IMPAKT: Circulating tumor cells and metastatic breast cancer

May 10, 2010

An increased number of circulating tumor cells may indicate decreased survival for metastatic breast cancer patients.

At the IMPAKT Breast Cancer Conference in Brussels, Belgium, researchers presented results of a retrospective analysis on 516 women with hormone receptor-positive, HER2-positive metastatic breast cancer.  Circulating tumor cells were measured before treatment was started.  As the number of circulating tumor cells increased, there was an increase in the risk of death among these metastatic breast cancer patients.  The risk of death after 1 year for patients with 40 circulating tumor cells in 7.5 ml of blood was significantly higher compared to patients with no increases in circulating tumor cells.  In past research findings, patients with 5 or more circulating tumor cells in 7.5 ml of blood usually had lower survival rates than those with fewer than 5 cells.  But determining exactly the number of circulating tumor cells that indicates poor prognosis has been hotly debated.  The validity and accuracy of circulating tumor cells as a prognostic biomarker remains to be seen.