Comparative Assessment of p53 Tumour Suppressor and Ki-67 Proliferative Markers in Prostatic Adenocarcinoma: A Prospective Immunohistochemical Study from Makurdi, North-Central Nigeria

Abstract

Background: Prostate cancer is the most common malignancy among Nigerian men, with the majority presenting late with high-grade disease. Objectives: This study aimed to evaluate the utility of p53 and Ki-67 biomarkers in Nigerian men with prostate cancer by determining their expression frequencies and correlations with Gleason scores. Patients and Methods: This was a prospective cross-sectional study conducted at Benue State University Teaching Hospital, Makurdi, Nigeria. Forty-seven patients with histologically confirmed prostate adenocarcinoma were recruited over one year. Clinical data, including age and serum PSA, were documented. Gleason scores were assigned using the 2019 ISUP modified system. Immunohistochemistry for p53 and Ki-67 was performed using the streptavidin-biotin immunoperoxidase method on 4µm sections. Positivity was assessed by a single pathologist. Chi-square tests and Spearman's correlation analyses were performed using SPSS version 26. Results: The age range was 37-84 years, with a mean of 67.3 ±10.2 years. All 47 tumours (100%) were acinar adenocarcinomas. Gleason Grade Group 4 (Gleason score 8) was the most common, occurring in 20 cases (42.6%). Poorly differentiated tumours accounted for 32 cases (68.1%). p53 was positive in 11 cases (23.4%) and negative in 36 (76.6%). The p53-positive cases comprised 7 (14.9% of the cohort) poorly differentiated, 3 (6.4%) moderately differentiated, and 1 (2.1%) well-differentiated tumour. There was no significant association with Gleason grade (p=0.103). Ki-67 was positive in 35 cases (74.5%) and negative in 12 (25.5%). Ki-67 positivity increased with grade, and the association was significant (p=0.001). Both markers correlated with PSA: p53 showed a moderate correlation (rho=+0.496, p=0.005), whereas Ki-67 showed a strong correlation (rho=+0.876, p=0.001). Conclusion: In this Nigerian cohort, Ki-67 showed a stronger association with aggressive disease indices than p53. While p53 was expressed in a minority of cases and was not significantly associated with grade, Ki-67 correlated with both higher Gleason grade and higher PSA.