clinical Trials Registry (ACTRN12619001649101).

Chemotherapy-related cognitive impairment in patients with breast cancer based on MRS and DTI analysis

The purpose of this study is to investigate chemotherapy-related cognitive impairment (CRCI) in breast cancer patients, analyze absolute concentration and structural changes of metabolites in different brain regions by multimodal neuroimaging technology, and explore correlation between them. Breast cancer patients with chemotherapy treatment group (Ctx+, N = 24) and control group without treatment (Ctx-, N = 20) underwent neuropsychological tests, multivoxel magnetic resonance spectroscopy (MRS), and diffusion tensor imaging (DTI) before and after chemotherapy. Regions of interest (ROls) in magnetic resonance scan include bilateral posterior cingulate gyrus (PCG), bilateral dorsal thalamus (DT), bilateral lenticular nucleus (LN), bilateral posterior horn of the lateral ventricle paratrigonal white matter (PWM). In MRS, absolute concentrations of N-acetylaspartate (NAA), myo-inositol (MI), choline-containing compounds (Cho), total creatine (tCr), glutamine + glutamate (Glx) were quantified using LC Model and SAGE software. In DTI, we used fractional anisotropy (FA) and mean diffusivity (MD) to reflect white matter integrity. In Ctx+ patients, scores of functional assessment of cancer treatment cognition test (FACT-Cog), perceived cognitive impairments (PCI), impact of perceived impairments on quality of life (QOL), perceived cognitive abilities (PCA), auditory-verbal learning test (AVLT) recognition and clock drawing test (CDT) were lower than those before chemotherapy (p < 0.05). In MRS, Ctx+ patients had significantly lower NAA values in bilateral PCG, DT, respectively. The concentrations of tCr were observed to decline in bilateral PCG and right DT. Glx values decreased in right DT. Cho values decreased significantly in bilateral DT. In DTI, Ctx+ patients had lower FA values in bilateral PCG compared with patients before chemotherapy. Among imaging metrics and cognitive scores, positive correlations were observed between changes in AVLT recognition scores and changes in NAA values in bilateral PCG (left PCG: r = 0.470, p < 0.01; right PCG: r = 0.500, p < 0.01). Positive correlations were also found between changes in AVLT recognition and changes in FA values in bilateral PCG (left PCG: r = 0.513, p < 0.01; right PCG: r = 0.563, p < 0.01). Chemotherapy can lead to a decrease in memory function, accompanied by changes in brain metabolite concentration and white matter integrity in some parts of brain.

Modulation of Interhemispheric Functional Coordination in Breast Cancer Patients Receiving Chemotherapy

Objectives

Chemotherapy induces cognitive impairments including memory impairment attention deficit and executive dysfunction in patients with breast cancer (BC) during or after chemotherapy. Previous studies identified brain structural and functional changes in BC patients receiving chemotherapy; however, there are no studies assessing functional connectivity (FC) between homotopic brain regions in BC patients using a voxel-mirrored homotopic connectivity (VMHC) method. In the present study, we explored cognitive function and whole brain homotopic FC in BC patients receiving chemotherapy compared with healthy controls using the VMHC method.

Methods

The present cross-sectional study included 35 premenopausal women with breast cancer who received chemotherapy, as well as 32 age- and sex-matched healthy controls (HC). All subjects underwent resting-state functional magnetic resonance imaging, which measured homotopic brain FC, and cognitive neuropsychological assessments evaluating attention, memory, and executive function domains.

Results

The BC group had lower VMHC than the HC group in the cingulated posterior, insular and postcentral regions. No region exhibited higher VMHC in the BC group than in HC group. Correlation analysis in the BC group indicated that VMHC values in the cingulated posterior were significantly correlated with executive function tests, and that the VMHC values in the insular were significantly correlated with memory tests.

Conclusion

The present study showed that VMHC decreased in different brain regions including cingulated posterior, insular and postcentral regions. A significant correlation was observed between the VMHC values in the brain regions and neuropsychological tests. These results suggested that changes in VMHC values in different brain regions may underlie cognitive changes in BC patients receiving chemotherapy.

