Background: Dendritic cells (DCs) are the most effective antigen presenting cells (APCs) and play a significant role in immune response against breast cancer. However, the number and function of DC are often altered by cancer.

Aim: The aim of this study was to correlate the absolute numbers of DCs and clinical response in breast cancer patients receiving neoadjuvant paclitaxel.

Patients and methods: Breast cancer patients (n=10) and healthy donors (n=4) were recruited from Tanta Cancer Center, Egypt. Peripheral blood samples (2ml) were collected in EDTA tubes from breast cancer patients during neoadjuvant chemotherapy (prior to each cycle of paclitaxel) as well as healthy volunteers. The relative and absolute numbers (CD11c⁺CD11b⁺) and their maturation markers(HLADR⁺ and CD83⁺)of myeloid DCs in peripheral blood samples were evaluated by flow-cytometry after staining with antibodies.
Results: As compared to control, the relative and absolute numbers of total myeloid DCs and mature ones in BC patients were decreased prior to the second cycle of Paclitaxel. Significant correlation between the absolute numbers of myeloid DCs and clinical response of patients during neoadjuvant chemotherapy was found. According to ROC curve, significant AUC was found in the first and second cycle of paclitaxel.

Conclusion: Myeloid DCs can be used as prognostic marker for progression of breast cancer and may be a useful tool for treatment to enhance response to neoadjuvant chemotherapy especially triple negative breast cancer patients who have poor prognosis.

Keywords: Myeloid dendritic cells, Neoadjuvanttaxanes chemotherapy, Breast cancer