Catechol-O-methyltransferase genotype modulates cancer treatment-related cognitive deficits in breast cancer survivors

The impact of APOE and smoking history on cognitive function in older, long-term breast cancer survivors

PURPOSE

This study aims to determine whether older breast cancer survivors score lower on neuropsychological tests compared to matched non-cancer controls and to test the hypotheses that survivors who were APOE ε4 carriers would have the lowest cognitive performance but that smoking history would decrease the negative effect of ε4 on cognition.

METHODS

Female breast cancer survivors who had been diagnosed and treated at age 60 or older and were 5-15-year survivors (N = 328) and age and education matched non-cancer controls (N = 162) were assessed at enrollment and at 8-, 16-, and 24-month follow-ups with standard neuropsychological and psychological assessments. Blood for APOE genotyping was collected, and smoking history was assessed at enrollment. Participants were purposely recruited so that approximately 50% had a history of treatment with chemotherapy or no chemotherapy and approximately 50% had a smoking history.

RESULTS

After adjusting for age, cognitive reserve, depression, and fatigue, breast cancer survivors scored significantly lower on all domains of cognitive function. A significant two-way interaction demonstrated that the negative effect of ε4 on cognitive performance was stronger among survivors. A significant three-way interaction supported the hypothesis that smoking history had a protective effect on cognitive function in ε4 carriers that was more pronounced in the controls than the survivors.

CONCLUSIONS

The results support the long-term cognitive impact of breast cancer diagnosis and treatments on older, disease-free survivors, particularly for ε4 carriers. The results also emphasize the importance of assessing smoking history when examining APOE and cognition and are an example of the complex interactions of age, genetics, health behaviors, and disease history in determining cognitive function.

IMPLICATIONS FOR CANCER SURVIVORS

These results help explain why only a subset of breast cancer survivors appear to be vulnerable to cognitive problems.

Cancer-Related Cognitive Dysfunction: A Narrative Review for Clinical Practice

BACKGROUND

Cancer-related cognitive dysfunction (CRCD) is a major functional disorder in patients with cancer. This central nervous dysfunction is found in up to 60% of patients after tumour therapy, often significantly limits the quality of life, and significantly impedes participation in working life. For this reason, diagnosis and treatment of CRCD are of central importance. This narrative review is intended to provide an overview and support for practical clinical care with regard to diagnostics and therapeutic options.

SUMMARY

In Germany, CRCD has received insufficient attention in clinical practice due to the lack of guidelines for diagnosis and therapy. The pathophysiology is complex and cannot be explained by chemotherapeutic treatment alone. In addition to the tumour disease as such and the tumour therapy, psychological factors such as anxiety and depression as well as sleep disorders also play a significant role. Today, it is known that in addition to age, molecular genetic changes also have an effect on cognitive function. Morphologically, CRCD can be located in the frontal cortex and hippocampus. In addition to easy-to-use screening instruments such as the visual analogue scale, validated questionnaires such as the Questionnaire of Subjectively Experienced Deficits in Attention (FEDA) developed in Germany are also available. These allow the suspected diagnosis to be substantiated and the patient to be referred to further neurological, neuropsychological, or psycho-oncological diagnostics. Within the framework of further neuropsychological diagnostics, the International Cognition and Cancer Task Force (ICCTF) recommends testing learning, memory, processing speed, and executive functions. From the authors' point of view, a step-by-step diagnosis is recommended in order to avoid overdiagnosis. In clinical practice, graduation according to the "Common Terminology Criteria for Adversity Events" (CTCAE Version 5.0) is suitable for assessing the degree of severity. Cognitive training should be behaviourally oriented and include regular practice of cognitive skills to restore attention, psychomotor speed, memory, and executive functions. The best evidence is currently found for web-based training programmes that can be used by the patient at home. There is also evidence for mindfulness training and physical exercises. In particular, the combination of these three therapeutic elements currently seems to be the optimal treatment strategy for CRCD.

KEY MESSAGES

Cognitive dysfunction should be given much more attention in the clinical care of cancer patients. Diagnostic tools for this purpose and evidence-based therapeutic interventions are available. In the future, networks should be created that allow for better care of patients with CRCD.

Prediction of cognitive decline in older breast cancer survivors: the Thinking and Living with Cancer study

PURPOSE

Cancer survivors commonly report cognitive declines after cancer therapy. Due to the complex etiology of cancer-related cognitive decline (CRCD), predicting who will be at risk of CRCD remains a clinical challenge. We developed a model to predict breast cancer survivors who would experience CRCD after systematic treatment.

METHODS

We used the Thinking and Living with Cancer study, a large ongoing multisite prospective study of older breast cancer survivors with complete assessments pre-systemic therapy, 12 months and 24 months after initiation of systemic therapy. Cognition was measured using neuropsychological testing of attention, processing speed, and executive function (APE). CRCD was defined as a 0.25 SD (of observed changes from baseline to 12 months in matched controls) decline or greater in APE score from baseline to 12 months (transient) or persistent as a decline 0.25 SD or greater sustained to 24 months. We used machine learning approaches to predict CRCD using baseline demographics, tumor characteristics and treatment, genotypes, comorbidity, and self-reported physical, psychosocial, and cognitive function.

RESULTS

Thirty-two percent of survivors had transient cognitive decline, and 41% of these women experienced persistent decline. Prediction of CRCD was good: yielding an area under the curve of 0.75 and 0.79 for transient and persistent decline, respectively. Variables most informative in predicting CRCD included apolipoprotein E4 positivity, tumor HER2 positivity, obesity, cardiovascular comorbidities, more prescription medications, and higher baseline APE score.

CONCLUSIONS

Our proof-of-concept tool demonstrates our prediction models are potentially useful to predict risk of CRCD. Future research is needed to validate this approach for predicting CRCD in routine practice settings.

Prevalence and associated factors of chemotherapy-related cognitive impairment in older breast cancer survivors

AIMS

To examine the prevalence and associated factors of chemotherapy-related cognitive impairment (CRCI) in older breast cancer survivors (BCS).

DESIGN

Systematic review.

DATA SOURCES

We searched EMBASE, PubMed, PsychInfo, CINAHL, Cochrance Library, Web of Science, CNKI and SinoMed, without language restrictions, for studies published from the establishment of the database to September 2022.

REVIEW METHODS

Two researchers independently examined the full texts, data extraction and quality assessment, and any discrepancies were resolved through discussion with a third reviewer. Quality of evidence was assessed using the Newcastle-Ottawa Scale and the Agency for Healthcare Research and Quality Scale.

