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

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.

Effects of high-intensity interval training on cardiometabolic biomarkers in patients with prostate cancer undergoing active surveillance: a randomized controlled trial

PURPOSE

To report the effects of a 12-week high-intensity interval training (HIIT) program on cardiometabolic biomarkers in patients with prostate cancer on active surveillance (AS) from the Exercise During Active Surveillance for Prostate Cancer (ERASE) Trial.

METHODS

Fifty-two men with prostate cancer on AS were randomized to either an exercise (HIIT; n = 26) or usual care (UC; n = 26) group. The HIIT intervention consisted of progressive, supervised, aerobic HIIT at an intensity of 85 to 95% VO2peak for 28 to 40 min per session performed three times/week for 12 weeks. Blood samples were collected at baseline and postintervention to analyze cardiometabolic biomarkers. Analysis of covariance was used to examine between-group mean differences.

RESULTS

Blood data were obtained from 49/52 (94%) participants at postintervention. Participants were aged 63.4 ± 7.1 years and 40% were obese. The HIIT group attended 96% of the planned exercise sessions. No significant between-group changes in weight were observed after the intervention. Compared to UC, HIIT significantly improved total cholesterol (-0.40 mmol/L; 95% confidence interval[CI], -0.70 to -0.10; p = 0.011), non-high-density lipoprotein-c (-0.35 mmol/L; 95% CI, -0.60 to -0.11; p = 0.006), insulin (-13.6 pmol/L; 95% CI, -25.3 to -1.8; p = 0.025), insulin-like growth factor (IGF)-1 (-15.0 ng/mL; 95% CI, -29.9 to -0.1; p = 0.048), and IGF binding protein (IGFBP)-3 (152.3 ng/mL; 95% CI, 12.6 to 292.1; p = 0.033). No significant differences were observed for fasting glucose, HbA1c, other lipid markers, IGFBP-1, adiponectin, and leptin.

CONCLUSIONS

The ERASE Trial showed that a 12-week aerobic HIIT program improved several cardiometabolic biomarkers in patients with prostate cancer on AS that may contribute to cardiovascular health benefits and potentially influence signaling pathways in the progression of prostate cancer. Further research is needed to confirm the effects of exercise on cardiometabolic markers in men with prostate cancer on AS and determine if these effects are associated with improved long-term clinical outcomes.

Advances in Diet and Physical Activity in Breast Cancer Prevention and Treatment

There is currently a growing interest in diets and physical activity patterns that may be beneficial in preventing and treating breast cancer (BC). Mounting evidence indicates that indeed, the so-called Mediterranean diet (MedDiet) and regular physical activity likely both help reduce the risk of developing BC. For those who have already received a BC diagnosis, these interventions may decrease the risk of tumor recurrence after treatment and improve quality of life. Studies also show the potential of other dietary interventions, including fasting or modified fasting, calorie restriction, ketogenic diets, and vegan or plant-based diets, to enhance the efficacy of BC therapies. In this review article, we discuss the biological rationale for utilizing these dietary interventions and physical activity in BC prevention and treatment. We highlight published and ongoing clinical studies that have applied these lifestyle interventions to BC patients. This review offers valuable insights into the potential application of these dietary interventions and physical activity as complimentary therapies in BC management.

Exercise Across the Phases of Cancer Survivorship: A Narrative Review

Exercise has long been recognized as an important component of treatment for various diseases. However, the benefits and risks of exercise interventions must be carefully evaluated to ensure the former outweighs the latter. As cancer patients undergo diverse treatment modalities with distinct objectives, a systematic approach partitioning the cancer journey into distinct phases is necessary to inform tailored exercise prescriptions. This narrative review summarizes exercise benefits and mechanisms for cancer patients and survivors across four distinct survivorship periods-before surgery, after surgery and before adjuvant treatment, during nonsurgical treatment (adjuvant and neoadjuvant), and during extended survival. In summary, exercise reduces the risks of complications and declines in physical functioning while improving fatigue, quality of life, and the ability to manage treatment effects. Although additional research is warranted, existing evidence is sufficient to integrate exercise into clinical oncology practice and cancer survivorship programs.

Changes in physical activity and diabetes risk after cancer diagnosis: a nationwide cohort study

PURPOSE

Physical activity has the potential to reduce the risk of diabetes after cancer diagnosis. However, current evidence supporting its effects is limited. This study aims to examine the associations between changes in physical activity and subsequent risk of diabetes among cancer survivors.

METHODS

A total of 264,250 cancer survivors (mean age 56.7 (12.5) years, 44.2% males) without a prior history of diabetes were assessed for adherence to physical activity both before and after their diagnosis. The primary outcome was incident diabetes. The Fine-Gray proportional sub-distribution hazards model was used to calculate sub-distribution hazard ratios (sHRs) and 95% confidence intervals (CIs) for diabetes risk, considering death as a competing risk.

RESULTS

Over a follow-up of 1,065,802 person-years, maintaining regular physical activity from pre-diagnosis was associated with a 10% reduced risk of diabetes after cancer diagnosis (sHR 0.90, 95% CI 0.85-0.96), considering traditional diabetes risk factors, sociodemographics, and primary cancer sites. Cancer survivors who became active and inactive after their cancer diagnosis exhibited a marginally decreased risk of diabetes (sHR 0.98, 95% CI 0.93-1.03; sHR 0.97, 95% CI 0.92-1.03). The strength and direction of the association varied depending on the primary site of cancer.

CONCLUSIONS

Regular physical activity starting before a cancer diagnosis is associated with a lower risk of diabetes following the diagnosis, independent of established diabetes risk factors.

IMPLICATIONS FOR CANCER SURVIVORS

The study underscores the importance of engaging in sufficient physical activity to mitigate the risk of diabetes in cancer survivors.

Comparison of the effects of high-intensity interval and moderate-intensity continuous training on inflammatory markers, cardiorespiratory fitness, and quality of life in breast cancer patients

BACKGROUND

As the effectiveness of breast cancer treatment has improved, a growing number of long-term breast cancer survivors are seeking help for unique health problems. These patients may be at increased risk of cardiovascular disease due to the side effects of treatment. The positive impact of most types of exercise has been repeatedly reported in people with cancer, but the most effective exercise approaches for maximum beneficial adaptations remain controversial. Thus, this study aimed to compare the effects of high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) on inflammatory indices, adipokines, metabolic markers, body composition, cardiorespiratory fitness, and quality of life in breast cancer patients during adjuvant endocrine therapy.

METHODS

Thirty non-metastatic breast cancer patients during adjuvant endocrine therapy who had been treated with chemotherapy and/or radiotherapy were recruited from Iran and randomized to HIIT, MICT, or control groups for a supervised exercise intervention that took place 3 times a week for 12 weeks. The training intensity was determined based on the peak oxygen uptake (VO2peak), and the volume of training was matched in HIIT and MICT based on the VO2peak. Body composition, functional capacity, cardiorespiratory fitness, metabolic indices, sex hormones, adipokines, and inflammatory markers were assessed before and after the intervention.

RESULTS

The VO2peak increased by 16.8% in the HIIT group in comparison to baseline values (mean difference = 3.61 mL/kg/min). HIIT significantly improved the VO2peak compared to control (mean difference = 3.609 mL/kg/min) and MICT (mean differences = 2.974 mL/kg/min) groups. Both HIIT (mean difference = 9.172 mg/dL) and MICT (mean difference = 7.879 mg/dL) interventions significantly increased high-density lipoprotein cholesterol levels compared to the control group. The analysis of covariance showed that physical well-being significantly improved in MICT compared to control group (mean difference = 3.268). HIIT significantly improved the social well-being compared to the control group (mean difference = 4.412). Emotional well-being subscale was significantly improved in both MICT (mean difference = 4.248) and HIIT (mean difference = 4.412) compared to the control group. Functional well-being scores significantly increased in HIIT group compared with control group (mean difference = 3.35) . Significant increase were also observed in total functional assessment of cancer therapy-General scores in both HIIT (mean difference = 14.204) and MICT groups (mean difference = 10.036) compared with control group. The serum level of suppressor of cytokine signaling 3 increased significantly (mean difference = 0.09 pg/mL) in the HIIT group compared to the baseline. There were no significant differences between groups for body weight, body mass index, fasting blood glucose, insulin resistance, sex hormone binding globulin, total cholesterol, low-density lipoprotein cholesterol, adipokines, interleukin-6, tumor necrosis factor-α, or interleukin-10.

