Myeloid-derived suppressor cells (MDSC) have been identified in most patients and experimental mice with tumors by their Th2-related suppression of T-cell activation. In contrast to the situation in mice, MDSC involvement in human cancer pathophysiology has not been clarified.Materials and methods
Here we report a study of 53 patients with breast cancer, including 31 preoperative, 22 postoperative and 8 having recurrent disease, and 11 healthy volunteers. PBMC was obtained and used for flow cytometric analysis and production assay for IL-6 and IL-10 which produced by Th2 cells.Results
A highly significant increase was seen in MDSCs (CD11b + CD14-CD33+ cells) levels in patients (3.33%) compared with normal volunteers (0.28%). MDSCs of preoperative, postoperative and recurrent patients were 3.24%, 1.9% and 3.68%, respectively, and the difference between pre- and postoperative patients was significant. MDSC levels were significantly correlated to IL-10 production, and IL-10 and IL-6 levels were significantly correlated with one another.Conclusion
Thus MDSC elevated in patients with breast cancer and it showed decrease after the removal of the tumor mass to range in healthy individuals, and re-increase with recurrence. These levels had a correlation with Th2-dominant condition. We report two cases of recurrent breast cancer with MDSC levels after gemcitabine treatment. In addition, MDSCs was also identified in pleural effusion and these cells also decreased in response to gemcitabine administration.