The Value Of PSAD In The Prediction Of Extraprostatic Extension In Patients With Clinically Organ-confined Prostate Cancer

Objective:To evaluate the role of MRI-based PSAD(the MRI-based PSAD was calculated by dividing the total PSA level in nanograms per milliliter by the MRI measured prostate volume in cubic centimmeter) in the prediction of extraprostatic extension in patients with clinically organ-confined prostate cancer.Method: A total of 71 patients with clinically organ-confined prostate cancer who underwent radical prostatectomy from January 2009 to December 2013 were included in the study.MRI-based PSAD,preoperative total serum PSA(t PSA),free PSA/total PSA(f PSA/t PSA), biopsy Gleason score,prostate volume, Age, BMI(Body Mass Index) in patients with extraprostatic extension were compared with that in patients with organ-confined disease.The receiver operating characteristic curve(ROC) was used to analyze the performance of each of the above significant parameters to predict the extraprostatic extension;multivariate logistic regression analysis was used to select the main influencing factors of extraprostatic extension.Results:Pathologic examination revealed 32 patients were positive for extraprostatic extension and 39 patients had organ-confined disease. MRI-based PSAD(P<0.001),t PSA(P<0.001) and biopsy Gleason score levels(P=0.006) were higher in patients with extraprostatic extension than that in patients with organ-confined disease,and prostate volume was lower(P=0.009).MRI-based PSAD showed the largest area under ROC curve(AUC) among those parameter(AUC=0.852,P<0.001),and t PSA was second(AUC=0.764)。Multivariate logistic regression analyses showed that MRI-based PSAD was an independent predictor of extraprostatic extension.Conclusion:MRI-based PSAD was better than t PSA in predicting pathological stage of extraprostatic extension。We can no ignore the value of PSAD in the perdiction of pathological stage.