Meta-analysis of cognitive functioning in breast cancer survivors previously treated with standard-dose chemotherapy

Cognitive impairment in older patients with breast cancer before systemic therapy: is there an interaction between cancer and comorbidity?

PURPOSE

To determine if older patients with breast cancer have cognitive impairment before systemic therapy.

PATIENTS AND METHODS

Participants were patients with newly diagnosed nonmetastatic breast cancer and matched friend or community controls age > 60 years without prior systemic treatment, dementia, or neurologic disease. Participants completed surveys and a 55-minute battery of 17 neuropsychological tests. Biospecimens were obtained for APOE genotyping, and clinical data were abstracted. Neuropsychological test scores were standardized using control means and standard deviations (SDs) and grouped into five domain z scores. Cognitive impairment was defined as any domain z score two SDs below or ≥ two z scores 1.5 SDs below the control mean. Multivariable analyses evaluated pretreatment differences considering age, race, education, and site; comparisons between patient cases also controlled for surgery.

RESULTS

The 164 patient cases and 182 controls had similar neuropsychological domain scores. However, among patient cases, those with stage II to III cancers had lower executive function compared with those with stage 0 to I disease, after adjustment (P = .05). The odds of impairment were significantly higher among older, nonwhite, less educated women and those with greater comorbidity, after adjustment. Patient case or control status, anxiety, depression, fatigue, and surgery were not associated with impairment. However, there was an interaction between comorbidity and patient case or control status; comorbidity was strongly associated with impairment among patient cases (adjusted odds ratio, 8.77; 95% CI, 2.06 to 37.4; P = .003) but not among controls (P = .97). Only diabetes and cardiovascular disease were associated with impairment among patient cases.

CONCLUSION

There were no overall differences between patients with breast cancer and controls before systemic treatment, but there may be pretreatment cognitive impairment within subgroups of patient cases with greater tumor or comorbidity burden.

Memory and cancer: a review of the literature

The mental health of cancer survivors has not always been the primary emphasis of treatment protocols since physical health outcomes have taken precedence. Older cancer survivors experience a double jeopardy since they are at risk for memory impairments and mild cognitive impairment and because they are greater than 55 years of age. Of the 9.6 million cancer survivors in the US who have completed active treatment, many report cognitive difficulties, with labels such as "chemo brain," "not as sharp," "woolly-headedness," or the "mind does not work as quickly". To date, most of our knowledge of cognitive impairment in cancer survivors comes from female breast cancer survivors. Studies indicate that these survivors have diminished executive function, verbal memory, and motor function. Cancer survivors want to live independently in the community for as long as possible however, these cognitive deficits may prevent this desired lifestyle. To broaden our understanding this paper reviews the literature on the cognitive impairment and memory deficits experienced by three groups of cancer survivors breast, colorectal, and prostate cancer, that make up 60% of all survivors nationally. Even though mental health declined after a cancer diagnosis, the long-term outcomes of cancer survivors did not differ from persons without cancer in depression or cognitive function.

Longitudinal assessment of chemotherapy-induced alterations in brain activation during multitasking and its relation with cognitive complaints

PURPOSE

To examine whether cognitive complaints after treatment for breast cancer are associated with detectable changes in brain activity during multitasking.

PATIENTS AND METHODS

Eighteen patients who were scheduled to receive chemotherapy performed a functional magnetic resonance imaging multitasking task in the scanner before the start of treatment (t1) and 4 to 6 months after finishing treatment (t2). Sixteen patients who were not scheduled to receive chemotherapy and 17 matched healthy controls performed the same task at matched intervals. Task difficulty level was adjusted individually to match performance across participants. Statistical Parametric Mapping 8 (SPM8) software was used for within-group, between-group, and group-by-time interaction image analyses.

RESULTS

Voxel-based paired t tests revealed significantly decreased activation (P < .05) from t1 to t2 at matched performance in the multitasking network of chemotherapy-treated patients, whereas no changes were noted in either of the control groups. At baseline, there were no differences between the groups. Furthermore, in contrast to controls, the chemotherapy-treated patients reported a significant increase in cognitive complaints (P < .05) at t2. Significant (P < .05) correlations were found between these increases and decreases in multitasking-related brain activation. Moreover, a significant group-by-time interaction (P < .05) was found whereby chemotherapy-treated patients showed decreased activation and healthy controls did not.

CONCLUSION

These results suggest that changes in brain activity may underlie chemotherapy-induced cognitive complaints. The observed changes might be related to chemotherapy-induced damage to the brain or reduced connectivity between brain regions rather than to changes in effort or changes in functional strategy. To the best of our knowledge, this is the first longitudinal study providing evidence for a relationship between longitudinal changes in cognitive complaints and changes in brain activation after chemotherapy.

