Plain language summary
Obesity is a risk factor for 13 different cancers and a recent meta-analysis has shown increased weight to be associated with biochemical recurrence in men with prostate cancer. However, few studies have explored whether presurgical intentional weight loss results in improved prostate cancer outcomes. The aim of this trial was to explore the efficacy of weight loss among overweight and obese men with prostate cancer. Forty participants were randomised to either the presurgical weight loss intervention group or control arm, and changes in weight, body composition, quality of life, tumour biology and biomarkers were recorded. This study found that intentional weight loss caused mixed effects on tumour proliferation and gene expression. Based on these results, the authors recommend that more research is needed before effectively recommending presurgical weight loss among overweight men with prostate cancer.
Abstract
BACKGROUND Obesity is associated with aggressive prostate cancer. To explore whether weight loss favourably affects tumour biology and other outcomes, we undertook a presurgical trial among overweight and obese men with prostate cancer. METHODS This single-blinded, two-arm randomised controlled trial explored outcomes of a presurgical weight loss intervention (WLI) that promoted ∼1 kg per week loss via caloric restriction and increased physical activity (PA). Forty overweight/obese men with clinically confirmed prostate cancer were randomised to the WLI presurgery or to a control arm; changes in weight, body composition, quality-of-life, circulating biomarkers, gene expression, and immunohistochemical markers in tumour and benign prostatic tissue were evaluated. RESULTS The study period averaged 50 days. Mean (s.d.) change scores for the WLI vs control arms were as follows: weight: -4.7 (3.1) kg vs -2.2 (4.4) kg (P=0.0508); caloric intake: -500 (636) vs -159 (600) kcal per day (P=0.0034); PA: +0.9 (3.1) vs +1.7 (4.6) MET-hours per day (NS); vitality: +5.3 (7.l4) vs -1.8 (8.1) (P=0.0491); testosterone: +55.1 (86.0) vs -48.3 (203.7) ng dl-1 (P=0.0418); sex hormone-binding globulin: +14.0 (14.6) vs +1.8 (7.6) nmol l-1 (P=0.0023); and leptin: -2.16 (2.6) vs -0.03 (3.75) (P=0.0355). Follow-up Ki67 was significantly higher in WLI vs control arms; median (interquartile range): 5.0 (2.5,10.0) vs 0.0 (0.0,2.5) (P=0.0061) and several genes were upregulated, for example, CTSL, GSK3B, MED12, and LAMC2. CONCLUSIONS Intentional weight loss shows mixed effects on circulating biomarkers, tumour gene expression, and proliferative markers. More study is needed before recommending weight loss, in particular rapid weight loss, among men with prostate cancer.
Methodological quality
Jadad score
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3
Allocation concealment
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Yes
