The following is a summary of “Baseline prostate health index risk category and risk category changes during active surveillance predict grade reclassification,” published in the November 2023  issue of Urology by Calle, et al.

For a study, researchers sought to find out if the initial prostate health index (PHI) at the start of active surveillance (AS) or continued PHI tests during AS is helpful for men who have had a positive biopsy and then had multiparametric magnetic resonance imaging (mpMRI) is still unknown. 382 AS patients with prostate cancer that were no worse than Grade Group 1 (GG1) were found through diagnostic and confirmation biopsy, at least one mpMRI, and at least two PHI tests. Of these, 241 had at least two PHI tests. Grade reclassification (GR) was set at ≥GG2 on the monitoring biopsy. Categories 1 through 4 of PHI risk were set by the maker. Researchers looked at the links between GR and changes in PHI risk categories or PSA density over time. 

They used multivariable Cox proportional hazard regression models considering age, the Prostate Imaging–-Reporting and Data System score, and the number of positive cores. The chances of GR-free survival were lower for men whose PHI scores were in the highest risk categories at the start of the study (log-rank P < 0.001) and for men whose PHI scores went up or stayed high during monitoring (log-rank P = 0.032). 

There was a strong link between baseline PHI risk category and GR (risk category 4 [vs. 1] hazard ratio [HR] 2.74, 95% CI 1.32–5.66, P = 0.002, model C-index 0.764, Akaike Information Criterion [AIC] 797), as well as a link between baseline and changing PHI risk category (risk category 4 [vs. 1] HR 4.20, 95% CI 1.76–10.05, P = 0.002, C-index 0.759, AIC 489). C-indices of 0.709 (AIC 809) and 0.733 (AIC 495) were found for two models with baseline PSAD and PSAD changes over time. The initial PHI risk group and changes in the PHI over time were good indicators of GR after a confirming biopsy, but the gain over PSAD didn’t seem very big. However, initial PHI and changes in PHI risk categories were clinically helpful in determining the risk of getting GR over time. This means that PHI may be able to help lower the number of mpMRIs and/or monitoring biopsies that need to be done. This could mean more research must be done with more PHI data points over time.

Source: sciencedirect.com/science/article/abs/pii/S1078143923002843