P53 Expression in Prostatic Cancer: An Immunohistochemical Study

Background: Prostate cancer is the most common malignancy in men and the second leading cause of cancer death in the Western world. P53 alterations are the most frequent genetic changes in human cancers. Mutation of the p53 gene has been implicated in the development of 50% of all human cancers.Objective: The current study aims at evaluating the immuno-histochemical expression of p53 protein in patients with cancer of prostate, as prognostic parameter in correlation with other parameters including PSA receptors, and to correlate the results with those of other studies.Patients and Methods: Fifty two cases of prostate carcinoma in which the PSA receptor status was previously tested by immuno-histochemical staining, were included in this retrospective study. The prostate carcinoma specimens include16 cases were obtained from needle biopsies, 34 cases were from Transurethral Resection of the Prostate (TURP), and 2 were obtained from open prostatectomy specimens. The blocks of these cases were collected from Al-Jumhuri Teaching hospital in the western side of Mosul City, northern Iraq, and from some private laboratories, during the period extending from 7th April 2010 to 7 June 2010. Sections from formalin fixed paraffin embedded biopsy blocks were taken on clean slides and stained with H E, then examined under light microscope. Grading of the cases was done according to Gleason grading system. The expression of p53 protein was evaluated immuno- histochemically; the findings were correlated with the age of the patients, Gleason score, tumor differentiation and the Prostatic Surface Antigen (PSA) receptor status.Results: P53 expression was detected in 15 cases of prostate carcinoma (29%). The patients age ranged from 41 -90 years, (mean=68.05±2.1 years). Most of them were in the 6th decade, expression has a statistically significant relationship with patients age (P value 0.05). A statistically significant direct relationship was found between p53 expression and different Gleason scores of prostate carcinoma (P value 0.01). It was highest in Gleason scores 9 and 10 (60%, 80%), respectively, while Gleason scores 3 and 5 failed to demonstrate positivity (0%).An inverse relationship was found between p53 expression and tumor differentiation, which was statistically significant (P value 0.05). P53 had higher expression in poorly differentiated adenocarcinoma of prostate (48.2%). Positive expression of p53 was inversely significantly associated with positive monoclonal and polyclonal antibodies PSA receptors cases. Most of monoclonal and polyclonal antibodies PSA receptors positive cases of prostate carcinoma (90.4%, 96.1%), respectively failed to show p53 expression positivity (76.6%, 72%), respectively, (P 0.01, 0.05), respectively.P53 Expression in Prostatic Cancer... WahdaM. Al- Nuaimy et al.Conclusions: In conclusion, P53 expression has been found in 29% of prostate carcinoma in Mosul city. P53 expression is directly correlated with the age of the patients and Gleason score, while inversely correlated with tumor differentiation of prostate carcinoma. Also, this study revealed a significant inverse relationship between p53 expression and monoclonal and polyclonal antibodies PSA receptors status.