Effects of a mindfulness-based intervention on cancer-related cognitive impairment: Results of a randomized controlled functional magnetic resonance imaging pilot study

BACKGROUND

Many breast cancer survivors suffer from cognitive complaints after cancer treatment, affecting their quality of life. The objective of this pilot study was to investigate the effect of a blended-care mindfulness-based intervention (MBI) on chemotherapy-related cognitive impairment and functional brain changes. Furthermore, correlations between changes in cognitive functioning and self-reported behavioral factors were investigated.

METHODS

Breast cancer survivors (n = 33) who reported cognitive impairment were randomly allocated to a mindfulness condition (n = 18) or a waitlist control condition (n = 15). Patients completed questionnaires on cognitive impairment, emotional distress, and fatigue; neuropsychological tests; and resting-state functional magnetic resonance imaging before the start of MBI (time 1 [T1]), immediately after the completion of an 8-week MBI program (T2), and 3 months postintervention (T3). Resting-state functional connectivity was estimated in the default mode network, the dorsal and salience attention networks, and the frontoparietal network. Mixed model repeated-measures analysis was performed to test the intervention effect.

RESULTS

Patients in the mindfulness condition exhibited significantly higher connectivity between the dorsal and salience attention networks after the mindfulness intervention compared with those in the control condition. MBI participants also had reduced subjective cognitive impairment, emotional distress, and fatigue. No intervention effect was observed on neurocognitive tests.

CONCLUSIONS

MBI may induce functional brain changes in networks related to attention and may have a positive effect on subjective measures of cognitive impairment in breast cancer survivors. Therefore, MBI could be a suitable intervention to improve quality of life in this population and deserves further study in this context.

The Developmental Trajectory of Cancer-Related Cognitive Impairment in Breast Cancer Patients: A Systematic Review of Longitudinal Neuroimaging Studies

This systematic review explored the neurobiological mechanisms underlying the clinical time course of cancer-related cognitive impairment (CRCI) in breast cancer patients through the review of longitudinal neuroimaging studies. Before chemotherapy, results reported no evidence for neuropsychological, structural (gray matter) and brain perfusion changes. However, functional brain alterations were evident and revealed a frontoparietal hyperactivation during working memory tasks. Fatigue and number of days since surgery were the two suggested confounding factors. Acutely after chemotherapy, this review found no evidence for neuropsychological changes while suggesting a pattern of frontal structural, perfusion and functional brain abnormalities. These findings seemed to be dependent on age, menopausal status at baseline, and fMRI task performed. Years after chemotherapy, results revealed evidence of partial neuropsychological, structural, and functional brain recovery. Regarding brain abnormality, this review suggested that it may begin quite early in the disease course, be more prominent shortly after chemotherapy and partially recover over time. Several hypotheses underlying these changes were discussed. The present review also provided important information for developing a time-specific treatment and prevention strategies and for the consideration of functional neuroimaging as a relevant tool for CRCI diagnosis, clinical monitoring, and intervention studies. The findings also suggested the need to implement studies with longitudinal designs, including a pre-treatment assessment, since cross-sectional studies were not able to detect this pattern of recovery over time, supporting only the theory of brain abnormalities, in breast cancer survivors.

Pathogenesis, Assessments, and Management of Chemotherapy-Related Cognitive Impairment (CRCI): An Updated Literature Review

There are various cancer treatments at present, and chemotherapy is one of the main methods. Chemotherapy-related cognitive impairment (CRCI), as one of the side effects of chemotherapy, has gradually attracted the attention of more and more researchers. CRCI has been verified by subjective reports and objective neuropsychological tests so far. But oncologists' understanding of it and its treatments are still incomplete. In this review, we mainly give a comprehensive overview of the mechanism of CRCI, then describe a variety of evaluation methods, and finally summarize the treatment approaches under current medical conditions and compare it with an excellent article published in 2015 with the aim of providing directions for future research and better understanding of CRCI for clinicians.

