A subset of survivors has cognitive impairment after cancer treatment. This is generally subtle, but may be sustained. In October 2006, the second international cognitive workshop was held in Venice. ...The workshop included neuropsychologists, clinical and experimental psychologists, medical oncologists, imaging experts, and patient advocates. The main developments since the first Cognitive Workshop in 2003 have been the following. (i) studies evaluating cognitive function in patients receiving chemotherapy for cancers other than breast cancer, and in patients receiving hormonal therapy for cancer. (ii) The publication of longitudinal prospective studies which have shown that some patients already exhibit cognitive impairment on neuropsychological testing before receiving chemotherapy, and some patients have deterioration in cognitive functioning from pre- to postchemotherapy. (iii) Studies of the underlying mechanisms of cognitive impairment both in patients and in animal models. (iv) Use of structural and functional imaging techniques to study changes in brain morphology and activation patterns associated with chemotherapy. (v) At present cognitive research in cancer is limited by methodological challenges and the lack of standardization in neuropsychological studies. The current workshop addressed many of these issues and established an international task force to provide guidelines for future research and information on how best to manage these symptoms.
Up to 60% of breast cancer patients treated with chemotherapy is confronted with cognitive problems, which can have a significant impact on daily activities and quality of life (QoL). We investigated ...whether exercise training improves cognition in chemotherapy-exposed breast cancer patients 2-4 years after diagnosis.
Chemotherapy-exposed breast cancer patients, with both self-reported cognitive problems and lower than expected performance on neuropsychological tests, were randomized to an exercise or control group. The 6-month exercise intervention consisted of supervised aerobic and strength training (2 h/week), and Nordic/power walking (2 h/week). Our primary outcome was memory functioning (Hopkins Verbal Learning Test-Revised; HVLT-R). Secondary outcomes included online neuropsychological tests (Amsterdam Cognition Scan; ACS), self-reported cognition (MD Anderson Symptom Inventory for multiple myeloma; MDASI-MM), physical fitness (relative maximum oxygen uptake; VO
), fatigue (Multidimensional Fatigue Inventory), QoL (European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire; EORTC QLQ C-30), depression (Patient Health Questionnaire-9, Hospital Anxiety and Depression Scale; HADS), and anxiety (HADS). HVLT-R total recall was analyzed with a Fisher exact test for clinically relevant improvement (≥ 5 words). Other outcomes were analyzed using multiple regression analyses adjusted for baseline and stratification factors.
We randomized 181 patients to the exercise (n = 91) or control group (n = 90). Two-third of the patients attended ≥ 80% of the exercise sessions, and physical fitness significantly improved compared to control patients (B VO
1.4 ml/min/kg, 95%CI:0.6;2.2). No difference in favor of the intervention group was seen on the primary outcome. Significant beneficial intervention effects were found for self-reported cognitive functioning MDASI-MM severity (B-0.7, 95% CI - 1.2; - 0.1), fatigue, QoL, and depression. A hypothesis-driven analysis in highly fatigued patients showed positive exercise effects on tested cognitive functioning ACS Reaction Time (B-26.8, 95% CI - 52.9; - 0.6) and ACS Wordlist Learning (B4.4, 95% CI 0.5; 8.3).
A 6-month exercise intervention improved self-reported cognitive functioning, physical fitness, fatigue, QoL, and depression in chemotherapy-exposed breast cancer patients with cognitive problems. Tested cognitive functioning was not affected. However, subgroup analysis indicated a positive effect of exercise on tested cognitive functioning in highly fatigued patients. Trial Registration Netherlands Trial Registry: Trial NL5924 (NTR6104). Registered 24 October 2016, https://www.trialregister.nl/trial/5924 .
Objective: Information about treatment side effects can increase their occurrence; breast cancer (BC) patients showed increased cognitive problem reporting (CPR) and decreased memory performance ...after information about cognitive side effects. The current study extends previous research on adverse information effects (AIE) by investigating (a) risk factors, (b) underlying mechanisms and (c) an intervention to reduce AIE.
Design: In an online experiment, 175 female BC patients were randomly assigned to one of three conditions. In the two experimental groups, patients were informed about the possible occurrence of cognitive problems after chemotherapy with (intervention group) or without (experimental group) reassuring information that 'there are still patients who score well on memory tests'. In the control group, no reference to chemotherapy-related cognitive problems was made.
Main outcome measures: Main dependent measure was CPR. Four moderating and five mediating processes were examined.
Results: CPR increased with higher levels of stigma consciousness in the two experimental groups, but not in the no-information control group.
Conclusion: Merely informing patients about cognitive side effects may increase their occurrence, especially among individuals vulnerable to patient stereotypes. Adding reassuring information is not sufficient to reduce AIE.
Rationale and objectives
Adjuvant chemotherapy is associated with changes in cognition in a subgroup of cancer patients. Chemotherapy is generally given as a combination of cytotoxic agents, which ...makes it hard to define the agent responsible for these observed changes. Literature on animal experiments has been difficult to interpret due to variance in experimental setup.
