A novel nomogram using PSA mass for predicting BPH

In 2019, there were 94 million cases of benign prostatic hyperplasia globally among men aged 40 years and older. Assessment of prostate volume (PV) is important in evaluating lower urinary tract symptoms and risks in asymptomatic individuals. Serum prostate-specific antigen (PSA) levels have been suggested as a convenient and useful biomarker for benign prostate hyperplasia (BPH). However, studies suggest that using PSA as a biomarker for BPH and prostate cancer can lead to underestimation of disease severity in patients with a high body mass index (BMI). PSA mass has been proposed as a potentially superior predictor compared to total PSA levels. This retrospective study recruited the male patients visiting Kuang Tien General Hospital who had serum PSA level test, underwent transrectal ultrasonography (TRUS) for evaluation of prostate volume between January 2009 and December 2019. PSA mass was obtained by calculating body surface area (BSA) and plasma volume. The data were proved to build a nomogram, to predict the volume of the prostate, and its accuracy was evaluated using internal validation techniques. Statistical analyses were performed using SAS and R. A total of 417 men were included in this study, with a mean age of 67.3 years, mean BMI of 24.9 kg/m2, mean prostate volume of 43.87 mL, mean PSA level of 2.94 ng/mL, and mean PSA mass of 8.68 ng/mL. The results showed that PSA mass had a higher accuracy than PSA in predicting prostate volume, as evidenced by a higher area under curve (AUC) value of 0.8271 for the PSA mass model compared to 0.8218 for the PSA model. Our nomogram showed a satisfying prediction accuracy. PSA mass may be a superior predictor of prostate volume compared to total PSA levels, although only slight improvement was shown.