For $300 you can test your DNA for your risk of developing prostate cancer. This article in the NYT describes some of the pitfalls of this kind of testing, namely that it doesn't distinguish between aggressive cancers and the more common, harmless, extremely slow growing ones. Many researchers are concerned that the costs (not just financial) of this test may outweigh the benefits... that is, until we know the genetic variants associated with the aggressiveness of the cancer.
New Genetic Risks for Prostate Cancer Identified
New York Times Jan. 16, 2008