Effect of prostate volume on the predictive value of prostate-specific antigen density for prostate cancer

Abstract

Background: In clinical practice, we observed that some patients with larger prostate volume (PV) and prostate-specific antigen (PSA) values below 20 ng/mL still yielded negative biopsy results. We aim to establish a more precise volume range for guiding biopsies in patients with enlarged prostate glands. Methods: We conducted a retrospective analysis of 424 cases involving patients who underwent prostate biopsy. The patients were categorized into three groups based on their body mass index: small (PV <45 cm3), medium (45 cm3≤ PV <70 cm3), and large (PV ≥70 cm3). Logistic regression, receiver operating characteristic (ROC) curves, restricted cubic spline (RCS) curves, and decision trees were employed for comparison purposes. Results: In the multivariate logistic regression analysis, a statistically significant association was observed between prostate-specific antigen density (PSAD) ≥0.15 ng/mL/cm3 and the need for biopsy to confirm prostate cancer diagnosis when the volume was less than 45 cm3 [odds ratio (OR) =4.587; 95% confidence intervals (CI): 1.667–15.091; P=0.006]. The point of intersection between the RCS curve and the reference line occurred at PV =45 cm3, indicating a higher risk of prostate cancer (PCa) increased with decreasing PV size. After constructing a decision tree model, it was found that when the volume was less than approximately 26 cm3, there was a significantly increased probability (approximately 69%) of having prostate cancer after biopsy. Conclusions: The likelihood of developing prostate cancer is higher in patients with small PVs (PV <45 cm3), especially those with (PV <26 cm3), when PSAD exceeds 0.15 ng/mL/cm3. Patients with larger volumes (PV ≥70 cm3) can be regularly monitored and followed up.