Effects of a physical activity behavior change intervention on inflammation and related health outcomes in breast cancer survivors: pilot randomized trial

Effects of Theory-Based Behavioral Interventions on Physical Activity Among Overweight and Obese Female Cancer Survivors: A Systematic Review of Randomized Controlled Trials

PURPOSE

To determine whether theory-based physical activity (PA) interventions for overweight and obese female cancer survivors lead to increased PA and improved health.

METHODS

This systematic review examined randomized controlled trials analyzing the impact of theory-based PA interventions on overweight and obese female cancer survivors through December 2016. Searches of 5 electronic databases revealed 10 articles that included 1351 participants who met the inclusion criteria.

RESULTS

Participants were primarily non-Hispanic white (74%-100%) breast or endometrial cancer survivors. Intervention characteristics and PA assessment tools varied greatly. Adherence (68%-99%) and retention (79%-100%) were relatively high. Social cognitive theory was utilized as the theoretical construct in 9 of the 10 studies. Home-based interventions led to small improvements in PA (Cohen's d range = 0.25-0.31), whereas home-based plus center-based interventions led to moderate to large improvements (Cohen's d range = 0.45-1.02). Only three of the studies assessed psychosocial behavioral processes associated with PA, and the results were mixed. Health-related outcomes included improvements in aerobic fitness (Cohen's d = 0.32-1.1 in 5 studies), large absolute decreases in waist circumferences (>6 cm in 3 of 5 studies; Cohen's d = -0.31 to -1.02), and no change in inflammatory biomarkers (in 2 studies). Only one serious adverse event (pelvic stress fracture) was attributed to the interventions.

CONCLUSIONS

Theory-based PA interventions are safe and feasible for overweight and obese female cancer survivors. Interventions that include a center-based component showed moderate to large effect sizes for PA. Future studies should evaluate behavioral variables and more health-related clinical outcomes.

Protocol for Exercise Program in Cancer and Cognition (EPICC): A randomized controlled trial of the effects of aerobic exercise on cognitive function in postmenopausal women with breast cancer receiving aromatase inhibitor therapy

The Exercise Program in Cancer and Cognition (EPICC) Study is a randomized controlled trial designed to test the effects of moderate-intensity aerobic exercise on cognitive function in postmenopausal women with early-stage breast cancer during the first six months of aromatase inhibitor therapy. It is estimated that up to 75% of survivors of breast cancer experience cognitive impairment related to disease and treatment. At present, there are no known interventions to improve or manage cognitive function for women with breast cancer. Here, we describe a single-blinded, randomized controlled trial with allocation of 254 postmenopausal women with early-stage breast cancer to a supervised six-month aerobic exercise intervention or usual care. Prior to beginning aromatase inhibitor (AI) therapy, participants complete baseline assessments of cognitive function, cardiorespiratory fitness, blood-based biomarkers, physical activity and sleep, and symptoms (fatigue, sleep problems, depressive symptoms, anxiety). A random subset of participants (n = 150) undergoes neuroimaging procedures that include structural and functional magnetic resonance imaging assessments. All participants maintain an activity diary; physical activity and sleep monitoring is repeated three and seven months post-randomization. The remaining baseline assessments are repeated seven months post-randomization. If successful, exercise could be a low-cost method to improve cognitive function in women with breast cancer that is easily adaptable to the home or community.

TRIAL REGISTRATION

Clinicaltrials.govNCT02793921. Registered 20 May 2016.

Association between expression of inflammatory markers in normal breast tissue and mammographic density among premenopausal and postmenopausal women

OBJECTIVE

Inflammatory markers may be associated with breast cancer risk. We assessed the association between expression levels of proinflammatory (interleukin 6, tumor necrosis factor-α, C-reactive protein, cyclooxygenase 2, leptin, serum amyloid A1, interleukin 8, and signal transducer and activator of transcription 3) and anti-inflammatory markers (transforming growth factor-β, interleukin 10, and lactoferrin) in normal breast tissue with mammographic density, a strong breast cancer risk indicator, among 163 breast cancer patients.

METHODS

The expression of inflammatory markers was visually evaluated on immunohistochemistry stained slides. The percent mammographic density (PMD) was estimated by a computer-assisted method in the contralateral cancer-free breast. We used generalized linear models to estimate means of PMD by median expression levels of the inflammatory markers while adjusting for age and waist circumference.

RESULTS

Higher expression levels (above median) of the proinflammatory marker interleukin 6 were associated with higher PMD among all women (24.1% vs 18.5%, P = 0.007). Similarly, higher expression levels (above median) of the proinflammatory markers (interleukin 6, tumor necrosis factor-α, C-reactive protein, and interleukin 8) were associated with higher PMD among premenopausal women (absolute difference in the PMD of 8.8% [P = 0.006], 7.7% [P = 0.022], 6.7% [P = 0.037], and 16.5% [P = 0.032], respectively). Higher expression levels (above median) of the anti-inflammatory marker transforming growth factor-β were associated with lower PMD among all (18.8% vs 24.3%, P = 0.005) and postmenopausal women (14.5% vs 20.7%, P = 0.013).

CONCLUSIONS

Our results provide support for the hypothesized role of inflammatory markers in breast carcinogenesis through their effects on mammographic density. Inflammatory markers could be targeted in future breast cancer prevention interventions.

Physical activity for women with breast cancer after adjuvant therapy

BACKGROUND

Women with a diagnosis of breast cancer may experience short- and long-term disease and treatment-related adverse physiological and psychosocial outcomes. These outcomes can negatively impact prognosis, health-related quality of life (HRQoL), and psychosocial and physical function. Physical activity may help to improve prognosis and may alleviate the adverse effects of adjuvant therapy.

OBJECTIVES

To assess effects of physical activity interventions after adjuvant therapy for women with breast cancer.

SEARCH METHODS

We searched the Cochrane Breast Cancer Group (CBCG) Specialised Registry, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, the Cumulative Index to Nursing and Allied Health Literature (CINAHL), the Physiotherapy Evidence Database (PEDro), SPORTDiscus, PsycINFO, ClinicalTrials.gov, and the World Health Organization (WHO) International Clinical Trials Registry Platform, on 18 September 2015. We also searched OpenGrey and Healthcare Management Information Consortium databases.

SELECTION CRITERIA

We searched for randomised and quasi-randomised trials comparing physical activity interventions versus control (e.g. usual or standard care, no physical activity, no exercise, attention control, placebo) after adjuvant therapy (i.e. after completion of chemotherapy and/or radiation therapy, but not hormone therapy) in women with breast cancer.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies, assessed risk of bias, and extracted data. We contacted trial authors to ask for additional information when needed. We calculated an overall effect size with 95% confidence intervals (CIs) for each outcome and used GRADE to assess the quality of evidence for the most important outcomes.

