With all the revisionist thinking about screening for prostate cancer, it would be nice to know which group of men bears watching more closely. The US Preventive Task Force has recently come out against mass PSA screening, so what happens next? A recent study just completed and published in the Journal of Clinical Oncology sheds some light on this. Email Dr. Stark (see form on right) if you want a copy of the actual paper. An entity called High-Grade Prostatic Intraepithelial Neoplasia (HGPIN) is seen fairly frequently on prostate biopsies done on men with an abnormal PSA test. It was thought since its discovery to be a possible precursor to invasive prostate cancer, even though it is not cancer. There were no clinical trials of sufficient size or design to answer this question. Several years ago a study was done to find out whether toremifene, an anti-estrogen related to tamoxifen, could prevent progression from HGPIN to invasive (real) prostate cancer. The answer from the trial is no, it doesn’t work, but that’s not the whole story. Over the period of the trial (averaging three years) fully a third of men with HGPIN on biopsy (that’s how they got into the trial) went on to develop invasive prostate cancer on follow up biopsy. This is a staggering number, far in excess of what you would see with other comparable conditions like ductal carcinoma in-situ of the breast or dysplastic PAP smears. The authors of the trial suggest that whatever one feels about mass screening this group of men deserves close follow up. The good news was that the vast majority of men diagnosed had low grade cancers with an excellent prognosis. Some of these men would have gone on to develop higher grade more invasive disease had their cancers not been caught so quickly.