¹Department of Internal Medicine, Breast Oncology Program, University of Michigan Comprehensive Cancer Center, Ann Arbor, MI 48109, USA

Correspondence: Dr JB Smerage, E-mail: smerage@umich.edu

Received 23 August 2005; Revised 13 October 2005; Accepted 18 October 2005; Published online 29 November 2005.

Abstract

Circulating tumours cells (CTCs) represent an important biologic link in the spread of breast cancer from primary to metastatic disease. CTCs are strong predictors of prognosis in patients with metastatic breast cancer. Research to date has focused on development of methods with adequate sensitivity and specificity to reproducibly identify these rare events. Future research will focus on the biologic phenotypes of these cells with goals to understand mechanisms of metastasis, to identify novel therapeutic targets, and to monitor response to therapy.