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

Resistance Exercise and Skeletal Muscle-Related Outcomes in Patients with Cancer: A Systematic Review

BACKGROUND

Skeletal muscle loss is prevalent throughout the cancer continuum and correlated with morbidity and mortality. Resistance exercise has been trialed to mitigate skeletal muscle loss. This systematic review summarizes and qualitatively synthesizes the effects of resistance exercise on muscle-related outcomes in adult cancer populations, including skeletal muscle mass, performance and muscle-related biomarkers.

METHODS

The systematic review protocol was developed in accordance with the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P). We searched electronic databases including AMED, CENTRAL, CINAHL, CIRRIE, EMBASE, MEDLINE, PEDro, REHABDATA, Scopus, and SPORTDiscus from inception to December 2021. We included randomized controlled trials that investigated the effects of resistance exercise on muscle-related outcomes in adult cancer populations. Interventions that involved any resistance exercise were included. Muscle-related outcomes were categorized as skeletal muscle mass (e.g., lean mass, appendicular muscle mass), muscle performance (e.g., muscle strength, physical function), and muscle-related biomarkers (e.g., muscle cells, metabolic/inflammatory markers). Risk of bias (RoB) was assessed using the Cochrane ROB tool.

RESULTS

A total of 102 studies from 101 randomized controlled trials were included. The majority of studies focused on breast cancer (46%) and those who completed treatment (43%). Resistance exercise interventions were largely 3-4 months long (48%), combined with aerobic exercise (56%), at a vigorous intensity (25%), and in-person/supervised settings (57%). Among the studies assessing muscle mass, performance, and biomarkers ( n = 42, 83, and 22, respectively), resistance exercise interventions improved upper/lower body or appendicular muscle mass (67%-100%), muscle strength (61%-68%), and physical function (74%-100%). Most biomarkers did not show significant changes (75%-100%) or showed inconsistent results.

CONCLUSIONS

Generally, resistance exercise had positive effects on skeletal muscle mass and performance with no negative effects compared to controls. Our findings demonstrated that resistance exercise may be an effective strategy to attenuate deterioration or exert improvements in muscle mass and performance outcomes.

[How could physical activity decrease the risk of breast cancer development and recurrence?]

OBJECTIVES

Breast cancer is the most frequent and deadly cancer among women. In France, 50% of adults are currently overweight, mostly as a result of a sedentary lifestyle. Numerous studies have highlighted overweight, obesity and lack of physical activity as risk factors for the occurrence and prognosis of cancers, particularly breast cancer. The aim of this study was to understand the extent to which physical activity can improve this prognosis, and what the pathophysiology is.

METHODS

The Senology Commission of the Collège national des gynécologues et obstétriciens français (CNGOF) based its responses on an analysis of the international literature using a Preferred Reporting Items for Systematic review and Meta-Analyses (PRISMA) methodology conducted on the PubMed database between 1994 and 2023.

RESULTS

A total of 70 articles were selected, demonstrating the role of regular physical activity in reducing the risk of breast cancer occurrence and recurrence. This role in controlling carcinogenesis is mediated by metabolic factors such as leptin, adiponectin and insulin, sex hormones and inflammation. The signaling pathways deregulated by these molecules are known carcinogenic pathways which could be used as therapeutic targets adapted to this population, without replacing the essential hygienic-dietary recommendations.

CONCLUSION

Physical activity has a protective effect on breast cancer risk and prognosis. We must therefore continue to raise awareness in the general population and promote physical activity as a means of primary, secondary, and tertiary prevention.

WISER Survivor Trial: Combined Effect of Exercise and Weight Loss Interventions on Adiponectin and Leptin Levels in Breast Cancer Survivors with Overweight or Obesity

Adipocyte dysregulation is one mechanism linking overweight and breast cancer recurrence. Exercise and weight loss are associated with a decreased risk of breast cancer recurrence in breast cancer survivors with overweight or obesity, which may be mediated through reduced leptin levels, increased adiponectin levels, and an elevated adiponectin to leptin (A:L) ratio. The four-arm randomized controlled WISER Survivor trial examined the 12-month intervention effects of exercise, weight loss, and the combination of exercise and weight loss on adipokine levels among breast cancer survivors (n = 339) with overweight or obesity. Compared with Control, the Combination of Exercise and Weight Loss decreased leptin levels (-35.9%; 95% CI: -46.8%, -25.0%) and increased A:L ratio (11.6%; 95% CI: 5.6%, 17.6%) but did not change adiponectin levels (4.1%; 95% CI: -3.1%, 11.2%). Compared with Control, Weight Loss Alone decreased leptin levels (-35.6%; 95% CI: -46.6%, -24.5%) and increased A:L ratio (10.6%; 95% CI: 4.7%, 16.5%) but did not change adiponectin levels (0.9%; 95% CI: -6.0%, 7.9%). Compared with Control, Exercise Alone did not change leptin levels, adiponectin levels, or A:L ratio. In analyses that consolidated intervention groups, compared with Control, weight loss of ≥5% decreased leptin levels (p trend < 0.01) and increased A:L ratio (p trend < 0.01) but did not alter adiponectin levels (p trend = 0.53). Weight loss, with or without exercise, was associated with decreased leptin levels in breast cancer survivors with overweight or obesity. Improvements in the adipokine secretion profile (A:L ratio) were primarily driven by a weight loss-induced change in leptin levels.

Associations of Post-Diagnosis Lifestyle with Prognosis in Women with Invasive Breast Cancer

BACKGROUND

Lifestyle habits can impact breast cancer development, but its impact on breast cancer prognosis remains unclear. We investigated associations of post-diagnosis lifestyle with mortality and recurrence in 1,964 women with invasive breast cancer enrolled in the Kaiser Permanente Northern California Pathways Study shortly after diagnosis with lifestyle information at baseline (2005-2013) and the 2-year follow-up.

METHODS

We calculated a post-diagnosis lifestyle score (range, 0-18) based on 9 diet, physical activity, and body weight recommendations from the American Cancer Society/American Society of Clinical Oncology (ACS/ASCO) using follow-up data (body weight also included baseline data); higher scores indicate greater guideline concordance. Similarly, we calculated a pre-diagnosis lifestyle score using baseline data to investigate pre- to post-diagnosis changes. We estimated hazard ratios (HR) and 95% confidence intervals (CI) using Cox proportional hazard models, with follow-up through December 2018 (observing 290 deaths and 176 recurrences).

