ObjectiveTo investigate the changes in the percentage of myeloid-derived suppressor cells (MDSCs) in the peripheral blood of prostate cancer (PCa) patients and explore the correlation of MDSCs and their subsets with the prognosis of PCa.

METHODSUsing flow cytometry, we determined the percentage of MDSCs and the levels of Arg-1, iNOS and PD-L1 in the peripheral blood of 32 PCa patients and 25 healthy controls, detected the distribution of CD14+ Mo-MDSC and CD15+ PMN-MDSC subsets, and analyzed the correlation between the obtained parameters and the prognosis of PCa.

RESULTSCompared with the healthy controls, the PCa patients showed significant increases in the percentage of MDSCs (P<0.01) and levels of Arg-1, iNOS and PD-L1 in the peripheral blood. Statistically significant differences were observed in the distribution of the CD14+ Mo-MDSC and CD15+ PMN-MDSC subsets between the two groups（60.4% vs 72.2%, 29.5% vs 18.8%） (P<0.05). The percentages of MDSCs and Mo-MDSCs were remarkably correlated with the total survival rate of the PCa patients (P=0.025 and 0.017).

CONCLUSIONSThe percentages of MDSCs and CD14+ Mo-MDSCs in the peripheral blood were correlated with the prognosis of PCa, which may provide a target or some evidence for the clinical treatment of PCa.