Cognitive functioning in men receiving androgen deprivation therapy for prostate cancer: a systematic review and meta-analysis

PURPOSE

Prior research examining the impact of androgen deprivation therapy (ADT) for prostate cancer on cognitive performance has found inconsistent relationships. The purpose of this study was to systematically review the existing literature and determine the effect of ADT on performance across seven cognitive domains using meta-analysis.

METHODS

A search of PubMed Medline, PsycINFO, Cochrane Library, and Web of Knowledge/Science databases yielded 157 unique abstracts reviewed by independent pairs of raters. Fourteen studies with a total of 417 patients treated with ADT were included in the meta-analysis. Objective neuropsychological tests were categorized into seven cognitive domains: attention/working memory, executive functioning, language, verbal memory, visual memory, visuomotor ability, and visuospatial ability.

RESULTS

Separate effect sizes were calculated for each cognitive domain using pairwise comparisons of patients who received ADT with (1) prostate cancer patient controls, (2) noncancer controls, or (3) ADT patients' own pre-ADT baselines. Patients treated with ADT performed worse than controls or their own baseline on visuomotor tasks (g = -0.67, p = .008; n = 193). The magnitude of the deficits was larger in studies with a shorter time to follow-up (p = .04). No significant effect sizes were observed for the other six cognitive domains (p = .08-.98).

CONCLUSIONS

Prostate cancer patients who received ADT performed significantly worse on visuomotor tasks compared to noncancer control groups. These findings are consistent with the known effects of testosterone on cognitive functioning in healthy men. Knowledge of the cognitive effects of ADT may help patients and providers better understand the impact of ADT on quality of life.

Improving quality of life in female cancer survivors: current status and future questions

ABSTRACT: 

Almost 14 million people in the USA alone have been diagnosed with cancer. Given the improvements in diagnosis and treatment, over 60% of patients are expected to survive 5 years or more from the point of diagnosis. Treatments for cancer may result in long-term issues including those that impact the physical, emotional, spiritual or social domains. However, how best to care for issues in survivors remains unclear. Although much attention has been focused on survivorship care plans and survivorship clinics, there are limited data to show they improve outcomes. This article reviews the issues in female cancer survivors that can occur following diagnosis and treatment and suggest strategies that may assist in management. Finally, we review the current views regarding the care of cancer survivors and suggest important issues that must be addressed so that we can reach our goal of improvement in the quality of life of this emerging population.

Longitudinal assessment of cognitive changes associated with adjuvant treatment for breast cancer: the impact of APOE and smoking

PURPOSE

This study examined the association of post-treatment changes in cognitive performance, apolipoprotein E (APOE), and smoking in breast cancer patients treated with adjuvant therapy.

PARTICIPANTS AND METHODS

Breast cancer patients treated with chemotherapy (N = 55, age = 51.9 ± 7.1, education = 15.7 ± 2.6) were evaluated with a battery of neuropsychological tests prior to chemotherapy and at 1, 6, and 18 months post-chemotherapy. Matched groups of breast cancer patients not exposed to chemotherapy (N = 68, age = 56.8 ± 8.3, education = 14.8 ± 2.2) and healthy controls (N = 43, age = 53.0 ± 10.1, education = 15.2 ± 2.6) were evaluated at similar intervals. APOE epsilon 4 carrier status (APOE4+) and smoking history were also evaluated.

RESULTS

The detrimental effect of APOE4+ genotype on post-treatment cognitive functioning was moderated by smoking history, that is, patients without a smoking history had significantly lower performance on measures of processing speed and working memory compared with those with a smoking history and healthy controls. Exploratory analyses revealed that APOE4+ patients without a smoking history who were exposed to chemotherapy showed a decline in performance in processing speed, compared with patients with a smoking history. A similar but less pronounced pattern was seen in the no chemotherapy group (primarily endocrine treatment). For working memory, the APOE4+ by smoking interaction was observed in the no chemotherapy group only.

CONCLUSIONS

The association between APOE status, breast cancer treatment, and cognitive functioning was moderated by smoking history suggesting that both chemotherapy and endocrine therapy interact with APOE status and smoking to influence cognition. A putative mechanism is that smoking corrects a deficit in nicotinic receptor functioning and dopamine levels in APOE4+ individuals.

Selective impairment of attention networks in breast cancer patients receiving chemotherapy treatment

INTRODUCTION

Complaints about attention disorders are common among breast cancer survivors who have undergone chemotherapy treatment. However, it is not known whether these complaints indicate a global attention deficit or the selective impairment of attention networks.

