Association between prostate-specific antigen density and prostate cancer prediction among Nigerian men

Background: Prostate - specific antigen density (PSAD) has been shown as a valuable diagnostic and predictive tool for prostate cancer. Objectives: To ascertain the utility of PSAD in predicting prostate cancer in patients with PSA > 4 .0 ng/ml. Subjects & Methods: The study was an analytic cross-sectional study comprising 382 patients at the University of Uyo Teaching Hospital with PSA levels of > 4.0 ng/ml and normal or abnormal digital rectal examination findings. PSAD was computed and transrectal ultrasound guided prostate biopsies were performed. Statistical analysis was done using a statistical package for social sciences version 24 (SPSS, IBM, Chicago, IL, United States). Appropriate test statistics including mean, standard deviation, Chi-square, t-test, Fischer’s exact test, Pearson’s r-test) with p-value < 0.05 considered as significant. Results: The mean age for all the patients was 55.7 + 2.6 year while the mean ages of 52.9 + 3.3 years and 65.1 + 11.3 years were for patients with benign and malignant prostate diseases respectively. 26.2 % were adenocarcinomas. The mean and median of PSAD for prostate cancer were 0.31 + 0.23 and 0.31 ng/mL/cm3 respectively. PSAD had positive predicting association with prostate cancer risk (p=0.004) using univariate logistic regression. The Area Under the Curve (AUC) and optimal cut-off point for the PSAD was 0.9 (95% CI: 0.83–0.97) and 0.052 respectively, indicating strong diagnostic performance for predicting prostate cancer. PSAD showed statistical significance in cancer detection (p < 0.001) with a detection rate, sensitivity and false positive rate of 90.0 %, 85.0 % and 8.0 % respectively. Conclusion: A PSAD of 0.052 ng/ml/cm3 can be used as a cut-off value to predict prostate cancer when evaluating patients with raised PSA in our population.