MAIN RESULTS

We included 63 trials that randomised 5761 women to a physical activity intervention (n = 3239) or to a control (n = 2524). The duration of interventions ranged from 4 to 24 months, with most lasting 8 or 12 weeks (37 studies). Twenty-eight studies included aerobic exercise only, 21 involved aerobic exercise and resistance training, and seven used resistance training only. Thirty studies described the comparison group as usual or standard care, no intervention, or control. One-fifth of studies reported at least 20% intervention attrition and the average physical activity adherence was approximately 77%.No data were available on effects of physical activity on breast cancer-related and all-cause mortality, or on breast cancer recurrence. Analysis of immediately postintervention follow-up values and change from baseline to end of intervention scores revealed that physical activity interventions resulted in significant small-to-moderate improvements in HRQoL (standardised mean difference (SMD) 0.39, 95% CI 0.21 to 0.57, 22 studies, 1996 women; SMD 0.78, 95% CI 0.39 to 1.17, 14 studies, 1459 women, respectively; low-quality evidence), emotional function (SMD 0.21, 95% CI 0.10 to 0.32, 26 studies, 2102 women, moderate-quality evidence; SMD 0.31, 95% CI 0.09 to 0.53, 15 studies, 1579 women, respectively; low-quality evidence), perceived physical function (SMD 0.33, 95% CI 0.18 to 0.49, 25 studies, 2129 women; SMD 0.60, 95% CI 0.23 to 0.97, 13 studies, 1433 women, respectively; moderate-quality evidence), anxiety (SMD -0.57, 95% CI -0.95 to -0.19, 7 studies, 326 women; SMD -0.37, 95% CI -0.63 to -0.12, 4 studies, 235 women, respectively; low-quality evidence), and cardiorespiratory fitness (SMD 0.44, 95% CI 0.30 to 0.58, 23 studies, 1265 women, moderate-quality evidence; SMD 0.83, 95% CI 0.40 to 1.27, 9 studies, 863 women, respectively; very low-quality evidence).Investigators reported few minor adverse events.Small improvements in physical activity interventions were sustained for three months or longer postintervention in fatigue (SMD -0.43, 95% CI -0.60 to -0.26; SMD -0.47, 95% CI -0.84 to -0.11, respectively), cardiorespiratory fitness (SMD 0.36, 95% CI 0.03 to 0.69; SMD 0.42, 95% CI 0.05 to 0.79, respectively), and self-reported physical activity (SMD 0.44, 95% CI 0.17 to 0.72; SMD 0.51, 95% CI 0.08 to 0.93, respectively) for both follow-up values and change from baseline scores.However, evidence of heterogeneity across trials was due to variation in intervention components (i.e. mode, frequency, intensity, duration of intervention and sessions) and measures used to assess outcomes. All trials reviewed were at high risk of performance bias, and most were also at high risk of detection, attrition, and selection bias. In light of the aforementioned issues, we determined that the evidence was of very low, low, or moderate quality.

AUTHORS' CONCLUSIONS

No conclusions regarding breast cancer-related and all-cause mortality or breast cancer recurrence were possible. However, physical activity interventions may have small-to-moderate beneficial effects on HRQoL, and on emotional or perceived physical and social function, anxiety, cardiorespiratory fitness, and self-reported and objectively measured physical activity. The positive results reported in the current review must be interpreted cautiously owing to very low-to-moderate quality of evidence, heterogeneity of interventions and outcome measures, imprecision of some estimates, and risk of bias in many trials. Future studies with low risk of bias are required to determine the optimal combination of physical activity modes, frequencies, intensities, and durations needed to improve specific outcomes among women who have undergone adjuvant therapy.

Protocol for Moving On: a randomized controlled trial to increase outcome expectations and exercise among breast cancer survivors

Aim

The aim of this study was to test the feasibility and fidelity of an intervention, Moving On, aimed to increase outcome expectations OEs (i.e. what one expects to obtain or avoid as a result of a behaviour) and exercise among breast cancer survivors.

Design

Randomized controlled trial.

Methods

Intervention arm participants will be given a theory-guided booklet that was co-created by the research team and three physically active breast cancer survivors who exercise to manage late and long-term treatment effects. Attention control arm participants will be given a similar booklet focused on diet. Participants will have 1 week to complete reading, writing and reflecting activities in the booklets. Study outcomes will be measured through online surveys; exercise will also be measured objectively with a Fitbit®. Four weeks postintervention, participants' thoughts about the usefulness, strengths and weakness of the intervention booklet will be assessed. OEs and exercise will be measured at baseline, 4-, 8- and 12-week postintervention.

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.

Adipose tissue inflammation in breast cancer survivors: effects of a 16-week combined aerobic and resistance exercise training intervention

PURPOSE

Obesity is a leading modifiable contributor to breast cancer mortality due to its association with increased recurrence and decreased overall survival rate. Obesity stimulates cancer progression through chronic, low-grade inflammation in white adipose tissue, leading to accumulation of adipose tissue macrophages (ATMs), in particular, the pro-inflammatory M1 phenotype macrophage. Exercise has been shown to reduce M1 ATMs and increase the more anti-inflammatory M2 ATMs in obese adults. The purpose of this study was to determine whether a 16-week exercise intervention would positively alter ATM phenotype in obese postmenopausal breast cancer survivors.

METHODS

Twenty obese postmenopausal breast cancer survivors were randomized to a 16-week aerobic and resistance exercise (EX) intervention or delayed intervention control (CON). The EX group participated in 16 weeks of supervised exercise sessions 3 times/week. Participants provided fasting blood, dual-energy X-ray absorptiometry (DXA), and superficial subcutaneous abdominal adipose tissue biopsies at baseline and following the 16-week study period.

RESULTS

EX participants experienced significant improvements in body composition, cardiometabolic biomarkers, and systemic inflammation (all p < 0.03 vs. CON). Adipose tissue from EX participants showed a significant decrease in ATM M1 (p < 0.001), an increase in ATM M2 (p < 0.001), increased adipose tissue secretion of anti-inflammatory cytokines such as adiponectin, and decreased secretion of the pro-inflammatory cytokines IL-6 and TNF- α (all p < 0.055).

CONCLUSIONS

A 16-week aerobic and resistance exercise intervention attenuates adipose tissue inflammation in obese postmenopausal breast cancer survivors. Future large randomized trials are warranted to investigate the impact of exercise-induced reductions in adipose tissue inflammation and breast cancer recurrence.

Updated systematic review of exercise studies in breast cancer survivors: attention to the principles of exercise training

OBJECTIVES

To update our previous evaluation of the exercise interventions used in randomised controlled trials of breast cancer survivors in relation to (1) the application of the principles of exercise training in the exercise prescription; (2) the reporting of the components of the exercise prescription; and (3) the reporting of adherence of participants to the prescribed interventions.

DESIGN

Systematic review.

DATA SOURCES

The OVID Medline, Embase, CINAHL and SPORTDiscus electronic databases were searched from January 2010 to January 2017.

ELIGIBILITY CRITERIA

Randomised controlled trials of at least 4 weeks of aerobic and/or resistance exercise in women diagnosed with breast cancer, reporting on physical fitness or body composition outcomes.

RESULTS

Specificity was appropriately applied by 84%, progression by 29%, overload by 38% and initial values by 67% of newly identified studies. Reversibility was reported by 3% anddiminishing returns by 22% of newly identified studies. No studies reported all components of the exercise prescription in the methods, or adherence to the prescribed intervention in the results. Reporting of reversibility has increased from 2010, but no other improvements in reporting were noted from the previous review.

SUMMARY/CONCLUSION

No studies of exercise in women with breast cancer attended to all principles of exercise training, or reported all components of the exercise prescription in the methods, or adherence to the prescription in the results. Full reporting of the exercise prescribed and completed is essential for study replication in research and translating research findings into the community, and should be prioritised in future trials.