Cellular mechanisms and treatments for chemobrain: insight from aging and neurodegenerative diseases

Chemotherapy is a life-saving treatment for cancer patients, but also causes long-term cognitive impairment, or "chemobrain", in survivors. However, several challenges, including imprecise diagnosis criteria, multiple confounding factors, and unclear and heterogeneous molecular mechanisms, impede effective investigation of preventions and treatments for chemobrain. With the rapid increase in the number of cancer survivors, chemobrain is an urgent but unmet clinical need. Here, we leverage the extensive knowledge in various fields of neuroscience to gain insights into the mechanisms for chemobrain. We start by outlining why the post-mitotic adult brain is particularly vulnerable to chemotherapy. Next, through drawing comparisons with normal aging, Alzheimer's disease, and traumatic brain injury, we identify universal cellular mechanisms that may underlie the cognitive deficits in chemobrain. We further identify existing neurological drugs targeting these cellular mechanisms that can be repurposed as treatments for chemobrain, some of which were already shown to be effective in animal models. Finally, we briefly describe future steps to further advance our understanding of chemobrain and facilitate the development of effective preventions and treatments.

ESO-ESMO 4th International Consensus Guidelines for Breast Cancer in Young Women (BCY4)

The 4th International Consensus Conference for Breast Cancer in Young Women (BCY4) took place in October 2018, in Lugano, Switzerland, organized by the European School of Oncology (ESO) and the European Society of Medical Oncology (ESMO). Consensus recommendations for the management of breast cancer in young women were updated from BCY3 with incorporation of new evidence to inform the guidelines. Areas of research priorities were also identified. This article summarizes the ESO-ESMO international consensus recommendations, which are also endorsed by the European Society of Breast Specialists (EUSOMA).

Episodic memory for visual scenes suggests compensatory brain activity in breast cancer patients: a prospective longitudinal fMRI study

It has been hypothesized that breast cancer and its chemotherapy can impart functional neural changes via an overlap with biological mechanisms associated with aging. Here we used fMRI to assess whether changes in neural activity accompanying visual episodic memory encoding and retrieval suggest altered activations according to patterns seen in functional imaging of cognitive aging. In a prospective longitudinal design, breast cancer patients (n = 13) were scanned during memory encoding and retrieval before and after chemotherapy treatment, and compared to healthy-age matched controls (n = 13). Our results indicate that despite equivalent behavioral performance, encoding and retrieval resulted in increased activation of prefrontal regions for the breast cancer group compared to controls for both before and after chemotherapy treatment. This was accompanied by decreased activity in posterior brain regions after chemotherapy, particularly those involved in visual processing, for the breast cancer group compared to controls. These findings are discussed as evidence for a possible anterior shift in neural processing to compensate for deficiencies in posterior brain regions, consistent with an accelerated aging account. Cancer and chemotherapy can impact brain regions underlying episodic memory, leading to additional recruitment of control regions, which may be linked to mechanisms related to aging.

Chemotherapy-induced brain changes in breast cancer survivors: evaluation with multimodality magnetic resonance imaging

Chemotherapy related cognitive impairments are common in breast cancer patients undergoing chemotherapy. These cognitive dysfunctions are mainly attributable to chemotherapy related brain structural and functional alterations. Multimodality magnetic resonance imaging (MRI) can reveal brain gray matter volume loss, white matter microstructural disruption, reduced gray matter density, impaired cerebral blood flow and brain structural and functional connection networks at both local and global levels. This review outlines the potential applications of multimodality MR imaging techniques in chemotherapy induced cognitive deficit in breast cancer survivors and provides future research perspective in this field.

Impact of transcranial direct current stimulation on sustained attention in breast cancer survivors: Evidence for feasibility, tolerability, and initial efficacy

BACKGROUND

A significant subset of breast cancer survivors experience cognitive difficulties in attention and memory, which persist for years following treatment. Transcranial direct current stimulation (tDCS) has been shown to be effective in improving working memory, attention, processing speed, and other cognitive functions in both healthy and clinical populations. To date, no studies have examined tDCS for rehabilitation of cancer-related cognitive dysfunction.

OBJECTIVE/HYPOTHESIS

We aimed to provide preliminary evidence for feasibility, tolerability, acceptability, and efficacy of tDCS in improving performance on a measure of sustained attention.

METHODS

In a within-subjects design, 16 breast cancer survivors underwent 2 consecutive days of active tDCS over the prefrontal cortex, and 2 days of sham tDCS, counterbalanced for order of stimulation condition, while performing a continuous performance test.

