Diagnostic value of PSA-based markers in prostate cancer: a retrospective analysis stratified by body mass index

Body mass index (BMI) influences the accuracy of prostate-specific antigen (PSA) in prostate cancer (PCa) diagnostic performance. This study investigates the effect of BMI on conventional PSA-based markers and evaluates a novel age-adjusted PSA density parameter (A-PSAD) to optimize diagnostic performance strategies across different BMI groups. The cohort comprised 307 low-BMI (91 PCa, 216 benign) and 356 high-BMI (109 PCa, 247 benign) patients. In the low-BMI group, A-PSAD yielded the highest diagnostic efficacy (AUC = 0.714), outperforming PSAD (0.685) and total PSA (TPSA, 0.588). In the high-BMI group, A-PSAD also demonstrated superior performance (AUC = 0.793) compared to PSAD (0.774) and TPSA (0.613). A-PSAD’s overall diagnostic value was significantly higher than conventional markers across both groups ( P < 0.01). Furthermore, LASSO regression identified four optimal predictive variables for the low-BMI group and seven for the high-BMI group; A-PSAD consistently emerged as a core independent predictor in both. BMI significantly modulates the diagnostic efficacy of PCa diagnostic performance indicators. A-PSAD demonstrates robust, superior diagnostic value across varying BMI categories, serving as a promising primary diagnostic performance tool to optimize individualized pre-biopsy risk stratification.