OBJECTIVE

This study sought to investigate the attentional abilities of breast cancer patients after chemotherapy treatment using the attention network test (ANT).

METHODS

The participants included breast cancer patients who had undergone chemotherapy (CT, N = 58), patients who had not undergone chemotherapy (non-CT, N = 53), and matched healthy controls (HC, N = 55). All participants completed the ANT, which provides measures of three independent attention networks (alerting, orienting, and executive control) and neuropsychological background tests.

RESULTS

Our results indicated that the chemotherapy-treated breast cancer patients had significant deficits in the alerting and executive control networks but not in the orienting network. The CT group scored significantly lower in several cognitive tasks, including attention, memory, and information processing tasks, relative to the other two groups. Additionally, significant correlations were found between information processing and the efficiency of the executive control network within the CT group.

CONCLUSIONS

These results suggest that the three attention networks were selectively impaired following chemotherapy treatment, which affected different brain areas in the breast cancer survivors.

Cognitive problems among breast cancer survivors: loneliness enhances risk

BACKGROUND

Cancer survivors often experience cognitive difficulties after treatment completion. Although chemotherapy enhances risk for cognitive problems, it is likely only one piece of a complex puzzle that explains survivors' cognitive functioning. Loneliness may be one psychosocial risk factor. The current studies included both subjective and objective cognitive measures and tested whether lonelier breast cancer survivors would have more concentration and memory complaints and experience more concentration difficulties than their less lonely counterparts.

METHODS

The relationship between loneliness and cognitive function was tested among three samples of breast cancer survivors. Study 1 was a sample of breast cancer survivors (n = 200) who reported their concentration and memory problems. Study 2a was a sample of breast cancer survivors (n = 185) and noncancer controls (n = 93) who reported their concentration and memory problems. Study 2b was a subsample of Study 2a breast cancer survivors (n = 22) and noncancer controls (n = 21) who completed a standardized neuropsychological test assessing concentration.

RESULTS

Studies 1 and 2a revealed that lonelier women reported more concentration and memory problems than less lonely women. Study 2b utilized a standardized neuropsychological continuous performance test and demonstrated that lonelier women experienced more concentration problems than their less lonely counterparts.

CONCLUSIONS

These studies demonstrated that loneliness is linked to concentration and memory complaints and the experience of concentration problems among breast cancer survivors. The results were also highly consistent across three samples of breast cancer survivors. These data suggest that loneliness may be a risk factor for cognitive difficulties among cancer survivors.

Self-reported cognitive concerns and abilities: two sides of one coin?

OBJECTIVE

Patient-reported cognitive function can be measured using negatively worded items (concerns) and positively worded (abilities) items. It is possible that reporting abilities is less subject to the influence of emotional states. This study evaluated the relationship between cognitive concerns and cognitive abilities.

METHODS

Cancer patients (N = 509; mean age = 61 years; 50% men; 86% White) completed concerns and abilities items developed by the National Institutes of Health Patient-Reported Outcomes Information System (PROMIS). Confirmatory factor analysis was used to evaluate the extent to which items were loaded on one single factor (unidimensionality). Multidimensionality was evaluated using bi-factor analysis (local factors: concerns and abilities). Slope parameters from multidimensional item response theory (IRT) and unidimensional IRT were compared to evaluate which factor solution fits best.

RESULTS

Acceptable fit indices were found in both one-factor confirmatory factor analysis (comparative fit index (CFI) = 0.96; root mean squared error of approximation (RMSEA) = 0.062) and bi-factor analysis (CFI = 0.98; RMSEA = 0.043). Thus, abilities and concerns could be considered as a single dimension. Yet, high loadings on the local factor in bi-factor analysis and slope discrepancies between unidimensional IRT and multidimensional IRT indicate that abilities should be considered as a separate factor from concerns.

CONCLUSIONS

Concerns and abilities could be measured using one-unidimensional item bank. Results also support measuring each construct separately. We recommend a conservative approach by measuring and reporting concerns and abilities separately. We therefore recommend two separate but co-calibrated item banks in the PROMIS network: cognitive function item bank-concerns and cognitive function item bank-abilities. Both item banks showed good psychometric properties and are available for research and clinical purposes.

