Varathon Lumyai, MD¹^,², Napongthon Boonyavarakul, MS², Wisaruta Charusaengphairot, MS²

Objective: The primary objective was to identify clinical factors associated with prostate cancer detection following an initial transrectal ultrasound-guided (TRUS) biopsy. The secondary objective was to evaluate the diagnostic accuracy of prostate-specific antigen (PSA) and PSA density (PSAD).

Materials and Methods: A retrospective study was conducted on patients who underwent their first TRUS prostate biopsy at Lerdsin Hospital between 2018 and 2022. Clinical data collected included age, body mass index (BMI), PSA level, prostate volume, digital rectal examination (DRE) findings, and PSAD. Univariate and multivariate logistic regression analyses were performed to identify independent factors associated with prostate cancer detection. Receiver operating characteristic (ROC) curve analysis was used to assess the diagnostic performance of PSA and PSAD, including their sensitivity, specificity, and optimal cut-off values. A p-value of less than 0.05 was considered statistically significant.

Results: Of 267 patients, 200 were analyzed, and prostate cancer was detected in 32%. Multivariate analysis identified prostate nodule (adjusted OR 5.34), PSA (adjusted OR 1.02), prostate volume (adjusted OR 0.97), and PSAD (adjusted OR 4.67) as significant predictors (p<0.05). ROC analysis demonstrated higher diagnostic accuracy for PSAD with an AUC of 0.883 and a cut-off of 0.225 ng/mL² compared with PSA with an AUC of 0.798 and a cut-off of 13 ng/mL.

Conclusion: PSA, prostate nodule, prostate volume, and PSAD were independent predictors of prostate cancer detection after initial TRUS biopsy. Among these, PSAD showed the highest diagnostic performance and may serve as a useful parameter for guiding biopsy decisions.

Received 3 April 2025 | Revised 12 November 2025 | Accepted 12 November 2025

DOI: 10.35755/jmedassocthai.2026.1.02854