Utility of immunohistochemical detection of prostate-specific Ets for the diagnosis of benign and malignant prostatic epithelial lesions

Background: Human prostate-specific Ets (hPSE) belongs to the Ets family. It regulates the proliferation, differentiation, and development of prostate epithelial cells. A recent study showed that hPSE can be detected in normal glands but not in cell lines established from prostate cancer (PCA), suggesting a translational disorder of hPSE from mRNA to protein in PCA. Immunohistochemical detection of hPSE could therefore be another method of differential diagnosis of PCA from other proliferative conditions in the prostate. Methods: An immunohistochemical detection of hPSE was carried out on the whole mounted prostatectomy specimen obtained from 19 cases with PCA. Results: Basal and secretory luminar cells showed a diffuse cytoplasmic staining for hPSE in normal glands, hyperplastic glands, and prostate intraepithelial neoplasia lesions. Whereas approximately 30% of PCA lesions showed a negative staining for hPSE, the positive rate for hPSE between PCA and benign glands or prostate intraepithelial neoplasia (PIN), was statistically significant (P < 0.05). Staining intensities in normal glands, hyperplastic glands, and PIN lesions were similar, but generally stronger than those in PCA lesions. Conclusions: Negative immunoreactivity for hPSE strongly suggests malignancy in the prostate glands. Decreased immunoreactivities of glands for hPSE could suggest PCA.