WISER Survivor Trial: Combined Effect of Exercise and Weight Loss Interventions on Insulin and Insulin Resistance in Breast Cancer Survivors

Combined Effects of Physical Activity and Diet on Cancer Patients: A Systematic Review and Meta-Analysis

BACKGROUND

The purpose of our systematic review was to examine the effects of any physical activity/exercise intervention combined with any diet/nutrition intervention on any biological/biochemical index, quality of life (QoL), and depression in breast, lung, colon and rectum, prostate, stomach, and liver cancer patients and/or cancer survivors.

METHODS

A systematic review and meta-analysis were undertaken, using PRISMA guidelines and the Cochrane Handbook. The systematic review protocol can be found in the PROSPERO database; registration number: CRD42023481429.

RESULTS

We found moderate-quality evidence that a combined intervention of physical activity/exercise and nutrition/diet reduced body mass index, body weight, fat mass, insulin, homeostatic model assessment for insulin resistance, C-reactive protein, triglycerides, and depression, while it increased high-density lipoprotein, the physical component of QoL, and general functional assessment of cancer therapy.

CONCLUSIONS

We conclude that a combined intervention of physical activity/exercise and diet/nutrition may decrease body weight, fat mass, insulin levels, and inflammation, and improve lipidemic profile, the physical component of QoL, and depression in cancer patients and survivors. These outcomes indicate a lower risk for carcinogenesis; however, their applicability depends on the heterogeneity of the population and interventions, as well as the potential medical treatment of cancer patients and survivors.

Physical Activity, Insulin Resistance and Cancer: A Systematic Review

INTRODUCTION

Insulin resistance (IR), a key aspect of type 2 diabetes and a defining characteristic of obesity and its associated conditions, emerges as a mechanistic pathway potentially implicated in cancer pathophysiology. This presents an appealing intervention target for cancer patients. The objective of this study is to conduct a systematic review, examining the scientific evidence regarding the impact of physical activity on modifying insulin resistance in individuals with cancer.

METHODS

The selection criteria were specific: only randomized controlled clinical trials published in the last 13 years and written in English or Spanish were included. The databases utilized for the search included PubMed, Scopus, Cochrane Library, EBSCO, and WEB OF SCIENCE. The protocol for this review was duly registered in the International Register of Systematic Reviews (CRD42023435002). The final search was conducted on 14 May 2023.

RESULTS

The outcomes were assessed using the tool proposed by the Cochrane Handbook to evaluate the risk of bias in the included studies. Among the 12 studies incorporated, 8 demonstrated a low risk of bias, two had an unclear risk of bias, and the remaining two showed a high risk of bias. The variety of exercise types used across all studies was extensive, making definitive conclusions challenging. Physical activity was linked to enhanced insulin sensitivity in seven studies, while five studies showed no significant changes in insulin resistance between the intervention and control groups. Importantly, none of the interventions employed in the included studies exhibited adverse effects on the study participants.

CONCLUSIONS

The role of exercise as a medicine against insulin resistance has been evidenced in many different studies, mostly related to obesity and cardiovascular diseases. Engaging in physical activity could be a healthy option to combat the effects of insulin resistance in cancer patients, although evidence is weak and limited, according to the results of our systemic review. We further found that literature is lacking at the level of optimal doses, timing, and type of exercise. More studies are needed with more defined PA programs in type and length.

Impact of pre-operative weight loss on non-alcoholic fatty liver disease histopathology and insulin resistance in individuals undergoing bariatric surgery: a propensity matched cross-sectional comparison

BACKGROUND

The effect of weight loss (WL) on histopathological aspects of non-alcoholic fatty liver disease (NAFLD) may provide further insights into the dynamics of hepatic recovery after WL.

OBJECTIVE

To analyze the effects of pre-operative WL on insulin resistance- and NAFLD-related histology in individuals undergoing bariatric surgery (BS) with or without pre-operative WL.

DESIGN AND SETTING

A matched cross-sectional study was conducted at a public university hospital and a private clinic in Campinas, Brazil.

METHODS

An analytical, observational, cross-sectional study was conducted using prospectively collected databases of individuals who underwent BS and liver biopsy at either a public tertiary university hospital (with pre-operative WL) or a private clinic (without pre-operative WL). Random electronic matching by gender, age, and body mass index (BMI) was performed and two paired groups of 24 individuals each were selected.

RESULTS

Of the 48 participants, 75% were female. The mean age was 37.4 ± 9.6. The mean BMI was 38.9 ± 2.6 kg/m2. Fibrosis was the most common histopathological abnormality (91.7%). Glucose was significantly lower in the WL group (92 ± 19.1 versus 111.8 ± 35.4 mg/dL; P = 0.02). Significantly lower frequencies of macrovesicular steatosis (58.3% versus 95.8%; P = 0.004), microvesicular steatosis (12.5% versus 87.5%; P < 0.001), and portal inflammation (50% versus 87.5%; P = 0.011) were observed in the WL group.

CONCLUSION

Pre-operative WL was significantly associated with lower frequencies of macro- and mi- crovesicular steatosis, portal inflammation, and lower glycemia, indicating an association between the recent trajectory of body weight and histological aspects of NAFLD.

