Auxiliary Diagnostic Value Of A New Parameter-(f/t)/PSAD For Prostate Cancer In PSA Grey Area

Objective: To investigate the auxiliary diagnostic value of a new parameter-(f/t)/PSADfor patients with serum prostate specific antigen (PSA) value being located in the greyarea (4~10ng/ml).Methods: The data of our hospital’patient with PSA being located in the grey area bytransrectal ultrasound guided prostate biopsy or transurethral resection of the prostate orProstatectomy was collected from January2012to December2013.Serum free PSA(fPSA) and total PSA (tPSA) were recorded to calculate the f/tPSA ratio; prostatevolume was measured by transrectal ultrasound to calculate the prostate-specific antigendensity (PSAD); then f/tPSA was divided by PSAD to get the value of (f/t)/PSAD.Statistical software, SPSS13, was used to build the receiver operating characteristiccurve (ROC) map of the new parameter-(f/t)/PSAD, then the area of curve (AUC)would be obtained. All the sensitivity and specificity of cut-off and avoiding biopsy ratefor prostate cancer were calculated，then the optimal cut-off in diagnosis of prostatecancer was found. At last, all the results of (f/t)/PSAD were compared to that of tPSA,f/tPSA and PSAD calculated by the same method.Results: After rigorous screening, there were a total of84cases with all the value ofPSA (total PSA) between4~10ng/ml.According to the postoperative pathology, theresult showed9cases of prostate cancer and75cases of benign prostatic hyperplasia.(f/t)/PSAD, f/tPSA, and PSAD in prostate cancer groups were significantly lower thanbenign prostatic hyperplasia, and the difference was statistically significant (P <0.05).And there was no statistically significant difference between two groups (P> 0.05). The AUC of (f/t)/PSAD was0.917, which suggested it was higher diagnosticvalue for prostate cancer than PSA (0.556), f/tPSA AUC (0.720), and PSAD(0.905).When (f/t)/PSAD had best cut-off(1.33), it yielded greatest sensitivity andspecificity of100%and81.3%respectively, and avoiding biopsy rate was72%.However, when tPSA, f/tPSA, PSAD had best cutoff value (6.49,0.145,0.195), thesensitivity and specificity were77.8%、44%,77.8%、58.7%,88.9%、82.7%, respectively.Meanwhile, avoiding biopsy rate were39%,62%,73%, respectively.Conclusion: According to the results of the study,(f/t)/PSAD in PSA grey area has animportant value in diagnosis of prostate cancer, which can reduce more unnecessarybiopsy.(f/t)/PSAD for the diagnostic value of prostate cancer is superior to theusefulness of f/tPSA, PSAD alone, and (f/t)/PSAD value is smaller, the greater thechance of prostate cancer.