Intra-individual variability in women with breast cancer

Studies assessing cognitive functioning in women treated for breast cancer have used primarily standardized neuropsychological tests and examined accuracy and/or reaction time as outcome measures: they have been inconsistent in identifying the cognitive domains affected and the severity of deficits. In other contexts of neural development and disorders, measures of Intra-individual variability (IIV) have proven useful in identifying subtleties in performance deficits that are not captured by measures of central tendency. This article presents proof of concept that assessing IIV may also increase understanding of the cognitive effects of cancer treatment. We analyzed mean accuracy and reaction time, as well as IIV from 65 women with breast cancer and 28 age and education matched controls who performed the Conner's Continuous Performance Test, a "Go-NoGo" task. Although there were no significant differences between groups using measures of central tendency, there was a group × inter-stimulus interval (ISI) interaction for IIV Dispersion (p < .001). Patient Dispersion was more variable at shorter ISI than controls and less variable at long ISI, suggesting greater sensitivity to presentation speed. Interpretation of IIV differences requires further investigation. Our results suggest that future studies would benefit from designs that allow analysis of IIV measures in studies assessing cognition in cancer survivors.

Longitudinal study of cognitive dysfunctions induced by adjuvant chemotherapy in colon cancer patients

BACKGROUND

Chemotherapy can induce cognitive impairment in cancer patients. The main goal of this longitudinal study was to determine the incidence, characteristics, and duration of cognitive dysfunction in patients treated with adjuvant chemotherapy for colon cancer.

PATIENTS AND METHODS

We assessed cognitive function, quality of life, anxiety and depression, fatigue, and hemoglobin levels in colon cancer patients at three assessment points: pre-chemotherapy (n=81), post-chemotherapy (n=73), and after 6-month follow-up (n=54). All patients were treated with oxaliplatin plus 5-fluorouracil/leucovorin (FOLFOX4) for 6 months.

RESULTS

Thirty patients (37%) had cognitive impairment in the pre-chemotherapy evaluation, mainly in processing speed and psychomotor executive function (Trail Making Test A and B). At the end of treatment, the main domain affected was the verbal memory, with an acute decline detected in 56% of patients. Fifty-four percent of the patients improved their dysfunction after 6 months of follow-up, whereas 18 (33%) of them showed worsening in at least one test. Cognitive impairment was most common in older patients and in those with less years of education. Quality of life, anxiety, depression, fatigue, and hemoglobin did not influence the results of the cognitive tests.

CONCLUSIONS

Adjuvant FOLFOX4 in patients with colon cancer can have a negative effect on verbal memory. This deterioration is usually mild and transient.

Effect of the addition of chemotherapy to radiotherapy on cognitive function in patients with low-grade glioma: secondary analysis of RTOG 98-02

PURPOSE

The addition of PCV (procarbazine, lomustine, and vincristine) chemotherapy to radiotherapy (RT) for patients with WHO grade 2 glioma improves progression-free survival (PFS). The effect of therapy intensification on cognitive function (CF) remains a concern in this population with substantial long-term survival.

PATIENTS AND METHODS

A total of 251 patients with WHO grade 2 glioma age ≥ 40 years with any extent of resection or age < 40 years with subtotal resection/biopsy were randomly assigned to RT (54 Gy) or RT plus PCV. We observed 111 patients age < 40 years with gross total resection. CF was assessed by Mini-Mental State Examination (MMSE) at baseline and years 1, 2, 3, and 5.

RESULTS

Overall, few patients experienced significant decline in MMSE score. There were no significant differences in the proportion of patients experiencing MMSE score decline between the randomized study arms at any time point. Both study arms experienced a significant gain in average MMSE score longitudinally over time, with no difference between arms.

CONCLUSION

The MMSE is a relatively insensitive tool, and subtle changes in CF may have been missed. However, the addition of PCV to RT did not result in significantly higher rates of MMSE score decline than RT alone through 5 years of follow-up. Patients in both randomly assigned arms experienced a statistically significant average MMSE score increase over time, with no difference between arms. The addition of PCV chemotherapy to RT improves PFS without excessive CF detriment over RT alone for patients with low-grade glioma.

Clearing the air: a review of our current understanding of "chemo fog"

An increasing number of cancer survivors has led to a greater interest in the long-term side effects of cancer treatments and their impact on quality of life. In particular, cognitive impairments have been frequently reported by cancer survivors as an adverse effect which they attribute to the neurotoxicity of chemotherapy and have dubbed "chemobrain" or "chemo fog." Research within the past 15-20 years has explored the many factors thought to contribute to cancer-related cognitive decline in an attempt to determine a potential cause. In spite of many confounding factors, there is growing evidence that the neurotoxicity of chemotherapy does contribute to cognitive changes. This review examines the evolution of "chemo fog" research with a look at methodological issues, the status of our current understanding, and suggestions for future research.