RESULTS

The seven included studies showed that the estimated prevalence of CRCI in older BCS ranged from 18.6% to 27% on objective neuropsychological tests and from 7.6% to 49% on subjective cognitive assessments. The areas most affected were attention, memory, executive functioning and processing speed. CRCI was associated with 10 factors in six categories, including sociodemographic (e.g. age, education level), physiological (e.g. sleep disorders, fatigue and comorbidities), psychological (e.g. anxiety, depression), treatment modalities (e.g. chemotherapy cycles, chemotherapy regimens), genetic (e.g. APOE2, APOE4) and lifestyle factor (e.g. physical inactivity).

CONCLUSION

CRCI is multifactorial and has a relatively high prevalence. However, the results of subjective and objective cognitive examinations were inconsistent, possibly due to variations in tools used to evaluate different definitions of CRCI. Nevertheless, as there are few published studies of older BCS, this conclusion still require verification by well-designed studies in the future.

IMPACT

We found that the prevalence of CRCI in older adults is relatively high and multifactorial, providing evidence for further health care for this population.

NO PATIENT OR PUBLIC CONTRIBUTION

There was no patient or public involvement.

Brain connectomics improve prediction of 1-year decreased quality of life in breast cancer: A multi-voxel pattern analysis

PURPOSE

Whether brain connectomics can predict 1-year decreased Quality of Life (QoL) in patients with breast cancer are unclear. A longitudinal study was utilized to explore their prediction abilities with a multi-center sample.

METHODS

232 breast cancer patients were consecutively enrolled and 214 completed the 1-year QoL assessment (92.2%). Resting state functional magnetic resonance imaging was collected before the treatment and a multivoxel pattern analysis (MVPA) was performed to differentiate whole-brain resting-state connectivity patterns. Net Reclassification Improvement (NRI) as well as Integrated Discrimination Improvement (IDI) were calculated to estimate the incremental value of brain connectomics over conventional risk factors.

RESULTS

Paracingulate Gyrus, Superior Frontal Gyrus and Frontal Pole were three significant brain areas. Brain connectomics yielded 7.8-17.2% of AUC improvement in predicting 1-year decreased QoL. The NRI and IDI ranged from 20.27 to 54.05%, 13.21-33.34% respectively.

CONCLUSION

Brain connectomics contribute to a more accurate prediction of 1-year decreased QoL in breast cancer. Significant brain areas in the prefrontal lobe could be used as potential intervention targets (i.e., Cognitive Behavioral Group Therapy) to improve long-term QoL outcomes in breast cancer.

Neurologic Complications in Adult Cancer Survivorship

Over the past decade, the improvement in cancer diagnostics and therapeutics has extended the overall survival of patients diagnosed with cancer including brain cancer. However, despite these unprecedented medical successes, patients continue to experience numerous neurologic complications after treatment that interfere with their independence, functionality, and overall quality of life. These include, among others, cognitive impairment, endocrinopathies, peripheral and cranial neuropathies, and vasculopathy. This article describes the long-term neurologic complications cancer survivors commonly experience to increase awareness of these complications and discuss treatments when available. Further research is necessary to understanding of mechanisms of neurologic injury and advance diagnosis and treatment. Effective patient education, monitoring, and managing neurologic issues after cancer treatment may improve independence, functionality, and quality of life during survivorship.

Natural products for the treatment of chemotherapy-related cognitive impairment and prospects of nose-to-brain drug delivery

Chemotherapy-related cognitive deficits (CRCI) as one of the common adverse drug reactions during chemotherapy that manifest as memory, attention, and executive function impairments. However, there are still no effective pharmacological therapies for the treatment of CRCI. Natural compounds have always inspired drug development and numerous natural products have shown potential therapeutic effects on CRCI. Nevertheless, improving the brain targeting of natural compounds in the treatment of CRCI is still a problem to be overcome at present and in the future. Accumulated evidence shows that nose-to-brain drug delivery may be an excellent carrier for natural compounds. Therefore, we reviewed natural products with potential anti-CRCI, focusing on the signaling pathway of these drugs' anti-CRCI effects, as well as the possibility and prospect of treating CRCI with natural compounds based on nose-to-brain drug delivery in the future. In conclusion, this review provides new insights to further explore natural products in the treatment of CRCI.

Subjective cognition and memory lapses in the daily lives of breast cancer survivors: Examining associations with objective cognitive performance, fatigue, and depressed mood

OBJECTIVE

Subjective reports of cancer-related cognitive impairment often far exceed that documented using in-person neuropsychological assessment. This study evaluated whether subjective cognition was associated with real-time objective cognitive performance in daily life versus performance on an in-person neuropsychological battery, as well as fatigue and depressed mood.

METHODS

Participants were 47 women (M age = 53.3 years) who completed adjuvant treatment for early-stage breast cancer 6-36 months previously. During an in-person assessment, participants completed a neuropsychological battery and questionnaires on subjective cognition, fatigue, and depressed mood. Over 14 days, participants responded to up to 5 prompts that assessed real-time processing speed and memory and self-reported ratings of depressed mood and fatigue. In the evenings, participants rated their subjective cognition that day and reported on memory lapses (e.g., forgetting a word).

RESULTS

During the in-person assessment, participants who rated their cognition worse reported worse depressed mood, but did not exhibit poorer objective cognitive performance. Women with worse rated daily subjective cognition reported more daily fatigue but did not demonstrate worse real-time objective cognition. Finally, women who reported memory lapses at the end of the day reported more fatigue and depressed mood, demonstrated better real-time performance on processing speed (p = 0.001), and worse in-person processing speed and visuospatial skills (p's ≤ 0.02).

CONCLUSION

Subjective cognition was consistently associated with self-reported fatigue and depressed mood. Specific memory lapses were related to in-person and daily objective cognitive performance. This suggests that incorporating reports of memory lapses may help clinicians identify those with objectively measured cancer-related cognitive impairment.

Cognitive impairment after cancer treatment: mechanisms, clinical characterization, and management

Cognitive impairment is a debilitating side effect experienced by patients with cancer treated with systemically administered anticancer therapies. With around 19.3 million new cases of cancer worldwide in 2020 and the five year survival rate growing from 50% in 1970 to 67% in 2013, an urgent need exists to understand enduring side effects with severe implications for quality of life. Whereas cognitive impairment associated with chemotherapy is recognized in patients with breast cancer, researchers have started to identify cognitive impairment associated with other treatments such as immune, endocrine, and targeted therapies only recently. The underlying mechanisms are diverse and therapy specific, so further evaluation is needed to develop effective therapeutic interventions. Drug and non-drug management strategies are emerging that target mechanistic pathways or the cognitive deficits themselves, but they need to be rigorously evaluated. Clinically, consistent use of objective diagnostic tools is necessary for accurate diagnosis and clinical characterization of cognitive impairment in patients treated with anticancer therapies. This should be supplemented with clinical guidelines that could be implemented in daily practice. This review summarizes the recent advances in the mechanisms, clinical characterization, and novel management strategies of cognitive impairment associated with treatment of non-central nervous system cancers.

