Exercise Therapy as Treatment for Cardiovascular and Oncologic Disease After a Diagnosis of Early-Stage Cancer

Inflammation and Clinical Decline After Adjuvant Chemotherapy in Older Adults With Breast Cancer: Results From the Hurria Older Patients Prospective Study

PURPOSE

Older breast cancer survivors are at increased risk of clinical decline after adjuvant chemotherapy. This study aimed to evaluate whether inflammatory markers assessed before adjuvant chemotherapy are associated with chemotherapy-induced clinical decline in a population of fit older adults with breast cancer.

METHODS

In a prospective study of women age ≥ 65 years with stage I-III breast cancer treated with chemotherapy, we measured interleukin-6 (IL-6) and C-reactive protein (CRP) prechemotherapy (T1). We assessed frailty status, using a Deficit Accumulation Index (DAI; categorized as robust, prefrail, and frail), at T1 and postchemotherapy (T2). The population of interest was robust women at T1. The primary outcome was chemotherapy-induced decline in frailty status, defined as decline in DAI from robust (T1) to prefrail or frail (T2). Multivariable logistic regression was used to examine the association between inflammatory markers and the primary outcome, adjusted for sociodemographic and clinical characteristics.

RESULTS

Of the 295 robust women at T1, 76 (26%) experienced chemotherapy-induced decline in frailty status, among whom 66% had high IL-6, 63% had high CRP, and 46% had high IL-6 and CRP at T1. After adjusting for sociodemographic and clinical characteristics, women with high IL-6 and CRP had a > three-fold (odds ratio, 3.52; 95% CI, 1.55 to 8.01; P = .003) odds of chemotherapy-induced decline in frailty status compared with women with low IL-6 and CRP.

CONCLUSION

In this cohort of older women with early breast cancer who were clinically fit before chemotherapy initiation, high IL-6 and CRP prechemotherapy were associated with chemotherapy-induced decline in frailty status independent of sociodemographic and clinical risk factors. Further research is needed to examine whether inflammatory markers can inform more personalized approaches to treating older breast cancer survivors.

Supplementing Soy-Based Diet with Creatine in Rats: Implications for Cardiac Cell Signaling and Response to Doxorubicin

Nutritional habits can have a significant impact on cardiovascular health and disease. This may also apply to cardiotoxicity caused as a frequent side effect of chemotherapeutic drugs, such as doxorubicin (DXR). The aim of this work was to analyze if diet, in particular creatine (Cr) supplementation, can modulate cardiac biochemical (energy status, oxidative damage and antioxidant capacity, DNA integrity, cell signaling) and functional parameters at baseline and upon DXR treatment. Here, male Wistar rats were fed for 4 weeks with either standard rodent diet (NORMAL), soy-based diet (SOY), or Cr-supplemented soy-based diet (SOY + Cr). Hearts were either freeze-clamped in situ or following ex vivo Langendorff perfusion without or with 25 μM DXR and after recording cardiac function. The diets had distinct cardiac effects. Soy-based diet (SOY vs. NORMAL) did not alter cardiac performance but increased phosphorylation of acetyl-CoA carboxylase (ACC), indicating activation of rather pro-catabolic AMP-activated protein kinase (AMPK) signaling, consistent with increased ADP/ATP ratios and lower lipid peroxidation. Creatine addition to the soy-based diet (SOY + Cr vs. SOY) slightly increased left ventricular developed pressure (LVDP) and contractility dp/dt, as measured at baseline in perfused heart, and resulted in activation of the rather pro-anabolic protein kinases Akt and ERK. Challenging perfused heart with DXR, as analyzed across all nutritional regimens, deteriorated most cardiac functional parameters and also altered activation of the AMPK, ERK, and Akt signaling pathways. Despite partial reprogramming of cell signaling and metabolism in the rat heart, diet did not modify the functional response to supraclinical DXR concentrations in the used acute cardiotoxicity model. However, the long-term effect of these diets on cardiac sensitivity to chronic and clinically relevant DXR doses remains to be established.

Association of Cardiotoxicity With Doxorubicin and Trastuzumab: A Double-Edged Sword in Chemotherapy

Anticancer drugs play an important role in reducing mortality rates and increasing life expectancy in cancer patients. Treatments include monotherapy and/or a combination of radiation therapy, chemotherapy, hormone therapy, or immunotherapy. Despite great advances in drug development, some of these treatments have been shown to induce cardiotoxicity directly affecting heart function and structure, as well as accelerating the development of cardiovascular disease. Such side effects restrict treatment options and can negatively affect disease management. Consequently, when managing cancer patients, it is vital to understand the mechanisms causing cardiotoxicity to better monitor heart function, develop preventative measures against cardiotoxicity, and treat heart failure when it occurs in this patient population. This review discusses the role and mechanism of major chemotherapy agents with principal cardiovascular complications in cancer patients.

