Timing of exercise therapy when initiating adjuvant chemotherapy for breast cancer: a randomized trial

Breast cancer and cardiovascular health

Modern cancer therapies greatly improve clinical outcomes for both early and advanced breast cancer patients. However, these advances have raised concerns about potential short- and long-term toxicities, including cardiovascular toxicities. Therefore, understanding the common risk factors and underlying pathophysiological mechanisms contributing to cardiovascular toxicity is essential to ensure best breast cancer outcomes. While cardio-oncology has emerged as a sub-speciality to address these challenges, it is essential that all cardiologists recognize and understand the cardiovascular consequences of cancer therapy. This review aims to provide a comprehensive overview of the potential adverse cardiovascular effects associated with modern breast cancer therapies. A preventive, diagnostic, and therapeutic workflow to minimize the impact of cardiovascular toxicity on patient outcomes is presented. Key aspects of this workflow include regular monitoring of cardiovascular function, early detection and management of cancer therapy-related cardiovascular toxicities, and optimization of cardiovascular risk factor control. By highlighting the gaps in knowledge in some areas, this review aims to emphasize the critical role of cardio-oncology research in ensuring the holistic well-being of patients with breast cancer.

An integrated framework for the study of exercise across the postdiagnosis cancer continuum

Exercise plays many important roles across the entire cancer continuum that have been described in previous frameworks. These frameworks, however, have generally provided a simplified description of the roles of exercise postdiagnosis. The modern cancer treatment landscape has become complex and often consists of multiple lines of multimodal treatments combined concurrently and/or sequentially and delivered over many months or years. This complexity requires a more multifaceted and targeted approach to the study of exercise after a cancer diagnosis. Here, we propose a new integrated framework-Exercise Across the Postdiagnosis Cancer Continuum (EPiCC)-that highlights the distinct roles of exercise for disease treatment and supportive care from diagnosis until death. We also propose new terminology to clarify the distinct roles of exercise that emerge in the context of the modern cancer treatment landscape. The EPiCC Framework is structured around multiple sequential cancer treatments that highlight six distinct cancer treatment-related time periods for exercise-before treatments, during treatments, between treatments, immediately after successful treatments, during longer term survivorship after successful treatments, and during end of life after unsuccessful treatments. The EPiCC Framework proposes that the specific roles of exercise as a disease treatment and supportive care intervention will vary depending on its positioning within different cancer treatment combinations. As a cancer treatment, exercise may serve as a "priming therapy", primary therapy, neoadjuvant therapy, induction therapy, "bridging therapy", adjuvant therapy, consolidation therapy, maintenance therapy, and/or salvage therapy. As a supportive care intervention, exercise may serve as prehabilitation, intrahabilitation, interhabilitation, rehabilitation, "perihabilitation", health promotion/disease prevention, and/or palliation. To date, exercise has been studied during all of the cancer treatment-related time periods but only in relation to some cancer treatments and combinations. Moreover, fewer studies have examined exercise across multiple cancer treatment-related time periods within any cancer treatment combination. Future research is needed to study exercise as a disease treatment and supportive care intervention within and across the distinct cancer treatment-related time periods contained within different cancer treatment combinations. The aim of the EPiCC Framework is to stimulate a more targeted, integrated, and clinically-informed approach to the study of exercise after a cancer diagnosis.

Testing home-based exercise strategies in underserved minority cancer patients undergoing chemotherapy (THRIVE) trial: a study protocol

Background

Higher rates of physical inactivity and comorbid conditions are reported in Hispanic/Latinx and Black cancer patients receiving chemotherapy compared to their White counterparts. Despite the beneficial effect of exercise training for cancer patients, rates of participation in exercise oncology clinical trials are low among disadvantaged and racial and ethnic minority groups. Here, we will examine the effect of an exercise intervention using a novel, accessible, and cost-effective home-based exercise approach among Hispanic/Latinx and Black cancer patients receiving chemotherapy on exercise participation and cardiovascular disease risk.