The Effects of Resistance Exercise on Biomarkers of Breast Cancer Prognosis: A Pooled Analysis of Three Randomized Trials

Background: Using a secondary data analysis from randomized controlled trials comparing one year of resistance exercise (n = 109) to a placebo control condition (n = 106) in postmenopausal, posttreatment breast cancer survivors, we investigated the influence of resistance training and changes in body composition on markers associated with cancer progression.Methods: Measures included serum levels of insulin, IGF-1, IGFBP1-3, leptin, serum amyloid A (SAA), adiponectin, C-reactive protein (CRP), IL1β, TNFα, IL6, and IL8, and body composition (total, lean and fat mass in kg) by DXA at baseline, 6, and 12 months. Linear mixed effects models were used to examine the association between group, biomarkers, and body composition and whether or not changes in muscle strength or body composition influenced the effect of exercise on biomarkers.Results: CRP decreased over time among women participating in resistance training compared with increases in controls (P = 0.045). In stratified analyses and compared with increases in controls, women who gained strength reduced CRP (P = 0.003) and maintained levels of IL1β and IL6. Among exercisers who lost weight (≥2 kg), CRP (P = 0.045), leptin (P < 0.01), and SAA (P = 0.029) decreased, whereas IGF-BP1 (P = 0.036) increased compared with controls.Conclusions: Resistance training may lower inflammation and improve insulin pathway profiles, but the magnitude and degree of benefit from exercise may depend upon whether or not women gained strength, a possible marker of compliance with training, and/or lost weight during exercise.Impact: Future resistance training trials should consider these potential influencing factors as they may determine how well exercise can slow cancer progression and prevent disease recurrence. Cancer Epidemiol Biomarkers Prev; 27(2); 146-53. ©2017 AACR.

Effect of home-based exercise intervention on fasting insulin and Adipocytokines in colorectal cancer survivors: a randomized controlled trial

BACKGROUND AND AIMS

Elevated circulating insulin is associated with increased risk of recurrence and cancer mortality in early-stage colorectal cancer (CRC). We conducted a randomized controlled trial to determine the effect of a 12-week home-based exercise program on fasting insulin, adipocytokines, and physical function in CRC survivors.

METHODS

One hundred and twenty-three stage II-III CRC patients were randomly assigned to either a home-based exercise (n=62) or standard care control group (n=61) for 12weeks. Home-based exercise consisted of aerobic and resistance training, with a goal of obtaining ≥18 metabolic equivalent task (MET)-h/wk. Participants in the exercise group were instructed to participate in >18MET-h/wk. of aerobic and resistance exercise while the participants in the control group were asked to maintain their usual daily activity. The primary outcome was fasting insulin levels. Secondary outcomes were adiponectin, TNF-α levels and 6min walk distance from baseline to post-intervention.

RESULTS

After the 12-weeks, moderate-vigorous physical activity participation increased from 9.1±14.7MET-h/wk. to 26.6±21.7MET-h/wk. in the exercise group, with no change in the control group (p<0.01 for group and time interaction). Circulating insulin level decreased by 1μU/ml (6.0±3.9 vs. 5.0±3.5, p=0.009) in the exercise group with no change in the control group (p=0.022 for group and time interaction). A similar trend was observed in TNF-α (p=0.030 for group and time interaction). Six minute walk distance increased by 25.2m in the exercise group with no change in the control group (p=0.061 for group and time interaction).

CONCLUSIONS

The 12week home-based exercise program increased level of physical activity and decreased circulating insulin levels in CRC survivors.

Physical Activity and Sleep Quality in Breast Cancer Survivors: A Randomized Trial

PURPOSE

Data from large randomized controlled trials confirming sleep quality improvements with aerobic physical activity have heretofore been lacking for post-primary treatment breast cancer survivors. Our primary purpose for this report was to determine the effects of a physical activity behavior change intervention, previously reported to significantly increase physical activity behavior, on sleep quality in post-primary treatment breast cancer survivors.

METHODS

Post-primary treatment breast cancer survivors (n = 222) were randomized to a 3-month physical activity behavior change intervention (Better Exercise Adherence after Treatment for Cancer [BEAT Cancer]) or usual care. Self-report (Pittsburgh Sleep Quality Index [PSQI]) and actigraphy (latency and efficiency) sleep outcomes were measured at baseline, 3 months (M3), and 6 months (M6).

RESULTS

After adjusting for covariates, BEAT Cancer significantly improved PSQI global sleep quality when compared with usual care at M3 (mean between-group difference [M] = -1.4, 95% confidence interval [CI] = -2.1 to -0.7, P < 0.001) and M6 (M = -1.0, 95% CI = -1.7 to -0.2, P = 0.01). BEAT Cancer improved several PSQI subscales at M3 (sleep quality M = -0.3, 95% CI = -0.4 to -0.1, P = 0.002; sleep disturbances M = -0.2, 95% CI = -0.3 to -0.03, P = 0.016; daytime dysfunction M = -0.2, 95% CI = -0.4 to -0.02, P = 0.027) but not M6. A nonsignificant increase in percent of participants classified as good sleepers occurred. No significant between-group difference was noted for accelerometer latency or efficiency.

CONCLUSION

A physical activity intervention significantly reduced perceived global sleep dysfunction at 3 and 6 months, primarily because of improvements in sleep quality aspects not detected with accelerometer.

Obesity and adverse breast cancer risk and outcome: Mechanistic insights and strategies for intervention

Answer questions and earn CME/CNE Recent decades have seen an unprecedented rise in obesity, and the health impact thereof is increasingly evident. In 2014, worldwide, more than 1.9 billion adults were overweight (body mass index [BMI], 25-29.9 kg/m2 ), and of these, over 600 million were obese (BMI ≥30 kg/m2 ). Although the association between obesity and the risk of diabetes and coronary artery disease is widely known, the impact of obesity on cancer incidence, morbidity, and mortality is not fully appreciated. Obesity is associated both with a higher risk of developing breast cancer, particularly in postmenopausal women, and with worse disease outcome for women of all ages. The first part of this review summarizes the relationships between obesity and breast cancer development and outcomes in premenopausal and postmenopausal women and in those with hormone receptor-positive and -negative disease. The second part of this review addresses hypothesized molecular mechanistic insights that may underlie the effects of obesity to increase local and circulating proinflammatory cytokines, promote tumor angiogenesis and stimulate the most malignant cancer stem cell population to drive cancer growth, invasion, and metastasis. Finally, a review of observational studies demonstrates that increased physical activity is associated with lower breast cancer risk and better outcomes. The effects of recent lifestyle interventions to decrease sex steroids, insulin/insulin-like growth factor-1 pathway activation, and inflammatory biomarkers associated with worse breast cancer outcomes in obesity also are discussed. Although many observational studies indicate that exercise with weight loss is associated with improved breast cancer outcome, further prospective studies are needed to determine whether weight reduction will lead to improved patient outcomes. It is hoped that several ongoing lifestyle intervention trials, which are reviewed herein, will support the systematic incorporation of weight loss intervention strategies into care for patients with breast cancer. CA Cancer J Clin 2017;67:378-397. © 2017 American Cancer Society.

