Systemic Therapy in Advancing or Metastatic Prostate Cancer: Evaluation of Drug Efficacy

The overall aim of this trial, which is called STAMPEDE, is to assess novel approaches for the treatment of men with prostate cancer who are starting long-term ADT for the first time, termed hormone-naïve prostate cancer. This trial aims to see if we can improve the way in which prostate cancer is currently managed, either by adding new treatments to the standard approach or by modifying the type of hormone therapy aiming to improve quality-of-life by reducing the side effects of treatment. Each new treatment approach is compared against a control arm receiving the current standard treatments. We aim to identify treatment strategies that enable men to live longer, or as long but with an improved quality-of-life, as well as offering value for money for the health service. Since opening to accrual in Oct-2005, the trial has tested many ways of treating prostate cancer and some results are now already known. More than 10,000 men will join the trial with answers becoming available throughout the trial. New patients joining the trial from Protocol version 17.0 onwards (activated in December 2018) may be eligible to join one of two treatment comparisons, metformin (treatment group K; the "metformin comparison") and transdermal oestradiol (treatment group L; the "transdermal oestradiol comparison"). A computer program will be used to allocate which treatment each participant receives, using a chance process. Summary of the research arms in STAMPEDE trial platform Summary of research treatment groups currently open to recruitment (June 2017) 1. Metformin (Arm K): This anti-diabetic medication is proposed to have both anti-cancer effects and may help prevent the adverse metabolic effects of long-term ADT. STAMPEDE will investigate whether adding metformin to the current standard-of-care for non-diabetic men can improve all-cause survival. 2. Transdermal oestradiol (Arm L): This is an alternative form of hormone treatment which has been shown to suppress testosterone as effectively as standard ADT and avoid some of the side-effects. It may also help to avoid the adverse metabolic effects and fatigue and therefore improve overall quality of life compared with standard forms of ADT. STAMPEDE will investigate whether transdermal oestradiol can treat the cancer as well as current standard forms of ADT. 3. Control group (Arm A): Patients allocated to this group receive the current standard-of-care ADT +/- RT +/- docetaxel.