Prostate cancer (PCa) is the most common malignancy and leading cause of cancer mortality among Nigerian men, with majority presenting late with high-grade disease. Affordable prognostic biomarkers are needed to complement Gleason grading in resource-constrained settings. The objectives of the study is to evaluate the immunohistochemically expression frequencies of p53 and Ki-67 in Nigerian men with PCa and determine their correlation with Gleason score (ISUP Grade Group) and serum prostate-specific antigen (PSA). A prospective cross-sectional study was conducted at Benue State University Teaching Hospital, Makurdi, from 1 May 2025 to 30 April 2026. Forty-seven patients with histologically confirmed prostate adenocarcinoma were recruited via purposive sampling. Formalin-fixed paraffin-embedded blocks were subjected to immunohistochemistry for p53 and Ki-67 using streptavidin-biotin immunoperoxidase technique. Positivity was defined as ≥10% nuclear staining. Correlation with Gleason score and PSA was assessed using Spearman’s rho. Significance set at p<0.05. The result showed that Mean age was 67.3 ± 10.2 years (range 37-84). Using ISUP 2019, Grade Group 1: 4.2%, Group 2: 12.8%, Group 3: 14.9%, Group 4: 42.6%, Group 5: 25.5%; 68.1% were poorly differentiated (Gleason 8-10). p53 positivity was 23.4% (11/47) and Ki-67 positivity was 74.5% (35/47). Ki-67 showed statistically significant association with higher Gleason score (p=0.001) and strong positive correlation with PSA (r = +0.876, p = 0.001). p53 showed moderate positive correlation with PSA (r = +0.496, p = 0.005) but no significant correlation with Gleason score (p = 0.103) In conclusion, Ki-67 is highly expressed and strongly associated with aggressive clinicopathological features, supporting its utility as a pragmatic prognostic biomarker in Nigerian men with PCa. The prognostic role of p53 remains inconclusive in this population.
Keywords: Gleason score, Ki-67, Nigeria, PSA, biomarker, immunohistochemistry, p53