Cardiovascular Consequences of Skeletal Muscle Impairments in Breast Cancer

Breast cancer survivors suffer from disproportionate cardiovascular disease risk compared to age-matched controls. Beyond direct cardiotoxic effects due to treatments such as chemotherapy and radiation, breast-cancer-related reductions in skeletal muscle mass, quality and oxidative capacity may further contribute to cardiovascular disease risk in this population by limiting the ability to engage in aerobic exercise—a known promoter of cardiovascular health. Indeed, 20–30% decreases in peak oxygen consumption are commonly observed in breast cancer survivors, which are indicative of exercise intolerance. Thus, breast-cancer-related skeletal muscle damage may reduce exercise-based opportunities for cardiovascular disease risk reduction. Resistance training is a potential strategy to improve skeletal muscle health in this population, which in turn may enhance the capacity to engage in aerobic exercise and reduce cardiovascular disease risk.

Association of Exercise With Mortality in Adult Survivors of Childhood Cancer

Importance

Adult survivors of childhood cancer are at excess risk for mortality compared with the general population. Whether exercise attenuates this risk is not known.

Objective

To examine the association between vigorous exercise and change in exercise with mortality in adult survivors of childhood cancer.

Design, Setting, and Participants

Multicenter cohort analysis among 15 450 adult cancer survivors diagnosed before age 21 years from pediatric tertiary hospitals in the United States and Canada between 1970 and 1999 enrolled in the Childhood Cancer Survivor Study, with follow-up through December 31, 2013.

Exposures

Self-reported vigorous exercise in metabolic equivalent task (MET) hours per week. The association between vigorous exercise and change in vigorous exercise and cause-specific mortality was assessed using multivariable piecewise exponential regression analysis to estimate rate ratios.

Main Outcomes and Measures

The primary outcome was all-cause mortality. Secondary end points were cause-specific mortality (recurrence/progression of primary malignant neoplasm and health-related mortality). Outcomes were assessed via the National Death Index.

Results

The 15 450 survivors had a median age at interview of 25.9 years (interquartile range [IQR], 9.5 years) and were 52.8% male. During a median follow-up of 9.6 years (IQR, 15.5 years), 1063 deaths (811 health-related, 120 recurrence/progression of primary cancer, 132 external/unknown causes) were documented. At 15 years, the cumulative incidence of all-cause mortality was 11.7% (95% CI, 10.6%-12.8%) for those who exercised 0 MET-h/wk, 8.6% (95% CI, 7.4%-9.7%) for 3 to 6 MET-h/wk, 7.4% (95% CI, 6.2%-8.6%) for 9 to 12 MET-h/wk, and 8.0% (95% CI, 6.5%-9.5%) for 15 to 21 MET-h/wk (P < .001). There was a significant inverse association across quartiles of exercise and all-cause mortality after adjusting for chronic health conditions and treatment exposures (P = .02 for trend). Among a subset of 5689 survivors, increased exercise (mean [SD], 7.9 [4.4] MET-h/wk) over an 8-year period was associated with a 40% reduction in all-cause mortality rate compared with maintenance of low exercise (rate ratio, 0.60; 95% CI, 0.44-0.82; P = .001).

Conclusions and Relevance

Vigorous exercise in early adulthood and increased exercise over 8 years was associated with lower risk of mortality in adult survivors of childhood cancer.

Risk of comorbid cardiovascular disease in Korean long-term cancer survivors

BACKGROUND

Cardiovascular disease (CVD) is a common cause of death in cancer survivors. We evaluated the risk of comorbid CVD in long-term cancer survivors according to specific cancer site.

METHODS

Study subjects included 47,171 Koreans aged over 40 years who visited a health promotion centre between 2010 and 2012. Information on CVD and cancer was obtained from self-report. Comorbid CVD was defined as stroke, myocardial infarction or angina pectoris. The risk of comorbid CVD in survivors was compared with that in non-cancer subjects using multiple logistic regression analysis.

RESULTS

Among cancer survivors (n = 3,753), 330 events of CVD were reported. Age- and sex-adjusted analysis showed that odds ratio (OR) for comorbid CVD in survivors was 1.52 (95% confidence interval: 1.34-1.72) compared to non-cancer subjects (n = 43,418). After adjusting for health-related behaviour and medical history, only lung cancer survivors had 2.44 (1.01-5.89)-fold higher OR for CVD. In stratified analysis, significantly higher OR for CVD was evident in lung cancer survivors with hypertension who did not perform regular physical exercise.

