Effects of Endocrine Therapy on Cognitive Function in Patients with Breast Cancer: A Comprehensive Review

Cognitive impairment following breast cancer treatments: an umbrella review

OBJECTIVES

Cancer-related cognitive impairment (CRCI) refers to a cognitive decline associated with cancer or its treatments. While research into CRCI is expanding, evidence remains scattered due to differences in study designs, methodologies, and definitions. The present umbrella review aims to provide a comprehensive overview of the current evidence regarding the impact of different breast cancer therapies on cognitive functioning, with a particular focus on the interplay among objective cognitive deficits (ie, measured with standardized tests), subjective cognitive concerns, (ie, self-reported), and other mediating psycho-physical factors.

METHODS

The search was made in Pubmed, Embase, and Scopus for articles published until July 2023, following the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-analysis protocol.

RESULTS

Chemotherapy and endocrine therapy appear consistently associated with CRCI in patients with breast cancer, primarily affecting memory, attention/concentration, executive functioning, and processing speed. Subjective cognitive concerns were often found weakly or not associated with neuropsychological test results, while overall CRCI seemed consistently associated with psychological distress, fatigue, sleep quality, and inflammatory and biological factors.

CONCLUSION

Current evidence suggests that CRCI is common after chemotherapy and endocrine therapy for breast cancer. However, heterogeneity in study designs and the scarcity of studies on more recent treatments such as targeted therapies and immunotherapies, highlight the need for more systematic and harmonized studies, possibly taking into account the complex and multifactorial etiology of CRCI. This may provide valuable insights into CRCI's underlying mechanisms and potential new ways to treat it.

Alzheimer Disease and Related Dementia Following Hormone-Modulating Therapy in Patients With Breast Cancer

Importance

Hormone-modulating therapy (HMT) is a widely accepted treatment for hormone receptor-positive breast cancer, although its cognitive effects, including a potential link to Alzheimer disease and related dementias (ADRD), remain understudied.

Objective

To investigate the association between HMT for breast cancer treatment and risk of developing ADRD in women aged 65 years or older.

Design, Setting, and Participants

This cohort study used a comprehensive dataset from the Surveillance, Epidemiology, and End Results (SEER)-Medicare linked database to identify patients who did and did not receive HMT treatment within 3 years after the initial diagnosis of breast cancer and assessed their risk of developing ADRD in later life. Individuals with a preexisting diagnosis of ADRD or receiving HMT before the diagnosis of breast cancer were excluded. This study was performed from June 2022 through January 2024.

Exposure

Receipt of HMT.

Main Outcomes and Measures

Risk of ADRD associated with HMT; associations of risk with age, self-identified race, and HMT type. Risk was measured using hazard ratios (HRs) with 95% CIs and adjusted for potential confounders such as demographic, sociocultural, and clinical variables.

Results

Among 18 808 women aged 65 years and older diagnosed with breast cancer between 2007 and 2009 (1266 Black [6.7%], 16 526 White [87.9%], 1016 other [5.4%]), 12 356 (65.7%) received HMT within 3 years after diagnosis, while 6452 (34.3%) did not. The most common age group in both samples was the 75 to 79 years age group (HMT, 2721 women [22.0%]; no HMT, 1469 women [22.8%]), and the majority of women in both groups self-identified as White (HMT, 10 904 women [88.3%]; no HMT, 5622 women [87.1%]). During an average of 12 years of follow-up, 2926 (23.7%) of HMT users and 1802 (27.9%) of non-HMT users developed ADRD. HMT was associated with a 7% lower relative risk of ADRD overall (HR, 0.93; 95% CI, 0.88-0.98; P = .005). The association decreased with age and varied by race. The reduction in ADRD risk associated with HMT was greatest for women aged 65 to 74 years who self-identified as Black (HR, 0.76; 95% CI, 0.62-0.92). This association decreased among women aged 75 years or older (HR, 0.81; 95% CI, 0.67-0.98). Women aged 65 to 74 years who self-identified as White had an 11% relative risk reduction (HR, 0.89; 95% CI, 0.81-0.97), but the association disappeared for women aged 75 years or older (HR, 0.96; 95% CI, 0.90-1.02). Other races showed no significant association between HMT and ADRD. Age- and race-based associations also varied by HMT type.

Conclusions and Relevance

In this retrospective cohort study, hormone therapy was associated with protection against ADRD in women aged 65 years or older with newly diagnosed breast cancer; the decrease in risk was relatively greater for Black women and women under age 75 years, while the protective effect of HMT diminished with age and varied by race in women. When deciding to use HMT for breast cancer in women aged 65 years or more, clinicians should consider age, self-identified race, and HMT type in treatment decisions.

Hormonal basis of brain fog in cancer treatment

The cognitive side effects of cancer treatment are common, but no targeted therapy exists yet to treat or prevent such neurological sequelae. We explore the role of hormones as mediators between cancer therapy and cognitive impairment, discussing potential future directions.

