Comparative Performance of Prostate Cancer Risk Prediction Tools in Gay, Bisexual, and Other Men Who Have Sex With Men vs Heterosexual Men.

OBJECTIVE

To compare the accuracy of clinical models and Magnetic Resonance Imaging (MRI)-based prostate cancer (PCa) risk calculators in men who have sex with men (MSM) vs heterosexual men (HSM). MSM comprise 3%-6% of US men yet remain underrepresented in validation studies of PCa risk tools. Behavioral and anatomic factors may influence the performance of Prostate-Specific Antigen (PSA), digital rectal examination (DRE), and prostate MRI.

METHODS

We analyzed 486 men (243 MSM, 243 HSM) undergoing prostate biopsy at a single academic center, matched by age, PSA, race/ethnicity, and MRI status. Sexual orientation, demographics, imaging, laboratory data, DRE findings, and biopsy results were extracted from electronic health records and validated by chart review. MRI-derived prostate volume, PSA density, and Prostate Imaging Reporting and Data System (PI-RADS) scores were included when available. Logistic regression models using PSA, DRE, PSA+DRE, PI-RADS, and PI-RADS+DRE generated predicted probabilities of clinically significant PCa (csPCa; Grade Group ≥2). Predictions from PLUM, UCLA, and My nMRIsk were evaluated using area under the curve (AUC), calibration, decision-curve analysis, and biopsy outcomes at 10% and 30% thresholds.

RESULTS

MSM and HSM were similar in age, PSA, prostate volume, and PI-RADS distribution. Abnormal DRE was more frequent in MSM (12.8% vs 6.6%, P = .02) but was not associated with higher csPCa risk. PI-RADS ≥3 demonstrated higher sensitivity in MSM (94% vs 87%). MRI-based calculators showed higher AUCs in MSM, with best performance for PLUM and UCLA.

CONCLUSION

MRI-based risk calculators demonstrated higher diagnostic accuracy in MSM, supporting use of current PCa risk tools without recalibration.