CONCLUSIONS

Adult cancer survivors may have an increased risk of comorbid CVD that might be mediated in part by known cardiovascular risk factors depending on the specific cancer site.

From Molecular Mechanisms to Clinical Management of Antineoplastic Drug-Induced Cardiovascular Toxicity: A Translational Overview

Significance: Antineoplastic therapies have significantly improved the prognosis of oncology patients. However, these treatments can bring to a higher incidence of side-effects, including the worrying cardiovascular toxicity (CTX). Recent Advances: Substantial evidence indicates multiple mechanisms of CTX, with redox mechanisms playing a key role. Recent data singled out mitochondria as key targets for antineoplastic drug-induced CTX; understanding the underlying mechanisms is, therefore, crucial for effective cardioprotection, without compromising the efficacy of anti-cancer treatments. Critical Issues: CTX can occur within a few days or many years after treatment. Type I CTX is associated with irreversible cardiac cell injury, and it is typically caused by anthracyclines and traditional chemotherapeutics. Type II CTX is generally caused by novel biologics and more targeted drugs, and it is associated with reversible myocardial dysfunction. Therefore, patients undergoing anti-cancer treatments should be closely monitored, and patients at risk of CTX should be identified before beginning treatment to reduce CTX-related morbidity. Future Directions: Genetic profiling of clinical risk factors and an integrated approach using molecular, imaging, and clinical data may allow the recognition of patients who are at a high risk of developing chemotherapy-related CTX, and it may suggest methodologies to limit damage in a wider range of patients. The involvement of redox mechanisms in cancer biology and anticancer treatments is a very active field of research. Further investigations will be necessary to uncover the hallmarks of cancer from a redox perspective and to develop more efficacious antineoplastic therapies that also spare the cardiovascular system.

Antineoplastic Drug-Induced Cardiotoxicity: A Redox Perspective

Antineoplastic drugs can be associated with several side effects, including cardiovascular toxicity (CTX). Biochemical studies have identified multiple mechanisms of CTX. Chemoterapeutic agents can alter redox homeostasis by increasing the production of reactive oxygen species (ROS) and reactive nitrogen species RNS. Cellular sources of ROS/RNS are cardiomyocytes, endothelial cells, stromal and inflammatory cells in the heart. Mitochondria, peroxisomes and other subcellular components are central hubs that control redox homeostasis. Mitochondria are central targets for antineoplastic drug-induced CTX. Understanding the mechanisms of CTX is fundamental for effective cardioprotection, without compromising the efficacy of anticancer treatments. Type 1 CTX is associated with irreversible cardiac cell injury and is typically caused by anthracyclines and conventional chemotherapeutic agents. Type 2 CTX, associated with reversible myocardial dysfunction, is generally caused by biologicals and targeted drugs. Although oxidative/nitrosative reactions play a central role in CTX caused by different antineoplastic drugs, additional mechanisms involving directly and indirectly cardiomyocytes and inflammatory cells play a role in cardiovascular toxicities. Identification of cardiologic risk factors and an integrated approach using molecular, imaging, and clinical data may allow the selection of patients at risk of developing chemotherapy-related CTX. Although the last decade has witnessed intense research related to the molecular and biochemical mechanisms of CTX of antineoplastic drugs, experimental and clinical studies are urgently needed to balance safety and efficacy of novel cancer therapies.

Exercise and the Tumor Microenvironment: Potential Therapeutic Implications

An imbalance in oxygen delivery to demand in solid tumors results in local areas of hypoxia leading to poor prognosis for the patient. We hypothesize that aerobic exercise increases tumor blood flow, recruits previously nonperfused tumor blood vessels, and thereby augments blood-tumor O2 transport and diminishes tumor hypoxia. When combined with conventional anticancer treatments, aerobic exercise can significantly improve the outcomes for several types of cancers.

Lifestyle Interventions to Improve Cardiorespiratory Fitness and Reduce Breast Cancer Recurrence

As patients are living longer after a cancer diagnosis, survivorship is becoming increasingly important in cancer care. The sequelae of multimodality therapies include weight gain and decreased cardiorespiratory fitness, which increase cardiovascular risk. Evidence suggests that physical activity reduces the risk of breast cancer recurrence and death. Avoidance of weight gain after therapy also improves outcomes after a diagnosis of breast cancer. Prospective randomized trials must be performed to determine the benefits of specific physical activity and dietary habits for survivors of breast cancer. This review outlines the important physiologic changes that occur with antineoplastic therapy and the important role of exercise and diet.