Methods
We examined the effects of cytotoxic agents administered separately on various cognitive measures in a standardized animal model. Male C57Bl/6 mice received cyclophosphamide, docetaxel, doxorubicin, 5-fluorouracil, methotrexate, or topotecan. These agents represent different compound classes based on their working mechanism and are frequently prescribed in the clinic. A control group received saline. Behavioral testing started 2 or 15 weeks after treatment and included testing general measures of behavior and cognitive task performance: spontaneous behavior in an automated home cage, open field, novel location recognition (NLR), novel object recognition (NOR), Barnes maze, contextual fear conditioning, and a simple choice reaction time task (SCRTT).
Results
Cyclophosphamide, docetaxel, and doxorubicin administration affected spontaneous activity in the automated home cage. All cytotoxic agents affected memory (NLR and/or NOR). Spatial memory measured in the Barnes maze was affected after administration with doxorubicin, 5-fluorouracil, and topotecan. Decreased inhibition in the SCRTT was observed after treatment with cyclophosphamide, docetaxel, and topotecan.
Conclusions
Our data show that, in mice, a single treatment with a cytotoxic agent causes cognitive impairment. Not all cytotoxic agents affected the same cognitive domains, which might be explained by differences in working mechanisms of the various agents.
Cancer survivors frequently experience cognitive impairments. This systematic review assessed animal literature to identify artificial (pharmaceutical) or natural interventions ...(plant/endogenously-derived) to reduce treatment-related cognitive impairments.
PubMed, EMBASE, PsycINFO, Web of Science, and Scopus were searched and SYRCLE’s tool was used for risk of bias assessment of the 134 included articles.
High variability was observed and risk of bias analysis showed overall poor quality of reporting. Results generally showed positive effects in the intervention group versus cancer-therapy only group (67% of 156 cognitive measures), with only 15 (7%) measures reporting cognitive impairment despite intervention. Both artificial (61%) and natural (75%) interventions prevented cognitive impairment. Artificial interventions involving GSK3B inhibitors, PLX5622, and NMDA receptor antagonists, and natural interventions utilizing melatonin, curcumin, and N-acetylcysteine, showed most consistent outcomes.
Both artificial and natural interventions may prevent cognitive impairment in rodents, which merit consideration in future clinical trials. Greater consistency in design is needed to enhance the generalizability across studies, including timing of cognitive tests and description of treatments and interventions.
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•Both natural and artificial interventions may improve cognitive impairments after cancer treatment.•Inhibition of GSK3B, NMDAR and CSF1R are potential avenues for artificial interventions.•Melatonin, curcumin and N-acetylcysteine seem promising natural interventions.•Urgent need for standardization in animal studies on cancer therapy and cognitive deficits.
Background: Neuropsychological examinations have shown an elevated risk for cognitive impairment 2 years after therapy in breast cancer patients randomized to receive adjuvant high-dose ...cyclophosphamide, thiotepa, carboplatin (CTC) chemotherapy compared with a non-treated control group of stage I breast cancer patients. Patients randomized to receive standard-dose fluorouracil, epirubicin, cyclophosphamide (FEC) chemotherapy showed no elevated risk compared with controls. However, breast cancer patients treated with conventional cyclophosphamide, methotrexate, 5-fluorouracil (CMF) chemotherapy showed a higher risk of cognitive impairment. The present study was designed to obtain a greater insight into these long-term neuropsychological sequelae following chemotherapy and their course in time. Patients and methods: At 4 years post-therapy, 22 of the original 34 CTC patients, 23 of 36 FEC patients, 31 of 39 CMF patients and 27 of 34 control patients were re-examined with neuropsychological tests. Results: Improvement in performance was observed in all chemotherapy groups, whereas in the control group there was a slight deterioration in test results. A differential attrition was observed among the groups, with a relatively high percentage of initially cognitively impaired patients from the CTC group dropping out due to factors related to disease progression. Conclusions: The results suggest that cognitive dysfunction following adjuvant chemotherapy in breast cancer patients may be transient. Additional studies are needed to investigate the differential attrition of patients with cognitive impairment.
•Adjuvant chemotherapy is frequently associated with cognitive change in patients.•Six cytotoxic agents were examined for their effect on brain functioning in mice.•Relatively small effects were seen ...on neurobiological markers involved in cognition.•Enhanced brain penetration did not result in more neurobiological damage.
Cognitive deficit is a frequently reported side-effect of adjuvant chemotherapy. A large number of animal studies has been performed to examine the neurobiological mechanisms underlying this phenomenon, however, definite conclusions from these studies are restricted due to differences in experimental set-up.
