Evaluation of the use of Circulating tumour Cells to guide chemotherapy from the 3rd line of chemotherapy for metastatic breast cancer.

Phase III multicentre, randomized, open-label study comparing early evaluation of the efficacy of chemotherapy by determination of circulating tumour cells versus conventional clinical and radiological evaluation.

Inclusion Criteria:

• Women over the age of 18 years.
• WHO performance status: 0 to 4.
• Metastatic breast cancer.
• Progression after 2 lines of chemotherapy with decision to initiate third-line chemotherapy.
• Disease evaluable by CTC (CTC-positive before starting chemotherapy).
• Histology: lobular or ductal adenocarcinoma.
• Information of the patient and signature of the informed consent form by the patient or her legal representative.

Exclusion Criteria:

• Disease not evaluable by CTC (CTC-negative before starting chemotherapy).
• History of other potentially metastatic cancer (stage III or IV cancer) different from breast cancer.
• Histology other than lobular or ductal adenocarcinoma.
• Pregnant woman, women likely to become pregnant or nursing mothers.
• Persons deprived of their freedom or under guardianship.
• Women unable to comply with the medical follow-up of the study for geographical, social or mental reasons.