Alterations of the p53 gene are among the most frequent genetic lesions in a variety of human malignancies. Their role in prostate cancer is, however, unclear. We have analyzed 10 primary and two metastatic human prostate carcinomas as well as 3 prostate cancer cell lines for mutations of the p53-gene. Using single strand conformational polymorphism analysis (SSCP) and direct sequencing of the polymerase chain reaction (PCR) products, p53 mutations were detected in 1 of 10 primary prostate cancers. By contrast, 1 of 2 metastatic tumors and all 3 prostate cancer cell lines (derived from metastases) were found to contain a mutant p53 gene. Thus, our data suggest that alterations of the p53 gene at the mutational "hot spots" appear to occur infrequently in primary human prostate cancer, but may emerge in later stages of tumor progression. Furthermore, we confirm that loss of heterozygosity at a locus telomeric to p53, but not including p53, is associated with metastatic progression in 1 case.