Immune Changes in Patients with Locally Advanced Breast Cancer Receiving Neoadjuvant Chemotherapy

Object: The effect of neoadjuvant chemotherapy on cellular immunity was investigated in patients with locally advanced breast cancer by evaluating the changes in peripheral blood lymphocyte (PBL) subpopulations and natural killer cell activity (NKA) after chemotherapy. Materials and Methods: Blood samples were obtained from 13 advanced breast cancer patients before and after 3 or 4 cycles of the combination chemotherapy 5-fluorouracil, epirubicin, and cyclophosphamide. PBLs including CD3(+), CD4(+), CD8(+), CD19(+), CD25(+), CD45RA(+), CD45R0(+), CD56(+) and gamma(delta)-T cells were evaluated by flow-cytometric analyses by using specific monoclonal antibodies. NKA was assessed by anti-candidal indexes. Results: After chemotherapy, the CD19(+) B and CD45RA(+) naive T-lymphocyte percentages and the CD4/CD8 ratio were decreased (p<0.001, p=0.06, p=00.04, respectively), while the CD8(+) cytotoxic-supressor T cells were increased (p<0.001). In subgroup analysis, the anti-candidal indexes were found to be decreased (p=0.04), while the CD56+ (p=0.005), and CD45RO(+) (p=0.05) memory T-cell percentages were increased in the responsive-group (n=7) after chemotherapy. However, the anti-candidal indexes (p=0.01) were observed to be increased, and the CD25(+) activated T-cell percentages (p=0.004) were decreased in the chemotherapy non-responsive group (n=6) unlike the other groups. No statistically significant changes were observed in CD3(+), CD4(+), and gamma(delta)-T cell percentages after chemotherapy in the whole group and subgroup analyses. Conclusion: Our results suggest that the anthracycline-based chemotherapy regimen induced increases in CD45RO+ memory T-cell percentages may enhance the efficacy of chemoimmunotherapy trials in chemotherapy-responsive patients. Detailed phenotypical and functional characterization of intratumoral lymphocytes warrants further investigation in terms of contrary findings on PBL percentages and NK cell function after chemotherapy.