Open Access Research article

Dynamics of circulating endothelial cells and endothelial progenitor cells in breast cancer patients receiving cytotoxic chemotherapy

Yu-Hsuan Kuo12, Ching-Hung Lin2, Wen-Yi Shau3, Te-Jung Chen24, Shih-Hung Yang2, Shu-Min Huang2, Chun Hsu2, Yen-Shen Lu2* and Ann-Lii Cheng25*

Author Affiliations

1 Department of Oncology, Chi-Mei Hospital, Tainan, Taiwan

2 Department of Oncology, National Taiwan University Hospital, No. 7, Chung-Shan South Road, Taipei, 10002, Taiwan

3 Center For Drug Evaluation, Division of Health Technology Assessment, Taipei, Taiwan

4 Oncology Translational Research Center, TTY Biopharm Company Limited, Taipei, Taiwan

5 Departments of Internal Medicine and Oncology, National Taiwan University Hospital, 7 Chung-Shan South Road, Taipei, 10002, Taiwan

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BMC Cancer 2012, 12:620  doi:10.1186/1471-2407-12-620

Published: 26 December 2012



The abundance of circulating endothelial cells (CECs) and circulating endothelial progenitor cells (CEPs), which serve as surrogate markers for angiogenesis, may be affected by chemotherapy. We studied their dynamic change during consecutive cycles of chemotherapy.


We collected blood samples from 15 breast cancer patients, who received a total of 56 courses of systemic chemotherapy, and measured the CECs, viable CECs (V-CECs), and CEPs by six-color flow cytometry within the seven days prior to chemotherapy, twice a week during the first and second cycles of chemotherapy, and then once a week during the subsequent cycles.


The CEC, V-CEC, and CEP levels all significantly decreased from day 1 of treatment to the first week of chemotherapy. After one week of chemotherapy, the CEC and V-CEC levels returned to a level similar to day 1. The CEP level remained significantly reduced after the first week of chemotherapy, but gradually rebounded until the next course of chemotherapy. After six cycles of chemotherapy, the total number of CEC and V-CEC cells trended toward a decrease and the CEP cells toward an increase. Clinical factors, including the existence of a tumor, chemotherapy regimens, and the use of granulocyte colony stimulating factor, did not significantly affect these results.


The CEC and CEP counts change dynamically during each course of chemotherapy and after the chemotherapy cycles, providing background data for any future study planning to use CECs and CEPs as surrogate markers of angiogenesis in antiangiogenesis treatments combined with chemotherapy.

Circulating endothelial cells; Endothelial progenitor cells; Breast cancer; Angiogenesis; Biomarkers