Detection and prognostic significance of circulating tumor cells in nonmetastatic breast cancer patients

Abstract

SUMMARY Distant metastasis remains the primary cause of death for breast cancer patients. Metastasis is a complex, multistep process wherein a subset of cells from a heterogeneous tumor acquire the ability to disseminate from the primary tumor and invade the blood and/or lymph nodes. Although tumor size, tumor characteristics and axillary lymph node status are the most common parameters utilized to predict disease recurrence in nonmetastatic patients, a significant number of lymph node-negative patients with localized disease will develop distant metastases despite successful primary treatment. These data suggest that tumor cell dissemination can occur early in disease progression, sometimes bypassing the lymphatic system. Occult micrometastases, or circulating tumor cells in the blood, are rare tumor cells that remain undetected by standard histopathogical and high-resolution imaging methodologies. This review focuses on current methodologies used to detect circulating tumor cells and their prognostic significance in nonmetastatic breast cancer patients.