The effects of exercise and diet on oxidative stress and telomere length in breast cancer survivors

PURPOSE

Cancer and its treatments accelerate biological aging. This analysis tested the hypothesis that exercise and diet reduce oxidative stress and prevent telomere shortening in breast cancer survivors.

METHODS

In a 2 × 2 factorial design, 342 breast cancer survivors who were insufficiently physically active and had overweight or obesity at enrollment were randomized to one of four treatment groups for 52 weeks: control, exercise alone, diet alone, or exercise plus diet. The endpoints of this analysis were the change from baseline to week 52 in 8-iso-prostaglandin F2α (8-iso-PGF2α) and lymphocyte telomere length.

RESULTS

Baseline telomere length was shorter than age-adjusted normative values (median difference: - 1.8 kilobases; 95% CI - 2.4, - 1.1); equivalent to 21 years (95% CI 17, 25) of accelerated chronological aging. Compared to control, exercise alone did not change 8-iso-PGF2α [9.9%; 95% confidence interval (CI) - 1.0, 20.8] or telomere length (13.8%; 95% CI - 15.6, 43.3). Compared to control, diet alone was associated with reduced 8-iso-PGF2α (- 10.5%; 95% CI - 19.5, - 1.5) but did not change telomere length (12.1%; 95% CI - 17.2, 41.3). Compared to control, exercise plus diet was associated with reduced 8-iso-PGF2α (- 9.8%; 95% CI - 18.7, - 0.9) but did not change telomere length (- 8.5%; 95% CI - 32.1, 15.2). Change in 8-iso-PGF2α did not correlate with change in telomere length (r = 0.07; 95% CI - 0.07, 0.20).

CONCLUSION

In breast cancer survivors, diet alone or exercise plus diet were associated with reduced oxidative stress but did not change telomere length. This analysis may inform future trials that aim to optimize healthy aging in cancer survivors.

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.

Randomised controlled trial of breast cancer and multiple disease prevention weight loss programmes vs written advice amongst women attending a breast cancer family history clinic

BACKGROUND

Overweight and obesity are common amongst women attending breast cancer Family History, Risk and Prevention Clinics (FHRPCs). Overweight increases risk of breast cancer (BC) and conditions including¹ cardiovascular disease (CVD) and type-2 diabetes (T2D). Clinics provide written health behaviour advice with is likely to have minimal effects. We assessed efficacy of two remotely delivered weight loss programmes vs. written advice.

METHOD

210 women with overweight or obesity attending three UK FHRPCs were randomised to either a BC prevention programme (BCPP) framed to reduce risk of BC (n = 86), a multiple disease prevention programme (MDPP) framed to reduce risk of BC, CVD and T2D (n = 87), or written advice (n = 37). Change in weight and health behaviours were assessed at 12-months.

RESULTS

Weight loss at 12 months was -6.3% (-8.2, -4.5) in BCPP, -6.0% (-7.9, -4.2) in MDPP and -3.3% (-6.2, -0.5) in the written group (p = 0.451 across groups). The percentage losing ≥10% weight in these groups were respectively 34%, 23% and 14% (p = 0.038 across groups).

DISCUSSION

BCPP and MDPP programmes resulted in more women achieving ≥10% weight loss, but no evidence of additional benefits of MDPP. A multicentre RCT to test the BCPP across UK FHRPCs is warranted. Clinical Trial Registration ISRCTN16431108.

WISER Survivor Trial: Combined Effect of Exercise and Weight Loss Interventions on Inflammation in Breast Cancer Survivors

PURPOSE

Physical inactivity and obesity increase risk for breast cancer recurrence and cardiovascular death; inflammation is hypothesized to mediate these associations.

METHODS

In a four-arm randomized controlled trial, 318 breast cancer survivors with overweight or obesity were randomized to exercise alone, weight loss alone, exercise plus weight loss, or control for 12 months. Inflammation outcomes included C-reactive protein (CRP), serum amyloid A (SAA), intracellular adhesion molecule 1 (ICAM-1), and vascular cell adhesion molecule 1 (VCAM-1).

RESULTS

Compared with control, exercise alone increased ICAM-1 (9.3%; 95% confidence interval [CI] = 1.6-16.9) and VCAM-1 (8.6%; 95% CI = 2.6-14.5) but did not change CRP or SAA. Compared with control, weight loss alone reduced CRP (-35.2%; 95% CI = -49.9 to -20.7), and SAA (-25.6%; 95% CI = -39.8 to -11.9) but did not change ICAM-1 or VCAM-1. Compared with control, exercise plus weight loss reduced CRP (-44.1%; 95% CI = -57.1 to -31.1) and SAA (-26.6%; 95% CI = -40.5 to -12.6) but did not change ICAM-1 or VCAM-1. Among 194 participants with elevated CRP at baseline (e.g., >3 mg·L -1 ), compared with control, weight loss alone (0.17; 95% CI = 0.04-0.30) and exercise plus weight loss (0.31; 95% CI = 0.16-0.46) increased the probability of achieving normal CRP at month 12. In analyses that consolidated randomized groups, body weight and adiposity reductions, but not change in fitness level, correlated with decreased CRP, SAA, and ICAM-1 levels.

CONCLUSIONS

In breast cancer survivors with overweight or obesity, weight loss or exercise plus weight loss reduced measures of inflammation that are associated with breast cancer recurrence and cardiovascular death.

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.