RESULTS

The 2-year post-diagnosis lifestyle score was inversely associated with all-cause mortality (ACM; HR per 2-point increase = 0.90; 95% CI, 0.82-0.98), and breast cancer-related mortality (HR, 0.79; 95% CI, 0.67-0.95), but not recurrence. Relative to women who maintained low concordance with recommendations at both time points, women who maintained high concordance had a lower risk of ACM (HR, 0.61, 95% CI, 0.37-1.03). Improved concordance with some specific recommendations (particularly PA) may be associated with a lower hazard of ACM (HRPA, 0.52; 95% CI, 0.35-0.78).

CONCLUSIONS

Results suggest that women with breast cancer may benefit from a post-diagnosis lifestyle aligned with ACS/ASCO guidelines.

IMPACT

This information may potentially guide lifestyle recommendations for breast cancer survivors to reduce mortality risk.

Association Between Recreational Physical Activity and mTOR Signaling Pathway Protein Expression in Breast Tumor Tissue

Physical activity (PA) is associated with decreased signaling in the mTOR pathway in animal models of mammary cancer, which may indicate favorable outcomes. We examined the association between PA and protein expression in the mTOR signaling pathway in breast tumor tissue. Data on 739 patients with breast cancer, among which 125 patients had adjacent-normal tissue, with tumor expression for mTOR, phosphorylated (p)-mTOR, p-AKT, and p-P70S6K were analyzed. Self-reported recreational PA levels during the year prior to diagnosis were classified using the Centers for Disease Control and Prevention guideline as sufficient (for moderate or vigorous) PA or insufficient PA (any PA but not meeting the guideline) or no PA. We performed linear models for mTOR protein and two-part gamma hurdle models for phosphorylated proteins. Overall, 34.8% of women reported sufficient PA; 14.2%, insufficient PA; 51.0%, no PA. Sufficient (vs. no) PA was associated with higher expression for p-P70S6K [35.8% increase; 95% confidence interval (CI), 2.6-80.2] and total phosphoprotein (28.5% increase; 95% CI, 5.8-56.3) among tumors with positive expression. In analyses stratified by PA intensity, sufficient versus no vigorous PA was also associated with higher expression levels of mTOR (beta = 17.7; 95% CI, 1.1-34.3) and total phosphoprotein (28.6% higher; 95% CI, 1.4-65.0 among women with positive expression) in tumors. The study found that guideline-concordant PA levels were associated with increased mTOR signaling pathway activity in breast tumors. Studying PA in relation to mTOR signaling in humans may need to consider the complexity of the behavioral and biological factors.

Significance

PA increases energy expenditure and limits energy utilization in the cell, which can influence the mTOR pathway that is central to sensing energy influx and regulating cell growth. We studied exercise-mediated mTOR pathway activities in breast tumor and adjacent-normal tissue. Despite the discrepancies between animal and human data and the limitations of our approach, the findings provide a foundation to study the mechanisms of PA and their clinical implications.

Lower-Body Resistance Training Reduces Interleukin-1β and Transforming Growth Factor-β1 Levels and Fatigue and Increases Physical Performance in Breast Cancer Survivors

ABSTRACT

Martins, FM, Santagnello, SB, de Oliveira Junior, GN, de Sousa, JdFR, Michelin, MA, Nomelini, RS, Murta, EFC, and Orsatti, FL. Lower-body resistance training reduces interleukin-1β and transforming growth factor-β1 levels and fatigue and increases physical performance in breast cancer survivors. J Strength Cond Res 37(2): 439-451, 2023-This article ascertains whether resistance training (RT) improves inflammatory markers, fatigue (sensations and fatigability), and physical performance in breast cancer survivors (BCS) and investigates whether the changes in the inflammatory markers, fatigue, and physical performance are associated with each other. Volunteers were randomly divided into 2 groups: control group (n = 11) and RT group (n = 11). Resistance training (3 sets of 8-12 repetitions with 80% 1 repetition maximum (1RM) on 4 exercises-leg extension, leg curl, 45° leg press, and calf raise) was performed 3 times a week for 12 weeks. Self-reported fatigue (SRF), fatigability (critical torque [CT] and W prime [W']), muscle strength, and circulating inflammatory markers were assessed using the Brief Fatigue Inventory, iDXA, 1RM test, protocol of 60 maximal voluntary isometric contractions, and enzyme-linked immunosorbent assay, respectively. Resistance training reduced interleukin (IL)-1β, transforming growth factor (TGF)-β1, and SRF score and increased muscle strength, 6-minute walk test (6MWT), CT, and W'. In the RT group, the changes in SRF were positively associated with the changes in IL-1β. The changes in muscle strength were associated with the changes in CT and W', and the changes in the 6MWT were associated with the changes in CT, W', muscle strength, and SRF. Resistance training improved fatigue and physical performance and reduced IL-1β, and TGF-β1 in BCS. Although improvement in fatigability seems to be dependent on the increase in muscle strength, improvement in the sensation of fatigue seems to be dependent on the reduction in IL-1β after RT. Increase in physical performance seems to be dependent on improvement in muscle strength and fatigue.

Resistance Training for Patients with Cancer: A Conceptual Framework for Maximizing Strength, Power, Functional Mobility, and Body Composition to Optimize Health and Outcomes

There are many benefits to the addition of exercise to cancer treatment and survivorship, particularly with resistance training regimens that target hypertrophy, bone mineral density, strength, functional mobility, and body composition. These goals are best achieved through a series of individualized high-intensity compound movements that mirror functional mobility patterns and sufficiently stress the musculoskeletal system. As a result of adequate stress, the body will engage compensatory cellular mechanisms that improve the structural integrity of bones and muscles, stimulate metabolism and the immune system, optimize functional performance, and minimize mechanical injury risk. The current evidence suggests that application of the above exercise principles, practiced in a safe environment under expert observation, may offer patients with cancer an effective means of improving overall health and cancer-specific outcomes. The following article poses several important questions certified exercise specialists and physicians should consider when prescribing resistance exercise for patients with cancer.

