Why are we doing this study?
This study is called STAMPEDE (Systemic Therapy in Advancing or Metastatic Prostate Cancer: Evaluation of Drug Efficacy) and looks at the effect of adding new or different treatments to the standard way in which prostate cancer is currently managed.
The standard treatment for prostate cancer involves hormone treatment and may also include chemotherapy and/or radiotherapy.
Prostate cancer needs the male hormone testosterone to grow. Hormone treatments work by stopping testosterone from reaching prostate cancer cells. There are different types of hormone treatments but the most common are injections or implants that work by stopping the testicles making testosterone. Some men will have an operation to remove a part or all of the testicles instead. Your doctor may also discuss chemotherapy or radiotherapy as part of your standard treatment.
This study aims to see if we can improve the way in which prostate cancer is currently managed ie by adding new treatments to the standard approach, can we enable men to live longer; or, by modifying the type of hormone therapy, live at least as long and enjoy a better quality of life.
A number of additional sub-studies are being conducted alongside the clinical trial. These sub-studies involve the analysis of samples from which genetic material can be extracted eg saliva, blood and tumour biopsy samples. We aim to understand how a patient’s inherited genetic profile influences treatment response and whether genetic changes present in the cancer can predict which treatments will work best. Through studying the genetic changes occurring over time, we also hope to better understand why treatments stop working.
What treatment might I receive if I chose to take part?
New patients joining STAMPEDE may be eligible to join one of two comparisons; each comparison is made between a control group (who receive standard treatment) and a treatment group (who receive the alternative or additional treatment being tested in the trial).
The groups currently open to recruitment are:
What do I need to know about the treatments being tested?
Metformin: Metformin is a diabetic treatment that may also have an effect on prostate cancer growth and help prevent some of the side effects of hormone treatment. Only men with no diabetes can join Treatment Group K, therefore all men wishing to take part must have a blood test to check for diabetes first. Metformin is given as a tablet for as long as men are receiving androgen-deprivation therapy
Transdermal oestradiol: Hormone patches containing oestradiol are being assessed as an alternative form of hormone therapy. STAMPEDE is looking at whether transdermal oestradiol can work as well as, or better than, standard hormone therapy in treating the cancer longer-term.
What have the results of the trial shown so far?
In the past, STAMPEDE tested whether adding docetaxel chemotherapy, zoledronic acid, or celecoxib, was beneficial in controlling prostate cancer growth and improving life expectancy. Recruitment to all of these original treatment groups has now been completed and the results have been presented.
The addition of docetaxel was shown to benefit patients and this has led to a change in clinical practice. See the summary of results that we prepared for the STAMPEDE participants letting them know about the details of these results
In results presented in July 2017, the addition of abiraterone to androgen-deprivation therapy has also been shown to be beneficial. See the summary of results that we prepared for the STAMPEDE participants letting them know about the details of these results STAMPEDE participant summary 2017 - Abiraterone comparison.
When will more results be known?
Further results are expected in the next few years from other treatments tested in STAMPEDE, which have completed recruitment. Prostate radiotherapy, which is a treatment used in localised prostate cancer, has been tested as an additional treatment for men with cancer that has spread to other parts of the body (metastatic prostate cancer). The results of this comparison are expected in 2018.
STAMPEDE has also tested the combination of using abiraterone and enzalutamide together. Both of these treatments are currently used when hormone treatment is no longer effective and the cancer has started to grow again, termed castrate resistant prostate cancer (CRPC). The results of this comparison are expected in several years.