Cytokines as mediators of chemotherapy-associated cognitive changes: current evidence, limitations and directions for future research

Objectives

While various clinical and pharmacological determinants for chemotherapy-associated cognitive impairment have been identified, conflicting evidence suggests that cytokines might play an intermediary role. The objective of this systematic review was to evaluate the current evidence pertaining to the associations among chemotherapy, cytokines induction and cognitive impairment in cancer patients.

Methods

A literature search with PubMed and SciVerse Scopus was conducted in March 2013 to gather relevant articles and abstracts that fulfilled the inclusion and exclusion criteria. This review included studies that had performed objective and/or subjective cognitive assessments and cytokine measurements on defined populations of cancer patients who received chemotherapy.

Results

High methodological heterogeneity existed among the selected studies which differed in cancer populations, subject characteristics, cognitive endpoints, types of cytokines tested and their measurement methods. Weak to moderate correlations were observed between IL-1β, IL-6, TNF-α levels, and different degrees of cognitive impairment. Different types of chemotherapy treatments might lead to varying presentations and severities of cytokine-induced cognitive impairment. Notably, the time concordance between the onset of cytokine induction and occurrence of cognitive impairment was not well elucidated. A number of confounding factors was identified to interfere with the expression levels of cytokines; these confounders included subjects' cancer types, ages, genders, genetics and psychosocial characteristics such as anxiety, depression and fatigue.

Conclusion

Although existing studies observed cognitive impairment and cytokine dysregulation in patients who receive chemotherapy, our results suggest that the intermediary role of cytokines in post-chemotherapy cognitive impairment is still controversial and requires further evaluation. A list of methodological recommendations is proposed to harmonize future studies of this subject matter.

Relationship between exercise behavior, cardiorespiratory fitness, and cognitive function in early breast cancer patients treated with doxorubicin-containing chemotherapy: a pilot study

The purpose of this study was to examine the relationship between self-reported exercise behavior, cardiorespiratory fitness (CRF), and cognitive function in early breast cancer patients. Thirty-seven breast cancer patients following completion of chemotherapy (median 16 months) and 14 controls were studied. Cognitive function was assessed using the Central Nervous System (CNS) Vital Signs software (CNS Vital Signs, LLC, Morrisville, N.C., USA), a computerized test battery consisting of 9 cognitive subtests. Exercise behavior was evaluated using the Godin Leisure Time Exercise Questionnaire, and CRF was assessed via a cardiopulmonary exercise test to assess peak oxygen consumption. Patients' mean total exercise was 184 ± 141 min·week(-1) compared with 442 ± 315 min·week(-1) in controls (p < 0.001). Significantly fewer patients (32%) were meeting exercise guidelines (i.e., ≥150 min of moderate-intensity or vigorous exercise per week) compared with 57% of controls (p = 0.014). Patients' peak oxygen consumption averaged 23.5 ± 6.3 mL·kg(-1)·min(-1) compared with 30.6 ± 7.0 mL·kg(-1)·min(-1) in controls (p < 0.01). Scores on the cognitive subdomains were generally lower in patients compared with controls, although only the difference in verbal memory was significant (unadjusted p = 0.041). In patients, weak to moderate correlations were indicated between exercise, peak oxygen consumption, and the majority of cognitive subdomain scores; however, there was a significant positive correlation between exercise and visual memory (r = 0.47, p = 0.004). In conclusion, breast cancer patients following the completion of primary adjuvant chemotherapy exhibit, in general, worse cognitive performance than healthy women from the general population, and such performance may be related to their level of exercise behavior.

Neuroimaging biomarkers and cognitive function in non-CNS cancer and its treatment: current status and recommendations for future research

Cognitive changes in patients undergoing treatment for non-central nervous system (CNS) cancers have been recognized for several decades, yet the underlying mechanisms are not well understood. Structural, functional and molecular neuroimaging has the potential to help clarify the neural bases of these cognitive abnormalities. Structural magnetic resonance imaging (MRI), functional MRI (fMRI), diffusion tensor imaging (DTI), MR spectroscopy (MRS), and positron emission tomography (PET) have all been employed in the study of cognitive effects of cancer treatment, with most studies focusing on breast cancer and changes thought to be induced by chemotherapy. Articles in this special issue of Brain Imaging and Behavior are devoted to neuroimaging studies of cognitive changes in patients with non-CNS cancer and include comprehensive critical reviews and novel research findings. The broad conclusions that can be drawn from past studies and the present body of new research is that there are structural and functional changes associated with cancer and various treatments, particularly systemic cytotoxic chemotherapy, although some cognitive and fMRI studies have identified changes at pre-treatment baseline. Recommendations to accelerate progress include well-powered multicenter neuroimaging studies, a better standardized definition of the cognitive phenotype and extension to other cancers. A systems biology framework incorporating multimodality neuroimaging, genetics and other biomarkers will be highly informative regarding individual differences in risk and protective factors and disease- and treatment-related mechanisms. Studies of interventions targeting cognitive changes are also needed. These next steps are expected to identify novel protective strategies and facilitate a more personalized medicine for cancer patients.

