Grant: Operating Grant: Impact Grant : CEEHRC Phase II

Over 25,000 Canadian men are diagnosed with prostate cancer each year, most with tumours that have not spread outside of the prostate gland. Many of these will never threaten a man's life and can be safely monitored (known as 'Active Surveillance') without requiring surgery or radiation therapy. While this reduces the occurrence of severe side-effects such as incontinence and erectile dysfunction, which are associated with these treatments, one-fifth of men on Active Surveillance eventually need treatment for cancer that has progressed over time. Unfortunately, there are no effective tools to accurately identify which men have a cancer that will progress. If it were possible to identify cancers that will progress, doctors could confidently recommend Active Surveillance to men with a very low risk of progression, leading to fewer unnecessary treatments and side effects and reducing anxiety for patients concerned about whether their disease will become life threatening. Men with a more aggressive disease would also be helped by this tool by ensuring that they are treated earlier and without delay. We will study 500 men whose cancers either did or did not progress on Active Surveillance. First, we examine cancer biopsies from these men to determine if a process called DNA methylation, which is often turned on inappropriately in life-threatening prostate cancer, is altered in tumours that ultimately progressed and required surgery. Second, we will study the blood of these men to see if these processes can be detected non-invasively. Finally, we will quantify the benefits for both individual patients and the healthcare system as a whole of adopting these biomarkers in routine clinical practice. Through this work, we will develop a tool that will allow men and their doctors to make more informed, accurate decisions about whether to elect for definitive treatment or whether a man's cancer can be safely monitored by Active Surveillance.