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

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.

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.

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.

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.