CONCLUSION

HIIT can be used as a safe, feasible, and time-efficient intervention to improve cardiovascular fitness in breast cancer patients. Both HIIT and MICT modalities enhance quality of life. Further large-scale studies will help determine whether these promising results translate into improved clinical and oncological outcomes.

Effect of a lifestyle intervention program's on breast cancer survivors' cardiometabolic health: Two-year follow-up

The purpose of this study is to assess the cardiometabolic responses of a lifestyle intervention (LI) conducted at home among breast cancer (BC) survivors during the two years of COVID-19 pandemic. A 3-month LI focused on diet and exercise was performed on thirty BC survivors (women; stages 0-II; non-metastatic; aged 53.6 ± 7.6 years; non-physically active) with a risk factor related to metabolic/endocrine diseases. Anthropometrics, cardiorespiratory fitness (V ˙ O2max), physical activity level (PAL), adherence to the Mediterranean diet (MeDiet modified questionnaire), and several biomarkers (i.e., glycemia, insulin, insulin resistance [HOMA-IR] index, triglycerides, high- [HDL] and low- [LDL] density lipoproteins, total cholesterol, progesterone, testosterone, and hs-troponin) were evaluated before and 3-, 6-, 12-, and 24-month after the LI. Beneficial effects of the LI were observed on several variables (i.e., body mass index, waist circumference, MeDiet, PAL, V ˙ O2max, glycemia, insulin, HOMA-IR index, LDL, total cholesterol, triglycerides, testosterone) after 3-month. The significant effect on Mediterranean diet adherence and V ˙ O2max persisted up to the 24-month follow-up. Decreases in HOMA-IR index and triglycerides were observed up to 12-month, however did not persist afterward. This study provides evidence on the positive association between LI and cardiometabolic health in BC survivors.

Comparative efficacy of four exercise types on obesity-related outcomes in breast cancer survivors: A Bayesian network meta-analysis

PURPOSE

Exercise training is associated with improving the prognosis of breast cancer survivors, but no studies have evaluated the optimal exercise intervention. We aimed to investigate the most effective exercise intervention to improve obesity-related outcomes in breast cancer survivors.

METHODS

A comprehensive search strategy was conducted in Medline, Embase, Web of Science, Cochrane Library, and Chinese biomedical literature databases from the time of library construction to April 2, 2023. We included randomized controlled trials reporting the effects of four types of exercise interventions (aerobic exercise; aerobic combined with resitance exercise, resitstance exercise and mind-body exercise ) on obesity-related outcomes in breast cancer survivors. A Bayesian network meta-analysis was used to analyze and rank the effectiveness of four exercise types.

RESULTS

A total of 76 randomized controlled trials that contained 5610 breast cancer survivors were included. The treatment effect of combined aerobic and resistance exercise (mean difference = -0.59; 95% credible interval: 1.15, -0.08) was significantly better than that of the control groups in terms of body mass index. For percentage of body fat, combined aerobic and resistance exercise (mean difference = -1.74; 95% credible interval: 0.87, -0.90) and aerobic exercise (mean difference = -1.16; 95% credible interval: 2.15, -0.16) were significantly better than controls. Subgroup analysis suggested that combined aerobic and resistance exercise significantly affected body mass index at an intervention duration >12 weeks or weekly time on exercise >150 min.

CONCLUSION

Our network meta-analysis found combined aerobic and resistance exercise may be the most effective intervention to improve obesity-related outcomes in breast cancer survivors. In addition, intervention duration and participant adherence are important factors that influence the effectiveness of exercise interventions.

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.

Randomized trial of exercise on cancer-related blood biomarkers and survival in women with ovarian cancer

BACKGROUND

In randomized trials in women with breast cancer, exercise has been shown to have beneficial effects on cancer-related circulating biomarkers that may impact survival. Such studies are lacking for ovarian cancer.

METHODS

This secondary analysis of a published randomized controlled trial examined the impact of a 6-month exercise intervention versus attention-control on change in prespecified circulating biomarkers (cancer antigen 125 (CA-125), C-reactive protein (CRP), insulin-like growth factor-1(IGF-1), insulin and leptin) in a subset of participants who provided a fasting blood draw (N = 104/144) at enrollment and at 6 months. Change in biomarkers between study arms was compared using a linear mixed effects model analysis. An exploratory analysis of the exercise intervention versus attention-control on all-cause mortality included all (N = 144) participants. All statistical tests were two-sided.

RESULTS

Participants included in the biomarker analysis were 57.0 ± 8.8 (mean ± SD) years old and 1.6 ± 0.9 years post-diagnosis. Adherence to the exercise intervention was 176.4 ± 63.5 min/week. Post intervention IGF-1 (group difference in change: -14.2 (-26.1 to -2.3) ng/mL (least squared means (95% CI))) and leptin (-8.9 (-16.5 to -1.4) ng/mL) were significantly reduced in the exercise group (N = 53) compared to those in attention-control (N = 51). No group difference in change was seen for CA-125 (p = 0.54), CRP (p = 0.95), or insulin (p = 0.37). With median follow-up of 70 months [range 6.6-105.4 months], 50/144 (34.7%) (exercise group; 24/74 (32.4%) versus attention-control group; 26/70 (37.1%)) participants died with no between group difference in overall survival (p = 0.99).

CONCLUSIONS

Further studies are needed to determine the clinical significance of exercise-induced changes in cancer-related circulating biomarkers in women with ovarian cancer.

Methodological consideration for a physical activity intervention in breast cancer population: An umbrella review

Objective

Breast cancer patients and survivors are increasing in the last years such as their mean age. A feasible and useful complementary intervention to improve physical and psychological health, and decrease some disease symptoms seems to be physical activity. Consequently, this umbrella review wanted to analyze the protocols of different physical activity interventions and to eventually propose a standard operating procedure for possible exercise training in breast cancer patients.Design, Data sources, Eligibility criteria. The electronic databases PubMed, Scopus, and Web of Science were searched till 25 March 2022 to detect all systematic review and meta-analysis of randomized controlled trials on this topic. The studies were analyzed narratively and evaluated with a scale to assess their quality.

Results

The studies presented heterogeneity in their population included in terms of disease stage and treatments, intervention protocols and outcomes evaluated. This made difficult to synthesize the findings.

Conclusion

It was not possible to propose a standard operating procedure but some indications were proposed to provide feedback for future studies. Ideally, an intervention should be composed of combined training (aerobic and resistance training) with a component of a mindfulness intervention, with an intensity from moderate to high, and 3 times a week. The intervention should be supervised in the first period and then it could be home-based. Exercise training should be personalized to the patients treated.

Physical exercise, health, and disease treatment: The role of macrophages

Subclinical inflammation is linked to comorbidities and risk factors, consolidating the diagnosis of chronic non-communicable diseases, such as insulin resistance, atherosclerosis, hepatic steatosis, and some types of cancer. In this context, the role of macrophages is highlighted as a marker of inflammation as well as for the high power of plasticity of these cells. Macrophages can be activated in a wide range between classical or proinflammatory, named M1, and alternative or anti-inflammatory, also known as M2 polarization. All nuances between M1 and M2 macrophages orchestrate the immune response by secreting different sets of chemokines, while M1 cells promote Th1 response, the M2 macrophages recruit Th2 and Tregs lymphocytes. In turn, physical exercise has been a faithful tool in combating the proinflammatory phenotype of macrophages. This review proposes to investigate the cellular and molecular mechanisms in which physical exercise can help control inflammation and infiltration of macrophages within the non-communicable diseases scope. During obesity progress, proinflammatory macrophages predominate in adipose tissue inflammation, which reduces insulin sensitivity until the development of type 2 diabetes, progression of atherosclerosis, and diagnosis of non-alcoholic fatty liver disease. In this case, physical activity restores the balance between the proinflammatory/anti-inflammatory macrophage ratio, reducing the level of meta-inflammation. In the case of cancer, the tumor microenvironment is compatible with a high level of hypoxia, which contributes to the advancement of the disease. However, exercise increases the level of oxygen supply, favoring macrophage polarization in favor of disease regression.

