Abstract: ObjectiveTo study the effect of dendritic cells (DCs) and cytokineinduced killer cells (CIKs) combined with chemotherapy on Treg cell expression and prognosis of patients with breast cancer. MethodsPatients in the test group (n=42) were treated with DCCIK therapy combined with chemotherapy, and patients in the control group (n=38) were treated with chemotherapy. The expressions of Treg cells in peripheral blood, the shortterm efficacy, progressionfree survival (PFS), overall survival (OS) and quality of life after treatment were compared between the two groups. ResultsIn the test group, the expressions of Treg cells in peripheral blood after 1 week treatment were significantly lower than those in the control group ［(11.37±1.10)% vs. (14.25±0.95)%］, and the expressions of Treg cells in peripheral blood after 2 weeks treatment were significantly lower than those in the control group ［(7.94±1.12)% vs. (9.14±1.21)%］, with significant differences (t=12.470, P=0.000; t=4.606, P=0.000). The test group and the control group had the similar clinical efficacy rate (47.62% vs. 44.74%), with no significant difference (χ2=0.07, P=0.80). The disease control rate in the test group was significantly higher than that in the control group (80.95% vs. 60.53%), with a significant difference (χ2=4.06, P=0.04). The PFS ［(7.50±1.45) months vs. (5.50±1.52) months］ and OS ［(13.50±3.20) months vs. (11.50±3.25) months］ of patients in the test group were significantly higher than those in the control group, with significant differences (t=6.021, P=0.000; t=2.771, P=0.007). After treatment, the scores of the test group patients in physical function (72.85±12.01 vs. 57.42±13.07), emotional function (68.45±9.97 vs. 44.79±9.15), cognitive function (67.54±9.95 vs. 62.37±10.34), social function (65.72±12.17 vs. 49.37±8.45) and overall quality of life (71.43±11.50 vs. 59.48±12.45) were significantly higher than those in the control group, with significant differences (t=5.503, P=0.000; t=11.020, P=0.000; t=2.278, P=0.025; t=7.032, P=0.000; t=4.463, P=0.000). ConclusionDCCIK combined with chemotherapy can significantly reduce the expressions of Treg cells in peripheral blood, improve immune suppression, while increasing the curative efficacy, prolonging PFS and improving the quality of life of patients.

Key words: reast neoplasms, Dendritic cells, Killer cells, Treg cells, Progressionfree survival