RESULTS

Stimulation was feasible and tolerable, with 89% of participants completing all sessions, and none reporting more than mild to moderate discomfort. Analyses of efficacy showed that during active stimulation, participants had significantly lower standard errors of reaction times overall, indicating better sustained attention ability, as compared to sham stimulation (p < 0.05). Furthermore, the effect of stimulation on standard errors of reaction times differed by inter-stimulus interval (ISI): for 1 and 2 s ISIs, there was no significant difference in performance between sham and active tDCS conditions, but for 4 s ISIs, stimulation improved variability in response times relative to sham (p < 0.05).

CONCLUSIONS

Results suggest that tDCS is feasible, tolerable, and may be an effective intervention to improve sustained attention difficulties in survivors with cancer-related cognitive dysfunction.

Iatrogenic Neuropathology of Systemic Therapies

Administration of systemic antineoplastic agents can result in adverse neurologic events. We describe the clinicopathologic features and putative mechanisms underlying iatrogenic neuropathology of the central nervous system secondary to chimeric antigen receptor (CAR) T-cell therapy and conventional chemotherapy.

A mindfulness-based intervention for breast cancer patients with cognitive impairment after chemotherapy: study protocol of a three-group randomized controlled trial

BACKGROUND

Mindfulness has been applied to improve cancer care by enhancing psychological well-being. However, little is known about its impact on cognitive impairment experienced by cancer patients after chemotherapy. Mindfulness may be relevant in tackling cognitive impairment by decreasing emotional distress and fatigue, by decreasing inflammation, and by strengthening functional brain connectivity. The aim of the present study protocol is to evaluate the efficacy and mechanisms of a mindfulness-based intervention to reduce cognitive impairment in breast cancer patients after chemotherapy.

METHODS/DESIGN

The present study is a three-arm, parallel-group, randomized controlled trial with assessments at baseline, 1 to 3 weeks after the intervention and at 3 months' follow-up. One hundred and twenty breast cancer patients who ended treatment a minimum of 6 months and a maximum of 5 years before, and who have cognitive complaints, will be enrolled. They will be randomized into one of the following three study arms: (1) a mindfulness-based intervention group (n = 40), (2) an active control condition based on physical training (n = 40), or (3) a treatment as usual (TAU) control group (n = 40). Both the mindfulness-based intervention and the active control condition consist of four group sessions (3 h for the mindfulness condition and 2 h for the physical training) spread over 8 weeks. The primary outcomes will be cognitive symptoms as measured by the Cognitive Failure Questionnaire and changes in functional brain connectivity in the attention network. Secondary outcomes will be (1) levels of emotional distress, fatigue, mindfulness, quality of life; (2) neurocognitive tests; (3) structural and functional brain changes using MR imaging and (4) measures of inflammation.

DISCUSSION

The study will examine the impact of a mindfulness-based intervention on cognitive impairment in breast cancer patients. If the findings of this study confirm the effectiveness of a mindfulness-based program to reduce cognitive impairment, it will be possible to improve quality of life for ex-cancer patients. We will inform health care providers about the potential use of a mindfulness-based intervention as a non-pharmaceutical, low-threshold mental health intervention to improve cognitive impairment after cancer.

TRIAL REGISTRATION

ClinicalTrials.gov, ID: NCT03736460. Retrospectively registered on 8 November 2018.

Post-chemotherapy cognitive impairment in hematological patients: current understanding of chemobrain in hematology

Introduction: Cognitive impairment caused by chemotherapies, a condition known as chemobrain, is a possible side effect that affects alertness, learning, memory, and concentration.Areas covered: Chemobrain has been principally investigated as a possible side-effect among cancer patients. However, numerous drugs used to treat hematological malignancies can determine the appearance of chemobrain. In this review, we have examined some commonly used drugs for the treatment of hematological malignancies which are known to have a deleterious action on cognitive functions.Numerous mechanisms have been suggested, comprising the direct neurotoxicity of chemotherapeutic drugs, oxidative stress, genetic predisposition, cytokine-provoked damage, histone modifications, immune alteration, and the action of chemotherapeutic on trophic factors and structural proteins of brain cells.Expert commentary: Cognitive dysfunction provoked by the treatment of hematological diseases is an actual challenge in clinical practice. Actually, there are no totally efficient and innocuous treatments for this syndrome. It is important that further investigations specify the existence of predictors and gravity factors to pre- and post-therapy cognitive change and identify the influence of tumor treatments on the cognitive alterations in long-term, cancer survivors. Moreover, future studies are needed to analyze the interactions between genetic risk, amyloid accumulation, intrinsic brain networks, and chemotherapy.