Effects of high-intensity aerobic interval training on cardiovascular disease risk in testicular cancer survivors: A phase 2 randomized controlled trial

BACKGROUND

Testicular cancer survivors (TCS) have an increased risk of treatment-related cardiovascular disease (CVD), which may limit their overall survival. We evaluated the effects of high-intensity aerobic interval training (HIIT) on traditional and novel CVD risk factors and surrogate markers of mortality in a population-based sample of TCS.

METHODS

This phase 2 trial (ClinicalTrials.gov identifier NCT02459132) randomly assigned 63 TCS to usual care (UC) or 12 weeks of supervised HIIT (ie, alternating periods of vigorous-intensity and light-intensity aerobic exercise). The primary outcome was peak aerobic fitness (VO_2peak ) assessed via a treadmill-based maximal cardiorespiratory exercise test. Secondary endpoints included CVD risk (eg, Framingham Risk Score), arterial health, parasympathetic nervous system function, and blood-based biomarkers.

RESULTS

Postintervention VO_2peak data were obtained for 61 participants (97%). HIIT participants attended 99% of the exercise sessions and achieved 98% of the target exercise intensity. Analysis of covariance demonstrated that HIIT was superior to UC for improving VO_2peak (adjusted between-group mean difference, 3.7 mL O₂ /kg/min; 95% confidence interval, 2.4-5.1 [P<.001]) and multiple secondary outcomes including CVD risk (P = .011), arterial thickness (P<.001), arterial stiffness (P<.001), postexercise parasympathetic reactivation (P = .001), inflammation (P = .045), and low-density lipoprotein (P = .014). Overall, HIIT reduced the prevalence of modifiable CVD risk factors by 20% compared with UC.

CONCLUSIONS

This randomized trial provides the first evidence that HIIT improves cardiorespiratory fitness, multiple pathways of CVD risk, and surrogate markers of mortality in TCS. These findings have important implications for the management of TCS. Further research concerning the long-term effects of HIIT on CVD morbidity and mortality in TCS is warranted. Cancer 2017;123:4057-65. © 2017 American Cancer Society.

Preventing antiblastic drug-related cardiomyopathy: old and new therapeutic strategies

Because of the recent advances in chemotherapeutic protocols, cancer survival has improved significantly, although cardiovascular disease has become a major cause of morbidity and mortality among cancer survivors: in addition to the well-known cardiotoxicity (CTX) from anthracyclines, biologic drugs that target molecules that are active in cancer biology also interfere with cardiovascular homeostasis.Pharmacological and non-pharmacological strategies to protect the cardiovascular structure and function are the best approaches to reducing the prevalence of cardiomyopathy linked to anticancer drugs. Extensive efforts have been devoted to identifying and testing strategies to achieve this end, but little consensus has been reached on a common and shared operability.Timing, dose and mode of chemotherapy administration play a crucial role in the development of acute or late myocardial dysfunction. Primary prevention initiatives cover a wide area that ranges from conventional heart failure drugs, such as β-blockers and renin-angiotensin-aldosterone system antagonists to nutritional supplementation and physical training. Additional studies on the pathophysiology and cellular mechanisms of anticancer-drug-related CTX will enable the introduction of novel therapies.We present various typologies of prevention strategies, describing the approaches that have already been used and those that could be effective on the basis of a better understanding of pharmacokinetic and pharmacodynamic CTX mechanisms.

Aerobic exercise in anthracycline-induced cardiotoxicity: a systematic review of current evidence and future directions

Cancer and cardiovascular disease are major causes of morbidity and mortality worldwide. Older cancer patients often wrestle with underlying heart disease during cancer therapy, whereas childhood cancer survivors are living long enough to face long-term unintended cardiac consequences of cancer therapies, including anthracyclines. Although effective and widely used, particularly in the pediatric population, anthracycline-related side effects including dose-dependent association with cardiac dysfunction limit their usage. Currently, there is only one United States Food and Drug Administration-approved drug, dexrazoxane, available for the prevention and mitigation of cardiotoxicity related to anthracycline therapy. While aerobic exercise has been shown to reduce cardiovascular complications in multiple diseases, its role as a therapeutic approach to mitigate cardiovascular consequences of cancer therapy is in its infancy. This systematic review aims to summarize how aerobic exercise can help to alleviate unintended cardiotoxic side effects and identify gaps in need of further research. While published work supports the benefits of aerobic exercise, additional clinical investigations are warranted to determine the effects of different exercise modalities, timing, and duration to identify optimal aerobic training regimens for reducing cardiovascular complications, particularly late cardiac effects, in cancer survivors exposed to anthracyclines.

