Abstract P1-08-21: Detection and monitoring of circulating endothelial cells, circulating tumor cells and disseminated tumor cells during neoadjuvant breast cancer treatment including bevacizumab

Circulating tumor cells in breast cancer

Over the past decade, technically reliable circulating tumor cell (CTC) detection methods allowed the collection of large datasets of CTC counts in cancer patients. These data can be used either as a dynamic prognostic biomarker or as tumor material for “liquid biopsy”. Breast cancer appears to be the cancer type in which CTC have been the most extensively studied so far, with level‐of‐evidence‐1 studies supporting the clinical validity of CTC count in both early and metastatic stage. This review summarizes and discusses the clinical results obtained in breast cancer patients, the issues faced by the molecular characterization of CTC and the biological findings about cancer biology and metastasis that were obtained from CTC.

In metastatic breast cancer, CTC count is a level‐of‐evidence 1 prognostic dynamic biomarker.

Several interventional trials are ongoing to demonstrate the clinical utility of CTC detection in metastatic breast cancer.

In early breast cancer, CTC count is also a prognostic biomarker, not correlated with the other usual prognostic factors.

Molecular characterization of CTC is promising, trials with anti‐HER2 therapy are ongoing.