High-intensity interval training improves metabolic syndrome in women with breast cancer receiving Anthracyclines

INTRODUCTION

Anthracycline chemotherapy is a frequent treatment for breast cancer, whereas it can increase risk of physiologic side-effects, such as metabolic syndrome (MetS). Exercise has been used as a non-pharmacological strategy to decrease MetS. Specifically, high-intensity interval training (HIIT) has been shown to improve MetS in patients with diabetes or cardiac rehabilitation patients; however, the effects of HIIT on MetS and associated biomarkers in patients with breast cancer receiving anthracycline chemotherapy have not been previously explored. Therefore, we purposed to determine the effects of HIIT on MetS in breast cancer patients undergoing anthracycline chemotherapy.

METHODS

In total, 30 patients with breast cancer were recruited prior to initiating treatment and randomized into HIIT (n = 15) or control (n = 15). The HIIT group attended supervised cycling sessions 3 days/week for 8 weeks. MetS was assessed by waist circumference, blood pressure, fasting levels of high-density lipoprotein cholesterol (HDL-C), triglycerides, and glucose. Circulating levels of MetS-related biomarkers were also measured (total cholesterol, insulin, HbA1c, leptin, adiponectin, and c-reactive protein).

RESULTS

After 8 weeks, MetS z-score was significantly improved in the HIIT group compared with controls (-7.60, 95% CI: -9.08 to -6.13, p < 0.001). MetS variables (HDL-C, glucose, and triglycerides) and circulating levels of MetS-related biomarkers were significantly improved in the HIIT group compared with controls (p < 0.001). Non-significant differences were found in body composition outcomes at the end of the study.

CONCLUSIONS

HIIT may be an effective strategy to improve MetS in breast cancer patients undergoing anthracycline chemotherapy. Furthermore, changes in MetS were independent of changes in body composition.

Effect of a 1-year tailored exercise program according to cancer trajectories in patients with breast cancer: study protocol for a randomized controlled trial

BACKGROUND

Patients with breast cancer undergo various treatments according to their tumor subtype and cancer stages within 1 year after being diagnosed. Each treatment may cause treatment-related symptoms that have negative impacts on patients' health and quality of life (QoL) The symptoms can be mitigated when exercise interventions are appropriately applied to patients' physical and mental conditions. Although many exercise programs were developed and implemented during this period, the effects of tailored exercise programs according to symptoms and cancer trajectories on patients' long-term health outcomes have not yet been fully elucidated. Therefore, this randomized controlled trial (RCT) aims to investigate the effect of tailored home-based exercise programs on short-term and long-term physiological outcomes in patients with breast cancer.

METHODS

This 12-month RCT includes 96 patients with (stages 1-3) breast cancer randomly assigned to the exercise or control groups. Participants in the exercise group will receive an exercise program tailored to their phase of treatment, type of surgery, and physical function. During post-operative recovery, exercise interventions will be emphasized to improve shoulder range of motion (ROM) and strength. During chemoradiation therapy, exercise intervention will focus on improving physical function and preventing loss of muscle mass. Once chemoradiation therapy is completed, exercise intervention will focus on improving cardiopulmonary fitness and insulin resistance. All interventions will be home-based exercise programs supplemented with once-monthly exercise education and counseling sessions. The main outcome of the study is fasting insulin level at baseline, 6 months, and 1 year post-intervention. Our secondary outcomes include shoulder ROM and strength at 1 month and 3 months, body composition, inflammatory markers, microbiome, QoL, and physical activity levels at 1 month, 6 months, and 1 year post-intervention.

CONCLUSION

This trial is the first tailored home-based exercise oncology trial to better understand the comprehensive phase-dependent short- and long-term effects of exercise on shoulder function, body composition, fasting insulin, biomarkers, and microbiome. The results of this study will inform the development of effective exercise programs tailored to the needs of patients with breast cancer post-operatively.

TRIAL REGISTRATION

The protocol for this study is registered with the Korean Clinical Trials Registry (KCT0007853).

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.

Effects of exercise on inflammatory factors and IGF system in breast cancer survivors: a meta-analysis

BACKGROUND

At present, there are multiple hypotheses regarding the mechanisms underlying the effect of exercise on the postoperative inflammatory factors and the IGF system among breast cancer patients, especially. To determine the underlying mechanisms, prevent the recurrence of breast cancer and improve its prognosis, this paper will systematically evaluate the impact of exercise on inflammatory factors and the IGF system in breast cancer survivors.

METHODS

The PubMed, Embase, Web of Science, CNKI, Wanfang and VIP (Chinese scientific and technical journals) databases were systematically searched until April 2021. The search terms included 'exercise', 'inflammatory factor', 'IGF system' and 'breast cancer'. A total of 1066 relevant articles were retrieved. The articles were screened according to inclusion and exclusion criteria, such as study population, intervention method and type of experiment, and 11 articles were ultimately included. All statistical results were analysed using STATA 14.0 and Rstudio 4.1.1.

RESULTS

We found that exercise significantly reduced the level of IGF-1 (WMD, -19.947 ng/ml; 95% CI, -22.669 to -17.225; P = 0.000). Subgroup analysis showed that in the studies with an intervention period > 12 weeks, exercise significantly reduced IL-6 levels (WMD, -0.761 pg/ml; 95% CI, -1.369 to -0.153; p = 0.014), while in the studies with an intervention period ≤ 12 weeks, exercise significantly reduced CRP (WMD, -2.381 mg/L; 95% CI, -4.835 to 0.073, P = 0.001) and IL-10 levels (WMD, -7.141 pg/ml, 95% CI, -10.853 to -3.428; P = 0.000). In addition, aerobic exercise plus resistance training significantly reduced IL-6 levels (WMD, -1.474 pg/ml; 95% CI, -1.653 to -1.296; P = 0.000). The results of the sensitivity analysis showed that after excluding the studies with high heterogeneity, exercise significantly reduced the TNF-α levels in patients with breast cancer (WMD, -1.399 pg/ml; 95% CI, -1.718 to -1.080; P = 0.000).

CONCLUSION

Exercise reduces the postoperative levels of IGF-1, IL-6, CRP, IL-10 and TNF-α among patients with breast cancer, which may have a significant impact on inhibiting breast cancer recurrence and improving its prognosis. Future studies should examine the effects of different durations and types of exercise to develop individualized exercise prescriptions for breast cancer patients.

Combined Exercise and Game-Based Cognitive Training Intervention: Correlative Pilot Study of Neurotrophic and Inflammatory Biomarkers for Women With Breast Cancer

BACKGROUND

Interventions that increase neuroprotective factors and/or decrease inflammatory biomarkers may be effective in improving cognitive function for cancer survivors. Concurrent investigation of potential mechanism(s) to fully understand and refine effective interventions is needed.

OBJECTIVE

This correlative prospective substudy was conducted to investigate biomarkers related to potential mechanism(s) for a combined exercise and game-based brain training intervention designed to improve cognitive function in breast cancer survivors.

INTERVENTIONS/METHODS

Fingerstick bloodspot samples were collected at 3 time points during the randomized, wait-list controlled interventional parent study. Samples were analyzed for neuroprotective factors and inflammatory biomarker levels.

RESULTS

Insulinlike growth factor 1 (IGF-1) levels significantly increased (P < .01) for the intervention group from baseline to 4 and 16 weeks postintervention. Insulinlike growth factor 1 levels correlated with neurocognitive test performace improvement for Trail Making Test B (r = 0.31, P = .02). This association was not significant in the mixed model. No significant correlation was seen between IGF-1 levels and changes in self-report of cognitive function, activity level, or intervention dose.

CONCLUSIONS

Further investigation of IGF-1 levels is warranted as related to potential mechanisms for the Combined Exercise and Game-based Cognitive Training intervention. Future investigations should involve a larger sample cohort and incorporate objective measures of physical activity and prescribed sampling time in relationship to the most recent performance of the intervention.

IMPLICATIONS FOR PRACTICE

Fingerstick bloodspot sample collection is feasible, acceptable, and effective for conducting biomarker research. This methodology minimizes participant burden and discomfort; increases clinical trial access for home, off-site, or rural settings; and facilitates research efforts during times of pandemic restrictions.

