Phenotypic analysis of circulating tumor cells and immunological performance in metastatic breast cancer

Abstract

Despite of the success of the breast cancer therapies, recurrence and metastasis still occurs after treatment. These may be due to the immune cells suppression through myeloid derived suppressor cells (MDSCs) and circulatory tumor cells (CTCs).The present study aimed To determine whether the MDSCs with certain phenotype emerge in metastatic cancer patients and whether it correlates with high numbers of CTCs. Blood samples were collected from metastatic breast cancer patients (n=16) before and after chemotherapy compared to healthy individuals (n=5) Multi-parametric flow cytometry was used to analyze the numbers of MDSC as well as CTCs in the peripheral blood samples (PB) of breast cancer patients, and correlated the results with clinical status of the patients compared to healthy woman. The study showed Significant increases in the relative and the absolute numbers of MDSCs were found in the peripheral blood of metastatic breast cancer groups than in the control group. Interestingly, the number of monocytic MDSC was higher than those of granulocytic MDSC. Meanwhile, significant increase in the relative and the absolute numbers of CTCs were found in the peripheral blood of metastatic breast cancer patients. A positive relationship between the numbers of CTC and MDSC in the same patients was found. These data shed a light on two of the escape cellular mechanisms in metastatic breast cancer patients.