Methods

The THRIVE trial is an 8-month prospective, three-arm study of 45 patients who are randomized in a 1:1:1 fashion to a supervised exercise intervention (SUP), unsupervised exercise (UNSUP), or an attention control (AC) group. Eligible patients include those with breast, colorectal, or prostate cancer, who are sedentary, overweight or obese, self-identify as Hispanic/Latinx or Black, and plan to receive chemotherapy. Patients randomized to the SUP group participate in a home-based 16-week periodized aerobic and resistance exercise program performed three days per week, supervised through video conference technology. Patients randomized to the UNSUP group participate in an unsupervised 16-week, telehealth-based, periodized aerobic and resistance exercise program performed three days per week using the same exercise prescription parameters as the SUP group. Patients randomized to the AC group receive a 16-week home-based stretching program. The primary outcome is changes in minutes of physical activity assessed by 7-day accelerometry at post-intervention. Secondary outcomes include cardiovascular risk factors, patient-reported outcomes, and physical function. Outcome measures are tested at baseline, post-intervention at month 4, and after a non-intervention follow-up period at month 8.

Discussion

The THRIVE trial is the first study to employ a novel and potentially achievable exercise intervention for a minority population receiving chemotherapy. In addition, this study utilizes an intervention approach to investigate the biological and behavioral mechanisms underlying exercise participation in these cancer patients. Results will guide and inform large randomized controlled trials to test the effect of home-based exercise on treatment outcomes and comorbid disease risk in minority patients with cancer undergoing chemotherapy.

Clinical trial registration

https://classic.clinicaltrials.gov/ct2/show/NCT05327452, identifier (NCT#05327452).

Dose/Exposure Relationship of Exercise and Distant Recurrence in Primary Breast Cancer

PURPOSE

Postdiagnosis exercise is associated with lower breast cancer (BC) mortality but its link with risk of recurrence is less clear. We investigated the impact and dose-response relationship of exercise and recurrence in patients with primary BC.

METHODS

Multicenter prospective cohort analysis among 10,359 patients with primary BC from 26 centers in France between 2012 and 2018 enrolled in the CANcer TOxicities study, with follow-up through October 2021. Exercise exposure was assessed using the Global Physical Activity Questionnaire-16, quantified in standardized metabolic equivalent of task-hours per week (MET-h/wk). We examined the dose/exposure response of pretreatment exercise on distant recurrence-free interval (DRFI) for all patients and stratified by clinical subtype and menopausal status using inverse probability treatment weighted multivariable Cox models to estimate hazard ratios (HRs).

RESULTS

For the overall cohort, the relationship between exercise and DRFI was nonlinear: increasing exercise ≥ 5 MET-h/wk was associated with an inverse linear reduction in DRFI events up to approximately 25 MET-h/wk; increasing exercise over this threshold did not provide any additional DRFI benefit. Compared with <5 MET-h/wk, the adjusted HR for DRFI was 0.82 (95% CI, 0.61 to 1.00) for ≥ 5 MET-h/wk. Stratification by subtype revealed the hormone receptor-/human epidermal growth factor receptor 2- (HR-/HER2-; HR, 0.59 [95% CI, 0.38 to 0.92]) and HR-/HER2+ (HR, 0.37 [95% CI, 0.14 to 0.96]) subtypes were preferentially responsive to exercise. The benefit of exercise was observed especially in the premenopausal population.

CONCLUSION

Postdiagnosis/pretreatment exercise is associated with lower risk of DRFI events in a nonlinear fashion in primary BC; exercise has different impact on DRFI as a function of subtype and menopausal status.

Machine Learning-Driven Phenogrouping and Cardiorespiratory Fitness Response in Metastatic Breast Cancer

PURPOSE

The magnitude of cardiorespiratory fitness (CRF) impairment during anticancer treatment and CRF response to aerobic exercise training (AT) are highly variable. The aim of this ancillary analysis was to leverage machine learning approaches to identify patients at high risk of impaired CRF and poor CRF response to AT.