Integrating molecular biomarkers in breast cancer rehabilitation. What is the current evidence? A systematic review of randomized controlled trials

Background: Quality of life issues is a crucial burden in breast cancer (BC) survivors with relevant implications in terms of survivorship and health-care costs. The increasing long-term survival of these patients provides new challenges, with translational research now focusing on innovative and tailored approaches to improve their complex management. In this scenario, several emerging biomarkers have the potential to improve the clinical rehabilitative management of patients with BC. However, to date, guidelines supporting biomarker implementation in this area are still lacking. Therefore, the aim of this systematic review was to summarize the currently available biomarkers that might be potentially integrated into rehabilitation practice to promote a precision medicine approach to BC survivorship issues. Methods: On 9th March 2022, PubMed, Scopus, Web of Science, Cochrane, and PEDro were systematically searched for randomized controlled trials (RCTs) assessing rehabilitation interventions in BC patients. Molecular biomarker modifications induced by physical exercise have been assessed through the review of the study protocols and published results. The Jadad scale was used to assess the quality of the studies included. Results: Out of 2,224 records, 22 studies were included in the present systematic review. Exercise therapy showed significant results in 15 RCTs, in terms of metabolic biomarkers, including glycemic and insulin profile, and lipid profile (p ≤ 0.05). Similarly, 12 studies underlined significant effects in inflammation and immune response biomarkers, including TNF-α, IL-6, IL-10, C-reactive protein, leptin, and adiponectin (p ≤ 0.05). On the other hand, cardiac biomarkers were assessed in three studies without reporting significant differences after exercise therapy (p = NS). The quality assessment identified 19 RCTs as high-quality studies and three RCTs of low quality. Conclusion: Our findings reveal significant biochemical perturbations in key molecules induced by physical exercise in patients with BC, suggesting room for the implementation of actionable biomarkers. Future research might clarify the role of biomarkers on treatment effectiveness monitoring, to optimize rehabilitative strategies tailored to patient's needs.

Effects of physical exercise on body fat and laboratory biomarkers in cancer patients: a meta-analysis of 35 randomized controlled trials

BACKGROUND

A growing number of articles had reported the beneficial effects of physical exercise on reduced risks of cancer recurrence and mortality. However, the associations between physical exercise and laboratory biomarkers still had controversy. As we knew, this meta-analysis of randomized controlled trials (RCTs) was the first time for us to comprehensively clarify their relationships in cancer patients.

METHODS

We comprehensively searched the PubMed, Cochrane Central, EMBASE, Web of Science, and SportDiscus online databases to identify eligible articles, up to June 1, 2021. Pooled standardized mean differences (SMDs) with 95% confidence intervals (CIs) were utilized to clarify their associations. Sensitivity analysis was performed to assess the impact of the individual on overall and Begg's/Egger's plot was utilized to evaluate potential publication bias.

RESULTS

Finally, 35 randomized controlled trials (RCTs) were finally enrolled in this meta-analysis. Our results indicated that physical exercise could significantly reduce BMI (pooled SMD = -0.32 - 0.56 to -0.09)), body weight (pooled SMD = -0.31 (-0.54 to -0.08)), body fat (pooled SMD = -0.44 (-0.70 to -0.18)), waist circumference (pooled SMD = -0.50 (-0.76 to -0.23)), hip circumference (pooled SMD = -0.54 (-0.80 to -0.28)), triglyceride (pooled SMD = -0.35 (-0.69 to -0.02)), fasting insulin (pooled SMD = -0.38 (-0.54 to -0.22)), glucose (pooled SMD = -0.56 (-0.84 to -0.28)), insulin resistance (pooled SMD = -0.40 (-0.72 to -0.07)), CRP (pooled SMD = -0.97 (-1.48 to -0.46)), IGF-1 levels (pooled SMD = -0.56 (-0.83 to -0.29)) and remarkably increase IGFBP-3 levels (pooled SMD = 0.81 (0.45 to 1.17)). Further sensitivity analysis and Begg's or Egger's test suggested that our results were robust with no significant publication bias.

CONCLUSIONS

Our results shed light on the beneficial effects of physical exercise on cancer patients by means of BMI/weight change and various biomarkers alteration (insulin-glucose pathways or inflammatory biomarkers). Our results were anticipated for clinical application to improve cancer patients' prognosis.

The Practice of Physical Activity on Psychological, Mental, Physical, and Social Wellbeing for Breast-Cancer Survivors: An Umbrella Review

(1) Background: The number of breast-cancer patients and survivors is increasing in the last years. Physical activity seems to be a feasible and useful complementary intervention to improve the physical, psychological, and social spheres and decrease some symptoms, especially for survivors. Consequently, the objective of the present umbrella review was to analyze the efficacy of different physical-activity interventions in the physical, mental, and social spheres of breast-cancer survivors. (2) Methods: Systematic reviews and meta-analyses of randomized controlled trials on breast-cancer survivors and physical-activity effects were searched on the electronic databases PubMed, Web of Science, and Scopus till 9 August 2022. The quality of the studies included was evaluated, and the results were narratively analyzed. (3) Results: Physical-activity intervention generally improves the physical, mental, and social spheres of breast-cancer survivors, but the studies included present heterogeneity in the protocols adopted. (4) Conclusions: A well-structured and planned physical-activity intervention is useful for improvements in the physical, mental, and social spheres of breast-cancer survivors, but the studies presented high heterogeneity. Yoga seems to be the most effective physical intervention to complement medical therapy.

Application of the theory of planned behavior to understand physical activity intentions and behavior among Korean breast cancer survivors

PURPOSE

The purpose of this study was to apply the theory of planned behavior (TPB) to understand physical activity intentions and behaviors among Korean breast cancer survivors.

METHODS

A total of 286 Korean breast cancer survivors (M_age52.3 ± 8.3) completed a self-reported survey administered face to face by a trained interviewer. The survey assessed the physical activity frequency and intensity in a typical week after breast cancer diagnosis, demographic factors, and theory of planned behavior variables including attitude, subjective norm, perceived behavioral control (PBC), planning, and intentions to participate in physical activity. We used structural equation modeling to examine the direct and indirect effects of the TPB variables on physical activity intentions and behavior. Covariates included age, cancer stage, and clinical treatment.

RESULTS

Confirmatory factor analyses indicated a satisfactory model fit. We observed direct effects for instrumental attitude (ß = 0.34, p < 0.001), subjective norm (ß = 0.12, p < 0.05), and PBC (ß = 0.57, p < 0.001) on physical activity intentions. PBC (ß = .17, p < 0.01) and physical activity intentions (ß = 0.46, p < 0.01) had direct effects on planning. PBC (ß = 0.28, p < 0.01) and planning (ß = 0.22, p < 0.01) had direct effects on physical activity behavior.

CONCLUSION

The TPB was a useful model for understanding Korean breast cancer survivors' physical activity intentions and behavior. Interventions that can enhance attitudes, subjective norm, PBC, intention, and planning may facilitate physical activity intentions and behaviors in this population.

Targeting Adiposity and Inflammation With Movement to Improve Prognosis in Breast Cancer Survivors (The AIM Trial): Rationale, Design, and Methods

Background

Obesity is a significant contributor to breast cancer recurrence and mortality. A central mechanism by which obesity stimulates cancer progression is through chronic, low-grade inflammation in adipose tissue. Exercise interventions to target chronic inflammation has a potential to improve obesity- and breast cancer-related outcomes; however, no studies have investigated the roles of exercise in modulating adipose tissue inflammation in breast cancer survivors. Also, it is unclear which exercise prescription would be optimal to maximize the outcomes. Therefore, we designed a randomized controlled trial (Taking AIM at Breast Cancer: Targeting Adiposity and Inflammation with Movement to Improve Prognosis in Breast Cancer Survivors [AIM] Trial) to examine the mechanisms by which different modalities of exercise impact chronic inflammation as a biomarker of breast cancer prognosis.

Methods

The AIM trial is a prospective, three-armed, phase II randomized controlled trial investigating the effects of a 16-week supervised circuit aerobic and resistance exercise (CARE) program versus a traditional aerobic and resistance exercise (TARE) program and attention control (AC) on adipose tissue inflammation in breast cancer survivors. 276 patients who are diagnosed with stage 0-III breast cancer, post-treatment, sedentary, and centrally obese are randomized to one of the three groups. The CARE and TARE groups participate in thrice-weekly supervised exercise sessions for 16 weeks. The AC group are offered the CARE program after the intervention period. The primary endpoint is adipose tissue inflammation assessed by core biopsy and blood draw. The secondary and tertiary endpoints are sarcopenic obesity, physical fitness and function, and patient reported outcomes. The exploratory outcomes are long-term breast cancer outcomes.