Perioperative considerations in patients with chemotherapy-induced cognitive impairment: a narrative review

Patients with cancer may suffer from a decline in their cognitive function after various cancer therapies, including surgery, radiation, and chemotherapy, and in some cases, this decline in cognitive function persists even years after completion of treatment. Chemobrain or chemotherapy-induced cognitive impairment, a well-established clinical syndrome, has become an increasing concern as the number of successfully treated cancer patients has increased significantly. Chemotherapy-induced cognitive impairment can originate from direct neurotoxicity, neuroinflammation, and oxidative stress, resulting in alterations in grey matter volume, white matter integrity, and brain connectivity. Surgery has been associated with exacerbating the inflammatory response associated with chemotherapy and predisposes patients to develop postoperative cognitive dysfunction. As the proportion of patients living longer after these therapies increases, the magnitude of impact and growing concern of post-treatment cognitive dysfunction in these patients has also come to the fore. We review the clinical presentation, potential mechanisms, predisposing factors, diagnostic methods, neuropsychological testing, and imaging findings of chemotherapy-induced cognitive impairment and its intersection with postoperative cognitive dysfunction.

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.

Pharmacogenetics of taxane-induced neurotoxicity in breast cancer: Systematic review and meta-analysis

Taxane-based chemotherapy regimens are used as first-line treatment for breast cancer. Neurotoxicity, mainly taxane-induced peripheral neuropathy (TIPN), remains the most important dose-limiting adverse event. Multiple genes may be associated with TIPN; however, the strength and direction of the association remain unclear. For this reason, we systematically reviewed observational studies of TIPN pharmacogenetic markers in breast cancer treatment. We conducted a systematic search of terms alluding to breast cancer, genetic markers, taxanes, and neurotoxicity in Ovid, ProQuest, PubMed, Scopus, Virtual Health, and Web of Science. We assessed the quality of evidence and bias profile. We extracted relevant variables and effect measures. Whenever possible, we performed random-effects gene meta-analyses and examined interstudy heterogeneity with meta-regression models and subgroup analyses. This study follows the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and STrengthening the REporting of Genetic Association Studies (STREGA) reporting guidance. A total of 42 studies with 19,431 participants were included. These evaluated 262 single-nucleotide polymorphisms (SNPs) across 121 genes. We conducted meta-analyses on 23 genes with 60 SNPs (19 studies and 6246 participants). Thirteen individual SNPs (ABCB1-rs2032582, ABCB1-rs3213619, BCL6/-rs1903216, /CAND1-rs17781082, CYP1B1-rs1056836, CYP2C8-rs10509681, CYP2C8-rs11572080, EPHA5-rs7349683, EPHA6-rs301927, FZD3-rs7001034, GSTP1-rs1138272, TUBB2A-rs9501929, and XKR4-rs4737264) and the overall SNPs' effect in four genes (CYP3A4, EphA5, GSTP1, and SLCO1B1) were statistically significantly associated with TIPN through meta-analysis. In conclusion, through systematic review and meta-analysis, we found that polymorphisms, and particularly 13 SNPs, are associated with TIPN, suggesting that genetics does play a role in interindividual predisposition. Further studies could potentially use these findings to develop individual risk profiles and guide decision making.

Clinical and genetic factors associated with self-reported cognitive deficits in women with breast cancer: the "CAGE-Cog" study

Background

Breast cancer patients undergoing chemotherapy treatment are at particular risk of experiencing acute cognitive impairment leading to daily challenges in decision-making and reduced quality of life and functional autonomy. The aim was to assess the relationship between clinical and genetic factors and cognitive function in a sample of patients with breast cancer undergoing chemotherapy.

Methods

A cross-sectional study was carried out between November 2017 and June 2019 on women (N = 112) treated for breast cancer by intravenous chemotherapy at the oncology outpatient unit of Hôtel-Dieu de France Hospital, Beirut. Patients were evaluated with the 37-item Functional Assessment of Cancer Therapy-Cognitive Function (FACT-Cog). Other validated scales were also used to assess depression, anxiety, sleep disorders, pain, and fatigue. DNA was obtained by a buccal swab (FTA®technology) for genotyping of different genes (ABCB1, COMT, DRD2, OPRM1, CLOCK, CRY2, and PER2) using the Lightcycler®(Roche).

Results

The mean age of participants was 56.04 years. Multivariable analysis, taking the four FACT-Cog subscores as the dependent variables, showed that the mean cognitive score decreased with higher depression, anxiety, and insomnia scores. Patients with university education levels had better perceived cognitive abilities than those with primary education. Moreover, carrying the G allele for the OPRM1 polymorphism (c.118A > G;rs197791) was significantly associated with a better cognitive function compared to AA patients (B = 2.05; p = 0.038).

Conclusions

A comprehensive oncological care plan should include a personalized assessment of all factors related to cognitive functioning in cancer patients, particularly anxiety and depression, to achieve an optimal patient outcome.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-10077-6.

Preventing late recurrence in hormone receptor-positive early breast cancer: a review

Late recurrences are a key challenge for patients with early-stage oestrogen receptor-positive breast cancer, with the risk of disease relapse continuing steadily from 5 to more than 20 years after diagnosis. Five years of adjuvant endocrine therapy with tamoxifen or an aromatase inhibitor was shown many years ago to improve survival. More recently, the trials of extended adjuvant endocrine therapy for more than 5 years have shown a further small gain, but with an associated small risk of increased long-term toxicity including bone loss, cardiovascular impairment and impaired quality of life. This review describes the efficacy and safety of extended endocrine therapy, the optimal selection criteria for patient benefit and the potential for novel agents to improve long-term outcomes.

