Feasibility outcomes of a presurgical randomized controlled trial exploring the impact of caloric restriction and increased physical activity versus a wait-list control on tumor characteristics and circulating biomarkers in men electing prostatectomy for prostate cancer.

BMC cancer. 2016;16:61
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There is a strong body of evidence associating obesity and increased risk for more aggressive and progressive cancer. This paper aims to assess the feasibility of a presurgical diet and exercise weight loss intervention in men with newly-diagnosed prostate cancer who elected for prostatectomy. It also aims to explore the intervention’s effects on tumour proliferation rates and other biomarkers. The 3-weeks randomised controlled study included 40 overweight or obese men newly-diagnosed with prostate cancer. Participants in experimental arm were assigned to a healthy energy-restricted diet versus wait-list control arm. All feasibility endpoints were achieved with accrual completed within 2 years, retention of 85%, adherence of 95% and no adverse events. Biologic outcomes were not included in this paper, as biological testing was still ongoing. Authors concluded that this study’s methods and data on feasibility could provide useful framework for the design of future trials. They also highlighted the importance of presurgical trials as a feasible and safe means to assess the impacts of diet and exercise on tumour tissue.

Abstract

BACKGROUND Obesity is associated with tumor aggressiveness and disease-specific mortality for more than 15 defined malignancies, including prostate cancer. Preclinical studies suggest that weight loss from caloric restriction and increased physical activity may suppress hormonal, energy-sensing, and inflammatory factors that drive neoplastic progression; however, exact mechanisms are yet to be determined, and experiments in humans are limited. METHODS We conducted a randomized controlled trial among 40 overweight or obese, newly-diagnosed prostate cancer patients who elected prostatectomy to explore feasibility of a presurgical weight loss intervention that promoted a weight loss of roughly one kg. week(-1) via caloric restriction and physical activity, as well as to assess effects on tumor biology and circulating biomarkers. Measures of feasibility (accrual, retention, adherence, and safety) were primary endpoints. Exploratory aims were directed at the intervention's effect on tumor proliferation (Ki-67) and other tumor markers (activated caspase-3, insulin and androgen receptors, VEGF, TNFβ, NFκB, and 4E-BP1), circulating biomarkers (PSA, insulin, glucose, VEGF, TNFβ, leptin, SHBG, and testosterone), lymphocytic gene expression of corresponding factors and cellular bioenergetics in neutrophils, and effects on the gut microbiome. Consenting patients were randomized in a 1:1 ratio to either: 1) weight loss via a healthful, guidelines-based diet and exercise regimen; or 2) a wait-list control. While biological testing is currently ongoing, this paper details our methods and feasibility outcomes. RESULTS The accrual target was met after screening 101 cases (enrollment rate: 39.6%). Other outcomes included a retention rate of 85%, excellent adherence (95%), and no serious reported adverse events. No significant differences by age, race, or weight status were noted between enrollees vs. non-enrollees. The most common reasons for non-participation were "too busy" (30%), medical exclusions (21%), and "distance" (16%). CONCLUSIONS Presurgical trials offer a means to study the impact of diet and exercise interventions directly on tumor tissue, and other host factors that are feasible and safe, though modifications are needed to conduct trials within an abbreviated period of time and via distance medicine-based approaches. Pre-surgical trials are critical to elucidate the impact of lifestyle interventions on specific mechanisms that mediate carcinogenesis and which can be used subsequently as therapeutic targets. TRIAL REGISTRATION NCT01886677.

Lifestyle medicine

Fundamental Clinical Imbalances : Immune and inflammation
Patient Centred Factors : Mediators/Energy expenditure
Environmental Inputs : Diet ; Physical exercise
Personal Lifestyle Factors : Nutrition ; Exercise and movement
Functional Laboratory Testing : Blood ; Saliva ; Stool ; Breath ; Imaging
Bioactive Substances : Insulin ; Sex steroid hormones ; Binding proteins

Methodological quality

Allocation concealment : Yes

Metadata