Physical Activity and Breast Cancer Survival-Epidemiologic Evidence and Potential Biologic Mechanisms

PURPOSE OF REVIEW

To review the biologic mechanisms that may be operative between physical activity and survival after breast cancer.

RECENT FINDINGS

Physical activity decreases risk of mortality from breast cancer by up to 40%. Several biologic mechanisms have been hypothesized to explain this association. Previous cohort studies and randomized trials have examined the primary mechanisms that appear to be operative, which involve a decrease in sex hormone levels, insulin resistance, and inflammation. The evidence is still inconsistent and several limitations in the existing literature exist. Understanding the biologic mechanisms involved in the association of physical activity and breast cancer survival will provide more precision to physical activity guidelines for cancer survival. To achieve this objective, future research should include direct measurements of physical activity, sedentary behaviour, and health-related fitness to provide a more comprehensive assessment of these factors and their association with biomarkers and survival after breast cancer.

White adipose tissue-derived factors and prostate cancer progression: mechanisms and targets for interventions

Obesity represents an important risk factor for prostate cancer, driving more aggressive disease, chemoresistance, and increased mortality. White adipose tissue (WAT) overgrowth in obesity is central to the mechanisms that lead to these clinical observations. Adipose stromal cells (ASCs), the progenitors to mature adipocytes and other cell types in WAT, play a vital role in driving PCa aggressiveness. ASCs produce numerous factors, especially chemokines, including the chemokine CXCL12, which is involved in driving EMT and chemoresistance in PCa. A greater understanding of the impact of WAT in obesity-induced progression of PCa and the underlying mechanisms has begun to provide opportunities for developing interventional strategies for preventing or offsetting these critical events. These include weight loss regimens, therapeutic targeting of ASCs, use of calorie restriction mimetic compounds, and combinations of compounds as well as specific receptor targeting strategies.

The Role of C-Reactive Protein as a Prognostic Biomarker in Patients with Early Breast Cancer Treated with Neoadjuvant Chemotherapy

Background

C-reactive protein (CRP) is an acute phase reactant influenced by inflammation and tissue damage. Elevated CRP levels have been associated with poor outcome of various cancers including breast cancer. However, evidence regarding a potential impact of CRP levels on outcome of neoadjuvant chemotherapy (NACT) in patients with early breast cancer (EBC) is insufficient.

Methods

Patients who had received NACT for EBC and had available data regarding CRP levels before therapy, pathologic complete remission (pCR), and follow-up were included. The association between CRP at baseline and outcome parameters was analyzed.

Results

152 women were included in this analysis; median follow-up was 5.8 years. No association between CRP at baseline and pCR rates could be detected. 6.6% of the patients developed a local recurrence, 10.5% developed a distant recurrence, and 5.2% died from breast cancer. A negative correlation (Spearman-Rho) between CRP at baseline and overall survival (OS) (correlation coefficient (CC) -0.255; p = 0.45), disease-free survival (DFS) (CC -0.348; p = 0.075), local recurrence-free survival (LRFS) (CC -0.245; p = 0.327), and distant DFS (DDFS) (CC -0.422; p = 0.057) was not statistically significant, although especially in DFS and DDFS a strong trend was detected. The probability of death from breast cancer was 2% if the CRP was <0.08 mg/dL and 40% if the CRP was >2.08 mg/dL; this association was highly statistically significant (χ²; p < 0.001). These results were independent from age, estrogen and progesterone receptor status, HER2 status, nodal status, and grading. The hazard ratio for OS was 5.75 (p = 0.004) for CRP <0.08 mg/dL versus CRP >2.08 mg/dL.

Discussion/Conclusion

CRP at baseline is not predictive for pCR in EBC after NACT in our patient dataset. However, an association of parameters of long-term prognosis with CRP could be demonstrated. Although the correlations of higher CRP levels at baseline and shorter OS, DFS, LRFS, and DDFS were not significant, a strong trend could be detected that was reproduced in the analysis of different groups of CRP levels and the probability of breast cancer mortality. Higher CRP levels are indicating a worse prognosis in EBC after NACT in this retrospective analysis. These results justify further investigation of CRP not as a predictive parameter for pCR but as a biomarker of long-term prognosis in EBC in prospective trials and may lead to therapeutic approaches with the aim of lowering CRP levels.

Exercise suppresses tumor growth independent of high fat food intake and associated immune dysfunction

Epidemiological data suggest that exercise training protects from cancer independent of BMI. Here, we aimed to elucidate mechanisms involved in voluntary wheel running-dependent control of tumor growth across chow and high-fat diets. Access to running wheels decreased tumor growth in B16F10 tumor-bearing on chow (− 50%) or high-fat diets (− 75%, p < 0.001), however, tumor growth was augmented in high-fat fed mice (+ 53%, p < 0.001). Tumor growth correlated with serum glucose (p < 0.01), leptin (p < 0.01), and ghrelin levels (p < 0.01), but not with serum insulin levels. Voluntary wheel running increased immune recognition of tumors as determined by microarray analysis and gene expression analysis of markers of macrophages, NK and T cells, but the induction of markers of macrophages and NK cells was attenuated with high-fat feeding. Moreover, we found that the regulator of innate immunity, ZBP1, was induced by wheel running, attenuated by high-fat feeding and associated with innate immune recognition in the B16F10 tumors. We observed no effects of ZBP1 on cell cycle arrest, or exercise-regulated necrosis in the tumors of running mice. Taken together, our data support epidemiological findings showing that exercise suppresses tumor growth independent of BMI, however, our data suggest that high-fat feeding attenuates exercise-mediated immune recognition of tumors.

A randomized-controlled trial comparing supervised aerobic training to resistance training followed by unsupervised exercise on physical functioning in older breast cancer survivors

INTRODUCTION

This study compared the relative efficacy of aerobic training to resistance training on physical functioning in older breast cancer survivors and determined whether benefits could be maintained by transitioning to unsupervised home-based training.

MATERIALS AND METHODS

Early-stage, post-treatment, older (≥65 years) breast cancer survivors (n = 114; mean age 72 years) were randomized to 12 months of supervised aerobic (n = 37), resistance (n = 39) or stretching (active control; n = 38) training followed by 6 months of unsupervised home-based training. Outcomes included aerobic capacity by 6-min walk distance (6MWD; m), maximal upper and lower body strength (1-repetition maximum; kg); physical function by short physical performance battery (SPPB), SF-36 and Late Life Function and Disability Instruments.