Cognitive effects of cancer and its treatments at the intersection of aging: what do we know; what do we need to know?

There is a fairly consistent, albeit non-universal body of research documenting cognitive declines after cancer and its treatments. While few of these studies have included subjects aged 65 years and older, it is logical to expect that older patients are at risk of cognitive decline. Here, we use breast cancer as an exemplar disease for inquiry into the intersection of aging and cognitive effects of cancer and its therapies. There are a striking number of common underlying potential biological risks and pathways for the development of cancer, cancer-related cognitive declines, and aging processes, including the development of a frail phenotype. Candidate shared pathways include changes in hormonal milieu, inflammation, oxidative stress, DNA damage and compromised DNA repair, genetic susceptibility, decreased brain blood flow or disruption of the blood-brain barrier, direct neurotoxicity, decreased telomere length, and cell senescence. There also are similar structure and functional changes seen in brain imaging studies of cancer patients and those seen with "normal" aging and Alzheimer's disease. Disentangling the role of these overlapping processes is difficult since they require aged animal models and large samples of older human subjects. From what we do know, frailty and its low cognitive reserve seem to be a clinically useful marker of risk for cognitive decline after cancer and its treatments. This and other results from this review suggest the value of geriatric assessments to identify older patients at the highest risk of cognitive decline. Further research is needed to understand the interactions between aging, genetic predisposition, lifestyle factors, and frailty phenotypes to best identify the subgroups of older patients at greatest risk for decline and to develop behavioral and pharmacological interventions targeting this group. We recommend that basic science and population trials be developed specifically for older hosts with intermediate endpoints of relevance to this group, including cognitive function and trajectories of frailty. Clinicians and their older patients can advance the field by active encouragement of and participation in research designed to improve the care and outcomes of the growing population of older cancer patients.

New approaches to understand cognitive changes associated with chemotherapy for non-central nervous system tumors

CONTEXT

Researchers have described a constellation of cognitive deficits (e.g., impairments in executive functions, working memory, attention, and information-processing speed) associated with cancer treatment, and specifically chemotherapy, for non-central nervous system tumors. However, findings have been inconsistent, largely because of measurement and study design issues.

OBJECTIVES

To propose ways for researchers to more clearly delineate and characterize the mild cognitive deficits and related outcomes that appear to affect a subset of cancer patients and suggest methods to make more effective use of the existing data to understand risk factors for impaired neuropsychological functioning.

METHODS

We examined the literature on the relationship between chemotherapy and cognitive impairment, as well as related literature on neuropsychological measurement, structural and functional neuroimaging, alternative measures of health outcomes, and integrative data analysis.

RESULTS

A more comprehensive picture of cognitive functioning might be obtained by incorporating nontraditional ecological measures, self-reports, computational modeling, new neuroimaging methods, and markers of occupational functioning. Case-control and integrative data analytic techniques potentially could leverage existing data to identify risk factors for cognitive dysfunction and test hypotheses about the etiology of these effects.

CONCLUSION

There is a need to apply new research approaches to understand the real-world functional implications of the cognitive side effects of chemotherapy to develop and implement strategies to minimize and remediate these effects before, during, and after cancer treatment.

Cognitive function in older women with breast cancer treated with standard chemotherapy and capecitabine on Cancer and Leukemia Group B 49907

Cognitive changes in older women receiving chemotherapy are poorly understood. We examined self-reported cognitive function for older women who received adjuvant chemotherapy on Cancer and Leukemia Group B (CALGB) 49907. CALGB 49907 randomized 633 women aged ≥65 with stage I-III breast cancer to standard adjuvant chemotherapy (cyclophosphamide-methotrexate-5-fluorouracil or doxorubicin-cyclophosphamide) versus capecitabine. We examined self-reported cognitive function in 297 women (CALGB 361002) who enrolled on the quality of life substudy and had no gross impairment on cognitive screening. Women were evaluated using an 18-item instrument at six time points (baseline through 24 months). At each time point for each patient, we calculated a cognitive function score (CFS) defined as the mean response of items 1-18 and defined impairment as a score >1.5 standard deviations above the overall average baseline score. Differences in scores by patient characteristics were evaluated using a Kruskal-Wallis test. A linear mixed-effects model was used to assess CFSs by treatment over time. Among 297 women, the median age was 71.5 (range 65-85) and 73 % had performance status of 0. Baseline depression and fatigue were reported in 6 and 14 % of patients, respectively. The average CFS at baseline was 2.08 (corresponding to "normal ability"), and baseline cognitive function did not differ by treatment regimen (p = 0.350). Over 24 months, women reported minimal changes at each time point and insignificant differences by treatment arm were observed. In a healthy group of older women, chemotherapy was not associated with longitudinal changes in self-reported cognitive function.