Mechanisms of Chemotherapy-Induced Neurotoxicity

Since the first clinical trials conducted after World War II, chemotherapeutic drugs have been extensively used in the clinic as the main cancer treatment either alone or as an adjuvant therapy before and after surgery. Although the use of chemotherapeutic drugs improved the survival of cancer patients, these drugs are notorious for causing many severe side effects that significantly reduce the efficacy of anti-cancer treatment and patients’ quality of life. Many widely used chemotherapy drugs including platinum-based agents, taxanes, vinca alkaloids, proteasome inhibitors, and thalidomide analogs may cause direct and indirect neurotoxicity. In this review we discuss the main effects of chemotherapy on the peripheral and central nervous systems, including neuropathic pain, chemobrain, enteric neuropathy, as well as nausea and emesis. Understanding mechanisms involved in chemotherapy-induced neurotoxicity is crucial for the development of drugs that can protect the nervous system, reduce symptoms experienced by millions of patients, and improve the outcome of the treatment and patients’ quality of life.

Genome-wide variants and polygenic risk scores for cognitive impairment following blood or marrow transplantation

Cognitive impairment is prevalent in blood or marrow transplantation (BMT) recipients, albeit with inter-individual variability. We conducted a genome-wide association study of objective cognitive function assessed longitudinally in 239 adult BMT recipients for discovery and replicated in an independent cohort of 540 BMT survivors. Weighted genome-wide polygenic risk scores (PRS) were constructed using linkage disequilibrium pruned significant SNPs. Forty-four genome-wide significant SNPs were identified using additive (n = 3); codominant (n = 20) and genotype models (n = 21). Each additional copy of a risk allele was associated with a 0.28-point (p = 1.07 × 10^-8) to a 1.82-point (p = 6.7 × 10^-12) increase in a global deficit score. We replicated two SNPs (rs11634183 and rs12486041) with links to neural integrity. Patients in the top PRS quintile were at increased risk of cognitive impairment in discovery (RR = 1.95, 95%CI: 1.28-2.96, p = 0.002) and replication cohorts (OR = 1.84, 95%CI, 1.02-3.32, p = 0.043). Associations were stronger among individuals with lowest clinical risk for cognitive impairment. These findings support potential utility of PRS-based risk classification in the development of targeted interventions aimed at improving cognitive outcomes in BMT survivors.

The COMT Genetic Factor Regulates Chemotherapy-Related Prospective Memory Impairment in Survivors With HER2-/+ Breast Cancer

Background

Previous findings indicated that polymorphism in gene catechol-O-methyltransferase (COMT) had been linked to chemotherapy-related cognitive impairment (CRCI). Nevertheless, the motivation of COMT polymorphisms in regulating cognitive impairment in breast cancer survivors with disparate status of human epidermal growth factor receptor 2 (HER2) was still vague.

Objective

The current research aimed to evaluate the regulation of the risk by COMT genotype on CRCI in breast cancer survivors with disparate status of HER2.

Methods

Breast cancer survivors (103 with HER2− and 118 with HER2+) underwent neuropsychological tests before and after chemotherapy, containing event- and time-based prospective memory (EBPM and TBPM). Three single-nucleotide polymorphisms (SNPs) were estimated by providing peripheral blood, containing COMT (rs165599, rs737865, and rs4680).

Results

The EBPM and TBPM performances was lower as compared with these before chemotherapy (z = −7.712, z = −2.403, respectively, p < 0.01). Furthermore, the EBPM and TBPM performances of HER2− group survivors were lower than those of HER2+ group survivors after chemotherapy (z = −7.181, p < 0.01; z = −2.205 p < 0.05, respectively). The survivors with COMT (rs165599) A/A genotype carriers had a meaningfully poorer chance of memory descend [dominant model: adjusted, OR = 2.21, CI (95%) = 1.156–4.225, p = 0.016] and showed better on TBPM test, relative to G/G genotype. Patients with the COMT (rs737865) A/G and G/G genotype showed protective function than the patients with the A/A and performed better on MMSE and TBPM tests.

Conclusion

The types of HER2 may be correlated to chemotherapy-related prospective memory impairments in breast cancer survivors. Furthermore, the COMT (rs165599, rs737865) polymorphisms were correlated to the risk of TBPM decline scores and possibly be a potential genetic identifying for increasing risk of CRCI in breast cancer patients with disparate status of HER2.

Cognitive adverse effects of chemotherapy and immunotherapy: are interventions within reach?

One in three people will be diagnosed with cancer during their lifetime. The community of cancer patients is growing, and several common cancers are becoming increasingly chronic; thus, cancer survivorship is an important part of health care. A large body of research indicates that cancer and cancer therapies are associated with cognitive impairment. This research has mainly concentrated on chemotherapy-associated cognitive impairment but, with the arrival of immunotherapies, the focus is expected to widen and the number of studies investigating the potential cognitive effects of these new therapies is rising. Meanwhile, patients with cognitive impairment and their healthcare providers are eagerly awaiting effective approaches to intervene against the cognitive effects of cancer treatment. In this Review, we take stock of the progress that has been made and discuss the steps that need to be taken to accelerate research into the biology underlying cognitive decline following chemotherapy and immunotherapy and to develop restorative and preventive interventions. We also provide recommendations to clinicians on how to best help patients who are currently experiencing cognitive impairment.

A systematic review on the use of quantitative imaging to detect cancer therapy adverse effects in normal-appearing brain tissue

Cancer therapy for both central nervous system (CNS) and non-CNS tumors has been previously associated with transient and long-term cognitive deterioration, commonly referred to as 'chemo fog'. This therapy-related damage to otherwise normal-appearing brain tissue is reported using post-mortem neuropathological analysis. Although the literature on monitoring therapy effects on structural magnetic resonance imaging (MRI) is well established, such macroscopic structural changes appear relatively late and irreversible. Early quantitative MRI biomarkers of therapy-induced damage would potentially permit taking these treatment side effects into account, paving the way towards a more personalized treatment planning.This systematic review (PROSPERO number 224196) provides an overview of quantitative tomographic imaging methods, potentially identifying the adverse side effects of cancer therapy in normal-appearing brain tissue. Seventy studies were obtained from the MEDLINE and Web of Science databases. Studies reporting changes in normal-appearing brain tissue using MRI, PET, or SPECT quantitative biomarkers, related to radio-, chemo-, immuno-, or hormone therapy for any kind of solid, cystic, or liquid tumor were included. The main findings of the reviewed studies were summarized, providing also the risk of bias of each study assessed using a modified QUADAS-2 tool. For each imaging method, this review provides the methodological background, and the benefits and shortcomings of each method from the imaging perspective. Finally, a set of recommendations is proposed to support future research.

