Lymphocyte subpopulations in patients with advanced breast cancer submitted to neoadjuvant chemotherapy

Aims and background: There is an enhanced immune response in patients with breast cancer after the use of chemotherapy. The objective of this study wa s therefore to investigate alterations in the number of peripheral lymphocy tes in patients with breast cancer after neoadjuvant chemotherapy (NC) and the relationship with prognosis. Methods: Thirty women were analyzed. Their UICC staging was IIb (only T3N0 included) and III (N3 not included). Sample analysis was performed using fl ow cytometry before the first cycle and 18 to 21 days after the last cycle of NC. The lymphocyte subsets studied were: T (CD3, CD4, CD8), B (CD19, CD2 3), natural killer (NK) (CD56, CD16), and interleukin-2 (CD25). CD3, CD56, CD8, and CD16 lymphocytes were analyzed with double marking. After x = 3.8 +/- 1.3 cycles of 5-fluorouracil, epirubicin and cyclophosphamide (FEC) 16 patients showed a complete or partial response (group 1). After three cycle s 14 showed no response or tumor progression (group 2). A control group of healthy women was used for pretreatment analysis. Results: Before NC there was a significant increase in B lymphocytes and NK cells in comparison to the control group. After NC there was a significant percentage increase in CD3, CD4, CD8, CD25 and-CD3(+)CD56(+) cells and a d ecrease in CD19, CD23, CD56, CD16 and CD16(+)CD8(+) cells. There was a sign ificant fall in the absolute number of CD4, CD19, CD23, CD56, CD16 and CD16 (+)CD8(+) lymphocytes and an increase in CD3(+)CD56(+) lymphocytes. Before NC the ratio CD4/CD8 in group I was 2.25 +/- 0.5 and in group 2 it was 1.79 +/- 0.5 (P < 0.05). Conclusions: Patients with advanced breast cancer showed increases in B and NK lymphocytes. Neoadjuvant chemotherapy (FEC) caused an increase in CD3()CD56(+) and a decrease in B lymphocytes. Patients with an increased CD4/CD 8 ratio have a better chance of responding to neoadjuvant chemotherapy.