Can Exercise Ameliorate Aromatase Inhibitor-Induced Cognitive Decline in Breast Cancer Patients?

Biological Sex Disparities in Alzheimer's Disease

Alzheimer's disease is a highly complex and multifactorial neurodegenerative disorder, with age being the most significant risk factor. The incidence of Alzheimer's disease doubles every 5 years after the age of 65. Consequently, one of the major challenges in Alzheimer's disease research is understanding how the brain changes with age. Gaining insights into these changes could help identify individuals who are more prone to developing Alzheimer's disease as they age. Over the past 25 years, studies on brain aging have examined thousands of human brains to explore the neuronal basis of age-related cognitive decline. However, most of these studies have focused on adults over 60, often neglecting the critical menopause transition period. During menopause, women experience a substantial decline in ovarian sex hormone production, with a decrease of about 90% in estrogen levels. Estrogen is known for its neuroprotective effects, and its significant loss during menopause affects various biological systems, including the brain. Importantly, despite known differences in dementia risk between sexes, the impact of biological sex and sex hormones on brain aging and the development of Alzheimer's disease remains underexplored.

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

Simple Summary

Many persons diagnosed with breast cancer are treated with endocrine therapy and will experience the side effects of endocrine therapy. Cognitive adverse effects of endocrine therapy are increasingly being recognised, and can significantly affect quality of life, adherence and treatment outcome. This review aims to discuss the nature of cognitive dysfunction associated with endocrine therapy, the mechanisms underpinning its development, and evidence-based management strategies.

Abstract

Endocrine therapy forms the backbone of systemic therapy for the majority of persons with early and late-stage breast cancer. However, the side effects can negatively affect quality of life, and impact treatment adherence and overall oncological outcomes. Adverse effects on cognition are common, underreported and challenging to manage. We aim to describe the nature, incidence, risk factors and underlying mechanisms of endocrine therapy-induced cognitive dysfunction. We conducted a comprehensive literature review of the studies reporting on cognitive dysfunction associated with endocrine therapies for breast cancer. We also summarise prevention and treatment strategies, and ongoing research. Given that patients are taking endocrine therapies for longer durations than ever before, it is essential that these side effects are managed pro-actively within a multi-disciplinary team in order to promote adherence to endocrine therapy and improve patients’ quality of life.

Roles and molecular mechanisms of physical exercise in cancer prevention and treatment

Exercise can enhance motivation to change lifestyle behaviors, improve aerobic fitness, improve physical function, control fatigue, and enhance quality of life. Studies have demonstrated the benefits to be gained from physical exercise, highlighting the importance of popularizing the concept of physical exercise for individuals and making professional exercise-treatment programs available to patients with cancer. However, the correlation between physical exercise and carcinogenesis is easily overlooked, and exercise interventions are not routinely provided to patients with cancer, especially those with advanced cancer. In this article, we present a literature review of the effects of exercise on cancer development and progression and give recent evidence for the type of exercise best suited for different types of cancer and in different disease stages. Moreover, the molecular mechanisms about regulating metabolism and systemic immune function in cancer are summarized and discussed. In conclusion, physical exercise should be considered as an important intervention for preventing and treating cancer and its complications.

The Effect of Exercise on the Alleviation of Side Effects Induced by Aromatase Inhibitors in Postmenopausal Breast Cancer Patients

PURPOSE OF REVIEW

Aromatase inhibitors (AIs) are effective in treating postmenopausal women suffering from estrogen receptor-positive breast cancer (BC). However, AIs are also commonly associated with a number of side effects which decrease the quality of life (QoL) of the patients. This review focuses on the effects of exercise interventions on reducing the side effects commonly experienced by BC patients on AI treatment.

RECENT FINDINGS

Recent studies in the literature support that exercise interventions are feasible and improve body composition, aromatase inhibitor-induced Arthralgia (AIIA), and the overall QoL of BC patients. Successful implementation of longitudinal exercise interventions is expected to improve the QoL of BC patients on AI treatment. Future studies should therefore be carried out with a larger number of postmenopausal BC patients on AI treatment to (a) investigate the effects of exercise interventions on depression, cognitive decline, and cardiotoxicity and (b) address the motivation that should be used to keep BC survivors engaged in exercise intervention programs.

Physical activity and cognitive changes in younger women after breast cancer treatment

OBJECTIVES

Studies indicate women aged 25-49 years previously treated for cancer report cognitive alterations. Good evidence indicates physical activity can be beneficial after cancer and might additionally benefit cognitive function. This short report presents data from a substudy of the Younger Women's Wellness after Cancer Program (YWWACP), which explored cognitive alterations and investigated potential associations between physical activity and cognitive function in participants in the YWWACP. The primary aim of this substudy was to determine in younger women previously treated for breast cancer (1) whether subjectively reported cognitive function changed over time and (2) if physical activity is associated with subjectively reported cognitive function, and if time had an impact on this.