Long-Term Cognitive Dysfunction in Cancer Survivors

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

Probiotic supplement attenuates chemotherapy-related cognitive impairment in patients with breast cancer: a randomised, double-blind, and placebo-controlled trial

BACKGROUND

Chemotherapy-related cognitive impairment (CRCI) is highly prevalent in patients with cancer and is associated with poor outcomes and quality of life. To date, the management of CRCI remains a clinical challenge. Herein, we aim to determine the preventive effects of probiotics on CRCI development and underlying mechanisms.

METHODS

We conducted a randomised, double-blind and placebo-controlled trial (ChiCTR-INQ-17014181) of 159 patients with breast cancer and further investigated the underlying mechanism in a pre-clinical setting. From 2018 to 2019, patients with breast cancer (Stage I-III) who needed adjuvant chemotherapy were screened, enrolled and randomly assigned to receive either probiotics or placebo (three capsules, twice/day) during chemotherapy. Their cognition, anxiety and depression were assessed with well-established assays; their plasma biomarkers, metabolites and faecal microbiota compositions were measured. In addition, the systemic effects of the metabolites found in the clinical trial on long-term potentiation, synapse injury, oxidative stress and glial activation were assessed in rats.

RESULTS

Probiotics supplement significantly decreased the incidence of CRCI, improved the allover cognitive functions, changed the gut microbial composition and modulated nine plasma metabolite changes. Among these metabolites, p-Mentha-1,8-dien-7-ol, Linoelaidyl carnitine and 1-aminocyclopropane-1-carboxylic acid were negatively correlated with the occurrence of CRCI. Furthermore, probiotics supplement increased plasma p-Mentha-1,8-dien-7-ol in rats. Administration of exogenous p-Mentha-1,8-dien-7-ol significantly alleviated chemotherapy-induced long-term potentiation impairment, synapse injury, oxidative stress and glial activation in the hippocampus of rats.

CONCLUSION

Our data indicated that probiotics supplement prevents the occurrence of CRCI in patients with breast cancer via modulating plasma metabolites, including p-Mentha-1,8-dien-7-ol.

TRIAL REGISTRATION

Chinese Clinical Trial Registry (ChiCTR-INQ-17014181) [http://www.chictr.org.cn/showproj.aspx?proj=24294].

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

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

Cognitive changes and brain connectomes, endocrine status, and risk genotypes in testicular cancer patients-A prospective controlled study

OBJECTIVE

Previous research has indicated cognitive decline (CD) among testicular cancer patients (TCPs), even in the absence of chemotherapy, but little is known about the underlying pathophysiology. The present study assessed changes in cognitive functions and structural brain connectomes in TCPs and explored the associations between cognitive changes and endocrine status and hypothesized risk genotypes.

METHODS

Thirty-eight newly orchiectomized TCPs and 21 healthy controls (HCs) comparable to TCPs in terms of age and years of education underwent neuropsychological testing, structural MRI, and a biological assessment at baseline and 6 months later. Cognitive change was assessed with a neuropsychological test battery and determined using a standardized regression-based approach, with substantial change defined as z-scores ≤-1.64 or ≥1.64. MRI scans and graph theory were used to evaluate changes in structural brain connectomes. The associations of cognitive changes with testosterone levels, androgen receptor gene (AR) CAG repeat length, and genotypes (APOE, COMT, and BDNF) were explored.

RESULTS

Compared with HCs, TCPs showed higher rates of substantial decline on processing speed and visuospatial ability and higher rates of substantial improvement on verbal recall and visuospatial learning (p < 0.05; OR = 8.15-15.84). Brain network analysis indicated bilateral thalamic changes in node degree in HCs, but not in TCPs (p < 0.01). In TCPs, higher baseline testosterone levels predicted decline in verbal memory (p < 0.05). No effects were found for AR CAG repeat length, APOE, COMT, or BDNF.

CONCLUSIONS

The present study confirms previous findings of domain-specific CD in TCPs following orchiectomy, but also points to domain-specific improvements. The results do not indicate changes in brain connectomes or endocrine status to be the main drivers of CD. Further studies evaluating the mechanisms underlying CD in TCPs, including the possible role of the dynamics of the hypothalamic-pituitary-gonadal axis, are warranted.

Cognitive impairment and associations with structural brain networks, endocrine status, and risk genotypes in newly orchiectomized testicular cancer patients

A higher incidence of cognitive impairment (CI) has previously been reported among orchiectomized testicular cancer patients (TCPs), but little is known about the underlying pathophysiology. The present study assessed CI in newly orchiectomized TCPs and explored the structural brain networks, endocrine status, and selected genotypes. Forty TCPs and 22 healthy controls (HCs) underwent neuropsychological testing and magnetic resonance imaging, and provided a blood sample. CI was defined as a z-score ≤ -2 on one neuropsychological test or ≤ -1.5 on two neuropsychological tests, and structural brain networks were investigated using graph theory. Associations of cognitive performance with brain networks, endocrine status (including testosterone levels and androgen receptor CAG repeat length), and genotypes (APOE, BDNF, COMT) were explored. Compared with HCs, TCPs performed poorer on 6 out of 15 neuropsychological tests, of which three tests remained statistically significant when adjusted for relevant between-group differences (p < 0.05). TCPs also demonstrated more CI than HCs (65% vs. 36%; p = 0.04). While global brain network analysis revealed no between-group differences, regional analysis indicated differences in node degree and betweenness centrality in several regions (p < 0.05), which was inconsistently associated with cognitive performance. In TCPs, CAG repeat length was positively correlated with delayed memory performance (r = 0.36; p = 0.02). A COMT group × genotype interaction effect was found for overall cognitive performance in TCPs, with risk carriers performing worse (p = 0.01). No effects were found for APOE, BDNF, or testosterone levels. In conclusion, our results support previous findings of a high incidence of CI in newly orchiectomized TCPs and provide novel insights into possible mechanisms.

An Overview on Chemotherapy-induced Cognitive Impairment and Potential Role of Antidepressants

BACKGROUND

Cognitive impairment is an adverse reaction of cancer chemotherapy and is likely to affect up to 75% of patients during the treatment and 35% of patients experience it for several months after the chemotherapy. Patients manifest symptoms like alteration in working ability, awareness, concentration, visual-verbal memory, attention, executive functions, processing speed, fatigue and behavioural dysfunctions. Post-chemotherapy, cancer survivors have a reduced quality of life due to the symptoms of chemobrain. Apart from this, there are clinical reports which also associate mood disorders, vascular complications, and seizures in some cases. Therefore, the quality of lifestyle of cancer patients/ survivors is severely affected and only worsens due to the absence of any efficacious treatments. With the increase in survivorship, it's vital to identify effective strategies, until then only symptomatic relief for chemobrain can be provided. The depressive symptoms were causally linked to the pathophysiological imbalance between the pro and antiinflammatory cytokines.

