Circulating Tumor Cells in Breast Cancer Patients: An Evolving Role in Patient Prognosis and Disease Progression

Brian J. Czerniecki,Holly Graves

doi:10.4061/2011/621090

Abstract

In this paper, we examine the role of circulating tumor cells (CTCs) in breast cancer. CTCs are tumor cells present in the peripheral blood. They are found in many different carcinomas but are not present in patients with benign disease. Recent advances in theories regarding metastasis support the role of early release of tumor cells in the neoplastic process. Furthermore, it has been found that phenotypic variation exists between the primary tumor and CTCs. Of particular interest is the incongruency found between primary tumor and CTC HER2 status in both metastatic and early breast cancer. Overall, CTCs have been shown to be a poor prognostic marker in metastatic breast cancer. CTCs in early breast cancer are not as well studied, however, several studies suggest that the presence of CTCs in early breast cancer may also suggest a poorer prognosis. Studies are currently underway looking at the use of CTC level monitoring in order to guide changes in therapy.

Highlights

Breast cancer is one of the most common cancers affecting women
It was previously thought that metastasis occurred late in disease progression; evidence from circulating tumor cells (CTCs)/disseminated tumor cells (DTCs) has shown that metastasis may be an early event
Evidence has shown that CTCs play a prognostic role in both early and metastatic breast cancer patients

Summary

Introduction

Breast cancer is one of the most common cancers affecting women. It is estimated that one in eight women will develop an invasive breast cancer at some point during her lifetime. In 2010, according to the American Cancer Society, approximately 207, 090 new cases of invasive breast cancer will be diagnosed and 39, 840 women will die from metastatic disease. In this era of molecular medicine, novel approaches are needed in the management of breast cancer. DTCs are tumor cells present in the bone marrow. This paper will address the current methodologies of CTC detection, the prognostic role of CTCs in both early and advanced breast cancer, and the implication of CTCs in disease progression, treatment, tumor biology, and further research

Evidence for CTC in Early Metastasis

Phenotypic Variability between CTC and Primary Tumor

CTC Detection Methods

Metastatic Breast Cancer

Early Breast Cancer

Treatment Monitoring

Findings

Conclusion and Future Directions