A nomogram based on age, prostate-specific antigen level, prostate volume and digital rectal examination for predicting risk of prostate cancer

Nomograms for predicting the risk of prostate cancer developed using other populations may introduce sizable bias when applied to a Chinese cohort. In the present study, we sought to develop a nomogram for predicting the probability of a positive initial prostate biopsy in a Chinese population. A total of 535 Chinese men who underwent a prostatic biopsy for the detection of prostate cancer in the past decade with complete biopsy data were included. Stepwise logistic regression was used to determine the independent predictors of a positive initial biopsy. Age, prostate-specific antigen （PSA）, prostate volume （PV）, digital rectal examination （DRE） status, % free PSA and transrectal ultrasound （TRUS） findings were included in the analysis. A nomogram model was developed that was based on these independent predictors to calculate the probability of a positive initial prostate biopsy. A receiver-operating characteristic curve was used to assess the accuracy of using the nomogram and PSA levels alone for predicting positive prostate biopsy. The rate for positive initial prostate biopsy was 41.7% （223/535）. The independent variables used to predict a positive initial prostate biopsy were age, PSA, PV and DRE status. The areas under the receiver-operating characteristic curve for a positive initial prostate biopsy for PSA alone and the nomogram were 79.7% and 84.8%, respectively. Our results indicate that the risk of a positive initial prostate biopsy can be predicted to a satisfactory level in a Chinese population using our nomogram. The nomogram can be used to identify and counsel patients who should consider a prostate biopsy, ultimately enhancing accuracy in diagnosing prostate cancer.

Prostate volume as an independent predictor of prostate ：ancer in men with PSA of 10-50 ng ml-1

Prostate volume （PV） has been shown to be associated with prostate cancer （PCa） detection rates in men with a prostate-specific antigen （PSA） in the ＇grey zone＇ （2.0-10.0 ng ml-1）. However, the PSA ＇grey zone＇ in Asian men should be higher because the incidence of PCa in Asian men is relatively low. Therefore, we evaluated the association between PV and PCa detection rates in men with PSAs measuring 10-50 ng ml-1, Men who underwent a 13-core prostatic biopsy with PV documentation participated in the study. A multivariate stepwise regression was used to evaluate whether the PV at time of prostate biopsy could predict the risk of PCa. The rates of PCa among men in different PSA ranges, stratified by PV medians （〈60 and ≥60 ml）, were calculated. There were 261 men included in the final analysis. PV was the strongest predictor of PCa risk （odds ratio, 0.02; P〈0.001） compared to other variables. The PCa rates in men with PVs measuring 〈60 and ≥ 60 ml in the 10-19.9 ng ml-1 PSA group were 40.6% and 15.1%, respectively, while the rates for men with PSAs measuring 20-50 ng ml- 1 were 65.1% and 26.8%. PV is an independent predictor of PCa in men with PSA measuring 10-50 ng ml-1. In clinical practice, particularly for those countries with lower incidences of PCa, PV should be considered when counselling patients with PSAs measuring 10-50 ng ml-1 regarding their PCa risks.