Changing the Paradigm of Cancer Screening, Prevention, and Treatment

The war on cancer has been fought during the past several decades primarily based on the somatic mutation model of cancer. This has resulted in the emphasis on cancer screening and elimination of any detected cancerous/precancerous cells as the primary method of cancer prevention. This approach has reduced mortality from some cancers, but age-adjusted cancer mortality rates continue to be high. The lack of significant progress in reducing cancer mortality rates may be indicative of a fundamental flaw in the cancer model used. An alternative model of cancer is the immune suppression model of cancer based on the tremendous increase in cancers when the immune system is suppressed. According to this model, the key carcinogenic event is the suppression of the immune system which enables the already existing covert cancers to grow uncontrollably, causing cancer. Hence, cancer screening would consist of identifying those with weak immune system response. The primary mode of cancer prevention and treatment would be boosting of the immune system, for example, through exercise, infection, and low-dose radiation, as they are all known to enhance immune system response and reduce cancers. There is sufficient evidence to justify clinical trials of this approach for cancer screening, prevention, and treatment.

Exercise and Risk of Cardiovascular Events in Women With Nonmetastatic Breast Cancer

PURPOSE

Cardiovascular disease (CVD) is a leading cause of death among women with nonmetastatic breast cancer. Whether exercise is associated with reductions in CVD risk in patients with breast cancer with an elevated CVD risk phenotype is not known.

METHODS

Using a prospective design, women (n = 2,973; mean age, 57 years) diagnosed with nonmetastatic breast cancer participating in two registry-based, regional cohort studies, completed a questionnaire that assessed leisure-time recreational physical activity (metabolic equivalent task [MET]-h/wk). The primary end point was the first occurrence of any of the following: new diagnosis of coronary artery disease, heart failure, valve abnormality, arrhythmia, stroke, or CVD death, occurring after study enrollment.

RESULTS

Median follow-up was 8.6 years (range, 0.2 to 14.8 years). In multivariable analysis, the incidence of cardiovascular events decreased across increasing total MET-h/wk categories (Ptrend < .001). Compared with < 2 MET-h/wk, the adjusted hazard ratio was 0.91 (95% CI, 0.76 to 1.09) for 2 to 10.9 MET-h/wk, 0.79 (95% CI, 0.66 to 0.96) for 11 to 24.5 MET-h/wk, and 0.65 (95% CI, 0.53 to 0.80) for ≥ 24.5 MET-h/wk. Similar trends were observed for the incidence of coronary artery disease and heart failure (P values < .05). Adherence to national exercise guidelines for adult patients with cancer (ie, ≥ 9 MET-h/wk) was associated with an adjusted 23% reduction in the risk of cardiovascular events in comparison with not meeting the guidelines (< 9 MET-h/wk; P < .001). The association with exercise did not differ according to age, CVD risk factors, menopausal status, or anticancer treatment.

CONCLUSION

Exercise is associated with substantial, graded reductions in the incidence of cardiovascular events in women with nonmetastatic breast cancer.

EXercise to prevent AnthrCycline-based Cardio-Toxicity (EXACT) in individuals with breast or hematological cancers: a feasibility study protocol

BACKGROUND

Anthracyclines (AC), widely used and effective anticancer agents, are known to induce both acute and chronic declines in cardiovascular health, ranging in severity from asymptomatic, subclinical dysfunction to substantial cardiomyopathy leading to congestive heart failure and death. There is substantial evidence that physical activity, higher levels of cardiorespiratory fitness, and exercise therapy can help prevent cardiovascular disease. Moreover, animal studies have shown that exercise performed concomitantly with AC treatment may attenuate early cardiac damage that results from AC exposure. Our primary objective is to assess the feasibility of a 12-week aerobic exercise training (AET) program in patients receiving AC-based chemotherapy.

METHODS/DESIGN

This is a prospective, single-arm (pre-post-test design), feasibility study of a supervised 12-week progressive, light-to-moderate to moderate-to-vigorous intensity AET program for patients (18-65 years) receiving AC chemotherapeutic treatment for a primary/non-recurrent breast cancer or hematological malignancy. Both feasibility (e.g., participant recruitment, program adherence, safety) and intervention outcome (e.g., biological markers of cardiotoxicity, aerobic capacity, quality of life) measures will be collected. The AET program will include two, 45-min community-based exercise sessions (treadmill or cycle) per week for a total of 12 weeks. All exercise sessions will be supervised by trained exercise specialists.