Embracing the complexity: Older adults with cancer-related cognitive decline-A Young International Society of Geriatric Oncology position paper

Cancer-related cognitive decline (CRCD) may have particularly significant consequences for older adults, impacting their functional and physical abilities, level of independence, ability to make decisions, treatment adherence, overall quality of life, and ultimately survival. In honor of Dr. Hurria's work we explore and examine multiple types of screening, assessment and non-pharmacologic treatments for CRCD. We then suggest future research and clinical practice questions to holistically appreciate the complexity of older adults with cancer's experiences and fully integrate the team-based approach to best serve this population.

Systematic review of longitudinal studies on chemotherapy-associated subjective cognitive impairment in cancer patients

OBJECTIVES

This systematic review of longitudinal studies, assessing subjective cognitive impairment (SCI) reported by adult cancer patients, aimed to summarize evidence on the impact of chemotherapy on SCI, identify moderators of SCI, and evaluate methodological issues.

METHODS

Data accrued from Pubmed, EMBASE, CINAHL, PsychInfo, and the Cochrane library. Inclusion criteria were original studies, an exclusively adult sample, valid and reliable subjective cognitive measures, and at least one baseline data point prior to and another after the initiation of chemotherapy. Data were collected on the sample composition, data-collection time points, outcome measures, statistical analysis, and major findings (ie, longitudinal changes in prevalence, severity, and associated factors).

RESULTS

Forty articles published between 2004 and 2019 were retained: 21 examined chemotherapy-treated patients only, and 19 employed control groups. Findings were mixed, with slightly more studies supporting the impact of chemotherapy on SCI. SCI tended to be more prevalent and severe after initiating chemotherapy, compared with patients' own baseline and controls not treated with chemotherapy. Impact appeared to be acute and more likely limited to subsamples. Most studies examining non-breast-cancer samples reported the lack or limited impact of chemotherapy on SCI. The most consistent moderators were depression and fatigue. Methodological issues regarding sampling design, measurement, and statistical analysis were discussed.

CONCLUSION

More rigorously designed longitudinal studies would clarify direct and indirect effects of chemotherapy on SCI.

Validation of the Japanese Version of the Functional Assessment of Cancer Therapy-Cognitive Function Version 3

CONTEXT

Cancer therapy-induced cognitive impairment adversely affects the quality of life of patients with cancer but cannot be detected by neuropsychological tests.

OBJECTIVES

This study aimed to validate a Japanese version of the Functional Assessment of Cancer Therapy-Cognitive Function (FACT-Cog) version 3, which is a self-report measure of the cognitive concerns of patients with cancer.

METHODS

The FACT-Cog was translated into Japanese and pilot tested with five patients with breast cancer and five patients with hematologic malignancy. Study participants were recruited in Hiroshima University Hospital and Kagawa Breast Clinic in Hiroshima, Japan. Patients with breast cancer (N = 236) responded to the resultant assessment and Functional Assessment of Cancer Therapy-General version 4. The internal consistency and concurrent and construct validity of the FACT-Cog were examined.

RESULTS

The Cronbach's alphas of the four FACT-Cog subscales, namely, CogPCI, CogOth, CogPCA, and CogQOL, were 0.95, 0.73, 0.93, and 0.88, respectively. The item-to-domain correlations ranged from 0.211 to 0.920. Most of the FACT-Cog subscales were significantly correlated with other subscale and total scores (r = 0.133-0.425). Structural equation modeling was barely acceptable (χ2 = 1361.8, df = 489, P < 0.001; goodness of fit index = 0.731, adjusted goodness of fit index = 0.691, comparative fit index = 0.848, root-mean-square error of approximation = 0.087).

