Circulating Tumor Cell Detection Predicts Early Metastatic Relapse After Neoadjuvant Chemotherapy in Large Operable and Locally Advanced Breast Cancer in a Phase II Randomized Trial

Circulating tumor cells can be detected by the CellSearch system at a low cutoff of 1 cell in 27% of patients receiving neoadjuvant chemotherapy. Circulating tumor cell detection was not correlated to the primary tumor response but is an independent prognostic factor for early relapse.