Neuropsychological functioning among patients with different types of cancer : Postchemotherapy cognitive impairment and implications for rehabilitation

What Do Cancer Surgery and orthopedic Surgery Elderly Patients Have in Common? A Long-term Postoperative Cognitive Dysfunction in Orthopedic and Cancer Patients Original Research

Objectives-background

Postoperative cognitive dysfunction (POCD) involves decline in several cognitive domains after surgery and is particularly common after cardiac surgery, while also common among other types of surgery. Given the potential effects of such cognitive dysfunction on the quality of life, it is important to study it in multiple populations in order to limit its occurrence.

Study design

We present the long-term neuropsychological outcome of 200 patients, 100 of whom had orthopedic surgery and 100 oncological surgery.

Methods

We administered a series of neuropsychological tests assessing attention, complex scanning, verbal working memory, executive functioning, short-term and long-term memory, and visuospatial perception before surgery, prior to discharge, at 3-month follow-up and 6 years after surgery. We compared the performance of these patients to normative datasets.

Results

Despite equivalent levels of pre-surgery performance between patients, oncology patients exceeded their preoperative neurocognitive levels, suggesting less postoperative cognitive dysfunction in orthopedic patients overall, in all neuropsychological domains at a 6-year follow-up, except short-term retention. In contrast, orthopedic patients showed no improvement, and, instead, showed some cognitive decline, which remained consistent over time.

Conclusions

Our findings highlight the critical role of the type of surgery utilized in the development of POCD and have implications for clinical management and patients' quality of life in the very long term. Health policy professionals should be aware that patients' low POCD may persist in the long term, and this is useful from a clinician's point of view.

Epirubicin Treatment Induces Neurobehavioral, Oxido-Inflammatory and Neurohistology Alterations in Rats: Protective Effect of the Endogenous Metabolite of Tryptophan - 3-Indolepropionic Acid

Epirubicin's (EPI) efficacy as a chemotherapeutic agent against breast cancer is limited by EPI's neurotoxicity associated with increased oxidative and inflammatory stressors. 3-Indolepropionic acid (3-IPA) derived from in vivo metabolism of tryptophan is reported to possess antioxidative properties devoid of pro-oxidant activity. In this regard, we investigated the effect of 3-IPA on EPI-mediated neurotoxicity in forty female rats (180-200 g; five cohorts (n = 6) treated as follows: Untreated control; EPI alone (2.5 mg/Kg); 3-IPA alone (40 mg/Kg body weight); EPI (2.5 mg/Kg) + 3-IPA (20 mg/Kg) and EPI (2.5 mg/Kg) + 3-IPA (40 mg/Kg) for 28 days. Experimental rats were treated with EPI via intraperitoneal injection thrice weekly or co-treated with 3-IPA daily by gavage. Subsequently, the rat's locomotor activities were measured as endpoints of neurobehavioural status. After sacrifice, inflammation, oxidative stress and DNA damage biomarkers were assessed in rats' cerebrum and cerebellum alongside histopathology. Our results demonstrated that locomotor and exploratory deficits were pronounced in EPI-alone treated rats and improved in the presence of 3-IPA co-treatment. EPI-mediated decreases in tissue antioxidant status, increases in reactive oxygen and nitrogen species (RONS), as well as in lipid peroxidation (LPO) and xanthine oxidase (XO) were lessened in the cerebrum and cerebellum of 3-IPA co-treated rats. Increases in nitric oxide (NO) and 8-hydroxydeguanosin (8-OHdG) levels and myeloperoxidase MPO activity were also abated by 3-IPA. Light microscopic examination of the cerebrum and cerebellum revealed EPI-precipitated histopathological lesions were subsequently alleviated in rats co-treated with 3-IPA. Our findings demonstrate that supplementing endogenously derived 3-IPA from tryptophan metabolism enhances tissue antioxidant status, protects against EPI-mediated neuronal toxicity, and improves neurobehavioural and cognitive levels in experimental rats. These findings may benefit breast cancer patients undergoing Epirubicin chemotherapy.