CONCLUSION

The common causative factor, cytokines can be targeted for the amelioration of an associated symptom of both depression and chemotherapy. Thus, antidepressants can have a beneficial effect on chemotherapy-induced inflammation and cognitive dysfunction via cytokine balance. Also, neurogenesis property of certain antidepressant drugs rationalises their evaluation against CICI. This review briefly glances upon chemotherapy-induced cognitive impairment (CICI), and the modulatory effect of antidepressants on CICI pathomechanisms.

Androgen deprivation therapy and cognitive decline-associations with brain connectomes, endocrine status, and risk genotypes

BACKGROUND

Evidence suggests that prostate cancer (PC) patients undergoing androgen deprivation therapy (ADT) are at risk for cognitive decline (CD), but the underlying mechanisms are less clear. In the present study, changes in cognitive performance and structural brain connectomes in PC patients undergoing ADT were assessed, and associations of cognitive changes with endocrine status and risk genotypes were explored.

METHODS

Thirty-seven PC patients underwent cognitive assessment, structural MRI, and provided blood samples prior to ADT and after 6 months of treatment. Twenty-seven age- and education-matched healthy controls (HCs) underwent the same assessments. CD was determined using a standardized regression-based approach and defined as z-scores ≤ -1.64. Changes in brain connectomes were evaluated using graph theory. Associations of CD with testosterone levels and genotypes (APOE, COMT, BDNF) were explored.

RESULTS

Compared with HCs, PC patients demonstrated reduced testosterone levels (p < 0.01) and higher rates of decline for 13 out of 15 cognitive outcomes, with three outcomes related to two cognitive domains, i.e., verbal memory and visuospatial learning and memory, reaching statistical significance (p ≤ 0.01-0.04). Testosterone level changes did not predict CD. COMT Met homozygote PC patients evidenced larger reductions in visuospatial memory compared with Val carriers (p = 0.02). No between-group differences were observed in brain connectomes across time, and no effects were found of APOE and BDNF.

CONCLUSIONS

Our results indicate that PC patients undergoing ADT may evidence CD, and that COMT Met homozygotes may be at increased risk of CD. The results did not reveal changes in brain connectomes or testosterone levels as underlying mechanisms. More research evaluating the role of ADT-related disruption of the dynamics of the hypothalamic-pituitary-gonadal axis is needed.

The association of genetic polymorphisms with neuroconnectivity in breast cancer patients

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

Cancer-related cognitive impairment in patients with non-central nervous system malignancies: an overview for oncology providers from the MASCC Neurological Complications Study Group

Cancer-related cognitive impairment (CRCI) is commonly experienced by individuals with non-central nervous system cancers throughout the disease and treatment trajectory. CRCI can have a substantial impact on the functional ability and quality of life of patients and their families. To mitigate the impact, oncology providers must know how to identify, assess, and educate patients and caregivers. The objective of this review is to provide oncology clinicians with an overview of CRCI in the context of adults with non-central nervous system cancers, with a particular focus on current approaches in its identification, assessment, and management.

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.

Chemotherapy-induced cognitive impairment from the forensic medicine perspective: A review of the updated literature

Chemotherapy treatments in some neoplastic patients can cause unwanted side-effects that can be accompanied by a physical weakening due to changes in executive functioning, processing speed and reaction times with a consequent inability to carry out daily life activities (ADL) or a working disability due to the loss of working memory and the inability to organize fundamental skills, influencing the quality of everyday life. Although chemotherapy-induced cognitive impairment (CICI), also known as post-chemotherapy cognitive impairment (PCCI), chemo-brain or chemo-fog, has been described in the literature since the late 1980s, the neurobiological factors behind this pathology to date are not yet fully understood. According to the finding of most studies conducted on patients affected by different forms of neoplastic diseases, there are strong enough evidence of a prominent role of some drug such as doxorubicin, cyclophosphamide, cytarabine, methotrexate, 5-fluorouracil and cisplatin in causing chemo-fog related neurological impairment. The physical incapacity that affects the patients seems, therefore, to be related to the cytotoxic effects that the chemotherapy drugs exert on the central nervous system, causing a short or long-term neurological decline. Cognitive dysfunctions could influence individual self-determination by configuring a state of transient or habitual mental infirmity capable of altering the preservation of the person's voluntary faculties, with potential consequences on the legal validity of any deeds signed by the person. The growing interest in this pathological condition by the forensic medicine community is due precisely to the non-negligible medico-legal implications that derive from it affecting aspects of private law. In this article, a review of the literature on chemotherapy-induced cognitive impairment and related issues that may arise in forensic medicine and private law was conducted.

Subjective and objective cognitive functioning among patients with breast cancer: effects of chemotherapy and mood symptoms

BACKGROUND

Previous findings regarding declines in cognitive functioning among patients with breast cancer (BC) before and after chemotherapy have been inconsistent. The present study explored the effect of BC and cancer-related chemotherapies on cognitive functioning.

METHODS

A cross-sectional design was adopted to compare BC patients before their chemotherapy treatment, BC patients 3 ~ 9 months after the completion of chemotherapy, and noncancer controls. Evaluations of cognitive functioning included subjective and objective dimensions, with focus on memory, executive functioning, attention, and language. ANCOVA and Pearson's correlation analysis were used to examine the relationship among cancer, chemotherapy, cognitive performance, and psychological distress.

RESULTS

After adjustment for intelligence quotient, anxiety, and depression, we found significant differences in the Semantic Association of Verbal Fluency between post-chemotherapy (C/T) patients and noncancer controls. Specifically, post-C/T patients scored lower than controls (p = 0.03, η² = 0.07). No significant differences were found in other objective cognitive measures. However, both subjective and objective cognitive scores were significantly associated with depression, anxiety, and fatigue. In BC patients, levels of anxiety were positively correlated with measures of executive function. Among pre-C/T patients, self-perceived interference by fatigue was positively associated with better performances in some of the objective cognitive measures.

CONCLUSION

Our findings suggest cognitive impairments in the domain of executive functioning among patients with BC who received chemotherapy. Providing relevant suggestions or strategies of managements for these negative consequences may help increase the long-term quality of life of patients with BC.

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.

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.

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.

Clinical and Genetic Risk Prediction of Cognitive Impairment After Blood or Marrow Transplantation for Hematologic Malignancy

PURPOSE

Using a candidate gene approach, we tested the hypothesis that individual single nucleotide polymorphisms (SNPs) and gene-level variants are associated with cognitive impairment in patients with hematologic malignancies treated with blood or marrow transplantation (BMT) and that inclusion of these SNPs improves risk prediction beyond that offered by clinical and demographic characteristics.