Cognitive complaints after breast cancer treatments: examining the relationship with neuropsychological test performance

BACKGROUND

Cognitive complaints are reported frequently after breast cancer treatments. Their association with neuropsychological (NP) test performance is not well-established.

METHODS

Early-stage, posttreatment breast cancer patients were enrolled in a prospective, longitudinal, cohort study prior to starting endocrine therapy. Evaluation included an NP test battery and self-report questionnaires assessing symptoms, including cognitive complaints. Multivariable regression models assessed associations among cognitive complaints, mood, treatment exposures, and NP test performance.

RESULTS

One hundred eighty-nine breast cancer patients, aged 21-65 years, completed the evaluation; 23.3% endorsed higher memory complaints and 19.0% reported higher executive function complaints (>1 SD above the mean for healthy control sample). Regression modeling demonstrated a statistically significant association of higher memory complaints with combined chemotherapy and radiation treatments (P = .01), poorer NP verbal memory performance (P = .02), and higher depressive symptoms (P < .001), controlling for age and IQ. For executive functioning complaints, multivariable modeling controlling for age, IQ, and other confounds demonstrated statistically significant associations with better NP visual memory performance (P = .03) and higher depressive symptoms (P < .001), whereas combined chemotherapy and radiation treatment (P = .05) approached statistical significance.

CONCLUSIONS

About one in five post-adjuvant treatment breast cancer patients had elevated memory and/or executive function complaints that were statistically significantly associated with domain-specific NP test performances and depressive symptoms; combined chemotherapy and radiation treatment was also statistically significantly associated with memory complaints. These results and other emerging studies suggest that subjective cognitive complaints in part reflect objective NP performance, although their etiology and biology appear to be multifactorial, motivating further transdisciplinary research.

Preoperative chemosensitivity testing as Predictor of Treatment benefit in Adjuvant stage III colon cancer (PePiTA): protocol of a prospective BGDO (Belgian Group for Digestive Oncology) multicentric study

Background

Surgery is a curative treatment for patients with locally advanced colon cancer, but recurrences are frequent for those with stage III disease. FOLFOX adjuvant chemotherapy has been shown to improve recurrence-free survival and overall survival by more than 20% and is nowadays considered a standard of care. However, the vast majority of patients will not benefit from receiving cytotoxic drugs because they have either already been cured by surgery or because their tumor cells are resistant to the chemotherapy, for which predictive factors are still not available.

Identifying which patients are unlikely to respond to adjuvant chemotherapy from among those who are eligible for such treatment would be a major step towards treatment personalization. It would spare such patients from unnecessary toxicities and would improve the allocation of societal healthcare resources.

Methods/design

PePiTA is a prospective, multicenter, non-randomised trial built on the hypothesis that preoperative chemosensitivity testing using FDG-PET/CT before and after one course of FOLFOX can identify the patients who are unlikely to benefit from 6 months of adjuvant FOLFOX treatment for stage III colon cancer.

The study’s primary objective is to examine the ability of PET/CT-assessed tumor FDG uptake after one course of preoperative chemotherapy to predict the outcome of adjuvant therapy, as measured by 3-year disease-free survival.

Secondary objectives are to examine the predictive value of changes in PET/CT-assessed tumor FDG uptake on overall survival, to define the best cut-off value of FDG uptake for predicting treatment outcome, and to analyse the cost-effectiveness of such preoperative chemo-sensitivity testing.

At study planning, exploratory translational research objectives were 1) to assess the predictive value of circulating tumor cells for disease-free survival, 2) to examine the predictive value of single nucleotide polymorphisms for disease-free survival with respect to genes related either to toxicity or to drug targets, 3) to assess genomic rearrangements associated with response or resistance to FOLFOX treatment, 4) to identify an immunologic signature associated with metabolic tumor response to FOLFOX therapy and, finally, 5) to create a bank of frozen tumor samples for future studies.

Discussion

PePiTA is the first study to use the primitive tumor chemosensitivity assessed by metabolic imaging as a guidance for adjuvant therapy in colon cancer. It could pave the way for tailoring the treatment and avoiding useless toxicities for the patients and inadequate expenses for the society. It could also give an interesting insight into tumoral heterogeneity, resistance to chemotherapy, genetic predisposants to oxaliplatin toxicity and immune response to cancer.