METHODS

We evaluated heterogeneity in CRF among 64 women with metastatic breast cancer randomly assigned to 12 weeks of highly structured AT (n = 33) or control (n = 31). Unsupervised hierarchical cluster analyses were used to identify representative variables from multidimensional prerandomization (baseline) data, and to categorize patients into mutually exclusive subgroups (ie, phenogroups). Logistic and linear regression evaluated the association between phenogroups and impaired CRF (ie, ≤16 mL O2·kg-1·min-1) and CRF response.

RESULTS

Baseline CRF ranged from 10.2 to 38.8 mL O2·kg-1·min-1; CRF response ranged from -15.7 to 4.1 mL O2·kg-1·min-1. Of the n = 120 candidate baseline variables, n = 32 representative variables were identified. Patients were categorized into two phenogroups. Compared with phenogroup 1 (n = 27), phenogroup 2 (n = 37) contained a higher number of patients with none or >three lines of previous anticancer therapy for metastatic disease and had lower resting left ventricular systolic and diastolic function, cardiac output reserve, hematocrit, lymphocyte count, patient-reported outcomes, and CRF (P < .05) at baseline. Among patients allocated to AT (phenogroup 1, n = 12; 44%; phenogroup 2, n = 21; 57%), CRF response (-1.94 ± 3.80 mL O2·kg-1·min-1 v 0.70 ± 2.22 mL O2·kg-1·min-1) was blunted in phenogroup 2 compared with phenogroup 1.

CONCLUSION

Phenotypic clustering identified two subgroups with unique baseline characteristics and CRF outcomes. The identification of CRF phenogroups could help improve cardiovascular risk stratification and guide investigation of targeted exercise interventions among patients with cancer.

Enhancing Early-Stage Breast Cancer Survivorship: Evidence-Based Strategies, Surveillance Testing, and Imaging Guidelines

Addressing the challenges of survivorship necessitates a comprehensive, patient-centered approach, focusing on mitigating risk through lifestyle modification, identifying distant recurrence, and optimization of breast imaging. This article will discuss the current and emerging clinical strategies for the survivorship period, advocating a multidisciplinary and comprehensive approach. In this manner, early-stage breast cancer survivors are empowered to navigate their journey with enhanced knowledge, facilitating a transition to life beyond cancer.

Mechanisms of Exercise Intolerance Across the Breast Cancer Continuum: A Pooled Analysis of Individual Patient Data

PURPOSE

The purpose of this study is to evaluate the prevalence of abnormal cardiopulmonary responses to exercise and pathophysiological mechanism(s) underpinning exercise intolerance across the continuum of breast cancer (BC) care from diagnosis to metastatic disease.

METHODS

Individual participant data from four randomized trials spanning the BC continuum ([1] prechemotherapy [n = 146], [2] immediately postchemotherapy [n = 48], [3] survivorship [n = 138], and [4] metastatic [n = 47]) were pooled and compared with women at high-risk of BC (BC risk; n = 64). Identical treadmill-based peak cardiopulmonary exercise testing protocols evaluated exercise intolerance (peak oxygen consumption; V̇O2peak) and other resting, submaximal, and peak cardiopulmonary responses. The prevalence of 12 abnormal exercise responses was evaluated. Graphical plots of exercise responses were used to identify oxygen delivery and/or uptake mechanisms contributing to exercise intolerance. Unsupervised, hierarchical cluster analysis was conducted to explore exercise response phenogroups.

RESULTS

Mean V̇O2peak was 2.78 ml O2.kg-1·min-1 (95% confidence interval [CI], -3.94, -1.62 mL O2.kg-1·min-1; P < 0.001) lower in the pooled BC cohort (52 ± 11 yr) than BC risk (55 ± 10 yr). Compared with BC risk, the pooled BC cohort had a 2.5-fold increased risk of any abnormal cardiopulmonary response (odds ratio, 2.5; 95% confidence interval, 1.2, 5.3; P = 0.014). Distinct exercise responses in BC reflected impaired oxygen delivery and uptake relative to control, although considerable inter-individual heterogeneity within cohorts was observed. In unsupervised, hierarchical cluster analysis, six phenogroups were identified with marked differences in cardiopulmonary response patterns and unique clinical characteristics.

