Significance of p53 and ki-67 expression in prostate cancer

BACKGROUND: Prostate cancer is a major health problem throughout the developed world. Tumor grade is one of the most important prognostic factors of prostate cancer. At present, adequate prognostic markers for prostate cancer progression are still lacking, in spite of intensive investigation. Accordingly, we studied the role of immunohistochemical (IHC) expression of p53 and Ki-67 as a prognostic factor in carcinoma prostate and correlated their expression with Gleason's grade. MATERIALS AND METHODS: In this prospective study, a total of 60 cases including 50 cases of prostate carcinoma and 10 of benign prostatic hyperplasia (BPH) were taken. Tumor grade was determined according to Gleason's grading system. p53 and Ki-67 expressions were determined by IHC staining. The obtained results were analyzed and evaluated using Spearman's statistical test (SPSS version 20). RESULTS: In BPH, p53 was expressed in only 2 of 10 (20%) cases while in carcinoma it was expressed in 38 of 50 (76%) cases. Ki-67 was expressed in only 1 of 10 (10%) BPH cases while in carcinoma it was expressed in 32 of 50 (64%) cases. In present study, 1 of 4 (25%) well differentiated, 23 of 31 (74.19%) moderately differentiated and 14 of 15 (93.33%) poorly differentiated tumors revealed p53 immunopositivity and a statistically significant correlation was observed between p53 expression and increased Gleason's grade (P = 0.038). All 4 (100%) cases of well-differentiated carcinoma were negative for Ki-67 expression. Nineteen of 31 (61.29%) moderately differentiated and 13 of 15 (86.66%) poorly differentiated tumors were positive for Ki-67 and a statistically significant correlation was observed between Ki-67 positivity and increased Gleason's grade (P = 0.002). CONCLUSIONS: Both p53 and Ki-67 were significantly up-regulated in malignant lesions as compared to benign lesions and a strong relationship with the Gleason's grading was noticed, therefore, we propose that these markers can be applied along with other prostate cancer prognostic factors.