EVALUATION OF MINIMAL PROSTATE CANCER IN NEEDLE BIOPSY SPECIMENS USING AMACR (P504S), P63 AND KI67

Background: Prostate cancer is a major health problem throughout the developed world. Immunohistochemistry plays a very important role in the diagnosis of minimal prostatic adenocarcinoma and to exclude one of its benign mimickers, but it should always be interpreted in the context of the H\&E appearances. In some cases of minimal prostate cancer morphologic features do not allow a diagnosis of carcinoma. In such situation, the presence of AMACR and the absence of basal cell marker (p63) confirm the presence of prostate cancer. In addition, Ki-67 a proliferating marker have a strong relationship with Gleason's grading, which has an important relationship with the prognosis of prostate cancer. The aim: Assessing the usefulness of immunohistochemical analysis with Alpha-methylacyl-CoA racemase (AMACR) and p63 to confirm the diagnosis of minimal prostate cancer. Also, detection of the prognostic role of ki67 in minimal prostate cancer detection and its association with p63 expression in prostate cancer. Methods: 50 needle biopsy specimens, including 30 with small foci of prostatic adenocarcinoma and 20 benign prostate (<= 1mm or <5\% of needle core tissue) were stained immunohistochemically with AMACR, P63 and Ki67 antibodies. Results: Of 30 cases of small foci of prostatic adenocarcinoma, 27 (90\%) expressed AMACR; all malignant glands were negative for basal cell staining p63 (nuclear stain). All benign glands were recognized easily by basal cell marker (p63) positivity. There was focal positive staining with AMACR in 2 benign cases showing atrophy. A statistical significant correlation was observed between ki67 expression and increased Gleason's grade (p=0.02). Cytoplasmic expression of p63 was high in high grade prostate cancer, and it was associated with higher frequency of ki67 positive cells in prostatic adenocarcinoma. Conclusions: Immunostaining with the p504s and p63 could improve the diagnostic performance and helped in avoid carrying out new biopsies in small foci of prostatic carcinoma detection. An important relationship with the prognosis of prostate cancer was noticed through the strong relationship of Ki-67 marker with Gleason's grading. Therefore, we propose that this marker can be applied along with other prostate cancer prognostic factors. {[}Hayam E. Rashed, Kateb M. I, El., RagabA. A., SoheirS. Shaker. EVALUATION OF MINIMAL PROSTATE CANCER IN NEEDLE BIOPSY SPECIMENS USING AMACR (P504S), P63 AND KI67. Life Sci J 2012; 9(4): 12-21] (ISSN: 1097-8135). http://www.lifesciencesite.com. 3