The role of prostate needle biopsy in evaluation of chemopreventive agents

Needle biopsy of the prostate safely furnishes tissue that can be studied f or the effects of promising chemopreventive agents on biomarkers. The modul ation of biomarkers, such as those for apoptosis (TUNEL, Bcl-2, or nuclear morphometry), angiogenesis (factor 8), and cell proliferation (Ki-67), can indicate the potential of a new agent without waiting for the definitive ev aluation of traditional endpoints, such as reduction in cancer mortality. A recent modification of prostate biopsy technique, including additional cor es taken from the lateral peripheral zone, may improve the cancer yield by as much as 35% without increasing major complications, facilitating serial in vivo tests on cancer tissue. The serial biopsy approach may be especiall y valuable in "watchful waiting" cohorts.