p53 Protein Expression and Its Relation to the Apoptotic Index in Prostate Adenocarcinoma

Background: Prostate cancer is one of the most commonly diagnosed cancers in males. Tumor suppressor gene p53 plays an important role in causing cell cycle arrest and allowing apoptosis to proceed. Objective: To investigate the expression of p53 protein and its relation to apoptosis and prostate cancer traditional prognostic indicators. Methods: In this study expression of p53 was examined in paraffin-embedded tissues from 50 cases of prostate carcinoma by immunohistochemistry and evaluated using an index of staining. Correlation between p53 expression and apoptosis was detected by TUNEL method. Pathological grade, Gleason score and stage of carcinoma were also determined. Results: P53 expression was observed in 48 of 50 cases (26-100% of tumor cells) with mean staining index of 141±65. A significant association between p53 expression and pathologic grade (r=0.37, p=0.004) and Gleason score (r= 0.4, p=0.009) of patients was observed. Apoptosis was detected in only 6 patients. p53 expression showed no correlation with apoptotic index. No correlation between p53 expression and stage or apoptosis and clinicopathological characteristics of patients was found. Conclusion: p53 expression showed a significant correlation with differentiation status of the prostate carcinoma and can be helpful as a prognostic marker. Decreased level of apoptosis observed in our cases was not correlated with p53 expression indicating the possible role of other regulatory molecules involved in the apoptosis.