RESULTS

Over 12-months of supervised exercise, all groups improved in muscle strength and SPPB scores, but resistance trained women also improved 6MWD. Improvements in upper and lower body strength in the resistance group were significantly greater than those in the stretching control (+2.5 kg vs. +1.8 kg; p = 0.05) and aerobic groups (+8.3 kg vs +2.7 kg; p = 0.047), respectively, with trends for greater improvements in 6MWD (+57.9 m vs. +22.5 m; p = 0.057) and self-report physical function (+4.8 vs. -4.4; 0.066) in resistance trained women versus controls. Compared to values at 12 months, there were no changes during unsupervised training in any measure within or between groups, except for self-reported advanced lower extremity function which improved in the resistance group and fell in the aerobic group (+1.3 vs. -3.1; p = 0.043).

DISCUSSION

Supervised exercise can improve strength and physical functioning among older breast cancer survivors. Resistance training may lead to better improvements compared to aerobic or flexibility training, whether in a supervised or unsupervised setting. Clinicaltrials.govNCT00662103.

Resistance Exercise for Breast Cancer Patients? Evidence from the Last Decade

Background

Breast cancer is associated with many therapy-induced side effects that impact patients' lives from diagnosis to long-term survivorship. Physical activity has become an important and proven supportive measure in treating side effects like loss of muscle strength, fatigue, chemotherapy-induced peripheral neuropathy, lymphedema, and loss of quality of life. Resistance training (RT) is an established exercise intervention for breast cancer patients, but the correct type, timing, intensity, and duration of exercise remain unclear. It is necessary to investigate different resistance training interventions and their effects on breast cancer patients by covering all stages of treatment, beginning with prehabilitation, through the period of acute therapy, to long-term survivorship.

Conclusion

Upon evaluation of randomized controlled trials (RCTs) from the past decade, RT was found to be feasible and safe. Furthermore, there is evidence on the impact of RT on muscle strength, CRF and QoL amongst other factors. Studies implementing mixes of aerobic and strength exercises are rather common, but RCTs of RT-only protocols remain scarce. Different strength training protocols at distinct stages of breast cancer treatment have been conducted, but with the complexity of treatments and the variety of training styles, a large field of study remains.

Key Messages

Although the overall data on RT for breast cancer patients has increased, there are many different methodological approaches and testing measures as well as gaps in study documentation. There is still very little of the evidence that would facilitate the compilation of standardized and individualized guidelines.

Probiotic supplement attenuates chemotherapy-related cognitive impairment in patients with breast cancer: a randomised, double-blind, and placebo-controlled trial

BACKGROUND

Chemotherapy-related cognitive impairment (CRCI) is highly prevalent in patients with cancer and is associated with poor outcomes and quality of life. To date, the management of CRCI remains a clinical challenge. Herein, we aim to determine the preventive effects of probiotics on CRCI development and underlying mechanisms.

METHODS

We conducted a randomised, double-blind and placebo-controlled trial (ChiCTR-INQ-17014181) of 159 patients with breast cancer and further investigated the underlying mechanism in a pre-clinical setting. From 2018 to 2019, patients with breast cancer (Stage I-III) who needed adjuvant chemotherapy were screened, enrolled and randomly assigned to receive either probiotics or placebo (three capsules, twice/day) during chemotherapy. Their cognition, anxiety and depression were assessed with well-established assays; their plasma biomarkers, metabolites and faecal microbiota compositions were measured. In addition, the systemic effects of the metabolites found in the clinical trial on long-term potentiation, synapse injury, oxidative stress and glial activation were assessed in rats.

RESULTS

Probiotics supplement significantly decreased the incidence of CRCI, improved the allover cognitive functions, changed the gut microbial composition and modulated nine plasma metabolite changes. Among these metabolites, p-Mentha-1,8-dien-7-ol, Linoelaidyl carnitine and 1-aminocyclopropane-1-carboxylic acid were negatively correlated with the occurrence of CRCI. Furthermore, probiotics supplement increased plasma p-Mentha-1,8-dien-7-ol in rats. Administration of exogenous p-Mentha-1,8-dien-7-ol significantly alleviated chemotherapy-induced long-term potentiation impairment, synapse injury, oxidative stress and glial activation in the hippocampus of rats.

CONCLUSION

Our data indicated that probiotics supplement prevents the occurrence of CRCI in patients with breast cancer via modulating plasma metabolites, including p-Mentha-1,8-dien-7-ol.

TRIAL REGISTRATION

Chinese Clinical Trial Registry (ChiCTR-INQ-17014181) [http://www.chictr.org.cn/showproj.aspx?proj=24294].

The effects of exercise training on inflammatory biomarkers in patients with breast cancer: A systematic review and meta-analysis

OBJECTIVE

Despite several studies on the effects of exercise training on inflammatory biomarkers in patients with breast cancer, no earlier study has systematically summarized their findings. Current systematic review and meta-analysis has been done on earlier clinical trials in this topic.

METHOD

Relevant studies published up to August 2021 were searched through PubMed, MEDLINE, SCOPUS, EMBASE, and Google Scholar using predefined keywords. Studies that examined the effect of exercise training on inflammatory biomarkers in adult women with breast cancer were included.

RESULT

A total of 18 studies were included. Combining 11 effect sizes, exercise training significantly reduced CRP level (WMD: -0.55; 95% CI: -1.10, -0.01). However, it had no significant influence on serum TNF-α (WMD: -0.40; 95% CI: -1.30, 0.50) and IL-6 concentrations (WMD: -0.05, 95% CI: -0.53, 0.43) in 8 and 15 studies, respectively. Pooling 7 effect sizes, we failed to find significant changes in IL-8 following exercise training (WMD: -0.65, 95% CI: -1.57, 0.28). Moreover, we reached no significant findings for serum levels of INF-ɣ (WMD: -2.66, 95% CI: -7.67, 2.36), IL-1β (WMD: 0.03, 95% CI: -0.26, 0.21), and IL-10 (WMD: -0.70, 95% CI: -2.92, 1.52). Based on subgroup analyses, best findings were reached in long-term intervention and after concurrent training.