Cognitive function and breast cancer molecular subtype before and after chemotherapy

Chemotherapy-related cognitive impairment has been reported in patients with breast cancer and received growing attention due to increased survival rate. However, cognitive outcome according to pathological tumor features, especially human epidermal growth factor receptor (HER2) status, has not been clearly elucidated. Despite its potential link with cognitive status through neuroinflammatory response, existing research is sparse and limited to cross-sectional studies. In this observational cohort study, 52 breast cancer patients received a series of neuropsychological examinations before and after chemotherapy. Patients' performances were compared with normative data, and analyzed with Reliable Change Indices and mixed-model analysis of covariance. Results showed that there was a higher percentage of HER2+ patients than HER2- patients who showed defective attention and processing speed before chemotherapy, and that there were more patients with HER2+ status showing cognitive decline on tests of attention and executive functions following chemotherapy. Group-wise analyses confirmed the foregoing pattern and further revealed that patients with HER2+ status also tended to deteriorate more in verbal memory after chemotherapy. These findings indicate that HER2 overexpression may serve as prognostic factors that help explain the heterogeneous cognitive outcome in breast cancer survivors. Further studies are needed to replicate this finding and delineate the underlying mechanisms.

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 effects of chemotherapy: An integrative review

PURPOSE

An estimated 18.1 million new cancer cases (excluding nonmelanoma skin cancers) were diagnosed worldwide in 2020. Despite a rising incidence of cancers worldwide, in developed countries with strong healthcare systems, survival rates are improving as a result of early detection, improved treatments and survivorship care (World Health Organisation (WHO), 2021). Whilst living longer, cancer survivors are often living with side effects of treatment, including chemotherapy related cognitive impairment, often termed "chemobrain".

METHOD

An integrative review of contemporary literature answering the research question how does chemotherapy affect cognitive function? was undertaken utilising three computerised databases CINAHL, Medline and PUBMED, between 2015 and 2021. Data was thematically analysed to identify themes within published literature.

RESULTS

Thematic analysis identified four broad themes within the literature regarding chemotherapy induced cognitive impairment. Identified themes included; cognition as part of a complex scenario, proof of existence and searching for the cause, learning to play the game and timing of cognitive impairment.

CONCLUSIONS

Aggressive treatment with chemotherapy in the adjuvant setting has drastically improved the survival of cancer patients. Subsequent to aggressive treatments, side effects such as cognitive impairment have presented, which may persist in the long term. Despite the exact aetiology of chemotherapy induced cognitive impairment being largely unknown, the consequences of the condition are impacting cancer survivors and their quality of life.

Language impairment among patients with different types of cancer. Comparison with healthy adults

PURPOSE

Language dysfunction is a crucial deficit in terms of cognitive functioning, quality of life and activities of daily living. Several studies have identified cognitive impairment in patients with cancer across several cognitive domains, including language.

METHODS

We investigated language functions among 182 patients with different types of cancer (not brain cancer) and compared them with the performance of Greek healthy adults with the same age and educational levels as the patients. The assessment included verbal fluency test, both semantic (animals) and phonological (X), and Boston Naming Test (BNT-60) among other neuropsychological measures.

RESULTS

Breast cancer patients performed worse compared to patients with prostate, colorectal and thyroid cancer in language tasks. In addition, breast cancer patients had a decreased performance compared with healthy adults, while patients with other types performed to the mean in two out of three language tasks.

CONCLUSIONS

Semantic and phonological fluency requirements of cognitive processes in the brain are discussed.

IMPLICATIONS FOR CANCER SURVIVORS

Language dysfunction is a crucial deficit in terms of cognitive functioning, quality of life and activities of daily living, especially in brain cancer patients, but it can be crucial for patients with other types of cancer as stated in the present study.