Clinical Trials For Prostate Cancer

What are clinical trials?

Clinical trials are studies, managed by government agencies, educational institutions, private not-for-profit organizations, or commercial businesses, to develop, produce, and evaluate the effectiveness of new treatments and preventive therapies for diseases.

What are the risks and benefits of participating in a clinical trial?

Individuals who participate in research studies are given the opportunity to benefit from treatments that are not currently available to the general public, but have shown promise in previous research.

Risks from participating in a clinical trial vary depending on the study. It is important to understand that not all new treatments produce the desired effect.

Are there clinical trials for prostate cancer?

At any given time, there are hundreds of prostate cancer clinical trials underway. The following are just a few examples:

• PLCO (Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial) Sponsored by the National Cancer Institute (NCI), the goal of this long-term study was to determine whether screening tests for prostate, lung, colorectal, and ovarian cancer would reduce the number of deaths from these cancers. Screening tests are medical tests designed to look for a disease in a healthy individual who has not yet developed symptoms of the disease. The trial enrollment began in 1992. Early results published in 2009 found that screening led to more diagnoses of prostate cancer, but it did not reduce the number of prostate cancer deaths. Researchers are continuing to monitor the men in this study to see if the result changes over time.

• Cancer Genetics Network (CGN) In 1998, the National Cancer Institute (NCI) developed a national network of centers specializing in the study of inherited predisposition to cancer. A number of genetic issues related to cancer are being explored, including the following:

  • How often are genetic mutations that predispose an individual to cancer found in various populations?

  • If you have one of these mutations, why do some of these people develop cancer, while others do not?

  • Are there any environmental exposures that interact with these susceptibility genes to cause cancer?

  • What are the issues - ethically, socially, psychologically - for individuals who carry cancer susceptibility genes?

  The CGN is compiling a registry of families who have a significant number of relatives with various forms of cancer, in order to answer these questions.

• SELECT (Selenium and Vitamin E Cancer Prevention Trial) This largest-ever prostate cancer prevention clinical trial looked at whether either vitamin E or selenium could protect against prostate cancer. Previous research indicated that selenium and vitamin E might reduce prostate cancer risk by 30 to 60 percent. The trial was sponsored by the National Cancer Institute. Enrollment in this study was closed in 2004, and results were published in 2008. Neither vitamin E nor selenium was found to reduce the risk of prostate cancer.

• Hundreds of smaller clinical trials are studying newer medicines and procedures to try to improve the treatment of prostate cancer.