CONCLUSION

The Japanese version of the FACT-Cog is a valid and reliable self-report measure of the cognitive function of patients with breast cancer. Its utility to clinicians and researchers in measuring the cognitive concerns of patients with cancer in Japan will serve as a further test of its validity.

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.

Effects of chemotherapy on aging white matter microstructure: A longitudinal diffusion tensor imaging study

OBJECTIVE

We aimed to use diffusion tensor imaging (DTI) to detect alterations in white matter microstructure in older patients with breast cancer receiving chemotherapy.

METHODS

We recruited women age ≥60 years with stage I-III breast cancer (chemotherapy [CT] group; n = 19) to undergo two study assessments: at baseline and within one month after chemotherapy. Each assessment consisted of a brain magnetic resonance imaging scan with DTI and neuropsychological (NP) testing using the National Institutes of Health (NIH) Toolbox Cognition Battery. An age- and sex-matched group of healthy controls (HC, n = 14) underwent the same assessments at matched intervals. Four DTI parameters (fractional anisotropy [FA], mean diffusivity [MD], axial diffusivity [AD], and radial diffusivity [RD]) were calculated and correlated with NP testing scores.

RESULTS

For CT group but not HCs, we detected statistically significant increases in MD and RD in the genu of the corpus callosum from time point 1 to time point 2 at p < 0.01, effect size:0.3655 and 0.3173, and 95% confidence interval: from 0.1490 to 0.5821, and from 0.1554 to 0.4792, for MD and RD respectively. AD values increased for the CT group and decreased for the HC group over time, resulting in significant between-group differences (p = 0.0056, effect size:1.0215, 95% confidence interval: from 0.2773 to 1.7657). There were no significant correlations between DTI parameters and NP scores (p > 0.05).

CONCLUSIONS

We identified alterations in white matter microstructures in older women with breast cancer undergoing chemotherapy. These findings may potentially serve as neuroimaging biomarkers for identifying cognitive impairment in older adults with cancer.

Risk of dementia among postmenopausal breast cancer survivors treated with aromatase inhibitors versus tamoxifen: a cohort study using primary care data from the UK

Purpose

Among a cohort of postmenopausal breast cancer survivors, we aimed to compare the risk of dementia associated with aromatase inhibitor (AI) therapy versus tamoxifen.

Methods

Using UK primary care electronic health records, we identified 14,214 postmenopausal breast cancer survivors (aged ≥ 54 years) with a first AI or tamoxifen prescription between January 2002 and December 2015 and no previous dementia diagnosis. Women were followed-up to identify incident cases of dementia. Cox regression was used to calculate hazard ratios (HRs) with 95% confidence intervals (CIs) to quantify the association between AI exposure (vs. tamoxifen) and dementia, adjusted for confounders.

Results

A total of 368 incident dementia cases was identified over 57,102 person-years of follow-up. The crude incidence rate of dementia was 7.46 per 1000 person-years (95% CI 6.43–8.65) among women starting endocrine treatment on an AI, and 6.32 per 1000 person-years (95% CI 5.34–7.47) among women starting on tamoxifen. After accounting for age differences and assessing other potential confounders, there was no evidence of a difference in dementia risk between exposure groups (HR for AI vs tamoxifen 1.04, 95% CI 0.83–1.03). There was no evidence of effect modification by age.

Conclusion

There was no evidence for a difference in dementia risk between AI and tamoxifen users among postmenopausal breast cancer survivors.

Implications for Cancer Survivors

Our findings suggest that there is no reason for concern about a difference in dementia risk with AI vs. tamoxifen, which is relevant to postmenopausal breast cancer patients recommended these treatments.

Electronic supplementary material

The online version of this article (10.1007/s11764-019-00782-w) contains supplementary material, which is available to authorized users.

Brain Connectivity and Cognitive Flexibility in Nonirradiated Adult Survivors of Childhood Leukemia

Background

This study aimed to assess functional and structural brain connectivity in adult childhood leukemia survivors and the link with cognitive functioning and previously identified risk factors such as intrathecal methotrexate dose and age at start of therapy.

