The Prostate cancer-Exercise and Metformin randomised controlled feasibility Trial (Pre-EMpT) in men following active surveillance, radical prostatectomy and radiotherapy.

Background: Moderate to vigorous physical activity and metformin are associated in epidemiological studies with reduced biochemical recurrence and mortality in men with prostate cancer. This study assessed the feasibility of a home-based physical activity and/or metformin intervention in men with non-metastatic prostate cancer following radical treatment (surgery or radiotherapy) or active surveillance.

Methods: A 2 × 2 factorial design randomised men into one of four groups for 6 months: (1) physical activity (defined as brisk walking ≥ 30 min for ≥ 5 days per week, aiming for ≥ 10,000 steps a day); (2) metformin (one 500 mg slow-release tablet daily); (3) physical activity and metformin; and (4) control. Men were recruited from a single tertiary referral centre in the South West of England, UK, (September 2018-March 2020 which terminated slightly early due to the COVID-19 pandemic). Co-primary outcomes were rates of randomisation and adherence which was defined as men brisk walking ≥30 minutes on at least 5 days with 10,000 steps daily (measured over one week 6-months after randomisation) with ≥ 60% adherence to metformin between 3- and 6 months post-randomisation using returned pill count. Secondary outcomes included self-reported adverse events and physical activity, feasibility of wearing activity monitors and questionnaire completion.

Results: In total, 295 men were eligible and 110 were randomised (37.3%, 95% confidence interval [CI] 31.8 to 43.1). Adherence to the physical activity and metformin interventions was 46.9% (95% CI 32.5 to 62.0) and 47.1% (95% CI 32.9 to 61.5) respectively. Adherence was > 60% for both the physical activity and metformin interventions on a complete case basis. Adverse events were infrequent (n = 7) across randomised groups. Completion of self-reported measures of physical activity, urinary incontinence, sexual function, quality of life and stages of change was over 80%. Step counts were not higher in men wearing activity monitors that alerted them about their step counts and sedentary behaviour. Retention over 6 months was 91.3% (95% CI 84.2 to 96.0). Follow up and intervention prompts were impacted by the pandemic.

Conclusion: Home-based physical activity and metformin interventions show some promise for men with prostate cancer following radical treatment or active surveillance.

Trial registration: ISRCTN, ISRCTN13543667. Registered 2 August 2018, https://www.isrctn.com/ISRCTN13543667.