Protective Effect of Aerobic Physical Activity on Sleep Behavior in Breast Cancer Survivors

HYPOTHESES

Sleep disorders are associated with an increased risk of cancer, including breast cancer (BC). Physical activity (PA) can produce beneficial effects on sleep.

STUDY DESIGN

We designed a randomized controlled trial to test the effect of 3 months of physical activity on sleep and circadian rhythm activity level evaluated by actigraphy.

METHODS

40 BC women, aged 35-70 years, were randomized into an intervention (IG) and a control group (CG). IG performed a 3 month of aerobic exercise. At baseline and after 3 months, the following parameters were evaluated both for IG and CG: anthropometric and body composition measurements, energy expenditure and motion level; sleep parameters (Actual Sleep Time-AST, Actual Wake Time-AWT, Sleep Efficiency-SE, Sleep Latency-SL, Mean Activity Score-MAS, Movement and Fragmentation Index-MFI and Immobility Time-IT) and activity level circadian rhythm using the Actigraph Actiwatch.

RESULTS

The CG showed a deterioration of sleep, whereas the IG showed a stable pattern. In the CG the SE, AST and IT decreased and the AWT, SL, MAS and MFI increased. In the IG, the SE, IT, AWT, SL, and MAS showed no changes and AST and MFI showed a less pronounced change in the IG than in the CG. The rhythmometric analysis revealed a significant circadian rhythm in two groups. After 3 months of PA, IG showed reduced fat mass %, while CG had improved weight and BMI.

CONCLUSION

Physical activity may be beneficial against sleep disruption. Indeed, PA prevented sleep worsening in IG. PA can represent an integrative intervention therapy able to modify sleep behaviour.

Effects of Exercise on Insulin, IGF Axis, Adipocytokines, and Inflammatory Markers in Breast Cancer Survivors: A Systematic Review and Meta-analysis

Background: Insulin, IGF axis, adiponectin, and inflammatory markers are associated with breast cancer. Given that physical activity improves prognosis of breast cancer survivors, we investigated the effects of exercise on these markers as potential mediators between physical activity and breast cancer.Methods: PubMed, EMBASE, CENTRAL, CINAHL, and SportDiscus were searched up to December 3, 2015, to identify randomized controlled trials (RCT) that investigated the effect of exercise on insulin, IGF axis, and cytokines in breast cancer survivors. Weighted mean difference (WMD) was calculated using either fixed- or random-effects models on the basis of the heterogeneity of the studies.Results: A total of 18 studies involving 681 breast cancer survivors were included, and these numbers were reduced for individual biomarker analyses. We found that exercise significantly reduced fasting insulin levels [WMD, -3.46 μU/mL; 95% confidence interval (CI), -5.97 to -0.95; P = 0.007]. Furthermore, potentially meaningful but statistically nonsignificant changes were observed in insulin resistance (WMD, -0.73; 95% CI, -0.54 to 0.13; P = 0.23), adiponectin (WMD, 1.17 μg/mL; 95% CI, -0.87 to 3.20; P = 0.26), and C-reactive protein (WMD, -1.10 mg/L; 95% CI, -2.39 to 0.20; P = 0.10). Subgroup analyses showed that fasting insulin levels were significantly more impacted in studies in which intervention participants experienced a weight reduction (WMD, -7.10 μU/mL; 95% CI, -10.31 to -3.90; P < 0.001).Conclusions: Exercise reduces fasting insulin levels in breast cancer survivors. This may be due to exercise-induced reductions in body weight.Impact: Practitioners and clinicians may better help breast cancer prognosis be improved through exercise, anticipating physiological effects on cancer. Cancer Epidemiol Biomarkers Prev; 26(3); 355-65. ©2016 AACR.

Every exercise bout matters: linking systemic exercise responses to breast cancer control

Cumulative epidemiological evidence shows that regular exercise lowers the risk of developing breast cancer and decreases the risk of disease recurrence. The causality underlying this relation has not been fully established, and the exercise recommendations for breast cancer patients follow the general physical activity guidelines, prescribing 150 min of exercise per week. Thus, elucidations of the causal mechanisms are important to prescribe and implement the most optimal training regimen in breast cancer prevention and treatment. The prevailing hypothesis on the positive association within exercise oncology has focused on lowering of the basal systemic levels of cancer risk factors with exercise training. However, another rather overlooked systemic exercise response is the marked acute increases in several potential anti-cancer components during each acute exercise bout. Here, we review the evidence of the exercise-mediated changes in systemic components with the ability to influence breast cancer progression. In the first part, we focus on systemic risk factors for breast cancer, i.e., sex hormones, insulin, and inflammatory markers, and their adaptation to long-term training. In the second part, we describe the systemic factors induced acutely during exercise, including catecholamines and myokines. In conclusion, we propose that the transient increases in exercise factors during acute exercise appear to be mediating the positive effect of regular exercise on breast cancer progression.

Adiponectin, Leptin and Objectively Measured Physical Activity in Adults: A Narrative Review

The objective of this study was to compile and analyse existing scientific evidences reporting the effects of objectively measured physical activity on the levels of adiponectin and leptin. Articles related to the effects of objectively measured physical activity on the levels of adiponectin and leptin were searched from the Medline and PubMed databases. The search was limited to 'objectively measured' physical activity, and studies that did not objectively measure the physical activity were excluded. Only English articles were included in the search and review. A total of 18 articles encompassing 2,026 respondents met the inclusion criteria. The eligible articles included all forms of evidence (e.g., cross-sectional and intervention). Seventeen and 11 studies showed the effects of objectively measured physical activity on adiponectin and leptin, respectively. Five and four cross-sectional studies showed the effects of objectively measured physical activity on adiponectin and leptin, respectively. Two out of five studies showed a weak to moderate positive association between adiponectin and objectively measured physical activity, while three out of four studies showed a weak to moderate inverse association between leptin and objectively measured physical activity. For intervention studies, six out of 12 studies involving adiponectin and five out of seven studies involving leptin showed a significant effect between the proteins and objectively measured physical activity. However, a definitive conclusion could not be drawn due to several methodological flaws in the existing articles and the acute lack of additional research in this area. In conclusion, the existing evidences are encouraging but yet not compelling. Hence, further well-designed large trials are needed before the effectiveness of objectively measured physical activity in elevating adiponectin levels and in decreasing leptin levels could be strongly confirmed.

Role of n-3 Polyunsaturated Fatty Acids and Exercise in Breast Cancer Prevention: Identifying Common Targets

Diet and exercise are recognized as important lifestyle factors that significantly influence breast cancer risk. In particular, dietary n-3 polyunsaturated fatty acids (PUFAs) have been shown to play an important role in breast cancer prevention. Growing evidence also demonstrates a role for exercise in cancer and chronic disease prevention. However, the potential synergistic effect of n-3 PUFA intake and exercise is yet to be determined. This review explores targets for breast cancer prevention that are common between n-3 PUFA intake and exercise and that may be important study outcomes for future research investigating the combined effect of n-3 PUFA intake and exercise. These lines of evidence highlight potential new avenues for research and strategies for breast cancer prevention.

