Prostate cancer antigen-1 as a potential novel marker for prostate cancer.

To examine the expression of prostate cancer antigen-1 (PCA-1) in prostate cancer (PCa) and to validate it as a potential marker for diagnosis of PCa. In situ hybridization analysis of PCA-1 mRNA expression was performed on 40 benign prostate hyperplasia (BPH), 16 high-grade prostatic intraepithelial neoplasm (HG-PIN), 74 PCa and 34 other malignant carcinoma specimens. The level of PCA-1 expression was semiquantitatively scored by assessing both the percentage and intensity of PCA-1 positive staining cells in the specimens. We then compared the PCA-1 expression between BPH, HG-PIN and PCa and evaluated the correlation of PCA-1 expression level with clinical parameters of PCa. PCA-1 mRNA was expressed in the majority of both PCa and HG-PIN specimens but not in BPH and other malignant carcinoma. The expression level of PCA-1 increased along with a high Gleason score (P < 0.05), and was unrelated to other clinical parameters of PCa (all P > 0.05). The data suggest that PCA-1 might be a novel diagnostic marker for PCa, and that increased PCA-1 expression might denote more aggressive variants of PCa.