Design and methods of the mobile assessment of cognition, environment, and sleep (MACES) feasibility study in newly diagnosed breast cancer patients

Endocrine therapy (ET) for breast cancer treatment is associated with cognitive complaints, but their etiology is poorly understood. To address this, we developed and implemented an ambulatory assessment protocol consisting of wearable activity monitors, brief surveys of affect, context, and perceived impairments, and ultra-brief performance-based measures of cognition. Newly diagnosed, ER/PR+, stage 0-III, female breast cancer patients, were recruited. Ambulatory assessments were conducted on smart phones and wearable activity monitors were used to monitor sleep and physical activity. Participants were asked to complete five 7-day measurement bursts (one before starting ET and one each month for 4 consecutive months while on ET). We observed a consent rate of 36%, 27 women completed the study. Of the women that withdrew, 91% dropped prior to the midpoint of follow up. There were no significant differences in demographics, clinical breast cancer characteristics, sleep or physical activity patterns, or measures of cognition between women who completed versus withdrew. Women who did not complete the study provided fewer valid days of baseline data. In conclusion, while some women may be overwhelmed with their cancer diagnosis, we did not identify any predictive characteristics of women whom did not complete the study. This novel method enables the prospective study of psychological changes associated with cancer treatment, capturing a wide array of information about behavior, experience, and cognition, thus providing a picture of the lived experiences of cancer patients before and during exposure to ET.

Effects of aerobic exercise on neurocognitive function in postmenopausal women receiving endocrine therapy for breast cancer: The Exercise Program in Cancer and Cognition randomized controlled trial

Objective

The Exercise Program in Cancer and Cognition (EPICC) Study was a randomized controlled trial (RCT) designed to determine whether six months of moderate-intensity aerobic exercise improves neurocognitive function in women with breast cancer (BC) receiving endocrine therapy (ET).

Methods

Postmenopausal women with hormone receptor+, early-stage BC, within two years post-primary therapy were randomized to the exercise intervention (six months, ≥150 minutes of moderate-intensity aerobic exercise/week) or usual care control condition. Outcomes were assessed at pre-randomization and after intervention completion. Groups were compared using linear mixed-effects modeling.

Results

Participants (N=153) wereX ¯ = 62.09 ± 8.27 years old, with stage I BC (64.1%) and a median of 4.7 months post-diagnosis. We found a group-by-time interaction (p=0.041) and a trend for the main effect of time (p=0.11) for processing speed with improved performance in the exercise group and no change in the controls. Similar main effects of time were observed for learning and memory (p=0.024) and working memory (p=0.01). Better intervention adherence was associated with improved processing speed (p=0.017).

Conclusions

Six months of moderate-intensity aerobic exercise improves processing speed in postmenopausal women with BC receiving ET who initiate exercise within two years of completing primary therapy (surgery +/- chemotherapy). This is the first large-scale study to examine the effects of aerobic exercise on neurocognitive function in women with BC. Additional research is needed to address the long-term effects of aerobic exercise on cognitive function.

Neurocognitive impairment in females with breast cancer treated with endocrine therapy and CDK4/6 inhibitors: a pharmacovigilance study using the World Health Organization's database

Importance: Endocrine therapies (ETs) and inhibitors of cyclin-dependent kinases-4/6 (iCDK4/6s) are a standard treatment in breast cancer. However, data on potential neurocognitive impacts remain inconsistent for ET and are scarce for iCDK4/6s. Objective: To evaluate whether ET and iCDK4/6s are associated with neurocognitive impairment (NCI). Methods: We used observational, real-world cases of NCI from the World Health Organization's database VigiBase® to perform disproportionality analysis. Cases were defined as any symptom of NCI in females treated with ETs or iCDK4/6s. The study period was from the date of the first adverse event reported in VigiBase® with iCDK4/6s (1 January 2014) until the date of data extraction (16 March 2022). In our primary analysis, we calculated the reporting odds ratio (ROR) adjusted for age to identify a potential association between NCI and individual ETs in isolation or in combination with iCDK4/6s. We also performed subgroup analyses by the NCI class. Results: We identified 2.582 and 1.943 reports of NCI associated with ETs and iCDK4/6s, respectively. NCI was significantly associated with each ET [anastrozole: n = 405, aROR = 1.52 (95% CI: 1.37-1.67); letrozole: n = 741, aROR = 1.37 (95% CI: 1.27-1.47); exemestane: n = 316, aROR = 1.37 (95% CI: 1.22-1.53); tamoxifen: n = 311, aROR = 1.25 (95% CI: 1.12-1.40); and fulvestrant: n = 319, aROR = 1.19 (95% CI: 1.06-1.33)] and only with palbociclib for iCDK4/6s [n = 1,542, aROR = 1.41 (95% CI: 1.34-1.48)]. Conclusion: These findings suggest that in females treated for breast cancer, all ETs may be associated with NCI. However, amongst iCDK4/6s, NCI may be specific to palbociclib. NCI most frequently involved learning and memory as well as language. Neurocognitive impact of treatments requires better consideration and management.