EudraCT number

2009-011445-13

Trial registration

ClinicalTrials.gov number, NCT00994864

Prognostic value of geriatric assessment in older patients with advanced breast cancer receiving chemotherapy

INTRODUCTION

The prognostic value of geriatric assessment in older patients with breast cancer treated with chemotherapy is largely unknown.

METHODS

Fifty-five patients with advanced breast cancer aged 70 years or older were assessed by Mini Nutritional Assessment (MNA), Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE), Groningen Frailty Indicator (GFI) and Mini Mental State Examination (MMSE). Levels of albumin, hemoglobin, creatinine and lactate dehydrogenase were measured. Patients completing at least four cycles of chemotherapy were reassessed by GFI and MMSE and mortality was evaluated using Cox regression analysis.

RESULTS

The mean age was 76 year (SD 4.8). Inferior MNA and GFI scores were associated with increased hazard ratios for mortality: 3.05 (95% confidence interval [CI]: 1.44-6.45; p = 0.004) and 3.40 (95% CI: 1.62-7.10; p = 0.001), respectively. Physical aspects of frailty worsened during the course of chemotherapy. Laboratory values were not associated with assessment scores nor were they predictive for mortality.

CONCLUSIONS

Malnutrition and frailty, rather than cognitive impairment and laboratory values, were associated with an increased mortality risk in these elderly breast cancer patients with advanced breast cancer.

Is basic research providing answers if adjuvant anti-estrogen treatment of breast cancer can induce cognitive impairment?

Adjuvant treatment of cancer by chemotherapy is associated with cognitive impairment in some cancer survivors. Breast cancer patients are frequently also receiving endocrine therapy with selective estrogen receptor modulators (SERMs) and/or aromatase inhibitors (AIs) to suppress the growth of estradiol sensitive breast tumors. Estrogens are well-known, however, to target brain areas involved in the regulation of cognitive behavior. In this review clinical and basic preclinical research is reviewed on the actions of estradiol, SERMs and AIs on brain and cognitive functioning to see if endocrine therapy potentially induces cognitive impairment and in that respect may contribute to the detrimental effects of chemotherapy on cognitive performance in breast cancer patients. Although many clinical studies may be underpowered to detect changes in cognitive function, current basic and clinical reports suggest that there is little evidence that AIs may have a lasting detrimental effect on cognitive performance in breast cancer patients. The clinical data on SERMs are not conclusive, but some studies do suggest that tamoxifen administration may form a risk for cognitive functioning particularly in older women. An explanation may come from basic preclinical research which indicates that tamoxifen often acts agonistic in the absence of estradiol but antagonistic in the presence of endogenous estradiol. It could be hypothesized that the negative effects of tamoxifen in older women is related to the so-called window of opportunity for estrogen. Administration of SERMs beyond this so-called window of opportunity may not be effective or might even have detrimental effects similar to estradiol.

Alterations in brain structure and function in breast cancer survivors: effect of post-chemotherapy interval and relation to oxidative DNA damage

Neuroimaging studies have begun to uncover the neural substrates of cancer and treatment-related cognitive dysfunction, but the time course of these changes in the years following chemotherapy is unclear. This study analyzed multimodality 3T MRI scans to examine the structural and functional effects of chemotherapy and post-chemotherapy interval (PCI) in a cohort of breast cancer survivors (BCS; n = 24; PCI mean 6, range 3-10 y) relative to age- and education-matched healthy controls (HC; n = 23). Assessments included voxel-based morphometry for gray matter density (GMD) and fMRI for activation profile during a 3-back working memory task. The relationships between brain regions associated with PCI and neuropsychological performance, self-reported cognition, and oxidative and direct DNA damage as measured in peripheral lymphocytes were assessed in secondary analyses. PCI was positively associated with GMD and activation on fMRI in the right anterior frontal region (Brodmann Areas 9 and 10) independent of participant age. GMD in this region was also positively correlated with global neuropsychological function. Memory dysfunction, cognitive complaints, and oxidative DNA damages were increased in BCS compared with HC. Imaging results indicated lower fMRI activation in several regions in the BCS group. BCS also had lower GMD than HC in several regions, and in these regions, GMD was inversely related to oxidative DNA damage and learning and memory neuropsychological domain scores. This is the first study to show structural and functional effects of PCI and to relate oxidative DNA damage to brain alterations in BCS. The relationship between neuroimaging and cognitive function indicates the potential clinical relevance of these findings. The relationship with oxidative DNA damage provides a mechanistic clue warranting further investigation.