CONCLUSIONS

Abnormal cardiopulmonary response to exercise is common in BC and is related to impairments in oxygen delivery and uptake. The identification of exercise response phenogroups could help improve cardiovascular risk stratification and guide investigation of targeted exercise interventions.

A Review on the Role of Exercise Training to Prevent a Decline in Cardiorespiratory Fitness and Cardiac Function in Breast Cancer Survivors

PURPOSE

Improvements in diagnosis and treatment mean that the long-term health of breast cancer survivors (BCS) is increasingly dictated by cardiovascular comorbidities. This is partly a consequence of exposure to cardiotoxic therapies, which result in cardiac dysfunction and decreased cardiorespiratory fitness (CRF). Exercise training (ExT) is a key therapeutic strategy for secondary prevention and increasing CRF in adults with established cardiovascular disease. Exercise-based cardio-oncology rehabilitation (CORE) has been proposed as an emerging strategy to address CRF and cardiac impairment in BCS. This review aims to (1) provide an overview of the impact of breast cancer therapy on CRF; (2) provide an up-to-date summary of the effects of ExT on CRF and cardiac function in BCS undergoing cardiotoxic therapy; and (3) discuss how traditional ExT approaches can be adapted for BCS undergoing therapy.

REVIEW METHODS

A literature review was performed based on an intensive literature search for systematic reviews and meta-analyses, randomized and non-randomized controlled trials and single-arm trials investigating the impact of exercise training or cardiac rehabilitation on CRF and/or cardiac function in BCS who are undergoing or have completed cardiotoxic cancer therapy.

SUMMARY

Overall, current evidence suggests that ExT induces clinically meaningful benefits for CRF in BCS during and after therapy. There is also emerging evidence that ExT can improve peak exercise measures of cardiac function; however, there is a need for further research to understand how to adapt these effective ExT approaches into clinical CORE-based settings.

Exercise mitigates age-related metabolic diseases by improving mitochondrial dysfunction

The benefits of regular physical activity are related to delaying and reversing the onset of ageing and age-related disorders, including cardiomyopathy, neurodegenerative diseases, cancer, obesity, diabetes, and fatty liver diseases. However, the molecular mechanisms of the benefits of exercise or physical activity on ageing and age-related disorders remain poorly understood. Mitochondrial dysfunction is implicated in the pathogenesis of ageing and age-related metabolic diseases. Mitochondrial health is an important mediator of cellular function. Therefore, exercise alleviates metabolic diseases in individuals with advancing ageing and age-related diseases by the remarkable promotion of mitochondrial biogenesis and function. Exerkines are identified as signaling moieties released in response to exercise. Exerkines released by exercise have potential roles in improving mitochondrial dysfunction in response to age-related disorders. This review comprehensive summarizes the benefits of exercise in metabolic diseases, linking mitochondrial dysfunction to the onset of age-related diseases. Using relevant examples utilizing this approach, the possibility of designing therapeutic interventions based on these molecular mechanisms is addressed.

Incorporating Exercise Training into Cardio-Oncology Care: Current Evidence and Opportunities: JACC: CardioOncology State-of-the-Art Review

Cancer treatment-induced cardiotoxicities are an ongoing concern throughout the cancer care continuum from treatment initiation to survivorship. Several "standard-of-care" primary, secondary, and tertiary prevention strategies are available to prevent the development or further progression of cancer treatment-induced cardiotoxicities and their risk factors. Despite exercise's established benefits on the cardiovascular system, it has not been widely adopted as a nonpharmacologic cardioprotective strategy within cardio-oncology care. In this state-of-the-art review, the authors discuss cancer treatment-induced cardiotoxicities, review the existing evidence supporting the role of exercise in preventing and managing these sequelae in at-risk and affected individuals living after cancer diagnoses, and propose considerations for implementing exercise-based services in cardio-oncology practice.