Tosoian JJ, Loeb S, Feng Z, Isharwal S, Landis P, Elliot DJ, Veltri R, Epstein JI, Partin AW, Carter HB, Trock B, Sokoll LJ.
“Association of [-2]proPSA with Biopsy Reclassification During Active Surveillance for Prostate Cancer.”
Journal of Urology October 2012; 188: 1131-6. PMID: 22901577.
Link: http://www.ncbi.nlm.nih.gov/pubmed/22901577
Longitudinal measurements of the Prostate Health Index (phi) during active surveillance were a robust predictor of biopsy reclassification (C-index 0.82). These results have since been validated in other surveillance populations. Since PSA kinetics are unreliable and biopsies are invasive, phi offers another non-invasive test that can be used to monitor patients during active surveillance.