Plasma chromogranin A in patients with prostate cancer improves the diagnostic efficacy of free/total prostate-specific antigen determination.

INTRODUCTION: We ascertained whether plasma chromogranin A enhances the power of serology assessing prostate cancer (PC). MATERIALS AND METHODS: We studied 56 PC and 83 benign prostatic hyperplasia (BPH) patients. In the sera we measured total prostate-specific antigen (tPSA) and free PSA (fPSA) and calculated the ratio between fPSA and tPSA (f/tPSA). In plasma samples the levels of chromogranin A (CgA) were also assayed. RESULTS: PC patients had higher CgA (p < 0.005) and tPSA (p < 0.05) levels, and a lower f/tPSA ratio (p < 0.001), than BPH patients. When f/tPSA and CgA were combined, the diagnostic sensitivity was enhanced (57-73%), while the specificity had only an 8% reduction (from 89 to 80%). CgA was only correlated to the Gleason PC score (p < 0.05). CONCLUSIONS: CgA determination in PC may enhance the diagnostic accuracy of the f/tPSA assay and provides useful information on the tumor grade.