Discussion

This is the first randomized controlled trial examining the effects of exercise on adipose tissue inflammation in obese, breast cancer survivors. Our findings are anticipated to contribute to a better understanding of exercise modalities and mechanisms on adipose tissue inflammation that can potentially improve breast cancer prognosis.

Clinical Trial Registration

https://clinicaltrials.gov/ct2/show/NCT03091842 identifier [NCT#03091842].

Association Between Skeletal Muscle Mass, Physical Activity, and Metabolic Syndrome: the Korean National Health and Nutrition Examination Survey 2008-2011

Background: Skeletal muscle mass (SM) and physical activity (PA) are major modifiable factors that can moderate and prevent the occurrence of metabolic syndrome (MetS). However, the joint association between SM and PA guidelines in MetS remains unclear. Therefore, we aimed to examine the relationship between SM and PA with MetS among Korean adults. Methods: This cross-sectional study analyzed 18,090 adults from the Korean National Health and Nutrition Examination Survey 2008-2011. We used the value of appendicular skeletal muscle mass divided by body mass index as SM. We decided on the PA guidelines using the American College of Sports Medicine guidelines. After adjusting for confounding factors, we performed logistic regression analysis to calculate the odds ratio and 95% confidence interval of MetS associated with SM and PA guidelines. Results: Participants from the highest SM quartile showed a decreased MetS risk of 58%-75%. Those who met both aerobic and resistance exercise guidelines were more likely to have lower MetS risk than those who neither. In addition, even with the same PA guideline status, participants with the highest muscle mass decreased MetS risk by 29%-81% compared with participants with the lowest muscle mass. Conclusions: Our results showed that increased SM and meeting PA guidelines are significantly associated with a decreased risk of MetS. To prevent MetS, customized strategies are needed for improving muscle mass and PA according to age and gender.

The Interplay between Housing Environmental Attributes and Design Exposures and Psychoneuroimmunology Profile-An Exploratory Review and Analysis Paper in the Cancer Survivors' Mental Health Morbidity Context

Adult cancer survivors have an increased prevalence of mental health comorbidities and other adverse late-effects interdependent with mental illness outcomes compared with the general population. Coronavirus Disease 2019 (COVID-19) heralds an era of renewed call for actions to identify sustainable modalities to facilitate the constructs of cancer survivorship care and health care delivery through physiological supportive domestic spaces. Building on the concept of therapeutic architecture, psychoneuroimmunology (PNI) indicators-with the central role in low-grade systemic inflammation-are associated with major psychiatric disorders and late effects of post-cancer treatment. Immune disturbances might mediate the effects of environmental determinants on behaviour and mental disorders. Whilst attention is paid to the non-objective measurements for examining the home environmental domains and mental health outcomes, little is gathered about the multidimensional effects on physiological responses. This exploratory review presents a first analysis of how addressing the PNI outcomes serves as a catalyst for therapeutic housing research. We argue the crucial component of housing in supporting the sustainable primary care and public health-based cancer survivorship care model, particularly in the psychopathology context. Ultimately, we illustrate a series of interventions aiming at how housing environmental attributes can trigger PNI profile changes and discuss the potential implications in the non-pharmacological treatment of cancer survivors and patients with mental morbidities.

Fasting and Exercise in Oncology: Potential Synergism of Combined Interventions

Nutrition and exercise interventions are strongly recommended for most cancer patients; however, much debate exists about the best prescription. Combining fasting with exercise is relatively untouched within the oncology setting. Separately, fasting has demonstrated reductions in chemotherapy-related side effects and improved treatment tolerability and effectiveness. Emerging evidence suggests fasting may have a protective effect on healthy cells allowing chemotherapy to exclusively target cancer cells. Exercise is commonly recommended and attenuates treatment- and cancer-related adverse changes to body composition, quality of life, and physical function. Given their independent benefits, in combination, fasting and exercise may induce synergistic effects and further improve cancer-related outcomes. In this narrative review, we provide a critical appraisal of the current evidence of fasting and exercise as independent interventions in the cancer population and discuss the potential benefits and mechanisms of combined fasting and exercise on cardiometabolic, body composition, patient-reported outcomes, and cancer-related outcomes. Our findings suggest that within the non-cancer population combined fasting and exercise is a viable strategy to improve health-related outcomes, however, its safety and efficacy in the oncology setting remain unknown. Therefore, we also provide a discussion on potential safety issues and considerations for future research in the growing cancer population.

Estrogen-Receptor-Positive Breast Cancer in Postmenopausal Women: The Role of Body Composition and Physical Exercise

Breast cancer (BC) is the most commonly diagnosed cancer among women worldwide and the most common cause of cancer-related death. To date, it is still a challenge to estimate the magnitude of the clinical impact of physical activity (PA) on those parameters producing significative changes in future BC risk and disease progression. However, studies conducted in recent years highlight the role of PA not only as a protective factor for the development of ER+ breast cancer but, more generally, as a useful tool in the management of BC treatment as an adjuvant to traditional therapies. In this review, we focused our attention on data obtained from human studies analyzing, at each level of disease prevention (i.e., primary, secondary, tertiary and quaternary), the positive impact of PA/exercise in ER+ BC, a subtype representing approximately 70% of all BC diagnoses. Moreover, given the importance of estrogen receptors and body composition (i.e., adipose tissue) in this subtype of BC, an overview of their role will also be made throughout this review.

Connected device and therapeutic patient education to promote physical activity among women with localised breast cancer (DISCO trial): protocol for a multicentre 2×2 factorial randomised controlled trial

INTRODUCTION

Despite safety and benefits of physical activity during treatment of localised breast cancer, successful exercise strategies remain to be determined. The primary objective of the 'dispositif connecté', that is, connected device in English trial is to evaluate the efficacy of two 6-month exercise interventions, either single or combined, concomitant to adjuvant treatments, on the physical activity level of patients with breast cancer, compared with usual care: an exercise programme using a connected device (activity tracker, smartphone application, website) and a therapeutic patient education intervention. Secondary objectives are to evaluate adherence to interventions, their impact at 6 and 12 months, representations and acceptability of interventions, and to assess the cost-effectiveness of the interventions using quality-adjusted life-years.

METHODS AND ANALYSIS

This is a 2×2 factorial, multicentre, phase III randomised controlled trial. The study population (with written informed consent) will consist of 432 women diagnosed with primary localised invasive breast carcinoma and eligible for adjuvant chemotherapy, hormonotherapy and/or radiotherapy. They will be randomly allocated between one of four arms: (1) web-based connected device (evolving target number of daily steps and an individualised, semisupervised, adaptive programme of two walking and one muscle strengthening sessions per week in autonomy), (2) therapeutic patient education (one educational diagnosis, two collective educational sessions, one evaluation), (3) combination of both interventions and (4) control. All participants will receive the international physical activity recommendations. Assessments (baseline, 6 and 12 months) will include physical fitness tests, anthropometrics measures, body composition (CT scan, bioelectrical impedance), self-administered questionnaires (physical activity profile (Recent Physical Activity Questionnaire), quality of life (European Organization for Research and Treatment of Cancer Quality-Of-Life Questionnaire-30, EQ-5D-5L), fatigue (Piper Fatigue Scale-12), social deprivation (Evaluation of Deprivation and Inequalities in Health Examination Centres), lifestyle, physical activity barriers, occupational status) and biological parameters (blood draw).

ETHICS AND DISSEMINATION

This study was reviewed and approved by the French Ethics Committee. The findings will be disseminated to the scientific and medical community via publications in peer-reviewed journals and conference presentations.

TRIAL REGISTRATION NUMBER

NCT03529383; Pre-results.

Exercise Training Protocols to Improve Obesity, Glucose Homeostasis, and Subclinical Inflammation

The global pandemics of obesity and sedentarism are associated with poor quality of life and increased risks for development of inflammatory chronic diseases, including type 2 diabetes, cardiovascular diseases, and cancer. Physical activity is considered as an antidote to counteract the development of chronic sterile inflammatory diseases. Thus, we review the most promising exercise training protocols for promoting weight loss, improving glucose homeostasis, and reducing inflammation. We discuss the advantages and disadvantages of moderate-intensity continuous aerobic training, high-intensity aerobic training, and combined (aerobic + resistance) training. Our aim with this chapter is to provide evidence and guidance for choosing the most appropriate protocols of exercise training according to the goals of the patient.