Impact of aerobic exercise on levels of IL-4 and IL-10: results from two randomized intervention trials

The mechanisms whereby regular exercise reduces chronic inflammation remain unclear. We investigated whether regular aerobic exercise alters basal levels of interleukin (IL)‐10 and IL‐4 in two randomized trials of physical activity. The Alberta Physical Activity and Breast Cancer Prevention Trial (ALPHA, n = 320) and the Breast Cancer and Exercise Trial in Alberta (BETA, n = 400) were two‐center, two‐armed randomized trials in inactive, healthy, postmenopausal women. Both trials included an exercise intervention prescribed five times/week and no dietary changes. In ALPHA, the exercise group was prescribed 225 min/week versus no activity in the controls. BETA examined dose‐response effects comparing 300 (HIGH) versus 150 (MODERATE) min/week. Plasma concentrations of IL‐10 and IL‐4 were measured at baseline, 6, and 12 months. Intention‐to‐treat (ITT) analysis was performed using linear mixed models adjusted for baseline biomarker concentrations. Circulating anti‐inflammatory cytokine levels decreased among all groups, with percent change ranging from −3.4% (controls) to −8.2% (HIGH) for IL‐4 and −1.6% (controls) to −7.5% (HIGH) for IL‐10. No significant group differences were found for IL‐4 (ALPHA P = 0.54; BETA P = 0.32) or IL‐10 (ALPHA P = 0.84; BETA P = 0.68). Some evidence for moderation of the effect of exercise by baseline characteristics was found for IL‐10 but not for IL‐4. Results from these two large randomized aerobic exercise intervention trials suggest that aerobic exercise does not alter IL‐10 or IL‐4 in a manner consistent with chronic disease and cancer prevention.

Reducing the Risk of Breast Cancer Recurrence: an Evaluation of the Effects and Mechanisms of Diet and Exercise

With recent medical advances in diagnosis and treatment, the increasing numbers of long-term survivors of breast cancer is considerable and has resulted in the expansion of scientific research to include examination of lifestyle modifications as means of prevention of recurrence, new breast cancer events, and mortality. The objective of this report is to review randomized controlled trials (RCTs) including diet and/or exercise interventions on breast cancer recurrence in women with a history of breast cancer as well as pertinent recent epidemiologic evidence. Implicated biologic mechanisms are discussed to elucidate the impact of diet and exercise on disease recurrence.

The Etiology and management of radiotherapy-induced fatigue

Fatigue is one of the most common side-effects accompanying radiotherapy, but arguably the least understood. Radiotherapy-induced fatigue (RIF) is a clinical subtype of cancer treatment-related fatigue. It is described as a pervasive, subjective sense of tiredness persisting over time, interferes with activities of daily living, and is not relieved by adequate rest or sleep. RIF is one of the early side-effects and long-lasting for cancer patients treated with localized radiation. Although the underlying mechanisms of fatigue have been studied in several disease conditions, the etiology, mechanisms, and risk factors of RIF remain elusive, and this symptom remains poorly managed. The purpose of this paper is to review and discuss recent articles that defined, proposed biologic underpinnings and mechanisms to explain the pathobiology of RIF, as well as articles that proposed interventions to manage RIF. Understanding the mechanisms of RIF can describe promising pathways to identify at-risk individuals and identify potential therapeutic targets to alleviate and prevent RIF using a multimodal, multidisciplinary approach.

Effects of exercise intervention in breast cancer survivors: a meta-analysis of 33 randomized controlled trails

Background

Exercise is associated with favorable outcomes in cancer survivors. The purpose of this meta-analysis is to comprehensively summarize the effects of exercise intervention in breast cancer survivors.

Methods

A systematic search of PubMed, Elsevier, and Google scholar was conducted up to March 2015. References from relevant meta-analyses and reviews were also checked.

Results

Thirty-three randomized controlled trials were included in this meta-analysis, including 2,659 breast cancer survivors. Compared with the control group, quality of life was significantly improved in exercise intervention group, especially in mental health and general health subscales of short form 36 questionnaire, as well as emotion well-being and social well-being subscales of the Functional Assessment of Cancer Therapy. Besides, exercise alleviated the symptoms of depression and anxiety in the exercise group. Furthermore, exercise was also associated with positive outcomes in body mass index, lean mass, and muscle strength. In addition, the serum concentration of insulin, insulin-like growth factor-II, and insulin-like growth factor binding protein-1 was significantly reduced in exercise intervention group. However, based on the current data of this meta-analysis, there were no significant differences in sleep dysfunction or fatigue between groups.

Conclusion

Our study suggested that exercise intervention was beneficial to breast cancer survivors. Therefore, exercise should be recommended to this patient group.

The Effect of Exercise Training on Mediators of Inflammation in Breast Cancer Survivors: A Systematic Review with Meta-analysis

Several sources of evidence indicate that exercise during and after breast cancer could positively modulate the tumor microenvironment. This meta-analysis aimed to determine the effects of exercise training on mediators of inflammation in breast cancer survivors. We searched for randomized controlled trials published from January 1990 to March 2014. An inverse variance method of meta-analysis was performed using a random effects model in the presence of statistical heterogeneity. Eight high-quality trials (n = 478) were included. Exercise improved the serum concentrations of IL6 [weighted mean difference (WMD) = -0.55 pg/mL; 95% confidence interval (CI), -1.02 to -0.09], TNFα (WMD = -0.64 pg/mL; 95% CI, -1.21 to -0.06), IL8 (MD = -0.49 pg/mL; 95% CI, -0.89 to -0.09), and IL2 (WMD = 1.03 pg/mL; 95% CI, 0.40 to 1.67). No significant differences were found in the serum concentrations of C-reactive protein (WMD = -0.15; 95% CI, -0.56 to 0.25) or IL10 (WMD = 0.41; 95% CI, -0.18 to 1.02). Exercise training positively modulates chronic low-grade inflammation in women with breast cancer, which may impact upon carcinogenic mechanisms and the tumor microenvironment. These findings align with the other positive effects of exercise for breast cancer survivors, reinforcing the appropriateness of exercise prescription in this population. Cancer Epidemiol Biomarkers Prev; 25(7); 1009-17. ©2016 AACR.

A Wellness Program for Cancer Survivors and Caregivers: Developing an Integrative Pilot Program with Exercise, Nutrition, and Complementary Medicine

The Integrative Wellness Program (IWP) at the University of Miami Sylvester Comprehensive Cancer Center (SCCC) sought to provide integrative wellness education to cancer patients, survivors, and caregivers by offering instruction in exercise, nutrition, and complementary and alternative medicine. The objective of this study was to assess the impact of the IWP on the overall wellness of the individuals participating in the program. Three different 10-week versions of the IWP were conducted over a 1-year period. Each session focused on a different wellness topic presented through interactive lectures and applied activities. A series of self-report questionnaires were administered at baseline and again at the completion of the program to assess improvements in physical activity levels, dietary habits, sleep hygiene, and quality of life. Participants were generally older, Caucasian, female, had higher levels of education, and still currently receiving treatment. Significant changes were observed in two measures: Starting the Conversation (-2.0 ± 2.40, p = .037) and the Sticking To It subscale of the Self-Efficacy and Eating Habits Survey (1.7 ± 1.22, p = .0013). A trend for improvement in the Reducing Fat subscale of the Self-Efficacy Eating Habits (0.44 ± 0.60, p = .056) was also observed. Participant satisfaction surveys indicated high levels of satisfaction and applicability of the material presented. The significant improvements detected related to dietary habits, combined with the responses from the participant satisfaction surveys, suggest that the IWP was well received and can positively impact the overall wellness of cancer patients, survivors, and their caregivers.

