There are several key questions that a participant will want answered before enrolling in a clinical trial. These studies are highly customized and, for this reason, vary greatly. Because clinical trials differ, it is important to ask the right questions to determine if a particular trial is a good fit for you. Here's a list we've put together of twenty-two questions you should ask before considering participating in a prostate cancer clinical trial: 1. How long will the trial last? 2. What are the advantages of participating in this trial? 3. What are the possible disadvantages of participation? 4. When do I need to decide whether I want to participate in the trial?