Dynamic and significant changes of T-cell subgroups in breast cancer patients during surgery and chemotherapy.

Objective: Breast cancer and its surgical treatment and chemotherapy have great impact on the immune system. This study aimed to monitor the various T cells in breast cancer patients and evaluate the immune functions.

Methods: Blood samples were collected from 249 breast cancer patients at the following time points: 1-3 days preoperative, postoperative (before the chemotherapy), after 3 chemotherapy cycles, and after 6 chemotherapy cycles. The percentages of the CD3, CD4, CD8, CD45RA, and CD45RO T cells were measured using flow cytometry. Another 200 healthy women were used as control.

Results: Patients with stage II/III breast cancer had significantly lower percentages of CD3, CD4, CD8, CD45RA, and CD28 T cells in comparison with normal control and those with stage I breast cancer (P < 0.05). The percentages of CD45RO T cells and CD4CD25 (Treg) cells were significantly higher in stage II/III malignancies versus stage I, and was significantly higher in stage I malignancies versus the normal control (P < 0.05). Breast cancer patients had significantly lower percentages of CD3 and CD4 T cells in comparison with the normal control (P < 0.05). The preoperative percentages of CD3 and CD4 T cells were significantly reduced after 3 cycles and after 6 cycles of chemotherapy (P < 0.05). In patients with stage II/III malignancies, there was a higher percentage of CD45RO T cells than CD45RA T cells, which was reversed after surgery. After 6 chemotherapy cycles, the percentage of Treg cells was significantly reduced in comparison with that before the chemotherapy in the patients with stage II/III malignancies.

Conclusions: Patients with breast cancer had significantly suppressed immune functions. Surgical removal of the tumor may improve the immune functions. Chemotherapy significantly reduced the percentages of CD3 and CD4 T cells.