Exercise, inflammation, and fatigue in cancer survivors

Cancer-related fatigue significantly disrupts normal functioning and quality of life for a substantial portion of cancer survivors, and may persist for years following cancer treatment. While the causes of persistent fatigue among cancer survivors are not yet fully understood, accumulating evidence suggests that several pathways, including chronic inflammation, autonomic imbalance, HPA-axis dysfunction, and/or mitochondrial damage, could contribute towards the disruption of normal neuronal function and result in the symptom of cancer-related fatigue. Exercise training interventions have been shown to be some of the more successful treatment options to address cancer-related fatigue. In this review, we discuss the literature regarding the causes of persistent fatigue in cancer survivors and the mechanisms by which exercise may relieve this symptom. There is still much work to be done until the prescription of exercise becomes standard practice for cancer survivors. With improvements in the quality of studies, evidenced-based exercise interventions will allow exercise scientists and oncologists to work together to treat cancer-related fatigue.

Influence of Exercise on Inflammation in Cancer: Direct Effect or Innocent Bystander?

We propose the hypothesis that the benefits of exercise on inflammation in cancer are a result of a direct effect on inflammatory cytokines, including interleukin-6, tumor necrosis factor-α, and monocyte chemoattractant protein 1, that are critical for cancer growth as well as a bystander effect of the established relationship between exercise and cancer.

Integrative Therapies and Cardiovascular Disease in the Breast Cancer Population: A Review, Part 2

In Part 1 of the current review, the cardiotoxicity of standard breast cancer treatment was reviewed. Part 2 presents a comprehensive review of the current evidence for lifestyle factors, including nutrition and exercise. Part 2 describes the results of several dietary interventions in breast cancer survivors. Specific dietary factors that may promote cardiovascular health in this population, including essential fatty acids and plant phytosterols, are also reviewed. In addition, the mechanisms by which exercise may provide a benefit are discussed, and evidence for the important role of attainment and maintenance of a healthy weight is outlined. Finally, recommendations for lifestyle changes in the survivor population are discussed, and opportunities for future research in this population are identified.

Exercise and dietary advice intervention for survivors of triple-negative breast cancer: effects on body fat, physical function, quality of life, and adipokine profile

PURPOSE

Regular exercise and healthy eating are routinely recommended for breast cancer survivors, and past studies show benefits in quality of life and decreased inflammation. However, this has not been tested specifically in triple-negative breast cancer survivors. Increasing physical activity and losing body fat are thought to positively affect inflammatory biomarkers that have been associated with breast cancer. Therefore, the primary purpose of this study was to determine if participation in an exercise and dietary counseling program can improve body fat, physical function, and quality of life in survivors of this aggressive breast cancer. Secondarily, we sought to determine if participation in the program had beneficial effects on obesity-related markers of the adipokine profile.

METHODS

Sixty-six survivors of triple-negative breast cancer with BMI >25 were invited to participate. Twenty-eight enrolled and 23 completed the randomized, controlled trial (13 intervention, 10 control). Moderate-intensity aerobic exercise (150 min per week, for 12 weeks) and diet counseling were compared to usual care, education only. The primary outcome of interest was weight loss (body mass, BMI, % fat), and secondary outcomes included physical function (exercise capacity), quality of life (Function After Cancer Therapy-Breast (FACT-B)), cytokines (C-reactive protein (CRP), TNF-α, IL-6), and adipokine profile (leptin, adiponectin, insulin).

RESULTS

Participants in the program lost more body fat (2.4 % loss vs. 0.4 % gain, p < 0.05) than the control group. The intervention group also improved quality of life (FACT-B total score +14 pts) and decreased sedentary time but did not improve peak exercise capacity. The intervention had no effect on serum cytokines and adipokines after 12 weeks in the program. However, serum leptin and adiponectin and their ratio were significantly correlated with BMI in the intervention group (p < 0.05).

CONCLUSIONS

Exercise and dietary counseling led to loss of body fat and improved quality of life in survivors of triple-negative breast cancer. BMI was associated with favorable changes in leptin and adiponectin which may reflect a change in adiposity with intervention. Exercise and healthy eating may be equally effective in this high-risk population as in other breast cancer survivors and should be encouraged as a part of a cancer survivorship program.

The integrative role of leptin, oestrogen and the insulin family in obesity-associated breast cancer: potential effects of exercise

Obesity is an established risk factor for postmenopausal breast cancer. The mechanisms through which obesity influences the development and progression of breast cancer are not fully elucidated; however, several factors such as increased oestrogen, concentrations of various members of the insulin family and inflammation that are associated with adiposity are purported to be important factors in this relationship. Emerging research has also begun to focus on the role of adipokines, (i.e. adipocyte secreted factors), in breast cancer. Leptin secretion is directly related to adiposity and is believed to promote breast cancer directly and independently, as well as through involvement with the oestrogen and insulin signalling pathways. As leptin is secreted from white adipose tissue, any intervention that reduces adiposity may be favourable. However, it is also important to consider that energy expenditure through exercise, independent of fat loss, may improve leptin regulation. The purpose of this narrative review was to explore the role of leptin in breast cancer development and progression, identify key interactions with oestrogen and the insulin family, and distinguish the potential effects of exercise on these interactions.

Effects of six months of Yoga on inflammatory serum markers prognostic of recurrence risk in breast cancer survivors

Yoga-based exercise has proven to be beneficial for practitioners, including cancer survivors. This study reports on the effect on inflammatory biological markers for 20 breast cancer survivors who participated in a six-month yoga-based (YE) exercise program. Results are compared to a comprehensive exercise (CE) program group and a comparison (C) exercise group who chose their own exercises. "Pre" and "post" assessments included measures of anthropometrics, cardiorespiratory capacity, and inflammatory markers interleukin 6 (IL-6), interleukin 8 (IL-8), tumor necrosis factor alpha (TNFα) and C-reactive protein (CRP). Descriptive statistics, effect size (d), and dependent sample 't' tests for all outcome measures were calculated for the YE group. Significant improvements were seen in decreased % body fat, (-3.00%, d = -0.44, p = <.001) but not in cardiorespiratory capacity or in inflammatory serum markers. To compare YE outcomes with the other two groups, a one-way analysis of co-variance (ANCOVA) was used, controlling for age, BMI, cardiorespiratory capacity and serum marker baseline values. We found no differences between groups. Moreover, we did not see significant changes in any inflammatory marker for any group. Our results support the effectiveness of yoga-based exercise modified for breast cancer survivors for improving body composition. Larger studies are needed to determine if there are significant changes in inflammatory serum markers as a result of specific exercise modalities.

Inflammation and psychosocial factors mediate exercise effects on sleep quality in breast cancer survivors: pilot randomized controlled trial

OBJECTIVE

To improve mechanistic understanding, this pilot randomized controlled trial examined mediators of an exercise intervention effects on sleep in breast cancer survivors (BCS).

METHODS

Forty-six postmenopausal BCS (≤Stage II, off primary treatment) were randomized to a 3-month exercise intervention or control group. Intervention included 160 min/week of moderate intensity aerobic walking, twice weekly resistance training (resistance bands), and six discussion groups (to improve adherence). Blinded assessments at baseline and post-intervention included sleep disturbance (PSQI and PROMIS®), objective sleep quality (accelerometer), serum cytokines, accelerometer physical activity, cardiorespiratory fitness, body composition, fatigue, and psychosocial factors. Mediation was tested using Freedman-Schatzkin difference-in-coefficients tests.