DISCUSSION

Chronic inflammation is hypothesized to be associated with breast cancer development. We found significant reduction in CRP level following exercise training, which was more considerable after concurrent aerobic and resistance training and in long-term intervention. No significant changes were seen in serum levels of TNF-α, IL-6, IL-8, IL-10, INF-ɣ, IL-1β following exercise training. Further studies are needed to find more details.

Effects of Diet and Exercise-Induced Weight Loss on Biomarkers of Inflammation in Breast Cancer Survivors: A Systematic Review and Meta-analysis

BACKGROUND

Adiponectin, leptin, and pro- and anti-inflammatory cytokines are implicated in breast cancer risk and recurrence. Weight loss, via the dynamic interplay of energy balance through exercise and/or caloric restriction, decreases risk of breast cancer recurrence.

METHODS

We investigated the effects of lifestyle modifications (exercise only, or combined caloric restriction and exercise) on adipokines, IL2, IL6, IL8, IL10, C-reactive protein (CRP), and TNFα biomarkers in breast cancer survivors. Searches were completed in June and July of 2019 to identify randomized controlled trials that met inclusion criteria. Weighted mean difference was calculated using random- or fixed-effects models based on the heterogeneity of the studies.

RESULTS

2501 records were identified, with 30 ultimately meeting inclusion criteria of the systematic review; 21 studies provided data suitable for meta-analysis. We observed leptin levels were significantly reduced in the exercise-only group compared with sedentary control [WMD -5.66; 95% confidence interval (CI), -11.0 to -0.33; P = 0.04].

CONCLUSIONS

Leptin may be a primary mediator of exercise-induced improvements in breast cancer recurrence.

IMPACT

This is the first review and meta-analysis to examine combined exercise and caloric restriction programs in breast cancer survivors. Future studies should further examine combined programs and their efficacy for altering leptin.

The Effect of Exercise Training on Serum Glucose and Lipid Profiles in Patients With Breast Cancer: A Systematic Review and Meta-Analysis of Randomized Clinical Trials

BACKGROUND

Despite several studies on the effects of exercise training on glucose and lipid profiles in patients with breast cancer, no earlier study has systematically summarized their findings. Current systematic review and meta-analysis have been done on earlier clinical trials in this topic.

METHODS

Relevant studies published up to May 2020 were searched through PubMed, SCOPUS, and Google Scholar using predefined keywords. Studies that examined the effect of exercise training on serum glucose and lipid profiles in adult women with breast cancer were included.

RESULTS

A total of 16 studies were included. Combining 10 effect sizes, exercise training had no significant influence on serum fasting plasma glucose concentrations (weighted mean difference [WMD] = 4.87; 95% confidence interval [CI], -4.65 to 14.29). However, it resulted in significant reduction of serum insulin (WMD = -2.37; 95% CI, -3.57 to -1.16) and homeostatic model assessment for insulin resistance (WMD = -0.71; 95% CI, -1.27 to -0.15) in 14 and 8 studies, respectively. Pooling 6 effect sizes, exercise training did not change serum total cholesterol (WMD = -11.99; 95% CI, -32.42 to 8.45), low-density lipoprotein (WMD = -3.21; 95% CI, -10.45 to 4.04), high-density lipoprotein (WMD = 4.13; 95% CI, -6.20 to 14.46), and triglyceride (WMD = -23.34; 95% CI, -66.96 to 20.29) concentrations. Subgroup analyses showed beneficial effects of exercise training on outcomes of interest among studies with higher methodological quality.

CONCLUSION

Current meta-analysis demonstrated significant reductions in serum levels of insulin and insulin resistance following exercise training. However, exercise training had no significant effect on serum levels of fasting plasma glucose, total cholesterol, triglyceride, high-density lipoprotein, and low-density lipoprotein. Further high-quality studies are needed to shed light on this issue.

Genetically determined elevated C-reactive protein associated with primary colorectal cancer risk: Mendelian randomization with lifestyle interactions

Systemic inflammation-related etiologic pathways via inflammatory cytokines in the development of colorectal cancer (CRC) have not been convincingly determined and may be confounded by lifestyle factors or reverse causality. We investigated the genetically predicted C-reactive protein (CRP) phenotype in the potential causal pathway of primary CRC risk in postmenopausal women in a Mendelian randomization (MR) framework. We employed individual-level data of the Women's Health Initiative Database for Genotypes and Phenotypes Study, which consists of 5 genome-wide association (GWA) studies, including 10,142 women, 737 of whom developed primary CRC. We examined 61 GWA single-nucleotide polymorphisms (SNPs) associated with CRP by using weighted/penalized MR weighted-medians and MR gene-environment interactions that allow some relaxation of the strict variable requirements and attenuate the heterogeneous estimates of outlying SNPs. In lifestyle-stratification analyses, genetically determined CRP exhibited its effects on the decreased CRC risk in non-viscerally obese and high-fat diet subgroups. In contrast, genetically driven CRP was associated with an increased risk for CRC in women who smoked ≥ 15 cigarettes/day, with significant interaction of the gene-smoking relationship. Further, a substantially increased risk of CRC induced by CRP was observed in relatively short-term users (< 5 years) of estrogen (E)-only and also longer-term users (5 to > 10 years) of E plus progestin. Our findings may provide novel evidence on immune-related etiologic pathways connected to CRC risk and suggest the possible use of CRP as a CRC-predictive biomarker in women with particular behaviors and CRP marker-informed interventions to reduce CRC risk.

The association of resistance training with risk of ovarian cancer

Background

Increasing evidence, including multiple putative inflammatory risk factors (e.g., c‐reactive protein, and adiposity), supports that inflammation plays an important role in ovarian carcinogenesis. Resistance training (RT) is associated with lower levels of circulating inflammatory markers, independent of physical activity.

Methods

We evaluated the relationship between RT and risk of ovarian cancer accounting for other physical activity (e.g., walking) in two large prospective cohorts, the Nurses’ Health Study (NHS) and NHSII.

