[Development of a nomogram for predicting positive initial prostate biopsy among Chinese patients].

ABSTRACT

OBJECTIVE: To develop a predictive nomogram for predicting the prostate carcinoma among Chinese population. METHODS: Totally 556 Chinese male patients who had undergone an initial prostate biopsy in our hospital from July 2004 to February 2009 were enrolled in this study. Variables including age, volume, prostate specific antigen (PSA) level, and free PSA (f-PSA)/total PSA (t-PSA) were collected. Logistic regression analysis was performed to estimate the relative risk. Regression equation was established for variables via stepwise regression, via which a nomogram for assessing the positive biopsy results was established, and then the predictive value of this nomogram was evaluated using receiver area under curve (ROC) analysis. RESULTS: Of these 556 patients, cancer was detected in 205 patients (36.87%) via biopsies. Univariate analysis showed that age, prostate volume, PSA levels, and f-PSA/t-PSA were the influencing factors of the nomogram. The risk model performed well in an independent sample, with an AUC(ROC) of 0.8767, which was significantly larger than that of the prediction based on age (AUC(ROC) 0.6397), prostate volume (AUC(ROC) 0.7255), PSA (AUC(ROC) 0.7111), or f-PSA/t-PSA (AUC(ROC) 0.6973) alone. CONCLUSION: A preliminary nomogram with high predictive value for Chinese population was successfully established.