We systematically investigated the effects of 6 cytotoxic agents on various neurobiological parameters. C57Bl/6J mice were treated with cyclophosphamide, docetaxel, doxorubicin, 5-fluorouracil, methotrexate, or topotecan. The animals were sacrificed 3 or 15 weeks after treatment and the effect on neurogenesis, blood vessel density, and neuroinflammation was analyzed using immunohistochemistry. None of the cytostatic agents tested affected neurogenesis (cell survival or cell proliferation). Blood vessel density was increased in the hippocampus and prefrontal cortex 3 weeks after treatment with docetaxel and doxorubicin compared with control animals. A decrease in the number of microglial cells was observed in the prefrontal cortex after treatment with cyclophosphamide, docetaxel, 5-FU, and topotecan compared with control mice. The observed decrease in microglia cells is indicative of inflammation that occurred after treatment.
Overall, the magnitude of the effects was relatively modest. Therefore, we conducted a similar study with topotecan in Abcg2;Abcb1a/b knock out and wildtype FVB mice. Animals were sacrificed 3 weeks after treatment and no notable effect was seen in hippocampal cell differentiation (DCX), microglia activation, or blood vessel density. Perhaps the FVB strain is more resistant to the neurotoxic effects of topotecan which makes this not the correct model to study the mechanism of chemotherapy-induced cognitive impairment.
Abstract The potentially detrimental effects of cancer and related treatments on cognitive functioning are emerging as a key focus of cancer survivorship research. Many patients with central nervous ...system (CNS) or non-CNS tumours develop cognitive problems during the course of their disease that can result in diminished functional independence. We review the state of knowledge on the cognitive functioning of patients with primary and secondary brain tumours at diagnosis, during and after therapy, and discuss current initiatives to diminish cognitive decline in these patients. Similarly, attention is paid to the cognitive sequelae of cancer and cancer therapies in patients without CNS disease. Disease and treatment effects on cognition are discussed, as well as current insights into the neural substrates and the mechanisms underlying cognitive dysfunction in these patients. In addition, rehabilitation strategies for patients with non-CNS disease confronted with cognitive dysfunction are described. Special attention is given to knowledge gaps in the area of cancer and cognition, in CNS and non-CNS diseases. Finally, we point to the important role for cooperative groups to include cognitive endpoints in clinical trials in order to accelerate our understanding and treatment of cognitive dysfunction related to cancer and cancer therapies.
Breast cancer patients receiving chemotherapy can develop cognitive impairment. There is no gold standard for defining cognitive impairment. We applied the National Institute on Aging-Alzheimer's ...Association (NIA-AA) criteria for mild cognitive impairment (MCI) to determine its prevalence in breast cancer patients receiving adjuvant chemotherapy and examine differences between patients with and without MCI.
We used pre-existing cognitive data on 5 neuropsychological test outcomes (verbal memory, processing speed, executive functioning, and verbal fluency) gathered from 240 breast cancer patients who received adjuvant conventional (n = 154) or high-dose chemotherapy (n = 86). Assessments occurred 6 or 12 months post-chemotherapy and results were compared with data from 66 women without cancer. MCI was defined by the following: (i) presence of concern regarding a change in cognition, (ii) impairment in one or more cognitive tests (1.5 standard deviation below a normative mean), (iii) preservation of independence in functional abilities, and (iv) the absence of dementia.
Twenty percent (n = 49) of breast cancer patients who received chemotherapy (conventional therapy n = 29 (12%), high-dose therapy = 20 (8.3%)) met the criteria for MCI, compared with 7.6% (n = 5) of controls. Prevalence was significantly different between patients and controls (P = 0.020, and corrected for IQ P < 0.001). Patients with MCI had significant lower education levels (P < 0.002) and premorbid IQ (P = 0.001) compared with patients without MCI.
Twenty percent of breast cancer patients treated with chemotherapy met NIA-AA criteria for MCI, compared with 7.6% of the controls.
These criteria, which include formal test performance as well as a person's symptoms and functional status, can be useful in clinical practice and scientific research.
Whole brain radiotherapy (WBRT) is used to improve tumor control in patients with primary brain tumors, or brain metastasis from various primary tumors to improve tumor control. However, WBRT can ...lead to cognitive decline in patients. We assessed whether fractionated WBRT (fWBRT) affects spontaneous behavior of mice in automated home cages and cognition (spatial memory) using the Barnes maze.
Male C57Bl/6j mice received bi-lateral fWBRT at a dosage of 4 Gy/day on 5 consecutive days. In line with previous reports, immunohistochemical analysis of doublecortin positive cells in the dentate gyrus showed a profound reduction in immature neurons 4 weeks after fWBRT. Surprisingly, spontaneous behavior as measured in automated home cages was not affected. Moreover, learning and memory measured with Barnes maze, was also not affected 4–6 weeks after fWBRT. At 10–11 weeks after fWBRT a significant difference in escape latency during the learning phase, but not in the probe test of the Barnes maze was observed.
In conclusion, although we confirmed the serious adverse effect of fWBRT on neurogenesis 4 weeks after fWBRT, we did not find similar profound effects on spontaneous behavior in the automated home cage nor on learning abilities as measured by the Barnes maze. The relationship between the neurobiological effects of fWBRT and cognition seems more complex than often assumed and the choice of animal model, cognitive tasks, neurobiological parameters, and experimental set-up might be important factors in these types of experiments.
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