DISCUSSION

Data from the EXACT study will be evaluated to determine the need to refine patient recruitment methods and general acceptability of the AET program. Preliminary data on the effects of the AET intervention on pertinent cardiac and health outcomes will also be evaluated and used to inform future studies in terms of the most appropriate outcome measure(s) to adopt and sample size estimation.

TRIAL REGISTRATION

ClinicalTrails.gov, NCT02471053.

Physical Activity and Cancer Outcomes: A Precision Medicine Approach

There is increasing interest in applying a precision medicine approach to understanding exercise as a potential treatment for cancer. We aimed to inform this new approach by appraising epidemiologic literature relating postdiagnosis physical activity to cancer outcomes overall and by molecular/genetic subgroups. Across 26 studies of breast, colorectal, and prostate cancer patients, a 37% reduction was seen in risk of cancer-specific mortality, comparing the most versus the least active patients (pooled relative risk = 0.63; 95% confidence interval: 0.54-0.73). Risks of recurrence or recurrence/cancer-specific death (combined outcome) were also reduced based on fewer studies. We identified ten studies of associations between physical activity and cancer outcomes by molecular or genetic markers. Two studies showed statistically significant risk reductions in breast cancer mortality/recurrence for the most (versus least) physically active estrogen receptor-positive/progesterone receptor-positive (ER⁺/PR⁺) patients, while others showed risk reductions among ER^-PR^- and triple-negative patients. In colorectal cancer, four studies showed statistically significant risk reductions in cancer-specific mortality for patients with high (versus low) physical activity and P21 expression, P27 expression, nuclear CTNNB1^-, PTGS2 (COX-2)⁺, or IRS1 low/negative status. One prostate cancer study showed effect modification by Gleason score. As a means to enhance this evidence, future observational studies are needed that will measure physical activity objectively before and after diagnosis, use standardized definitions for outcomes, control for competing risks, assess nonlinear dose-response relations, and consider reverse causality. Ultimately, randomized controlled trials with clinical cancer outcomes and a correlative component will provide the best evidence of causality, relating exercise to cancer outcomes, overall and for molecular and genetic subgroups. Clin Cancer Res; 22(19); 4766-75. ©2016 AACR.

Cardiovascular Late Effects and Exercise Treatment in Breast Cancer: Current Evidence and Future Directions

Advances in detection and supportive care strategies have led to improvements in cancer-specific and overall survival after a diagnosis of early-stage breast cancer. These improvements, however, are associated with an increase in competing forms of morbidity and mortality, particularly cardiovascular disease (CVD). Indeed, in certain subpopulations of patients, CVD is the leading cause of mortality after early breast cancer, and these women also have an increased risk of CVD-specific morbidity, including an elevated incidence of coronary artery disease and heart failure compared with their sex- and age-matched counterparts. Exercise treatment is established as the cornerstone of primary and secondary prevention of CVD in multiple clinical populations. The potential benefits of exercise treatment to modulate CVD or CVD risk factors before, immediately after, or in the months/years after adjuvant therapy for early-stage breast cancer have received limited attention. We discuss the risk and extent of CVD in patients with breast cancer, review the pathogenesis of CVD, and highlight existing evidence from select clinical trials investigating the efficacy of structured exercise treatment across the CVD continuum in early breast cancer.

Cardiovascular disease following hematopoietic stem cell transplantation: Pathogenesis, detection, and the cardioprotective role of aerobic training

Advances in hematopoietic cell transplantation (HCT) techniques and supportive care strategies have led to dramatic improvements in relapse mortality in patients with high-risk hematological malignancies. These improvements, however, conversely increase the risk of late-occurring non-cancer competing causes, mostly cardiovascular disease (CVD). HCT recipients have a significantly increased risk of CVD-specific mortality, including elevated incidence of coronary artery disease (CAD), cerebrovascular disease, and heart failure (HF) compared to age-matched counterparts. Accordingly, there is an urgent need to identify techniques for the detection of early CVD in HCT patients to inform early prevention strategies. Aerobic training (AT) is established as the cornerstone of primary and secondary disease prevention in multiple clinical settings, and may confer similar benefits in HCT patients at high-risk of CVD. The potential benefits of AT either before, immediately after, or in the months/years following HCT have received limited attention. Here, we discuss the risk and extent of CVD in adult HCT patients, highlight novel tools for early detection of CVD, and review existing evidence in oncology and non-oncology populations supporting the efficacy of AT to attenuate HCT-induced CVD. This knowledge can be utilized to optimize treatment, while minimizing CVD risk in individuals with hematological malignancies undergoing HCT.

Physical Activity and Survival After Prostate Cancer

BACKGROUND

Despite the high global prevalence of prostate cancer (PCa), few epidemiologic studies have assessed physical activity in relation to PCa survival.

