Analysis of Circulating Tumor Cells in Patients with Triple Negative Breast Cancer during Preoperative Chemotherapy

The presence of circulating tumor cells in the blood of patients with triple negative breast cancer (early and locally advanced cancer) before and after preoperative chemotherapy was assessed using expression markers. Before therapy, circulating tumor cells were detected in 5 of 13 (38%) patients with early cancer and in 7 of 17 (41.2%) patients with locally advanced cancer. After therapy, the circulating immune cells were detected in one patient with locally advanced cancer, who had no circulating cells before therapy. The tumor was resistant to chemotherapy and the disease progressed. The detected circulating tumor cells were HER-2-positive, while the primary tumor was HER-2-negative. It was concluded that the circulating immune cells can be a potential marker of the efficiency of therapy and predictors of the disease course, while their phenotype can differ from the phenotype of the primary tumor.