Key Results

In total, analyses included 42,005 NHS participants (2000–2016) and 67,289 NHSII participants (2001–2017) with RT assessed every 4 years. Multivariable Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) of RT with ovarian cancer risk overall and by tumor subtype, adjusting for known and putative ovarian cancer risk factors. We identified a total of 609 cases over 1,748,884 person‐years. No association was observed with overall ovarian cancer risk (RT ≥60 vs 0 min/wk, HR = 0.95, 95%CI: 0.74–1.22) or by histotype (comparable HR = 0.86 and 0.98 for type I and II tumors, respectively). Results did not differ by body mass index (Pinteraction = 0.97), or other physical activity (Pinteraction = 0.31).

Conclusions & Inferences

We observed no evidence that moderate levels of RT were associated with risk of ovarian cancer. Further investigations are required to confirm these findings.

Genetically Predicted C-Reactive Protein Associated With Postmenopausal Breast Cancer Risk: Interrelation With Estrogen and Cancer Molecular Subtypes Using Mendelian Randomization

Background

Immune-related etiologic pathways that influence breast cancer risk are incompletely understood and may be confounded by lifestyles or reverse causality. Using a Mendelian randomization (MR) approach, we investigated the potential causal relationship between genetically elevated C-reactive protein (CRP) concentrations and primary invasive breast cancer risk in postmenopausal women.

Methods

We used individual-level data obtained from 10,179 women, including 537 who developed breast cancer, from the Women’s Health Initiative Database for Genotypes and Phenotypes Study, which consists of five genome-wide association (GWA) studies. We examined 61 GWA single-nucleotide polymorphisms (SNPs) previously associated with CRP. We employed weighted/penalized weighted–medians and MR gene–environment interactions that allow instruments’ invalidity to some extent and attenuate the heterogeneous estimates of outlying SNPs.

Results

In lifestyle-stratification analyses, genetically elevated CRP decreased risk for breast cancer in exogenous estrogen-only, estrogen + progestin, and past oral contraceptive (OC) users, but only among relatively short-term users (<5 years). Estrogen-only users for ≥5 years had more profound CRP-decreased breast cancer risk in dose–response fashion, whereas past OC users for ≥5 years had CRP-increased cancer risk. Also, genetically predicted CRP was strongly associated with increased risk for hormone-receptor positive or human epidermal growth factor receptor-2 negative breast cancer.

Conclusions

Our findings may provide novel evidence on the immune-related molecular pathways linking to breast cancer risk and suggest potential clinical use of CRP to predict the specific cancer subtypes. Our findings suggest potential interventions targeting CRP–inflammatory markers to reduce breast cancer risk.

A Phenomic Perspective on Factors Influencing Breast Cancer Treatment: Integrating Aging and Lifestyle in Blood and Tissue Biomarker Profiling

Breast cancer is the most common malignancy among women worldwide. Over the last four decades, diagnostic and therapeutic procedures have improved substantially, giving patients with localized disease a better chance of cure, and those with more advanced cancer, longer periods of disease control and survival. However, understanding and managing heterogeneity in the clinical response exhibited by patients remains a challenge. For some treatments, biomarkers are available to inform therapeutic options, assess pathological response and predict clinical outcomes. Nevertheless, some measurements are not employed universally and lack sensitivity and specificity, which might be influenced by tissue-specific alterations associated with aging and lifestyle. The first part of this article summarizes available and emerging biomarkers for clinical use, such as measurements that can be made in tumor biopsies or blood samples, including so-called liquid biopsies. The second part of this article outlines underappreciated factors that could influence the interpretation of these clinical measurements and affect treatment outcomes. For example, it has been shown that both adiposity and physical activity can modify the characteristics of tumors and surrounding tissues. In addition, evidence shows that inflammaging and immunosenescence interact with treatment and clinical outcomes and could be considered prognostic and predictive factors independently. In summary, changes to blood and tissues that reflect aging and patient characteristics, including lifestyle, are not commonly considered clinically or in research, either for practical reasons or because the supporting evidence base is developing. Thus, an aim of this article is to encourage an integrative phenomic approach in oncology research and clinical management.

Pro-inflammatory cytokine polymorphisms and interactions with dietary alcohol and estrogen, risk factors for invasive breast cancer using a post genome-wide analysis for gene-gene and gene-lifestyle interaction

Molecular and genetic immune-related pathways connected to breast cancer and lifestyles in postmenopausal women are not fully characterized. In this study, we explored the role of pro-inflammatory cytokines such as C-reactive protein (CRP) and interleukin-6 (IL-6) in those pathways at the genome-wide level. With single-nucleotide polymorphisms (SNPs) in the biomarkers and lifestyles together, we further constructed risk profiles to improve predictability for breast cancer. Our earlier genome-wide association gene-environment interaction study used large cohort data from the Women's Health Initiative Database for Genotypes and Phenotypes Study and identified 88 SNPs associated with CRP and IL-6. For this study, we added an additional 68 SNPs from previous GWA studies, and together with 48 selected lifestyles, evaluated for the association with breast cancer risk via a 2-stage multimodal random survival forest and generalized multifactor dimensionality reduction methods. Overall and in obesity strata (by body mass index, waist, waist-to-hip ratio, exercise, and dietary fat intake), we identified the most predictive genetic and lifestyle variables. Two SNPs (SALL1 rs10521222 and HLA-DQA1 rs9271608) and lifestyles, including alcohol intake, lifetime cumulative exposure to estrogen, and overall and visceral obesity, are the most common and strongest predictive markers for breast cancer across the analyses. The risk profile that combined those variables presented their synergistic effect on the increased breast cancer risk in a gene-lifestyle dose-dependent manner. Our study may contribute to improved predictability for breast cancer and suggest potential interventions for the women with the risk genotypes and lifestyles to reduce their breast cancer risk.

Pathophysiological mechanisms explaining poor clinical outcome of older cancer patients with low skeletal muscle mass

Low skeletal muscle mass is highly prevalent in older cancer patients and affects 5% to 89% depending on the type and stage of cancer. Low skeletal muscle mass is associated with poor clinical outcomes such as post-operative complications, chemotherapy toxicity and mortality in older cancer patients. Little is known about the mediating pathophysiological mechanisms. In this review, we summarize proposed pathophysiological mechanisms underlying the association between low skeletal muscle mass and poor clinical outcomes in older cancer patients including a) systemic inflammation; b) insulin-dependent glucose handling; c) mitochondrial function; d) protein status and; e) pharmacokinetics of anticancer drugs. The mechanisms of altered myokine balance negatively affecting the innate and adaptive immune system, and altered pharmacokinetics of anticancer drugs leading to a relative overdosage of anticancer drugs are best-substantiated. The effects of glucose intolerance and circulating mitochondrial DNA as a consequence of low skeletal muscle mass are topics of interest for future research. Restoring myokine balance through physical exercise, exercise mimetics, neuro-muscular activation and adapting anticancer drug dosing on skeletal muscle mass could be targeted approaches to improve clinical outcomes in older cancer patients with low skeletal muscle mass.