RESULTS

When compared with control, the intervention group demonstrated a significant increase in PSQI sleep duration (i.e., fewer hours of sleep/night) (d = 0.73, p = .03). Medium to large but non-significant standardized effect sizes were noted for PSQI daytime somnolence (d = -0.63, p = .05) and accelerometer latency (d = -0.49, p = .14). No statistically significant mediators were detected for PSQI sleep duration score or accelerometer latency. Daytime somnolence was mediated by tumor necrosis factor-alpha (mediated 23% of intervention effect, p < .05), interleukin (IL)-6:IL-10 (16%, p < .01), IL-8:IL-10 (26%, p < .01), and fatigue (38%, p < .05). Mediating or enhancing relationships for several of the sleep outcomes were noted for accelerometer physical activity, PROMIS® fatigue, exercise social support, and/or physical activity enjoyment.

CONCLUSIONS

Inflammation and psychosocial factors may mediate or enhance sleep response to our exercise intervention. Further study is warranted to confirm our results and translate our findings into more effective interventions aimed at improving sleep quality in BCS.

Biobehavioral factors mediate exercise effects on fatigue in breast cancer survivors

PURPOSE

This study aimed to examine mediators of fatigue response to an exercise intervention for breast cancer survivors in a pilot randomized controlled trial.

METHODS

Postmenopausal breast cancer survivors (n = 46; ≤stage 2), off primary treatment, and reporting fatigue and/or sleep dysfunction were randomized to a 3-month exercise intervention (160 min·wk of moderate-intensity aerobic walking, twice weekly resistance training with resistance bands) or control group. Six discussion group sessions provided behavioral support to improve adherence. Fatigue, serum cytokines, accelerometer physical activity, cardiorespiratory fitness, sleep dysfunction, and psychosocial factors were assessed at baseline and 3 months.

RESULTS

The exercise intervention effect sizes for fatigue were as follows: fatigue intensity d = 0.30 (P = 0.34), interference d = -0.38 (P = 0.22), and general fatigue d = -0.49 (P = 0.13). Using the Freedman-Schatzkin difference-in-coefficients tests, increase in fatigue intensity was significantly mediated by interleukin 6 (IL-6) (82%), IL-10 (94%), IL-6/IL-10 (49%), and tumor necrosis factor-α (TNF-α):IL-10 (78%) with reduced sleep dysfunction increasing the relationship between intervention and fatigue intensity rather than mediating intervention effects (-88%). Decrease in fatigue interference was mediated by sleep dysfunction (35%), whereas IL-10 and pro-anti-inflammatory cytokine ratios increased the relationship between intervention and interference (-25% to -40%). The reduction in general fatigue was significantly mediated by minutes of physical activity (76%), sleep dysfunction (45%), and physical activity enjoyment (40%), with IL-10 (-40%) and IL-6/IL-10 (-11%) increasing the intervention-fatigue relationship. In the intervention group, higher baseline fatigue, anxiety, depression, and perceived exercise barrier interference predicted a greater decline in fatigue interference and/or general fatigue during the intervention.

CONCLUSIONS

Biobehavioral factors mediated and enhanced intervention effects on fatigue, whereas psychosocial factors predicted fatigue response. Further study is warranted to confirm our results and to improve understanding of relationships that mediate and strengthen the intervention-fatigue association.

Effects of the BEAT Cancer physical activity behavior change intervention on physical activity, aerobic fitness, and quality of life in breast cancer survivors: a multicenter randomized controlled trial

Most breast cancer survivors (BCS) are not meeting recommended physical activity guidelines. Here, we report the effects of the Better Exercise Adherence after Treatment for Cancer (BEAT Cancer) behavior change intervention on physical activity, aerobic fitness, and quality of life (QoL). We randomized 222 post-primary treatment BCS to the 3-month intervention (BEAT Cancer) or usual care (UC). BEAT Cancer combined supervised exercise, face-to-face counseling, and group discussions with tapering to home-based exercise. Assessments at baseline, immediately post-intervention (month 3; M3), and 3 months post-intervention (month 6; M6) included accelerometer and self-reported physical activity, submaximal treadmill test, and QoL [Functional Assessment of Cancer Therapy (FACT)-Breast scale]. Adjusted linear mixed-model analyses demonstrated significant effects of BEAT Cancer compared to UC on weekly minutes of ≥ moderate intensity physical activity at M3 by accelerometer [mean between group difference (M) = +41; 95 % confidence interval (CI) = 10-73; p = 0.010] and self-report (M = +93; CI = 62-123; p < 0.001). Statistical significance remained at M6 for self-reported physical activity (M = +74; CI = 43-105; p < 0.001). BEAT Cancer participants were significantly more likely to meet physical activity recommendations at both time points [accelerometer M3 adjusted odds ratio (OR) = 2.2; CI = 1.0-4.8 and M6 adjusted OR = 2.4; CI = 1.1-5.3; self-report M3 adjusted OR = 5.2; CI = 2.6-10.4 and M6 adjusted OR = 4.8; CI = 2.3-10.0]. BEAT Cancer significantly improved fitness at M6 (M = +1.8 ml/kg/min; CI = 0.8-2.8; p = 0.001) and QoL at M3 and M6 (M = +6.4; CI = 3.1-9.7; p < 0.001 and M = +3.8; CI = 0.5-7.2; p = 0.025, respectively). The BEAT Cancer intervention significantly improved physical activity, fitness, and QoL with benefits continuing 3 months post-intervention.

Twenty-five years of research on the effects of exercise training in breast cancer survivors: A systematic review of the literature

AIM: To investigate the role of exercise training the past 25 years on major physiological-psychological outcomes studied thus far in this patient population.

METHODS: PubMed, MedlinePlus, the Cochrane Library, Web of Science, SportDiscus, Embase, Scorpus, and Google Scholar were searched from September to November 2013 to identify exercise training studies that used objective measurements of fitness and/or patient reported outcomes assessed pre and post-exercise training with statistical analyses performed in at least one of the following outcome measurements: Cardiorespiratory function, body composition, muscular strength, fatigue, depression, and overall quality of life. Five reviewers independently identified the studies that met the criteria for the review and discrepancies were resolved by consensus among all authors.

RESULTS: Fifty-one studies were included in this review with 5 from the period between 1989-1999, 11 from 2000-2006, and 35 from 2007-2013. The evolution of study designs changed from aerobic only exercise training interventions (1989-1999), to a combination of aerobic and resistance training (2000-2006), to studies including an arm of resistance training or examining the effects of resistance training as the main mode of exercise (2007-2013). Overall, the benefits of exercise showed improvements in cardiorespiratory function, body composition, strength, and patient reported outcomes including fatigue, depression, and quality of life.

CONCLUSION: Exercise training appears to be safe for most breast cancer patients and improvements in physiological, psychological, and functional parameters can be attained with regular participation in moderate intensity exercise.

