HLA-DR association with prostate cancer in southwestern Nigeria: A preliminary experience using tissue microarray analysis

Background: Prostate cancer is a disease of gargantuan proportion worldwide. Current therapeutic modalities do not guarantee long survival or cure. Immune-based therapy may be a key solution to the treatment and cure of the disease, despite the limited gain recorded presently. This study aims to determine the association of immune marker HLA-DR with prostate cancer and the usefulness of tissue microarray analysis in small biopsies.
Methods: Forty and eight formalin-fixed, paraffin-embedded prostate needle biopsies were processed by tissue microarray analysis and stained with anti HLA-DR monoclonal antibody. The age, Gleason score and Gleason grade groups were noted. Semi-quantitative IHC scoring was done and results analyzed using SPSS version 25.
Results: The age range was 54-to 89 years (mean = 68.8; median = 68.0; SD = 7.7). Majority of cases fell into the 60-79 years age group. There was moderate and strong staining with HLA-DR in 18.7% of cases. There was no significant association between HLA-DR and independent variables such as age (r=-0.015, p=0.921) and Gleason score (r=0.226, p=0.123).
Conclusions: Prostate cancer is at its peak occurrence in the 60-79 years age group and a proportion of cases express HLA-DR, an expression that is independent of age, Gleason score or Gleason grade group. Contribution of HLA-DR to prostate cancer is probably minimal. Tissue microarray technique on needle biopsies is advocated in low-income countries if tissue loss can be minimized.