Clinical performance of prostate health index in men with tPSA>10ng/ml: Results from a multicentric European study

Abstract

Background: Evidence regarding the diagnostic accuracy of a [-2]proPSA derivative, namely, the prostate health index (PHI), to predict the presence of prostate cancer (PCa) in individuals with high total prostate-specific antigen (tPSA) levels is lacking. We tested the hypothesis that these markers could assist clinicians in the biopsy decision path of patients with tPSA>10ng/ml.

Methods: The primary endpoint was to evaluate the sensitivity, specificity, and diagnostic accuracy of PHI in determining the presence of PCa at biopsy in comparison to tPSA, free PSA, and % of free to total PSA. We calculated the number of prostate biopsies that could have been spared by using this marker to decide whether or not to perform a biopsy. A secondary endpoint was to determine the relationship between PHI and PCa characteristics.

Results: The PCa was diagnosed in 136 of 262 patients (51.9%). Total PSA and PHI values were significantly higher (P<0.005) and % of free to total PSA values significantly lower (P<0.0001) in patients with PCa relative to those with a negative biopsy. In multivariable logistic regression models, PHI achieved the independent predictor status and significantly increased the accuracy of the base multivariable model by an extent of 8.2% (P = 0.0005). The inclusion of PHI in the biopsy decision path would decrease the number of unnecessary biopsies by an extent of 50.0%, while missing only few cases with clinically significant PCa. Finally, Gleason score was significantly related to PHI levels.

Conclusions: The results of our study support the diagnostic effectiveness of PHI even in patients with tPSA >10ng/ml. Further validation studies with larger sample size are needed to corroborate our findings.

Keywords: High total PSA; PHI; Prostate biopsy; Prostate cancer; Prostate health index.