PATIENTS AND METHODS

In the discovery cohort, BMT recipients underwent a standardized battery of neuropsychological tests pre-BMT and at 6 months, 1 year, 2 years, and 3 years post-BMT. Associations between 68 candidate genes and cognitive impairment were assessed using generalized estimating equation models. Elastic-Net regression was used to build Base (sociodemographic), Clinical, and Combined (Base plus Clinical plus genetic) risk prediction models of post-BMT impairment. An independent nonoverlapping cohort from the BMT Survivor Study with self-report of learning/memory problems (as identified by their health care provider) was used for model replication.

RESULTS

The discovery cohort included 277 participants (58.5% males; 68.6% non-Hispanic whites; and 46.6% allogeneic BMT recipients). Adjusting for BMT type, age at BMT, sex, race/ethnicity, and cognitive reserve, SNPs in the blood-brain barrier, telomere homeostasis, and DNA repair genes were significantly associated with cognitive impairment. Compared with the Clinical Model, the Combined Model had higher predictive power in both the discovery cohort (mean area under the receiver operating characteristic curve [AUC], 0.89; 95% CI, 0.85 to 0.93 v 0.77; 95% CI, 0.71 to 0.83; P = 1.24 × 10^-9) and the replication cohort (AUC, 0.71; 95% CI, 0.66 to 0.76 v 0.63; 95% CI, 0.57 to 0.68; P = .004).

CONCLUSION

Inclusion of candidate genetic variants enhanced the prediction of risk of post-BMT cognitive impairment beyond that offered by demographic/clinical characteristics and represents a step toward a personalized approach to managing patients at high risk for cognitive impairment after BMT.

[Management of side effects related to adjuvant hormone therapy in young women with breast cancer]

Despite proven survival benefits after breast cancer, long-trem compliance with adjuvant hormone therapy remains a major issue, partly due to the side effects of treatment. In young women treated for breast cancer, these treatments include tamoxifen, anti-aromatase and LH-RH analogues, with even more side effects when these treatments are combined, especially for younger patients with more aggressive disease. The management of the potential side effects requires first of all detailed and precise information at initiation of treatment, and preventive measures including patient education. Once the treatment has been initiated, clinicians should be able to propose to their patients appropriate measures to alleviate the potential of the side effects, which can be of various types: biological (dyslipidemia), physical (weight gain, hot flushes, vaginal dryness, sexual disorders with low libido, musculoskeletal symptoms…) or psychosocial (anxio-depressive disorders, poor body image, difficulties of professional reintegration). Management of these effects can combine various modalities: drugs (switching hormone therapy, anti-depressants, hormonal treatments of vaginal dryness in some cases, gabapentin), physical treatments (CO2 laser for vulvovaginal atrophy) or psycho-physical techniques (physical activity, mindfulness, acupuncture…). Eventually, the lenghth of these adjuvant hormonal treatments requires supportive measures to help young patients engage in new lifestyle measures, in particular in term of physical activity and diet. This will help them mitigate the symptoms related to these side-effects while reducing the long-term risks related to their disease and treatments.

Sleep disturbance and neurocognitive outcomes in older patients with breast cancer: Interaction with genotype

BACKGROUND

Sleep disturbance and genetic profile are risks for cognitive decline in noncancer populations, yet their role in cancer-related cognitive problems remains understudied. This study examined whether sleep disturbance was associated with worse neurocognitive outcomes in breast cancer survivors and whether sleep effects on cognition varied by genotype.

METHODS

Newly diagnosed female patients (n = 319) who were 60 years old or older and had stage 0 to III breast cancer were recruited from August 2010 to December 2015. Assessments were performed before systemic therapy and 12 and 24 months later. Neuropsychological testing measured attention, processing speed, executive function, learning, and memory; self-perceived cognitive functioning was also assessed. Sleep disturbance was defined by self-report of routine poor or restless sleep. Genotyping included APOE, BDNF, and COMT polymorphisms. Random effects fluctuation models tested associations of between-person and within-person differences in sleep, genotype, and sleep-genotype interactions and cognition and controlled for age, reading level, race, site, and treatment.

RESULTS

One-third of the patients reported sleep disturbances at each time point. There was a sleep-APOE ε4 interaction (P = .001) in which patients with the APOE ε4 allele and sleep disturbances had significantly lower learning and memory scores than those who were APOE ε4-negative and without sleep disturbances. There was also a sleep disturbance-COMT genotype interaction (P = .02) in which COMT Val carriers with sleep disturbances had lower perceived cognition than noncarriers.

CONCLUSIONS

Sleep disturbance was common and was associated with worse cognitive performance in older breast cancer survivors, especially those with a genetic risk for cognitive decline. Survivorship care should include sleep assessments and interventions to address sleep problems.

BDNF, COMT, and DRD2 polymorphisms and ability to return to work in adult patients with low- and high-grade glioma

BACKGROUND

Cognitive and language dysfunction is common among patients with glioma and has a significant impact on survival and health-related quality of life (HRQOL). Little is known about the factors that make individual patients more or less susceptible to the cognitive sequelae of the disease. A better understanding of the individual and population characteristics related to cognitive function in glioma patients is required to appropriately stratify patients, prognosticate, and develop more efficacious treatment regimens. There is evidence that allelic variation among genes involved in neurotransmission and synaptic plasticity are related to neurocognitive performance in states of health and neurologic disease.

METHODS

We studied the association of single-nucleotide polymorphism variations in brain-derived neurotrophic factor (BDNF, rs6265), dopamine receptor 2 (DRD2, rs1076560), and catechol-O-methyltransferase (COMT, rs4680) with neurocognitive function and ability to return to work in glioma patients at diagnosis and at 3 months. We developed a functional score based on the number of high-performance alleles that correlates with the capacity for patients to return to work.

RESULTS

Patients with higher-performing alleles have better scores on neurocognitive testing with the Repeatable Battery for the Assessment of Neuropsychological Status and Stroop test, but not the Trail Making Test.

CONCLUSIONS

A better understanding of the genetic contributors to neurocognitive performance in glioma patients and capacity for functional recovery is necessary to develop improved treatment strategies based on patient-specific factors.

