Clinical utility of multiple secondary combined tests in prostate cancer screening

The clinical utility of concurrent Prostate Health Index (PHI) and ExosomeDx Prostate Intelliscore (EPI) testing is unclear. We sought to examine the performance of combined PHI and EPI testing on men undergoing elevated PSA work up.

Patients who received both EPI and PHI testing were identified from an institutional database of men referred to urology for an elevated total PSA. Cut points of EPI > 15.6 and PHI ≥ 36 were used to denote a positive test. Patients were placed into one of four groups determined by combination of EPI and PHI results. Demographic variables and biopsy recommendations were compared between groups. The concordance of test positivity between EPI and PHI was compared by Cohen's kappa. Demographic variables and secondary testing results were compared between patients' compliant and non-compliant with prostate biopsy recommendation. Biopsy pathology was compared between groups.

A total of 162 patients had both EPI and PHI testing. Median age was 65 years, with a median PSA of 6.64 ng/mL. Age (p = 0.001), PSA (< 0.001) and biopsy recommendation (< 0.001) differed between combined secondary screening test result groups. Seventy-five percent of patients with both a positive EPI and PHI were found to have prostate cancer, with 54.2% being ≥ Gleason 7. Cohen's kappa was 0.19, indicating poor concordance. The AUC of EPI and PHI for clinically significant cancer was 0.563 (95% CI: 0.4331-0.6923) and 0.685 (95% CI: 0.569-0.8) (p = 0.147).

Concurrently positive EPI and PHI indicate increased prostate cancer risk, with combined usage potentially influencing biopsy recommendation and compliance.