Continuous, objective measurement of physical activity during chemotherapy for breast cancer: the Activity in Treatment pilot study

Despite many potential benefits of physical activity during and after breast cancer treatment, activity levels typically decline from pre- to posttreatment. Most previous research has relied on self-reported activity. The purpose of this study were to assess patterns of daily, to objectively measured physical activity throughout chemotherapy for breast cancer, and to identify predictors of physical activity patterns. Participants were given a Fitbit before starting chemotherapy and asked to wear it throughout chemotherapy. Restricted cubic splines assessed nonlinear patterns of Fitbit measured total physical activity (TPA) and moderate-to-vigorous physical activity (MVPA) throughout the duration of chemotherapy (mean = 17 weeks, standard deviation [SD] = 6.3). Mixed-effects regression models assessed the rate of physical activity decline. Regressions of subject-level random slope assessed predictors of the rate of physical activity decline on participant and cancer characteristics and self-reported physical and cognitive functioning. Participants (n = 32) were on average 50 years old; the majority had stage II breast cancer. MVPA declined linearly at a mean rate of 1.4 min/day (p = .002) for every 10% of chemotherapy completed, whereas TPA declined linearly at an average rate of 13.4 min/day (p = .0007) for every 10% of chemotherapy completed, until around halfway through chemotherapy, when activity rates leveled off. HER+ receptor status was associated with a greater rate of MVPA decline, β = 13.3, p = .04. This novel study of objectively measured daily MVPA throughout chemotherapy showed that most reductions in activity occurred during the first half of a course of chemotherapy. Targeting this early period of chemotherapy may be important for preventing declines in activity levels throughout chemotherapy.

Role of physical exercise in modulating the insulin-like growth factor system for improving breast cancer outcomes: A meta-analysis

BACKGROUND

Physical activity prevents cancer and improves cancer outcomes. Insulin-like growth factor (IGF) signaling plays a significant role in cancer development and progression. However, there are heterogeneous results regarding physical activity and its effect on the IGF system. This study meta-analyzed the results of randomized clinical trials which evaluated the effects of physical exercise on the changes of physiologic markers to identify the role of physical exercise in modulating the IGF system in women with breast cancer.

METHODS

PubMed, Embase, CENTRAL, and SPORTDiscus were systematically searched until October 2020. Eligibility criteria included randomized controlled trials that evaluated the effects of physical exercise on the insulin-like growth factor system among women with breast cancer.

RESULTS

Twelve randomized controlled studies involving 736 participants were analyzed. Physical exercise significantly reduced levels of serum insulin (MD -1.24 μIU/mL, 95% CI -2.12 to -0.36, p = 0.006), IGF-II (MD -54.21 ng/mL, 95% CI -61.41 to -47.00, p < 0.00001), IGFBP-1 (MD -2.90 ng/mL, 95% CI -3.91 to -1.90, p < 0.00001), and HOMA score (MD -0.47, 95% CI -0.87 to -0.06, p = 0.02). In addition, serum glucose (MD -0.71 mg/dL, 95% CI -2.57 to 1.15; p = 0.45) and IGF-I levels (MD -5.23 ng/mL, 95% CI -13.00 to 2.53; p = 0.19) were decreased after physical exercise although they did not show a statistical significance.

CONCLUSION

Physical exercise had a positive effect on the IGF system in women with breast cancer.

Effects of a Home-Based Lifestyle Intervention Program on Cardiometabolic Health in Breast Cancer Survivors during the COVID-19 Lockdown

This study aimed to evaluate the cardiometabolic effects of a home-based lifestyle intervention (LI) in breast cancer survivors (BCSs) during the COVID-19 lockdown. In total, 30 BCSs (women; stages 0-II; non-metastatic; aged 53.5 ± 7.6 years; non-physically active; normal left ventricular systolic function) with a risk factor for recurrence underwent a 3-month LI based on nutrition and exercise. Anthropometrics, Mediterranean diet adherence, physical activity level (PAL), cardiorespiratory fitness (VO2max), echocardiographic parameters, heart rate variability (average standard deviation of NN intervals (ASDNN/5 min) and 24 h very- (24 hVLF) and low-frequency (24 hLF)), and metabolic, endocrine, and inflammatory serum biomarkers (glycemia, insulin resistance, progesterone, testosterone, and high-sensitivity C-reactive protein (hs-CRP)) were evaluated before (T0) and after (T1) the LI. After the LI, there were improvements in: body mass index (kg/m2: T0 = 26.0 ± 5.0, T1 = 25.5 ± 4.7; p = 0.035); diet (Mediet score: T0 = 6.9 ± 2.3, T1 = 8.8 ± 2.2; p < 0.001); PAL (MET-min/week: T0 = 647 ± 547, T1 = 1043 ± 564; p < 0.001); VO2max (mL·min-1·kg-1: T0 = 30.5 ± 5.8, T1 = 33.4 ± 6.8; p < 0.001); signs of diastolic dysfunction (participants: T0 = 15, T1 = 10; p = 0.007); AS-DNN/5 min (ms: T0 = 50.6 ± 14.4, T1 = 55.3 ± 16.7; p = 0.032); 24 hLF (ms2: T0 = 589 ± 391, T1 = 732 ± 542; p = 0.014); glycemia (mg/dL: T0 = 100.8 ± 11.4, T1 = 91.7 ± 11.0; p < 0.001); insulin resistance (HOMA-IR score: T0 = 2.07 ± 1.54, T1 = 1.53 ± 1.11; p = 0.005); testosterone (ng/mL: T0 = 0.34 ± 0.27, T1 = 0.24 ± 0.20; p = 0.003); hs-CRP (mg/L: T0 = 2.18 ± 2.14, T1 = 1.75 ± 1.74; p = 0.027). The other parameters did not change. Despite the home-confinement, LI based on exercise and nutrition improved cardiometabolic health in BCSs.

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.

Special Attention to Physical Activity in Breast Cancer Patients during the First Wave of COVID-19 Pandemic in Italy: The DianaWeb Cohort

Recent evidence highlights that physical activity (PA) is associated with decreased recurrence risk, improved survival and quality of life for breast cancer (BC) patients. Our study aimed to explore patterns of increased/decreased PA, and sedentary behaviors among BC women of the DianaWeb cohort during the first wave of COVID-19 pandemic, and examined the association with residential locations, work changes, different modality used to increase PA, and quality of life. The study analyzed the questionnaires completed by the 781 BC women (age 54.68 ± 8.75 years on both December 2019 and June 2020. Results showed a decrease of 22%, 57%, and 26% for walking activity, vigorous activity, and total PA, respectively. Sitting/lying time increased up to 54.2% of the subjects recruited. High quality of life was associated with lower odds of being sedentary (p = 0.003). Our findings suggest that innovative health management fostering compliance with current guidelines for PA and active behavior should be implemented, especially in unpredictable emergency conditions.

Effects of an Exercise and Nutritional Intervention on Circulating Biomarkers and Metabolomic Profiling During Adjuvant Treatment for Localized Breast Cancer: Results From the PASAPAS Feasibility Randomized Controlled Trial

Purpose:

Exercise has been shown to improve physical and psychological conditions during cancer therapy, but mechanisms remain poorly understood. The purpose of the present study was to report the results of cancer-related biomarkers and metabolomics outcomes from the PASAPAS feasibility study.

Methods:

In the PASAPAS randomized controlled trial, 61 women beginning adjuvant chemotherapy for localized breast cancer were randomized in a 6-month program of weekly aerobic exercises associated with nutritional counseling versus usual care with nutritional counseling. In the present analysis of 58 women for whom blood samples were available, first, circulating levels of biomarkers (ie, insulin, insulin-like growth factor 1, estradiol, adiponectin, leptin, interleukin-6, and tumor necrosis factor α) were measured at baseline and 6-month follow-up. Changes in biomarkers were compared between exercisers (n = 40) and controls (n = 18) using mixed-effect models. Second, serum metabolites were studied using an untargeted ¹H nuclear magnetic resonance spectroscopy, and orthogonal partial least squares analyses were performed to discriminate exercisers and controls at baseline and at 6 months.

Results:

Over the 6-month intervention, no statistically significant differences were observed between exercisers and controls regarding changes in biomarkers and metabolomic profiles.

Conclusion:

The present analysis of the PASAPAS feasibility trial did not reveal any improvement in circulating biomarkers nor identified metabolic signatures in exercisers versus controls during adjuvant breast cancer treatment. Larger studies preferably in women with poor physical activity level to avoid ceiling effect, testing different doses and types of exercise on additional biological pathways, could allow to clarify the mechanisms mediating beneficial effects of physical exercise during cancer treatment.

