Use of the Prostate Health Index for detection of prostate cancer: results from a large academic practice
The Prostate Health Index (phi) outperforms PSA and other PSA derivatives for the diagnosis of prostate cancer (PCa). The impact of phi testing in the real-world clinical setting has not been previously assessed.METHODS:
In a single, large, academic center, phi was tested in 345 patients presenting for diagnostic evaluation for PCa. Findings on prostate biopsy (including Grade Group (GG), defined as GG1: Gleason score (GS) 6, GG2: GS 3+4 = 7, GG3: GS 4+3 = 7, GG4: GS 8 and GG5: GS 9-10), magnetic resonance imaging (MRI) and radical prostatectomy (RP) were prospectively recorded. Biopsy rates and outcomes were compared with a contemporary cohort that did not undergo phi testing (n = 1318).RESULTS:
Overall, 39% of men with phi testing underwent prostate biopsy. No men with phi < 19.6 were diagnosed with PCa, and only three men with phi < 27 had cancer of GG ≥ 2. Phi was superior to PSA for the prediction of any PCa (area under the receiver operating characteristic curve (AUC) 0.72 vs 0.47) and GG ≥ 2 PCa (AUC 0.77 vs 0.53) on prostate biopsy. Among men undergoing MRI and phi, no men with phi < 27 and PI-RADS ≤ 3 had GG ≥ 2 cancer. For those men proceeding to RP, increasing phi was associated with higher pathologic GG (P = 0.002) and stage (P = 0.001). Compared with patients who did not undergo phi testing, the use of phi was associated with a 9% reduction in the rate of prostate biopsy (39% vs 48%; P < 0.001). Importantly, the reduction in biopsy among the phi population was secondary to decreased incidence of negative (8%) and GG1 (1%) biopsies, whereas the proportion of biopsies detecting GG ≥ 2 cancers remained unchanged.CONCLUSIONS:
In this large, real-time clinical experience, phi outperformed PSA alone, was associated with high-grade PCa, and provided complementary information to MRI. Incorporation of phi into clinical practice reduced the rate of unnecessary biopsies without changing the frequency of detection of higher-grade cancers.