Methods

Thirty-one nonirradiated adult childhood leukemia survivors and 35 controls underwent cognitive testing and multimodal magnetic resonance imaging (resting state functional MRI, T1-weighted, diffusion-weighted, and myelin water imaging [MWI]). Analyses included dual regression, voxel-based morphometry, advanced diffusion, and MWI modeling techniques besides stepwise discriminant function analysis to identify the most affected executive cognitive domain. Correlations with discrete intrathecal MTX doses and (semi)continuous variables were calculated using Spearman's rank and Pearson's correlation, respectively. All correlation tests were two-sided. Positive and negative T-contrasts in functional and structural MRI analysis were one-sided.

Results

Survivors demonstrated lower functional connectivity between the default mode network (DMN) and inferior temporal gyrus (ITG; P < .008). Additionally, we observed higher fractional anisotropy (FA; P = .04) and lower orientation dispersion index (ODI; P = .008) at the left centrum semiovale, which could-given that several fiber bundles cross this region-suggest selective reduced integrity of the respective white matter tracts. Set shifting reaction time, a measure of cognitive flexibility, was mostly impaired and correlated with lower FA (r = -0.53, P = .003) and higher ODI (r = 0.40, P = .04) in survivors but not with DMN-ITG connectivity. There were no statistically significant differences between survivors and controls in WM or GM volume, nor was there a statistically significant correlation between imaging measurements and age at start of therapy or intrathecal methotrexate dose.

Conclusions

Adult, nonirradiated childhood leukemia survivors show altered brain connectivity, which is linked with cognitive flexibility.

Functional Corticomuscular Signal Coupling Is Weakened during Voluntary Motor Action in Cancer-Related Fatigue

Background and Purpose

Cancer-related fatigue (CRF) is widely recognized as one of the most common symptoms and side effects of cancer and/or its treatment. However, neuropathological mechanisms contributing to CRF are largely unknown, and the lack of knowledge makes CRF difficult to treat. Recent research has shown dissociation between changes in the brain and muscle signals during voluntary motor performance in cancer survivors with CRF, and this dissociation may be caused by an interruption in functional coupling (FC) of the two signals. The goal of this study was to assess the FC between EEG (cortical signal) and EMG (muscular signal) in individuals with CRF and compare the FC with that of healthy controls during a motor task that led to progressive muscle fatigue.

Method

Eight cancer survivors with CRF and nine healthy participants sustained an isometric elbow flexion contraction (at 30% maximal level) until self-perceived exhaustion. The entire duration of the EEG and EMG recordings was divided into the first-half (less-fatigue stage) and second-half (more-fatigue stage) artifact-free epochs without overlapping. The EEG-EMG coupling (measured by coherence of the two signals) in each group and stage was computed. Coherence values at different frequencies were statistically analyzed using a repeated-measure general linear model.

Results

The results demonstrated that compared to healthy controls, CRF participants sustained the contraction for a significantly shorter time and exhibited robust and significantly lower EEG-EMG coherence at the alpha (8~14 Hz) and beta (15~35 Hz) frequency bands. Both the CRF and healthy control groups exhibited significantly decreased EEG-EMG coherence from the less-fatigue to more-fatigue stages at the alpha and beta frequency bands, indicating fatigue-induced weakening of functional corticomuscular coupling.

Conclusion

Impaired functional coupling between the brain and muscle signals could be a consequence of cancer and/or its treatment, and it may be one of the contributing factors to the abnormal feeling of fatigue that caused the early failure of sustaining a prolonged motor task.

Plausible biochemical mechanisms of chemotherapy-induced cognitive impairment ("chemobrain"), a condition that significantly impairs the quality of life of many cancer survivors

Increasing numbers of cancer patients survive and live longer than five years after therapy, but very often side effects of cancer treatment arise at same time. One of the side effects, chemotherapy-induced cognitive impairment (CICI), also called "chemobrain" or "chemofog" by patients, brings enormous challenges to cancer survivors following successful chemotherapeutic treatment. Decreased abilities of learning, memory, attention, executive function and processing speed in cancer survivors with CICI, are some of the challenges that greatly impair survivors' quality of life. The molecular mechanisms of CICI involve very complicated processes, which have been the subject of investigation over the past decades. Many mechanistic candidates have been studied including disruption of the blood-brain barrier (BBB), DNA damage, telomere shortening, oxidative stress and associated inflammatory response, gene polymorphism of neural repair, altered neurotransmission, and hormone changes. Oxidative stress is considered as a vital mechanism, since over 50% of FDA-approved anti-cancer drugs can generate reactive oxygen species (ROS) or reactive nitrogen species (RNS), which lead to neuronal death. In this review paper, we discuss these important candidate mechanisms, in particular oxidative stress and the cytokine, TNF-alpha and their potential roles in CICI.