Trial registration:

ClinicalTrials.gov Identifier: NCT01331772. Registered 8 April 2011, https://clinicaltrials.gov/ct2/show/NCT01331772?term=pasapas&rank=1

Dissecting the molecular pathways involved in the effects of physical activity on breast cancers cells: A narrative review

Epidemiologic evidence suggests that obesity and sedentary are modifiable factors strongly associated with breast cancer risk worldwide. Since breast cancer represents the most frequent malignant neoplasm and the second cause of cancer-related deaths in women worldwide, an insight into the molecular mechanisms clarifying the effects of physical activity in breast cancer cells could have important implication for changing this cancer burden. In this narrative Review article, we summarize the current knowledge, regarding the effects of adapted physical activity program, focusing on the cellular signaling pathways activated and on the molecular markers involved in breast cancer. Regular exercise training in breast cancer patients has been shown to positively affect tumor-growth and survival rate. Indeed, emerging work demonstrates that regular exercise is able to affect multiple cancer hallmarks influencing the development and progression of cancer. In conclusion, changes in the circulating insulin, adipokines and estrogen levels, inflammation and oxidative stress could represent some of the possible biological mechanisms through which exercise may influence breast cancer development and recurrence.

The serological responses to acute exercise in humans reduce cancer cell growth in vitro: A systematic review and meta-analysis

We systematically reviewed and meta-analyzed the effects of acute exercise-conditioned serum on cancer cell growth in vitro. Five literature databases were systematically searched for studies that measured cancer cell growth after exposure to human sera obtained before and immediately after an acute bout of exercise. Standardized mean differences (SMDs) with 95% confidence intervals (CIs) were pooled using a three-level random-effects model. Meta-regressions were also performed with participant age and disease status, exercise type, cell line TP53 status, and serum incubation time entered as covariates. Seven studies met the inclusion criteria encompassing a total of 21 effect estimates and 98 participants. Exercise-conditioned serum significantly reduced cancer cell growth compared with preexercise serum (SMD = -1.23, 95% CI: -1.96 to -0.50; p = .002; I2  = 75.1%). The weighted mean reduction as a percentage of preexercise values was 8.6%. The overall treatment effect and magnitude of heterogeneity were not statistically influenced by any covariate. There were concerns regarding the risk of bias within individual studies and Egger's test of the intercept showed evidence of small study effects (β = -3.6, p = .004). These findings provide in vitro evidence that the transient serological responses to acute exercises reduce cancer cell growth, although many questions remain regarding the underlying mechanistic pathways and potential effect modifiers. To strengthen this evidence-base, future studies should seek to reduce the risk of bias by using more rigorous experimental designs, and consider using 3D cell culture models to better replicate in vivo tumor conditions. PROSPERO registration: CRD42020161333.

Translating Preclinical Research for Exercise Oncology: Take It to the VO2max

Several observational studies have found that the risk for breast cancer is significantly reduced in persons who engage in greater amounts of physical activity. Additional observational studies of breast cancer survivors indicate that greater physical activity before or after diagnosis associates with reduced disease-specific mortality. However, no large randomized controlled trials have examined the effect of structured exercise training on disease outcomes in breast cancer. Among the many hurdles in designing such trials lies the challenge of determining how a given regimen of exercise from efficacious preclinical studies can be extrapolated to an equivalent “dose” in humans to guide decisions around treatment regimen in early-phase studies. We argue that preclinical researchers in exercise oncology could better facilitate this endeavor by routinely measuring changes in exercise capacity in the subjects of their breast cancer models. VO_2max, the maximal rate of whole-organism oxygen consumption during a progressive exercise test, is emphasized here because it has become a standard measure of cardiorespiratory fitness, is well-integrated in clinical settings, and scales allometrically among nonhuman animals in preclinical research and breast cancer patients/survivors in the clinic. We also conduct secondary analyses of existing whole-transcriptome datasets to highlight how greater uptake and delivery of oxygen during exercise may reverse the typically hypoxic microenvironment of breast tumors, which often associates with more aggressive disease and worse prognosis.

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.

Effects of exercise on physical outcomes of breast cancer survivors receiving hormone therapy - A systematic review and meta-analysis

BACKGROUND

Side-effects of hormone therapy can impair the physical health of breast cancer survivors. Exercise has been clearly shown to improve the quality of life of breast cancer survivors. Less is known about the effects of exercise on physical outcomes for breast cancer survivors receiving hormone therapy.

OBJECTIVE

To investigate the effects of exercise on physical outcomes of breast cancer survivors receiving hormone therapy.

METHODS

Five electronic databases were searched by two authors using the terms "Breast Neoplasms" [MeSH] and "Tamoxifen" [MeSH] and "Aromatase Inhibitors" [MeSH] and "Exercise" [MeSH]. Randomized and non-randomized clinical trials were included. Risk of bias was assessed by the Cochrane Collaboration tool and ROBINS-I, and the quality of evidence was evaluated using GRADE. Pooled effects were reported as standardized mean differences (SMDs) and 95 % confidence intervals (CIs) using a random effects model.

RESULTS

Eleven studies were included in the meta-analysis. Two hundred and fourteen breast cancer survivors receiving hormone therapy, tamoxifen, or aromatase inhibitors participated in interventions based on aerobic plus resistance exercise or walking activity. The physical outcomes reported in the articles were: cardiorespiratory fitness, pain, bone mineral density, grip strength, and body fat percentage. Exercise effects were found only for cardiorespiratory fitness (SMD = 0.37; 95 % CI: 0.11; 0.63; I² = 93 %) and pain (SMD = -0.55; IC95 % -1.11; -0.00; I² = 80 %), with low quality of evidence. No effects were observed for the other variables.

CONCLUSIONS

Aerobic plus resistance exercise had positive effects on cardiorespiratory fitness and pain in breast cancer survivors receiving hormone therapy. However, high-quality randomized clinical trials are required to confirm this finding.

Effect of Serum SPARC Levels on Survival in Patients with Digestive Tract Cancer: A Post Hoc Analysis of the AMATERASU Randomized Clinical Trial

Observational studies suggest that physical activity may improve, whereas sarcopenia may worsen the survival of cancer patients. It has been suggested that secreted protein acidic and rich in cysteine (SPARC), one of the myokines that is secreted into the bloodstream by muscle contraction, has tumor-suppressive effects. Based on the hypothesis that serum SPARC level may be a potential prognostic biomarker, a post hoc analysis of the AMATERASU randomized, double-blind, placebo-controlled trial of postoperative oral vitamin D supplementation (2000 IU/day) in patients with stage I–III digestive tract cancer from the esophagus to the rectum (UMIN000001977) was conducted with the aim of exploring the association between serum SPARC levels after operation and survival. On multivariate analyses adjusting serum 25-hydroxyvitamin D, vitamin D supplementation, sarcopenia, body mass index, age, sex, cancer loci, stage, and adjuvant chemotherapy, patients with SPARC levels lower than the median level had a significantly higher risk for death than those with higher levels (hazard ratio, 2.25; 95% confidence interval, 1.25–4.05; p = 0.007), whereas there were no significant associations with other outcomes including recurrence. However, on the same multivariate analyses, sarcopenia was not a risk factor for death and/or relapse. These results suggest that serum SPARC levels may be a potential biomarker for death but not cancer relapse.

Metrics of Diabetes Risk Are Only Minimally Improved by Exercise Training in Postmenopausal Breast Cancer Survivors

CONTEXT

Insulin resistance is a risk factor for breast cancer recurrence. How exercise training changes fasting and postglucose insulin resistance in breast cancer survivors is unknown.

OBJECTIVE

To evaluate exercise-induced changes in postglucose ingestion insulin concentrations, insulin resistance, and their associations with cancer-relevant biomarkers in breast cancer survivors.

SETTING

The University of Massachusetts Kinesiology Department.

PARTICIPANTS

15 postmenopausal breast cancer survivors not meeting the physical activity guidelines (150 min/week of exercise).

INTERVENTION

A supervised 12-week aerobic exercise program (60 min/day, 3-4 days/week).