OBJECTIVE

To evaluate different types, intensities, and timing of physical activity relative to PCa survival.

DESIGN, SETTING, AND PARTICIPANTS

A prospective study was conducted in Alberta, Canada, in a cohort of 830 stage II-IV incident PCa cases diagnosed between 1997 and 2000 with follow-up to 2014 (up to 17 yr). Prediagnosis lifetime activity was self-reported at diagnosis. Postdiagnosis activity was self-reported up to three times during follow-up.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Cox proportional hazards models related physical activity to all-cause and PCa-specific deaths and to first recurrence/progression of PCa.

RESULTS AND LIMITATIONS

A total of 458 deaths, 170 PCa-specific deaths, and, after first follow-up, 239 first recurrences/progressions occurred. Postdiagnosis total activity (>119 vs ≤42 metabolic equivalent [MET]-hours/week per year) was associated with a significantly lower all-cause mortality risk (hazard ratio [HR]: 0.58; 95% confidence interval [CI], 0.42-0.79; p value for trend <0.01). Postdiagnosis recreational activity (>26 vs ≤4 MET-hours/week per year) was associated with a significantly lower PCa-specific mortality risk (HR: 0.56; 95% CI, 0.35-0.90; p value for trend = 0.01). Sustained recreational activity before and after diagnosis (>18-20 vs <7-8 MET-hours/week per year) was associated with a lower risk of all-cause mortality (HR: 0.66; 95% CI, 0.49-0.88). Limitations included generalisability to healthier cases and an observational study design.

CONCLUSIONS

These findings support emerging recommendations to increase physical activity after the diagnosis of PCa and would inform a future exercise intervention trial examining PCa outcomes.

PATIENT SUMMARY

In a 17-yr prostate cancer (PCa) survival study, men who survived at least 2 yr who were more physically active postdiagnosis or performed more recreational physical activity before and after diagnosis survived longer. Recreational physical activity after diagnosis was associated with a lower risk of PCa death.

Randomized trial of exercise and an online recovery tool to improve rehabilitation outcomes of cancer survivors

PURPOSE

The purpose of this study was to test the effects of a cancer survivor exercise program and an online recovery awareness program (Restwise) on physical outcomes of aerobic capacity and muscle strength.

DESIGN

Randomized controlled trial design.

SETTING

Treasure Valley Family YMCA, Boise, ID.

SAMPLE

Fifty cancer survivors.

METHODS

Subjects were randomly assigned to the 12-week exercise program or the exercise program and Restwise. Restwise required users to complete daily objective and subjective ratings. Restwise compiles these data to provide individualized feedback recommending the exercise dose to maximize recovery and minimize fatigue.

MAIN RESEARCH VARIABLE

Baseline and posttest measures of physical performance (6-minute walk, 1-repetition maximum of lower and upper body strength).

FINDINGS

The exercise plus Restwise group demonstrated significant improvements (P < 0.001) that were found on all 3 physical measurements of strength and endurance. The exercise-only group demonstrated significant within-group improvement only on the 6-minute walk. The exercise plus Restwise group demonstrated an 18.5% greater improvement in the 6-minute walk, and a 35.2% and 45%, respectively, greater improvement on the leg and chest press than the exercise-only group. However, the between-group differences were not significant.

CONCLUSION

Cancer survivors who use the Restwise online recovery program in conjunction with an exercise program demonstrated minimal clinically important differences compared with other clinical populations on all 3 measures, whereas the exercise-only group had improvements only on the 6-minute walk. Patient adherence to the Restwise program was good, and patients provided positive feedback.

Exercise and risk of major cardiovascular events in adult survivors of childhood hodgkin lymphoma: a report from the childhood cancer survivor study

PURPOSE

Survivors of Hodgkin lymphoma (HL) are at increased risk of treatment-related cardiovascular (CV) events; whether exercise modifies this risk is unknown.

METHODS

Survivors of HL (n = 1,187; median age, 31.2 years) completed a questionnaire evaluating vigorous-intensity exercise behavior. CV events were collected in follow-up questionnaires and graded according to Common Terminology Criteria for Adverse Events (version 4.03). The primary end point was incidence of any major (grade 3 to 5) CV event. Poisson regression analyses were used to estimate the association between exercise exposure (metabolic equivalent [MET] hours/week(-1)) and risk of major CV events after adjustment for clinical covariates and cancer treatment.

