Value of prostate-specific antigen (PSA) mass ratio in the detection of prostate cancer in men with PSA levels of ≤10 ng/mL

OBJECTIVE To investigate the value of prostate-specific antigen (PSA) mass ratio, defined as total PSA in circulation per prostate volume (PV), in the prediction of prostate cancer detection among men with PSA levels of <= 10 ng/mL who are undergoing prostate biopsy. PATIENTS AND METHODS We reviewed records of 2431 men aged 56-80 years who presented with PSA levels of <= 10 ng/mL and underwent multi (>= 12)-core transrectal ultrasound-guided prostate biopsy at our institution. Predictive accuracies of relevant variables and multivariate models in the prostate cancer detection via biopsy were assessed with receiver operating characteristics-derived area under the curve and compared. RESULTS When compared one-on-one, PSA mass ratio had a significantly higher accuracy than PSA in the prediction of prostate cancer among our subjects (0.638 vs 0.565, P < 0.001). Meanwhile, when multivariable model for the prediction of prostate cancer detection via prostate biopsy was devised incorporating patient age, body mass index, digital rectal examination findings, PV, number of biopsy cores, and PSA level, the replacement of PSA level with PSA mass ratio (P = 0.102) or the addition of PSA mass ratio (P = 0.164) in the model was not associated with significantly increased accuracy of model for predicting prostate cancer detection via biopsy. CONCLUSION Although PSA mass ratio appears to be an attractive alternative to PSA level, PSA mass ratio may not significantly enhance the currently available method to predict prostate cancer detection among men with PSA levels of <= 10 ng/mL who are undergoing prostate biopsy.