MAIN OUTCOME MEASURES

Postglucose ingestion insulin was determined by peak insulin and area under the insulin curve (iAUC) during a 5-sample oral glucose tolerance test. Insulin sensitivity was estimated from the Matsuda composite insulin sensitivity index (C-ISI). Changes in fitness and body composition were determined from submaximal VO2peak and dual energy X-ray absorptiometry.

RESULTS

Participants averaged 156.8 ± 16.6 min/week of supervised exercise. Estimated VO2peak significantly increased (+2.8 ± 1.4 mL/kg/min, P < .05) and body weight significantly decreased (-1.1 ± 0.8 kg, P < .05) following the intervention. There were no differences in fasting insulin, iAUC, C-ISI, or peak insulin following the intervention. Insulin was only significantly lower 120 min following glucose consumption (68.8 ± 34.5 vs 56.2 ± 31.9 uU/mL, P < .05), and there was a significant interaction with past/present aromatase inhibitor (AI) use for peak insulin (-11.99 non-AI vs +13.91 AI uU/mL) and iAUC (-24.03 non-AI vs +32.73 AI uU/mL).

CONCLUSIONS

Exercise training had limited overall benefits on insulin concentrations following glucose ingestion in breast cancer survivors but was strongly influenced by AI use.

Team triathlon effects on physiological, psychological, and immunological measures in women breast cancer survivors

PURPOSE

Exercise after breast cancer diagnosis and treatment improves cancer-related outcomes, although the mechanisms involved are not clear. This study evaluated the impact of exercise on body composition, strength, endurance, quality of life (QOL), fatigue, and endocrine and inflammatory biomarkers in breast cancer survivors participating in a highly monitored, clinically supervised, moderate-intensity exercise program. The association of hormonal and inflammatory biomarkers with the observed physiological changes was assessed.

METHODS

Female breast cancer survivors (BCS; n = 46) who engaged in a goal-oriented 14-week triathlon exercise training program were compared to an untrained control group of female BCS (n = 16). Psychosocial metrics, QOL, cancer-related fatigue, and exercise self-efficacy were evaluated via pre- and post-exercise intervention questionnaires. Serum estradiol and inflammatory biomarkers (C-reactive protein (CRP), sTNFR1a, estradiol, leptin, and adiponectin) were measured prior to the exercise training program start and after the completion of the goal triathlon.

RESULTS

After exercise training, the exercise group had lower BMI and arm circumferences. Greater positive change was noted in the trained group for QOL, fatigue, and self-efficacy questionnaires. Functional endurance improved in the trained but not the control group. Knee and elbow strength were not different between the groups, except that knee flexion at 180 degrees∙sec^-1 was higher in trained. The only significantly different biomarker was adiponectin, which decreased in the trained group.

CONCLUSIONS

Group triathlon exercise training may be beneficial to BCS by significantly improving their psychosocial measures, functional endurance, and BMI.

Effects of a home-based exercise program on the insulin-like growth factor axis in patients operated for colorectal cancer in Sweden: Results from the randomised controlled trial PHYSSURG-C

OBJECTIVES

We report results from a subgroup within the ongoing PHYSSURG-C trial with the aim to examine effects of exercise on IGF-1 and IGFBP-3 in patients undergoing colorectal cancer surgery.

DESIGN

Randomised controlled trial.

SETTING

A Swedish university hospital.

PARTICIPANTS

Between 2015 and 2016, 217 patients were enrolled (I = 106, C = 111), with 122 patients that had given blood samples at baseline and at least at one follow-up (I = 51, C = 71). Patients 20 year or older with colorectal cancer were eligible. Exclusion criteria were emergency surgery, local surgery, language problems or inability to perform intervention.

INTERVENTIONS

Patients were computer-randomised to either a daily home-based aerobic exercise intervention (I), or to usual care (C). The intervention lasted two weeks before surgery and four weeks after discharge from hospital and consisted of medium-intensity aerobic exercise and inspiratory muscle training. Circulating concentrations of IGF-1 and IGFBP-3 were determined by blinded personnel at baseline, time of surgery and 4-6 weeks postoperatively.

PRIMARY AND SECONDARY OUTCOME MEASURES

The outcome of this subpopulation report was change in IGF-1/IGFBP-3 ratio, IGF-1 and IGFBP-3 concentrations from baseline to surgery, and 4-6 weeks postoperatively.

RESULTS

The IGF-1/IGFBP-3 ratio increased from baseline to surgery by 11% in I and 8% in C with no difference between groups (I vs. C: 1.04, 95%CI: 0.97-1.11; p = 1.000). Postoperative change was 5% in I and 3% in C with no difference between groups (I vs. C:1.03, 95%CI: 0.96-1.10; p = 1.000). Results concerning IGF-1 and IGFBP-3 also showed statistically significant dynamics over time with no difference between groups. No adverse events were reported.

CONCLUSIONS

The home-based exercise program in our trial did not have any effect on IGF-1, or IGFBP-3.

TRIAL REGISTRATION

The study was registered at ClinicalTrials.gov with identifier NCT02299596. This work was funded externally.

MTHFR, XRCC1 and OGG1 genetic polymorphisms in breast cancer: a case-control study in a population from North Sardinia

BACKGROUND

Despite conflicting results, considerable evidence suggests the association between single nucleotide polymorphisms in MTHFR, XRCC1 and OGG1 genes and, risk of developing breast cancer. Here a case-control study is reported, including 135 breat cancer patients and 112 healthy women, all representative of Northern Sardinian population.

METHODS

Polymerase chain reaction/restriction fragment length polymorphism method was used to determine the genotypes of five polymorphisms: MTHFR C677T (rs1801133) and A1298C (rs1801131), XRCC1 Arg194Trp (rs1799782) and Arg399Gln (rs25487) and OGG1 Ser326Cys (rs1052133). Allelic, genotypic and haplotype association analyses with disease risk and clinicopathological parameters were performed.

RESULTS

A nominally significant association with breast cancer risk was observed for MTHFR C677T polymorphism heterozygous genotype in the codominant model (OR: 0.57, 95% CI: 0.32-1.00, p = 0.049) and for Cys/Cys genotype of the OGG1 Ser326Cys polymorphism in the recessive model (OR: 0.23, 95% CI: 0.05-1.11, p = 0.0465). No significant differences were found at genotype-level for A1298C polymorphism of the MTHFR gene and Arg194Trp and Arg399Gln of the XRCC1 gene. Furthermore, the OGG1 and XRCC1 rs25487 polymorphisms were nominally associated with PgR, Her2 status and with sporadic breast cancer, respectively.

CONCLUSIONS

Based on genetic characteristics of individuals included in this study, results suggest that MTHFR CT and OGG1 Cys/Cys genotypes have a protective effect that may have an influence on breast cancer risk in a representative Northern Sardinian population.

Insulin Resistance and Cancer-Specific and All-Cause Mortality in Postmenopausal Women: The Women's Health Initiative

BACKGROUND

Insulin resistance has been proposed as a mediator of the increased cancer incidence and mortality associated with obesity. However, prior studies included limited cancer deaths and had inconsistent findings. Therefore, we evaluated insulin resistance and cancer-specific and all-cause mortality in postmenopausal women participating in the Women's Health Initiative (WHI).

METHODS

Eligible were a subsample of 22 837 WHI participants aged 50-79 years enrolled at 40 US clinical centers from 1993 to 1998 who had baseline fasting glucose and insulin levels. Baseline insulin resistance was measured by the homeostasis model assessment of insulin resistance (HOMA-IR). Cancers were verified by central medical record review and deaths verified by medical record and death certificate review enhanced by National Death Index queries. Cox proportional hazards regression models were used to calculate adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for cancer-specific and all-cause mortality. All statistical tests were two-sided.

RESULTS

During a median of 18.9 years of follow-up, 1820 cancer deaths and 7415 total deaths occurred. Higher HOMA-IR quartile was associated with higher cancer-specific mortality (Q4 vs Q1, HR = 1.26, 95% CI = 1.09 to 1.47; Ptrend = .003) and all-cause mortality (Q4 vs Q1, HR = 1.63, 95% CI = 1.51 to 1.76; Ptrend < .001). A sensitivity analysis for diabetes status did not change findings. Among women with body mass index less than 25 kg/m2, higher HOMA-IR quartile was associated with higher cancer mortality (Fine and Gray, P = .004).

CONCLUSIONS

High insulin resistance, as measured by HOMA-IR, identifies postmenopausal women at higher risk for cancer-specific and all-cause mortality who could potentially benefit from early intervention.