Physical Activity Reduces the Risk of Recurrence and Mortality in Cancer Patients

The biological mechanisms through which physical activity reduces metastatic disease recurrence and mortality in cancer patients are not known. This review offers the hypothesis that physical activity reduces the risk of recurrence and mortality in cancer patients through two synergistic processes: 1) indirect (systemic) effects related to the host tumor microenvironment; and 2) direct (physical) effects on cancer cells.

Application of physical exercise therapies in breast cancer survivors and their effects on the inflammatory profile: A narrative review

BACKGROUND

One of the adverse effects of cancer treatments is the exacerbation of inflammation, which generates numerous limitations and contributes to the development of several comorbidities and the recurrence of cancer itself. Physical exercise (PE) has been proposed as an efficient complementary strategy to combat the inflammatory effects of oncological treatments and to prevent the development of comorbidities, but its adequate application in breast cancer survivors (BCS) requires the establishment of consensuses and practical recommendations.

OBJECTIVE

This study aimed to review the randomized controlled trials that evaluated the influence of PE in the inflammatory profile of BCS.

METHODS

The search for articles published between 1999 and 2020 was done in PsycINFO, PubMed, Cochrane, Science Direct, and Scopus databases.

RESULTS

Current knowledge reveals the effectiveness of PE in the functional independence and health of BCS. Evidence of the capacity of PE to improve the inflammatory profile and the immune response in BCS has also been described. However, the heterogeneity of the studies regarding structural training variables, types of exercise, stages of intervention, and severity of the disease, still do not allow the establishment of precise guidelines for the prescription and progression of exercise to improve the inflammatory process in BCS.

DISCUSSION

. This review suggests a possible strategy to be used in the assessment, training prescription, and rehabilitation of BCS, to support the development of new studies and the work of exercise professionals in the prescription and application of physical training to improve health and inflammatory status in BCS.

Pro-inflammatory cytokine polymorphisms in ONECUT2 and HNF4A and primary colorectal carcinoma: a post genome-wide gene-lifestyle interaction study

Immune-related molecular and genetic pathways that are connected to colorectal cancer (CRC) and lifestyles in postmenopausal women are incompletely characterized. In this study, we examined the role of pro-inflammatory biomarkers such as C-reactive protein (CRP) and interleukin-6 (IL-6) in those pathways. Through selection of the best predictive single-nucleotide polymorphisms (SNPs) and lifestyles, our goal was to improve the prediction accuracy and ability for CRC risk. Using large cohort data of postmenopausal women from the Women's Health Initiative Database for Genotypes and Phenotypes Study, we previously conducted a genome-wide association (GWA) for a CRP and IL-6 gene-behavioral interaction study. For the present study, we added GWA-SNPs from outside GWA studies, resulting in a total of 152 SNPs. Together with 41 selected lifestyles, we performed a 2-stage multimodal random survival forest analysis with generalized multifactor dimensionality reduction approach to construct CRC risk profiles. Overall and in obesity strata (by body mass index, waist circumference, waist-to-hip ratio, exercise, and dietary fat intake), we identified the best predictive genetic markers in inflammatory cytokines and lifestyles. Across the strata, 2 SNPs (ONECUT2 rs4092465 and HNF4A rs1800961) and 1 lifestyle factor (relatively short-term past use of oral contraceptives) were the most common and strongest predictive markers for CRC risk. The risk profile that combined those variables exhibited synergistically increased risk for CRC; this pattern appeared more strongly in obese and inactive subgroups. Our results may contribute to improved predictability for CRC and suggest genetically targeted lifestyle interventions for women carrying the inflammatory-risk genotypes, reducing CRC risk.

IMPROVE, a community-based exercise intervention versus support group to improve functional and health outcomes among older African American and non-Hispanic White breast cancer survivors from diverse socioeconomic backgrounds: Rationale, design and methods

BACKGROUND

African Americans (AA) and socioeconomic status (SES) disadvantaged older breast cancer survivors (BCS) are more likely to experience poor functional and health outcomes. However, few studies have evaluated the putative beneficial effects of exercise on these outcomes in older racial minority and SES-disadvantaged BCS.

METHODS

This is a mixed-methods study that includes a randomized-controlled trial, "IMPROVE", to evaluate a group-based exercise intervention compared to a support group program in older BCS, followed by post-intervention semi-structured interviews to evaluate the intervention. The trial aims to recruit 220 BCS with 55 in each of four strata defined by race (AA versus Non-Hispanic Whites) and SES (disadvantaged vs. non-disadvantaged). Participants are ≥65 years old and within five years of treatment completion for stage I-III breast cancer. Participants are randomized to a 52-week, three sessions/week, one-hour/session, moderate intensity aerobic and resistance group exercise intervention, (n = 110) or a 52-week, one hour/week, support group intervention [attention-control arm], (n = 110). The first 20 weeks of both programs are supervised and the last 32 weeks, unsupervised. The primary outcome is the change in Short Physical Performance Battery (SPPB) Scores at 20 weeks from baseline, between the two arms. Secondary outcomes include change in SPPB scores at 52 weeks, change in body composition and biomarkers, at 20 and 52 weeks from baseline, between arms.

DISCUSSION

Results of the trial may contribute to a better understanding of factors associated with recruitment, and acceptability, and will inform future exercise programs to optimally improve health outcomes for older BCS.

Exercise training, circulating cytokine levels and immune function in cancer survivors: A meta-analysis

BACKGROUND

Anti-cancer therapies lead to chronic non-resolving inflammation and reduced immune function. One potential therapy is exercise training, but the effectiveness of these interventions to improve immune-related outcomes, the gaps in the literature, and recommendations to progress the field need to be determined.

