Boosting Diagnostic Accuracy of Prostate Cancer: Combining Clinical PSA Level and a Pair of NIR Fluorescent Probes for SLC39A1 and PSMA

Prostate cancer (PCa) is a leading malignancy in men globally. Although serum prostate-specific antigen (PSA) testing is prevalent for PCa screening, its inherent limitation in specificity and sensitivity frequently leads to high false-positive and false-negative diagnoses. To address this challenge, we present a PSA+ strategy that integrates a clinically defined PSA threshold (10 ng/mL) with a pair of complementary near-infrared (NIR) fluorescent probes: a zinc-complex-based probe (Cy-O-NS-a-Zn) targeting the zinc transporter solute carrier family 39 member 1 (SLC39A1), and a glutamate-urea-lysine (Glu-Urea-Lys) ligand-based probe (Cy-S-Glu) targeting prostate-specific membrane antigen (PSMA). This combinatorial approach accurately discriminates PCa from normal prostate cells, delineates tumor margins in patient-derived xenograft (PDX) mouse models with robust tumor-to-background ratios (TBR), and enables fluorescence-guided surgery. Importantly, a double-blind histopathological validation using 70 cases of human prostate tissue specimens revealed that the PSA+ strategy substantially outperformed PSA testing alone, improving diagnostic specificity from 70% to 97.6% and sensitivity from 75% to 96.8%. Collectively, this work provides a rapid, accurate, and comprehensive diagnostic paradigm that complements standard PSA testing, thereby refining clinical diagnosis and decision-making in PCa.