Breast cancer plus adjuvant chemotherapy- related cognitive impairment: a case study

Breast cancer-related cognitive impairment (CRCI), a frequent concomitant of cancer diagnosis and management, has been difficult to measure objectively. This study longitudinally investigated cognitive function in an individual before and after breast cancer diagnosis and treatment. Comparison of test scores pre- and post- diagnosis/treatment revealed declines in multiple cognitive domains, including Performance IQ, processing speed, immediate auditory and visual memory, and delayed visual memory. Twelve years later, improvements were noted in domains of processing speed, memory and executive functioning. The results highlight the importance of heeding individuals' subjective reports of cognitive decline, and offer hope that such decrements may not be permanent.

Assessment of neurocognitive decline in cancer patients, except brain cancer, under long-term treatment with bevacizumab

PURPOSE

We performed a cross-sectional study of neurocognitive function in non-brain cancer patients treated with long-term bevacizumab.

METHODS/PATIENTS

From 2015 to 2017, we included patients with different types of cancer treated with bevacizumab with or without chemotherapy (BEV; N = 20) or only chemotherapy (ChT; N = 19) for at least 34 weeks, patients who received non-brain radiotherapy (RxT; N = 19), and healthy controls (HC; N = 19) were assessed once at week 34 of treatment (BEV and ChT) or at completion of radiotherapy. Neurocognition was evaluated with the Hopkins Verbal Learning Test-Revised (HVLT-R) total and delayed recall, the Trail Making Test A and B, and the Controlled Oral Word Association Test in the four groups. Non-parametric tests were used to assess differences between groups.

RESULTS

The BEV, ChT, and RxT groups scored significantly lower than the HC group on all tests and especially on the HVLT-R total recall. In no case were the mean scores of the BEV group significantly lower than those of the ChT or RxT groups.

CONCLUSIONS

Neurocognitive impairment was seen even in patients treated with local non-brain radiotherapy. Treatment with bevacizumab for a long period of time does not seem to worsen neurocognitive function to a greater extent than chemotherapy.

Structural brain alterations following adult non-CNS cancers: a systematic review of the neuroimaging literature

Background: Cancer and cancer treatments may impact the brain through several pathways leading to cognitive impairment. Neuroimaging evidence has begun to elucidate the neurobiological underpinnings of cancer-related cognitive impairment. The aim of this paper was to systematically review available literature on structural brain alterations following adult non-central nervous system (CNS) cancers and associated treatments. Methods: This review followed PRISMA guidelines and was registered in PROSPERO (ID#107387). Comprehensive searches were conducted in June 2018 using PubMed and Web of Science. Inclusion criteria were English peer-reviewed journal articles of formal, controlled studies that examined structural neuroimaging outcomes in adult non-CNS cancer patients and survivors. Selected articles were assessed for quality and risk of bias using the National Institutes of Health Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. Results: Thirty-six publications of prospective and cross-sectional studies met inclusion criteria and were included. Structural brain alterations following cancer and its treatment were reported in a majority of the publications as evidenced by reduced global and local gray matter volumes, impaired white matter microstructural integrity, and brain network alterations. Structural alterations were most often evident when cancer-treated groups were compared with healthy controls, and more subtle when compared with cancer controls. Regarding the existence of pretreatment impairments, the evidence was equivocal. There was significant between-study heterogeneity in imaging analytical approaches and use of statistical adjustments. Over half reported associations with cognitive outcomes, though regions and associated cognitive domains were heterogeneous. Conclusions: Structural brain alterations following cancer and cancer treatments were reported in a majority of the reviewed studies. However, the extent of observed alterations depended on the choice of comparison groups. Methodological issues exist that will need to be addressed systematically to ensure the validity of findings. Large-scale prospective studies with extended assessment points are warranted to replicate and build upon initial findings.