OBJECTIVES

(1) to conduct separate meta-analyses in cancer survivors to determine the effects of exercise training on pro- and anti-inflammatory markers, and immune cell proportions and function; and (2) to perform subgroup analyses to determine whether exercise modality, cancer type, and specific markers help to explain heterogeneity in each meta-analysis.

DATA SOURCES

Electronic databases (PubMed/MEDLINE, EMBASE, CENTRAL, and CINAHL) from inception to March 2018. The reference lists of eligible articles and relevant reviews were also checked.

STUDY SELECTION

Inclusion criteria were adult cancer survivors from randomized controlled trials performing structured exercise intervention (aerobic, resistance or combined training or Tai Chi/yoga) compared to usual care control group and included pro-inflammatory, anti-inflammatory, and/or immune cell outcomes.

APPRAISAL AND SYNTHESIS METHODS

A total of 5349 potentially eligible articles were identified, of which 26 articles (27 trials) met the inclusion criteria. Effect sizes were calculated as standardized mean differences (SMD), where <0.2 was defined as trivial, 0.2-0.3 as small, 0.4-0.8 as moderate, and >0.8 as a large effect.

RESULTS

Exercise training decreased pro-inflammatory markers (SMD: -0.2, 95% CI: -0.4, -0.1, p < 0.001). Sub-group analysis for the pro-inflammatory markers indicated that combined aerobic and resistance training had the greatest effect (SMD: -0.3, 95% CI: -0.5, -1.9, p < 0.001), that prostate (SMD: -0.5, 95% CI: -0.8, 0.1, p = 0.004) and breast cancer populations were most responsive (SMD: -0.2, 95% CI: -0.3, -0.1, p = 0.001), and that C-reactive protein (SMD: -0.5, 95% CI: -0.9, -0.06, p = 0.025) and tumor necrosis factor (SMD: -0.3, 95% CI: -0.5, -0.06, p = 0.004) were the most sensitive to change. Exercise training tended to decrease anti-inflammatory markers (p = 0.072) but had no effect on natural killer or natural killer T cell proportions or cytotoxic activity.

CONCLUSIONS

Exercise training reduces pro-inflammatory markers in cancer survivors, with the strongest evidence for combined training and for prostate and breast cancer survivors. Further research is warranted to determine if these changes are clinically relevant or are associated with improvements in symptoms. To strengthen future research, focusing on novel immune populations that include functional parameters and standardized reporting of key immune outcomes is recommended.

Resistance Exercise Training as a Primary Countermeasure to Age-Related Chronic Disease

Age is a primary risk factor for a number of chronic diseases including mobility disability, cardiovascular disease (CVD), type 2 diabetes (T2D), and cancer. Most physical activity guidelines emphasize the performance of 150 min of moderate-to-vigorous or 75 min of vigorous aerobic exercise training (AET) weekly for reduction of chronic disease risk. Nonetheless, there is an emerging body of evidence showing that resistance exercise training (RET) appears to be as effective as AET in reducing risk of several chronic diseases. It may also be that RET is more effective than AET in some regards; the converse is likely also true. We posit that the perceived divergent exercise mode-dependent health benefits of AET and RET are likely small in most cases. In this short review, our aim is to examine evidence of associations between the performance of RET and chronic health disease risk (mobility disability, T2D, CVD, cancer). We also postulate on how RET may be influencing chronic disease risk and how it is a critical component for healthy aging. Accumulating evidence points to RET as a potent and robust preventive strategy against a number of chronic diseases traditionally associated with the performance of AET, but evidence favors RET as a potent countermeasure against declines in mobility. On the basis of this review we propose that the promotion of RET should assume a more prominent position in exercise guidelines particularly for older persons.

Metabolite and lipoprotein responses and prediction of weight gain during breast cancer treatment

Background

Breast cancer treatment has metabolic side effects, potentially affecting risk of cardiovascular disease (CVD) and recurrence. We aimed to compare alterations in serum metabolites and lipoproteins during treatment between recipients and non-recipients of chemotherapy, and describe metabolite profiles associated with treatment-related weight gain.

Methods

This pilot study includes 60 stage I/II breast cancer patients who underwent surgery and were treated according to national guidelines. Serum sampled pre-surgery and after 6 and 12 months was analysed by MR spectroscopy and mass spectrometry. In all, 170 metabolites and 105 lipoprotein subfractions were quantified.

Results

The metabolite and lipoprotein profiles of chemotherapy recipients and non-recipients changed significantly 6 months after surgery (p < 0.001). Kynurenine, the lipid signal at 1.55–1.60 ppm, ADMA, 2 phosphatidylcholines (PC aa C38:3, PC ae C42:1), alpha-aminoadipic acid, hexoses and sphingolipids were increased in chemotherapy recipients after 6 months. VLDL and small dense LDL increased after 6 months, while HDL decreased, with triglyceride enrichment in HDL and LDL. At baseline, weight gainers had less acylcarnitines, phosphatidylcholines, lyso-phosphatidylcholines and sphingolipids, and showed an inflammatory lipid profile.

Conclusion

Chemotherapy recipients exhibit metabolic changes associated with inflammation, altered immune response and increased risk of CVD. Altered lipid metabolism may predispose for treatment-related weight gain.

New Insights into the Role of Exercise in Inhibiting mTOR Signaling in Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) does not express estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 and is characterized by its aggressive nature, lack of targets for targeted therapies, and early peak of recurrence. Due to these specific characteristics, chemotherapy does not usually yield substantial improvements and new target therapies and alternative strategies are needed. The beneficial responses of TNBC survivors to regular exercise, including a reduction in the rate of tumor growth, are becoming increasingly apparent. Physiological adaptations to exercise occur in skeletal muscle but have an impact on the entire body through systemic control of energy homeostasis and metabolism, which in turn influence the TNBC tumor microenvironment. Gaining insights into the causal mechanisms of the therapeutic cancer control properties of regular exercise is important to improve the prescription and implementation of exercise and training in TNBC survivors. Here, we provide new evidence of the effects of exercise on TNBC prevention, control, and outcomes, based on the inhibition of the phosphatidylinositol-3-kinase (PI3K)/protein kinase B (PKB also known as Akt)/mammalian target of rapamycin (mTOR) (PI3K-Akt-mTOR) signaling. These findings have wide-ranging clinical implications for cancer treatment, including recurrence and case management.