This is the second revision of a competing continuation of the molecular and cytogenetic study of prostate cancer. The principal investigator has examined more than 250 primary prostate tumors and has shown that when using a collagen-based culture system and single-copy interphase FISH, prostate tumors frequently demonstrate chromosomal changes. Chromosome 17 loss is frequent and the PI has shown LOH in 17q. In addition, data has been accumulated implicating 8p and 10q in prostate cancer as well. Four specific aims are proposed. The first will consist of continued collection and culture of prostate tumor specimens for study. It is anticipated that approximately 50 specimens of various grades will be available each year. The second aim will be to perform single-copy FISH with selected P1 clones on interphase nuclei to screen for deletions. Both primary and archival samples will be utilized and initial probes will focus on 8p, 10q and 17q. Samples with regions of deletion will be further characterized by PCR and shared with a significant group of collaborators for additional analysis. The third specific aim will be to evaluate, by microcell-mediated chromosome transfer into prostate cancer cells, regions identified in the previous specific aims (or through the literature) for tumor suppressor activity. The final specific aim will examine the clinical correlation with the data obtained above with various clinical parameters such as tumor stage, grade, race, etc. It is hoped that these studies will lead to both the ultimate identification of tumor suppressor genes in prostate cancer as well as FISH prognostic tests.