Table 3 Summary of ongoing clinical trials with circulating tumor cells in metastatic breast cancer

STIC CTC METABREAST

1,000 hormone receptor-positive, metastatic breast cancer patients randomly assigned to either standard arm or CTC-driven arm, which dictates whether hormone therapy (5 CTCs <7.5 mL) or to chemotherapy (5 CTCs ≥7.5 mL) is administered. Trial aims to show non-inferiority of the CTC arm versus standard arm for progression-free survival.

[54]

SWOG 0500

Screening patients with metastatic disease and more than 5 CTCs (n = 610) and randomization between continuation of first-line therapy (CTC response, <5 CTC/7.5 mL) and switch to another chemotherapy regime (no CTC response, ≥5 CTCs/7.5 mL) (n = 120). Primary endpoint is improvement in overall survival in the CTC-driven arm.

[55]

CirCe01

304 women with metastatic disease starting with third-line chemotherapy will be randomly assigned between a CTC-driven arm and standard care arm. Patients in the CTC-driven arm change chemotherapy regimens according to their CTC counts during treatment. Primary endpoint is overall survival.

[56]

Treat CTC

Patients with HER2-negative breast cancer having completed chemotherapy and primary surgery and with at least 1 CTC/15 mL will be randomly assigned to an observation arm or to receive trastuzamab. Primary endpoint is detection rate of CTCs after 18 weeks between the two arms.

NCT01548677

DETECT III

Around 300 patients with metastatic and HER2-negative disease with detectable at least one HER2-positive CTC/7.5 mL will be randomly assigned to receive standard care (endocrine or chemotherapy or both) versus standard care plus lapatinib. Primary endpoint is progression-free survival.

NCT01619111