Supplementary Material for: Association Between Pre-Operative Total Prostate Specific Antigen and Survivorship of Prostate Cancer Following Radical Prostatectomy: A Systematic Review

Objective: This review aimed to systematically quantify the association between pre-operative total prostate specific antigen (tPSA) and survivorship of prostate cancer (PCa). Methods: Data sources for the review included MEDLINE, PubMed, Cochrane Library, CINAHL, Academic Search Complete, PsycINFO, and relevant reference lists. Databases were searched from inception to June, 2022. The study took place between May 2022 and March 2023. We included studies that applied a quantitative approach to examine the interaction between pre-operative PSA and survivorship of PCa. Pre-operative PSA constituted the independent variable, whereas survivorship of prostate cancer as measured by biochemical recurrence and mortality constitute the outcome variable. A risk of bias assessment was conducted with the aid of a mixed-method appraisal tool. We employed meta-analysis to quantify the association of pre-operative PSA with biochemical recurrence and mortality and computed I2 to assess the degree of heterogeneity. Results: We found a positive weak association between pre-operative PSA and biochemical recurrence (HR = 1.074; 95% CI = 1.042 - 1.106). With a median rise in PSA (≥ 2 ng/mL), the likelihood for biochemical recurrence increase by approximately 7.4%. There was statistically a significant association between PSA and mortality (HR = 1.222, CI 0.917 - 1.630). Conclusions: Biochemical recurrence associates with pre-operative PSA in an inconsistent manner. The sole use of pre-operative PSA in estimating post-prostatectomy biochemical recurrence should be discouraged. There is need for a multi-factorial model which employs a prudent combination of the most important and cost-effective biomarkers in predicting post-prostatectomy biochemical recurrence.