This is the fourth volume of our series Progress in Anti-cancer Therapy. For the past four years we have taken the challenge to select each year, some of the most interesting topics on the wide field of oncology. As usual, this volume continues the tradition and covers five cancers (breast, prostate, bladder, lym- phoma and ovarian), the role of HIV and HTLV in cancer, as well as some deve- lopmental pharmacology and behavioral issues. This year, we have particularly focused our attention on one of the most com- mon (although rarely addressed) cancer accounting for more than 315, 00 newly diagnosed cases and 41, 000 cancer-related deaths annually (Landis SH et al., 1999) : prostate cancer. Five chapters address some of the issues concerning this disease. The chap- ter by Schroder describes the hopes and pitfalls of early detection of prostate cancer. It reviews the literature on screening studies that have been performed both in the US and in Europe. These studies suggest that cancer mortality could be reduced by screening for prostate cancer, mostly through PSA testing. However, the effectiveness of early detection still needs to be definitely confir- med and ongoing randomized studies are described, the results of which will probably help the medical community determine the worth of PSA-based scree- ning for prostate cancer. On the same hand, the paper from von Eschenbach is reviewing the clinical problems that are related this disease.