Evaluation of Neuroendocrine and Proliferative Markers in Prostatic Adenocarcinomas

Background: Certain marker studies have practical importance in the biology of prostate cancer. The purpose of this study was to determine whether the quantification of certain neuroendocrine and proliferative markers obtained during transurethral resection or prostatectomy, would help in the prognostic evaluation of prostatic adenocarcinomas. Methods: The present study was performed on samples obtained from two groups of patients with acinar type prostatic adenocarcinoma. Each group comprised 21 patients with Gleason scores ≥7 (high-grade) and Gleason scores ≤6 (low-grade). Tumors with their surrounding benign tissues were stained with Ki67 and chromogranin A (ChA), and their cell proliferation and neuroendocrine differentiation were examined. Results: The mean number of neuroendocrine cells (ChA positive cells) in high grade tumors was 21% and that of low grade was less than one percent (P<0.001). Whereas, the mean proliferative index determined by Ki67 positive cells was 49% in high grade tumors as compared to less than 4% in low grade tumors (P<0.001). No significant difference was found between the mean percentages of chA cells in the non-tumoral tissues of high grade (2.7%) and low grade (1.9%). The mean proliferative index in the non-tumoral tissues of high grade (2.8%) was significantly higher (P<0.001) than of low grade tumors (1.4%). Conclusion: The usage of proliferative index seems to be an acceptable diagnostic index for the determination of tumor grading.Iran J Med Sci 2006; 31(1): 18-21. Keywords ● Prostate cancer ● proliferative index ● chromogranin A ● Ki67