Efficacy of Tango Argentino for Cancer-Associated Fatigue and Quality of Life in Breast Cancer Survivors: A Randomized Controlled Trial

BACKGROUND

Persistent impairments of quality of life-in particular, cancer-associated fatigue-are a major limitation for breast cancer survivors. As physical activity and mindfulness interventions have been shown to be effective in reducing fatigue symptoms, we investigated the efficacy of a six-week Argentine tango program.

METHODS

A randomized controlled trial was conducted with 60 breast cancer survivors diagnosed with stage I-III tumors 12-48 months prior to study enrollment and who had increased symptoms of fatigue. The participants were randomly assigned with a 1:1 allocation to either the tango or the waiting group. The treatment consisted of six weeks of supervised weekly one-hour tango group-sessions. Self-reported fatigue and further quality of life parameters were assessed at baseline and six weeks post-baseline. Longitudinal changes, correlations, Cohen's D (d) effect sizes, and association factors were also calculated.

RESULTS

Superiority of the tango intervention over the waiting list control was found in terms of improvement in fatigue (d = -0.64; 95%CI, -1.2 to -0.08; p = 0.03), especially cognitive fatigue. In addition, a superiority of the tango intervention over the waiting list was found in the improvement of diarrhea (d = -0.69; 95%CI, -1.25 to -0.13; p = 0.02). A pooled pre-post analysis of the 50 participants completing the six-week tango program revealed a close to 10% improvement of fatigue (p = 0.0003), insomnia (p = 0.008) and further quality of life outcomes. Adjusted multivariate linear regression analyses revealed the greatest improvements for participants who were more active in sports. In particular, survivors who received endocrine therapies, were obese, or had no prior dance experience seemed to especially benefit from the tango program.

CONCLUSIONS

This randomized controlled trial demonstrated that a six-week Argentine tango program improves fatigue in breast cancer survivors. Further trials are warranted to determine whether such improvements lead to better long-term clinical outcomes.

TRIAL REGISTRATION

trial registration number DRKS00021601. Retrospectively registered on 21 August 2020.

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.

Facing points of view: Representations on adjuvant endocrine therapy of premenopausal patients after breast cancer and their healthcare providers in France. The FOR-AD study

PURPOSE

Adjuvant endocrine therapy (ET) for 5-10 years is the backbone of the therapeutic strategy in patients with hormone receptor positive (HR+) early breast cancer (BC). However, long-term adherence to adjuvant ET represents a major challenge for most patients. According to prior studies, side effects of adjuvant ET are an important reason for poor adherence. In contrast, better communication and relational bond between patients and healthcare providers (HCPs) may improve adherence. The FOR-AD (Focus on non-adherence) study aimed at better understanding the representation of adjuvant ET by patients and their HCPs, in order to improve the care process.

METHODS

Three focus groups of premenopausal women (receiving adjuvant ET for variable amount of time) and two focus groups of HCPs (including oncologists, pharmacists, and nurses) were conducted, each including around ten participants. Thematic analyses using a general inductive approach were constructed to report participants' representations.

RESULTS

Two main themes emerged across groups, and appeared of major importance. Representations on adjuvant ET were often homogenous within each group, but differed between patients and their HCPs. The relationship between both groups was considerably discussed, particularly its importance in facilitating adherence to adjuvant ET. Suggestions on improving the care process were also given, such as systematically including psychologists in follow-up care paths and having a nurse navigator follow patients under treatment with adjuvant ET.

CONCLUSION

The present qualitative exploration may help buildi future tailored interventions to improve adherence to adjuvant ET, in particular regarding the role of nurse navigators.

Adjuvant aromatase inhibitor treatment worsens depressive symptoms and sleep quality in postmenopausal women with localized breast cancer: A one-year follow-up study

First-line treatment in postmenopausal women with estrogen- and/or progesterone-positive breast cancer consists of aromatase inhibitors (AROi). The ability of AROi to promote or worsen cognitive function, depressive symptoms, sleep quality and performance in basic activities of daily life as primary and concomitant outcomes in long longitudinal studies in post-menopausal women has been seldom investigated. This study is a cohort trial which aimed to determine if there were differences in cognitive function assessment, depressive symptoms, and sleep quality after 1 year under AROi treatment and to determine the interrelations between these symptoms.

METHODS

A prospective 1-year longitudinal study was performed in a representative sample of tertiary hospital. Women with localized breast cancer newly treated with AROi therapy were evaluated for cognitive functions, depressive symptoms, sleep problems and ability to perform basic activities of the daily life at baseline and after 6 months and 12 months under adjuvant AROi treatment.

RESULTS

Analysis of cognitive functions by the Mini-Mental State Examination (MMSE) scores did not show significantly worsening under AROi treatment after 6 months and 12 months of treatment compared to the baseline. Analysis of depressive symptoms with the Geriatric Depression Scale and sleep quality with the Athens Insomnia Scale (AIS) scores showed significant (p < 0.05) changes after 6 and 12 months of treatment with AROi, with women describing more depressive symptoms and more sleep disturbances.

CONCLUSIONS

Our study found impairments in sleep quality and an increase in depressive symptoms, which has important implications for clinicians as they impair quality of life and adherence to treatment.