Association of ferritin with prostate cancer.

PURPOSE Prostate specific antigen (PSA) has been widely used as the unique serum biomarker for the diagnosis and/ or pre-diagnosis of prostate cancer (PCa). However, the diagnostic value of PSA is a subject of ongoing debate owing to its lack of specificity, especially when the PSA level is moderately increased (e.g., 4-10 ng/ml). Thus, we suggest the need for identification of a new biomarker to discriminate PCa cases from benign prostatic hyperplasia (BPH) and normal controls (N). METHODS Urine or tissue samples of PCa patients, BPH patients, and normal controls were systematically collected. The expression of ferritin light chain (FTL) and ferritin heavy chain (FTH) was verified by immunohistochemistry in the tissue. The concentration of urinary ferritin was measured by Access Immunoassay. The level of creatinine in the urine was detected on a HITACHI 7080 system to calculate the ferritin-creatinine ratio (FCR). The data were statistically analyzed using the rank sum test. RESULTS Immunohistochemical characterization of tissues in patients with PCa and BPH was conducted. We found representative immunohistochemical expression of FTL and FTH, with strong staining intensity in PCa and weak staining intensity in BPH. Furthermore, there were differences in urinary FCR among the three groups, with significant differences in the PCa group (134.46±47.01) compared to both the BPH (24.18±3.17, p = 0.009) and control (6.42±0.82, p = 0.003) groups. In contrast, there was no significant difference between the BPH and N groups (p = 0.649). CONCLUSIONS Ferritin is a potential urinary biomarker to discriminate between PCa and BPH patients.