22 Questions to Ask Before a Prostate Cancer Clinical Trial May 19, 2016July 20, 2016 by Marta Ribeiro In Social Clips. 5. What are the eligibility criteria? 6. In addition to the experimental treatment, what other treatments are offered in the trial? 7. How frequent are the study visits? 8. How long do the study visits last? Print This Page Pages: 1 2 3 4 5 6