Interventions for promoting habitual exercise in people living with and beyond cancer

BACKGROUND

The beneficial effects of regular exercise for people living with or beyond cancer are becoming apparent. However, how to promote exercise behaviour in sedentary cancer cohorts is not as well understood. A large majority of people living with or recovering from cancer do not meet exercise recommendations. Hence, reviewing the evidence on how to promote and sustain exercise behaviour is important.

OBJECTIVES

To assess the effects of interventions to promote exercise behaviour in sedentary people living with and beyond cancer and to address the following questions: Which interventions are most effective in improving aerobic fitness and skeletal muscle strength and endurance? What adverse effects are attributed to different exercise interventions? Which interventions are most effective in improving exercise behaviour amongst patients with different cancers? Which interventions are most likely to promote long-term (12 months or longer) exercise behaviour? What frequency of contact with exercise professionals is associated with increased exercise behaviour? What theoretical basis is most often associated with increased exercise behaviour? What behaviour change techniques are most often associated with increased exercise behaviour?

SEARCH METHODS

We searched the following electronic databases: Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 8, 2012), MEDLINE, EMBASE, AMED, CINAHL, PsycLIT/PsycINFO, SportDiscus and PEDro from inception to August 2012. We also searched the grey literature, wrote to leading experts in the field, wrote to charities and searched reference lists of other recent systematic reviews.

SELECTION CRITERIA

We included only randomised controlled trials (RCTs) that compared an exercise intervention with a usual care approach in sedentary people over the age of 18 with a homogenous primary cancer diagnosis.

DATA COLLECTION AND ANALYSIS

Two review authors working independently (LB and KH) screened all titles and abstracts to identify studies that might meet the inclusion criteria, or that cannot be safely excluded without assessment of the full text (e.g. when no abstract is available). All eligible papers were formally abstracted by at least two members of the review author team working independently (LB and KH) and using the data collection form. When possible, and if appropriate, we performed a fixed-effect meta-analysis of study outcomes. For continuous outcomes (e.g. cardiorespiratory fitness), we extracted the final value, the standard deviation of the outcome of interest and the number of participants assessed at follow-up in each treatment arm, to estimate standardised mean difference (SMD) between treatment arms. SMD was used, as investigators used heterogeneous methods to assess individual outcomes. If a meta-analysis was not possible or was not appropriate, we synthesised studies as a narrative.

MAIN RESULTS

Fourteen trials were included in this review, involving a total of 648 participants. Only studies involving breast, prostate or colorectal cancer were identified as eligible. Just six trials incorporated a target level of exercise that could meet current recommendations. Only three trials were identified that attempted to objectively validate independent exercise behaviour with accelerometers or heart rate monitoring. Adherence to exercise interventions, which is crucial for understanding treatment dose, is often poorly reported. It is important to note that the fundamental metrics of exercise behaviour (i.e. frequency, intensity and duration, repetitions, sets and intensity of resistance training), although easy to devise and report, are seldom included in published clinical trials.None of the included trials reported that 75% or greater adherence (the stated primary outcome for this review) of the intervention group met current aerobic exercise recommendations at any given follow-up. Just two trials reported six weeks of resistance exercise behaviour that would meet the guideline recommendations. However, three trials reported adherence of 75% or greater to an aerobic exercise goal that was less than the current guideline recommendation of 150 minutes per week. All three incorporated both supervised and independent exercise components as part of the intervention, and none placed restrictions on the control group in terms of exercise behaviour. These three trials shared programme set goals and the following behaviour change techniques: generalisation of a target behaviour; prompting of self-monitoring of behaviour; and prompting of practise. Despite the uncertainty surrounding adherence in many of the included trials, interventions caused improvements in aerobic exercise tolerance at 8 to 12 weeks (from 7 studies, SMD 0.73, 95% confidence interval (CI) 0.51 to 0.95) in intervention participants compared with controls. At six months, aerobic exercise tolerance was also improved (from 5 studies, SMD 0.70, 95% CI 0.45 to 0.94), but it should be noted that four of the five trials used in this analysis had a high risk of bias, hence caution is warranted in interpretation of results. Attrition over the course of these interventions is typically low (median 6%).

AUTHORS' CONCLUSIONS

Interventions to promote exercise in cancer survivors who report better levels of adherence share some common behaviour change techniques. These involve setting programme goals, prompting practise and self-monitoring and encouraging participants to attempt to generalise behaviours learned in supervised exercise environments to other, non-supervised contexts. However, expecting most sedentary survivors to achieve current guideline recommendations of at least 150 minutes per week of aerobic exercise is likely to be unrealistic. As with all well-designed exercise programmes in any context, prescriptions should be designed around individual capabilities, and frequency, duration and intensity or sets, repetitions, intensity or resistance training should be generated on this basis.

Efficacy of multimodal exercise-based rehabilitation on physical activity, cardiorespiratory fitness, and patient-reported outcomes in cancer survivors: a randomized, controlled trial

BACKGROUND

Sedentary behavior and impaired cardiovascular reserve capacity are common late effects of cancer therapy emphasizing the need for effective strategies to increase physical activity (PA) in cancer survivors. We examined the efficacy of a 12-month exercise-based rehabilitation program on self-reported PA, cardiorespiratory fitness (VO2peak), strength, and patient-reported outcomes.

PATIENTS AND METHODS

Two hundred fourteen post-treatment cancer survivors were randomly assigned to a 12-month rehabilitation program consisting of individual (x3) and group-based (x6) counseling in combination with once weekly high-intensity group-based exercise training (the Copenhagen Physical Activity after Cancer Treatment, PACT; n = 108) or to a health evaluation program (HE, n = 106). Study outcomes were assessed at baseline, 6 months, and 12 months.

RESULTS

After 12 months, the percentage of patients reporting meeting PA goal behavior (≥3 h/week) was significantly increased in the PACT group versus the HE group (70.4% versus 43.4%, P = 0.001). Repeated measures analyses indicated a statistically significant improvement in VO2peak (l min(-1)) in favour of PACT (treatment effect ratio = 1.04; 95% confidence interval 1.00-1.07; P = 0.032). Significant between group differences were also observed for strength (P < 0.001), depression (P = 0.020) and mental health (P = 0.040).

CONCLUSION

A 12-month exercise-based rehabilitation program is an effective strategy to promote PA and improve VO2peak in cancer survivors.

The role of intratumoral and systemic IL-6 in breast cancer

Chronic low-grade inflammation plays an important role in the pathogenesis of several cancer forms including breast cancer. The pleiotropic cytokine IL-6 is a key player in systemic inflammation, regulating both the inflammatory response and tissue metabolism during acute stimulations. Here, we review the associations between IL-6 and breast cancer ranging from in vitro cell culture studies to clinical studies, covering the role of IL-6 in controlling breast cancer cell growth, regulation of cancer stem cell renewal, as well as breast cancer cell migration. Moreover, associations between circulating IL-6 and risk of breast cancer, prognosis for patients with prevalent disease, adverse effects and interventions to control systemic IL-6 levels in patients are discussed. In summary, direct application of IL-6 on breast cancer cells inhibits proliferation in estrogen receptor positive cells, while high circulating IL-6 levels are correlated with a poor prognosis in breast cancer patients. This discrepancy reflects distinct roles of IL-6, with elevated systemic levels being a biomarker for tumor burden, physical inactivity, and impaired metabolism, while local intratumoral IL-6 signaling is important for controlling breast cancer cell growth, metastasis, and self renewal of cancer stem cells.