RESULTS

Median follow-up was 11.9 years (range, 1.7 to 14.3 years). Cumulative incidence of any CV event was 12.2% at 10 years for survivors reporting 0 MET hours/week(-1) compared with 5.2% for those reporting ≥ 9 MET hours/week(-1). In multivariable analyses, the incidence of any CV event decreased across increasing MET categories (Ptrend = .002). Compared with survivors reporting 0 MET hours/week(-1), the adjusted rate ratio for any CV event was 0.87 (95% CI, 0.56 to 1.34) for 3 to 6 MET hours/week(-1), 0.45 (95% CI, 0.26 to 0.80) for 9 to 12 MET hours/week(-1), and 0.47 (95% CI, 0.23 to 0.95) for 15 to 21 MET hours/week(-1). Adherence to national vigorous intensity exercise guidelines (ie, ≥ 9 MET hours/week(-1)) was associated with a 51% reduction in the risk of any CV event in comparison with not meeting the guidelines (P = .002).

CONCLUSION

Vigorous exercise was associated with a lower risk of CV events in a dose-dependent manner independent of CV risk profile and treatment in survivors of HL.

Relationship between exercise behavior, cardiorespiratory fitness, and cognitive function in early breast cancer patients treated with doxorubicin-containing chemotherapy: a pilot study

The purpose of this study was to examine the relationship between self-reported exercise behavior, cardiorespiratory fitness (CRF), and cognitive function in early breast cancer patients. Thirty-seven breast cancer patients following completion of chemotherapy (median 16 months) and 14 controls were studied. Cognitive function was assessed using the Central Nervous System (CNS) Vital Signs software (CNS Vital Signs, LLC, Morrisville, N.C., USA), a computerized test battery consisting of 9 cognitive subtests. Exercise behavior was evaluated using the Godin Leisure Time Exercise Questionnaire, and CRF was assessed via a cardiopulmonary exercise test to assess peak oxygen consumption. Patients' mean total exercise was 184 ± 141 min·week(-1) compared with 442 ± 315 min·week(-1) in controls (p < 0.001). Significantly fewer patients (32%) were meeting exercise guidelines (i.e., ≥150 min of moderate-intensity or vigorous exercise per week) compared with 57% of controls (p = 0.014). Patients' peak oxygen consumption averaged 23.5 ± 6.3 mL·kg(-1)·min(-1) compared with 30.6 ± 7.0 mL·kg(-1)·min(-1) in controls (p < 0.01). Scores on the cognitive subdomains were generally lower in patients compared with controls, although only the difference in verbal memory was significant (unadjusted p = 0.041). In patients, weak to moderate correlations were indicated between exercise, peak oxygen consumption, and the majority of cognitive subdomain scores; however, there was a significant positive correlation between exercise and visual memory (r = 0.47, p = 0.004). In conclusion, breast cancer patients following the completion of primary adjuvant chemotherapy exhibit, in general, worse cognitive performance than healthy women from the general population, and such performance may be related to their level of exercise behavior.

Skeletal muscle mitochondria: a major player in exercise, health and disease

BACKGROUND

Maintaining skeletal muscle mitochondrial content and function is important for sustained health throughout the lifespan. Exercise stimulates important key stress signals that control skeletal mitochondrial biogenesis and function. Perturbations in mitochondrial content and function can directly or indirectly impact skeletal muscle function and consequently whole-body health and wellbeing.

SCOPE OF REVIEW

This review will describe the exercise-stimulated stress signals and molecular mechanisms positively regulating mitochondrial biogenesis and function. It will then discuss the major myopathies, neuromuscular diseases and conditions such as diabetes and ageing that have dysregulated mitochondrial function. Finally, the impact of exercise and potential pharmacological approaches to improve mitochondrial function in diseased populations will be discussed.

MAJOR CONCLUSIONS

Exercise activates key stress signals that positively impact major transcriptional pathways that transcribe genes involved in skeletal muscle mitochondrial biogenesis, fusion and metabolism. The positive impact of exercise is not limited to younger healthy adults but also benefits skeletal muscle from diseased populations and the elderly. Impaired mitochondrial function can directly influence skeletal muscle atrophy and contribute to the risk or severity of disease conditions. Pharmacological manipulation of exercise-induced pathways that increase skeletal muscle mitochondrial biogenesis and function in critically ill patients, where exercise may not be possible, may assist in the treatment of chronic disease.

GENERAL SIGNIFICANCE

This review highlights our understanding of how exercise positively impacts skeletal muscle mitochondrial biogenesis and function. Exercise not only improves skeletal muscle mitochondrial health but also enables us to identify molecular mechanisms that may be attractive targets for therapeutic manipulation. This article is part of a Special Issue entitled Frontiers of mitochondrial research.