METHODS

All participants had completed breast cancer treatment. Data were collected at baseline (n=41) and at 12 weeks. Measures assessed demographics, self-reported physical activity, cognitive function, sleep quality, stress, anxiety and depression using validated and reliable, subjectively reported instruments.

RESULTS

Cognitive function and physical activity scores increased across the time points, with cognitive function revealing a statistically significant increase over time (p=0.004). Statistical testing revealed that physical activity was not correlated with cognitive function and that change in physical activity was not correlated with change in cognitive function.

CONCLUSION

These data provide early evidence that cognitive function and physical activity improved over time in this sample. However, interpretations of a correlation between physical activity and cognitive function should be made with caution, and future research would benefit from larger samples.

Exercise for Toxicity Management in Cancer-A Narrative Review

Although the treatment of cancer is more effective now than ever, patients with cancer still face acute and chronic toxicities such as fatigue, cardiotoxicity, pain, cognitive impairment, and neurotoxicity. In this narrative review, we briefly discuss the use of exercise for toxicity management in patients with cancer, biological mechanisms underlying the toxicities and the effects of exercise, barriers that patients- especially underserved patients-face in adopting and adhering to exercise programs, and new technologies to overcome barriers to exercise. Our conclusions and clinical suggestions are: (1) exercise is safe and effective for treating many toxicities; (2) patients can benefit from a variety of exercise modalities (e.g., walking, cycling, resistance bands, yoga); (3) exercise should be started as soon as possible, even before treatments begin; (4) exercise should be continued as long as possible, as a lifestyle; and (5) barriers to exercise should be identified and addressed, (e.g., continually encouraging patients to exercise, using mobile technology, advocating for safe communities that encourage active lifestyles). Future research should inform definitive clinical guidelines for the use of exercise to ameliorate toxicities from cancer and its treatment.

Cognitive Effects of Aromatase and Possible Role in Memory Disorders

Diverse cognitive functions in many vertebrate species are influenced by local conversion of androgens to 17β-estradiol (E2) by aromatase. This enzyme is highly expressed in various brain regions across species, with some inter-species variation in terms of regional brain expression. Since women with breast cancer and men and women with other disorders are often treated with aromatase inhibitors (AI), these populations might be especially vulnerable to cognitive deficits due to low neuroE2 synthesis, i.e., synthesis of E2 directly within the brain. Animal models have been useful in deciphering aromatase effects on cognitive functions. Consequences of AI administration at various life cycle stages have been assessed on auditory, song processing, and spatial memory in birds and various aspects of cognition in rodent models. Additionally, cognitive deficits have been described in aromatase knockout (ArKO) mice that systemically lack this gene throughout their lifespan. This review will consider evidence to date that AI treatment in male and female rodent models, birds, and humans results in cognitive impairments. How brain aromatase regulates cognitive function throughout the lifespan, and gaps in current knowledge will be considered, along with future directions to better define how aromatase might guide learning and memory from early development through the geriatric period. Better understanding the importance of E2 synthesis on neurobehavioral responses at various ages will likely aid in the discovery of therapeutic strategies to prevent potential cognitive deficits, including Alzheimer's Disease, in individuals treated with AI or those possessing CYP19 gene polymorphisms, as well as cognitive effects of normal aging that may be related to changes in brain aromatase activity.

Cognitive impairment following hormone therapy: current opinion of research in breast and prostate cancer patients

PURPOSE OF REVIEW

Hormone therapy is a common cancer treatment that may be associated with numerous side and late effects, and in recent years, has been linked to changes in cognition. Here, we present the most important recent findings from empirical studies and reviews that have focused on the effects of hormone therapy on cognitive functioning in breast and prostate cancer populations, underline some general shortcomings, and propose directions for future research.

RECENT FINDINGS

Recent research indicates that cognitive impairment may occur in breast and prostate cancer patients following onset of hormone therapy. However, because of methodological shortcomings and heterogeneity of current research, conclusions regarding the effects of hormone therapy on cognitive functions remain tentative.

SUMMARY

The review highlights the general findings while also describing the many methodological shortcomings that need to be addressed in future research. It is clear that larger scale neuropsychological studies that also evaluate the impact of impairments on daily life functioning will improve our understanding of the effects of hormone therapy on cognition and inform the development of appropriate interventions.

Mindfulness-Based Movement: A Polyvagal Perspective

Compelling evidence suggests that physical activity is an effective intervention for cancer survivors, including for those undergoing active cancer treatments. However, to date most evidence has emerged from interventions that have promoted moderate to vigorous physical activity. In this conceptual review, we argue that attention should be given to the entire continuum of physical activity from reducing sedentary behavior to increasing higher levels of physical activity when possible. In addition, considerable evidence in the cancer literature supports the value of mindfulness-based interventions as a means of helping patients and survivors cope with the variety of threats that accompany this disease. Based on the success of these two areas of research, we argue for conceptualizing and promoting physical activity as Mindfulness-Based Movement, using Polyvagal Theory as a theoretical framework to understand the role and value of Mindfulness-Based Movement as a potential intervention for cancer care and control.