Definition of the ideal tumor marker

It is evident that the ideal tumor marker is not, nor should it be, a perfect tumor marker given the present level of our knowledge about prostate cancer. Further refinement of our information about prognosis and optimal treatment of this disease will ultimately lead to greater utility of many of the features of an ideal marker. On the other hand, the perfect tumor marker may become a moot issue if its development is overtaken by definitive information about prostate cancer etiology and prevention from the realm of molecular biology. Until that millennium is reached, we must continue to seek improvement in tumor markers that will permit us to take advantage of those features that are clinically useful at the current stage of our knowledge.