Cognitive performance of breast cancer survivors in daily life: Role of fatigue and depressed mood

OBJECTIVE

Cancer and its treatment are associated with long-term cognitive deficits. However, most studies of cancer patients have used traditional, office-based cognitive evaluations instead of assessing patients in their daily lives. Recent research in cognitive aging suggests that variability in performance may be a sensitive indicator of cognitive decline. Using ecological momentary assessment (EMA), we examined cognitive variability among breast cancer survivors and evaluated whether ratings of fatigue and depressed mood were associated with cognition.

METHODS

Participants were 47 women (M age = 53.3 years) who completed treatment for early stage breast cancer 6 to 36 months previously. Smartphones were preloaded with cognitive tests measuring processing speed, executive functioning, and memory, as well as rating scales for fatigue and depressed mood. Participants were prompted five times per day over a 14-day period to complete EMA cognitive tasks and fatigue and depressed mood ratings.

RESULTS

Cognitive variability was observed across all three EMA cognitive tasks. Processing speed responses were slower at times that women rated themselves as more fatigued than their average (P < .001). Ratings of depressed mood were not associated with cognition.

CONCLUSIONS

This study is the first to report cognitive variability in the daily lives of women treated for breast cancer. Performance was worse on a measure of processing speed at times when a woman rated her fatigue as greater than her own average. The ability to identify moments when cognition is most vulnerable may allow for personalized interventions to be applied at times when they are most needed.

Neurocognitive Function in Adult Cancer Patients

Impaired neurocognitive function is an increasingly recognized morbidity in patients who have cancer. Cancer treatments, psychosocial stressors, and the malignancy itself can alter brain function. The mechanisms by which this occurs are under active investigation. Although there is a growing appreciation of its prevalence and causes, there remain limited therapeutic options for the treatment of neurocognitive dysfunction in this population. A persistent scientific and clinical effort to understand its mechanisms and impact is critical to the care of oncology patients.

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.

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.

Chemotherapy and cognition: comprehensive review on doxorubicin-induced chemobrain

Chemobrain refers to a common sequela experienced by a substantial subset of cancer patients exposed to chemotherapeutic treatment, a phenomenon that dramatically deteriorates the survivors' quality of life and prevents them from restoring their pre-cancer life. This review is intended to address the current knowledge regarding the mechanisms underlying the pathophysiology of the chemobrain phenomenon, with special focus on the antineoplastic agent ''doxorubicin'', which has been shown to be implicated in strenuous central neurotoxicity despite being-almost entirely-peripherally confined. Moreover, the assessment of the post-chemotherapy cognitive impairment in both human and animal subjects, and the potential pharmacotherapy and behavioral intervention strategies are reviewed.

Relationship of fatigue with cognitive performance in women with early-stage breast cancer over 2 years

OBJECTIVE

Fatigue and cognitive dysfunction are major concerns for women with early-stage breast cancer during treatment and into survivorship. However, interrelationships of these phenomena and their temporal patterns over time are not well documented, thus limiting the strategies for symptom management interventions. In this study, changes in fatigue across treatment phases and the relationship among fatigue severity and its functional impact with objective cognitive performance were examined.

METHODS

Participants (N = 75) were assessed at five time points beginning prior to chemotherapy to 24 months after initial chemotherapy. Fatigue severity and impact were measured on the Brief Fatigue Inventory. Central nervous system (CNS) Vital Signs was used to measure performance based cognitive testing. Temporal changes in fatigue were examined, as well as the relationship between fatigue and cognitive performance, at each time point using linear mixed effect models.

RESULTS

Severity of fatigue varied as a function of phase of treatment. Fatigue severity and its functional impact were moderate at baseline, increased significantly during chemotherapy, and returned to near baseline levels by 2 years. At each time point, fatigue severity and impact were significantly associated with diminished processing speed and complex attention performance.

CONCLUSIONS

A strong association between fatigue and objective cognitive performance suggests that they are likely functionally related. That cognitive deficits were evident at baseline, whereas fatigue was more chemotherapy dependent, implicates that two symptoms share some common bases but may differ in underlying mechanisms and severity over time. This knowledge provides a basis for introducing strategies for tailored symptom management that vary over time.

International Cognition and Cancer Task Force Recommendations for Neuroimaging Methods in the Study of Cognitive Impairment in Non-CNS Cancer Patients

Cancer- and treatment-related cognitive changes have been a focus of increasing research since the early 1980s, with meta-analyses demonstrating poorer performance in cancer patients in cognitive domains including executive functions, processing speed, and memory. To facilitate collaborative efforts, in 2011 the International Cognition and Cancer Task Force (ICCTF) published consensus recommendations for core neuropsychological tests for studies of cancer populations. Over the past decade, studies have used neuroimaging techniques, including structural and functional magnetic resonance imaging (fMRI) and positron emission tomography, to examine the underlying brain basis for cancer- and treatment-related cognitive declines. As yet, however, there have been no consensus recommendations to guide researchers new to this field or to promote the ability to combine data sets. We first discuss important methodological issues with regard to neuroimaging study design, scanner considerations, and sequence selection, focusing on concerns relevant to cancer populations. We propose a minimum recommended set of sequences, including a high-resolution T1-weighted volume and a resting state fMRI scan. Additional advanced imaging sequences are discussed for consideration when feasible, including task-based fMRI and diffusion tensor imaging. Important image data processing and analytic considerations are also reviewed. These recommendations are offered to facilitate increased use of neuroimaging in studies of cancer- and treatment-related cognitive dysfunction. They are not intended to discourage investigator-initiated efforts to develop cutting-edge techniques, which will be helpful in advancing the state of the knowledge. Use of common imaging protocols will facilitate multicenter and data-pooling initiatives, which are needed to address critical mechanistic research questions.

Brain metastases and treatment: multiplying cognitive toxicities

INTRODUCTION

Thirty per cent of cancer patients develop brain metastases, with multiple combination or sequential treatment modalities available, to treat systemic or central nervous system (CNS) disease. Most patients experience toxicities as a result of these treatments, of which cognitive impairment is one of the adverse events most commonly reported, causing major impairment of the patient's quality of life. Areas covered: This article reviews the role of cancer treatments in cognitive decline of patients with brain metastases: surgery, radiotherapy, chemotherapy, targeted therapies, immunotherapies and hormone therapy. Pathological and molecular mechanisms, as well as future directions for limiting cognitive toxicities are also presented. Other causes of cognitive impairment in this population are discussed in order to refine the benefit-risk balance of each treatment modality. Expert opinion: Cumulative cognitive toxicity should be taken into account, and tailored to the patient's cognitive risk in the light of the expected survival benefit. Standardization of cognitive assessment in this context is needed in order to better appreciate each treatment's responsibility in cognitive impairment, keeping in mind disease itself impacts cognition in this context.