OVEREXPRESSION OF HER-2 NEU IN HUMAN PROSTATE-CANCER AND BENIGN HYPERPLASIA/

Overexpression of the neu oncoprotein has been described in several tu mor models including breast and prostate cancer. Overexpression of neu has been reported to have prognostic significance in certain tumors b ut controversy continues regarding the role and frequency of neu overe xpression in prostatic cancer. The objectives of the study were twofol d. First, to characterize nea expression in prostate cancer in compari son to benign prostatic hyperplasia. Second, to determine whether nea expression correlates with Gleason grade in prostate cancer. Thirty-ni ne prostate cancers obtained from radical prostatectomy specimens and 10 benign prostatic hyperplasia specimens were included in the study. Specimens were formalin fixed and paraffin-embedded. neu expression wa s studied by immunohistochemical staining using a monoclonal nea speci fic AB-3 antibody. All 39 specimens (100%) of prostate cancer showed p ositive immunostaining of variable degree while 2 (20%) benign prostat ic hyperplasia specimens showed positive staining. Thus, nea oncogene is overexpressed in localized prostate cancer compared to benign prost atic hyperplasia. The degree of neu immunostaining did not correlate w ith Gleason grade and there appeared to be a tendency towards an inver se relationship. The prognostic significance of the varying overexpres sion is unknown.