Ridwan I. Alam, MD, MPH, discusses combining PHI and MRI to predict prostate cancer risk

In this video, Ridwan I. Alam, MD, MPH, discusses how the Prostate Health Index (PHI) performs alongside multiparametric MRI (mpMRI) in predicting clinically significant prostate cancer among men with prostate-specific antigen (PSA) levels ng/mL between 10 and 20 ng/mL.¹

He explains that the study incorporated PI-RADS scores into logistic regression models to assess their association with clinically significant cancer. As expected, higher PI-RADS scores were strongly associated with increased cancer risk, with a clear gradient from PI-RADS 3 to PI-RADS 4 and 5. Similarly, increasing PHI categories independently correlated with higher risk, suggesting that both metrics contribute meaningful predictive information.

Rather than emphasizing a formal statistical interaction term, Alam highlights a visual representation demonstrating the combined effect of PHI and PI-RADS. In this figure, patients with both high PHI values and high PI-RADS scores cluster in a “top right” region associated with the greatest detection of clinically significant prostate cancer. Conversely, men with low PHI scores and PI-RADS 1–2 findings fall into a low-risk region with minimal cancer detection. This visualization supports the complementary role of PHI and MRI compared with either strategy alone.

Addressing the finding of zero Grade Group 2 or higher cancers among men with PHI <36 and PI-RADS 1–2, Alam emphasizes that no diagnostic approach can reduce risk to 0. He frames PHI and MRI as noninvasive tools that help refine risk before proceeding to biopsy. In patients with low PI-RADS scores, especially those with large prostates and low PSA density, elevated PSA may reflect benign prostatic hyperplasia rather than cancer. Although acknowledging a residual risk of delayed or missed cancer, he argues that this risk is not unacceptably high, noting that even PI-RADS 3 lesions carry only a 10% to 15% cancer detection rate. Ultimately, biopsy decisions are individualized, balancing risk thresholds, patient anxiety, and informed discussion of benefits and harms.

REFERENCE

1. Holzbeierlein H, Kundu N, Handa N, et al. Performance of the Prostate Health Index test in men with prostate specific antigen levels between 10 and 20 ng/mL. Urology. 2025 Dec 18:S0090-4295(25)01382-2. doi:10.1016/j.urology.2025.12.010