Objectives: To identify predictors for repeat biopsies in Chinese men with increasing prostate-specific antigen (PSA) levels or other risk factors for prostate cancer.
Methods: The study included 129 patients who underwent transrectal sonography-guided repeat biopsies. Potential predictors, including age, body mass index, symptoms, digital rectal examination (DRE), total PSA, free PSA, free/total PSA ratio, prostate volume, PSA density, PSA velocity, PSA doubling time, and volume/biopsy ratio, were subjected to univariate analysis. Multivariate stepwise logistic regression was performed to identify major independent predictors for repeat biopsies, and a scoring system for predicting cancer was devised. A receiver operating characteristic (ROC) curve was constructed to test the sensitivity and specificity of the scoring system.
Results: Thirty-four patients (26.36%) had cancer. On univariate analysis, the DRE (P = .002), total PSA (P = .020), free/total PSA ratio (P < .001), prostate volume (P < .001), PSA density (P = .003), and volume/biopsy ratio (P < .001) were significant predictors of cancer. On multivariate analysis, the DRE, total PSA, free/total PSA ratio, and volume/biopsy ratio were independently significant predictors, with odds ratios and 95% confidence intervals of 4.61 (1.62-13.07), 1.02 (1.00-1.04), 0.87 (0.78-0.96), and 0.56 (0.43-0.79). Using ROC analysis, we determined a cutoff value of 2.5 for the scores, at which the sensitivity and specificity of the scoring system for predicting positive repeat biopsy results were 76.50% and 74.70%, with an area under the curve of 0.816 (P < .001). Patients with scores of 3 to 5 had higher cancer detection rates than those with scores of 0 to 2 (52.00% versus 10.13%; P < .001).
Conclusions: Key predictors may exist to help formulate a scoring system to identify Chinese men who need repeat prostate biopsies. More studies are required to learn its applicability to broader populations.