M. Cristofanilli, G. Budd, M. Ellis, A. Stopeck, J. Matera et al., Circulating Tumor Cells, Disease Progression, and Survival in Metastatic Breast Cancer, New England Journal of Medicine, vol.351, issue.8, pp.781-91, 2004.
DOI : 10.1056/NEJMoa040766

F. Nole, E. Munzone, L. Zorzino, I. Minchella, M. Salvatici et al., Variation of circulating tumor cell levels during treatment of metastatic breast cancer: prognostic and therapeutic implications, Annals of Oncology, vol.19, issue.5, pp.891-898, 2008.
DOI : 10.1093/annonc/mdm558

S. Nakamura, H. Yagata, S. Ohno, H. Yamaguchi, H. Iwata et al., Multi-center study evaluating circulating tumor cells as a surrogate for response to treatment and overall survival in metastatic breast cancer, Breast Cancer, vol.12, issue.3, pp.199-204, 2010.
DOI : 10.1007/s12282-009-0139-3

S. Dawood, K. Broglio, A. Buzdar, G. Hortobagyi, and S. Giordano, Status and Trastuzumab Treatment: An Institutional-Based Review, Journal of Clinical Oncology, vol.28, issue.1, pp.92-100, 2009.
DOI : 10.1200/JCO.2008.19.9844

M. Liu, M. Mego, S. Nakamura, F. Nole, J. Pierga et al., Clinical validity of circulating tumor cell (CTC) enumeration in 841 subjects with metastatic breast cancer (MBC) High independent prognostic and predictive value of circulating tumor cells compared with serum tumor markers in a large prospective trial in first-line chemotherapy for metastatic breast cancer patients, J Clin Oncol Ann Oncol, vol.2923, issue.3, pp.618-642, 2011.

J. Pierga, F. Bidard, C. Mathiot, E. Brain, S. Delaloge et al., 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 Single circulating tumor cell detection and overall survival in nonmetastatic breast cancer, Artificial neural network analysis of circulating tumor cells in metastatic breast cancer patients, pp.729-762, 2008.

S. Riethdorf, V. Muller, L. Zhang, T. Rau, S. Loibl et al., Prognostic Relevance of Circulating Tumor Cells in the Peripheral Blood of Primary Breast Cancer Patients Detection and HER2 expression of circulating tumor cells: prospective monitoring in breast cancer patients treated in the neoadjuvant GeparQuattro trial, Cancer Res Clin Cancer Res Ignatiadis M, vol.7016, issue.14, pp.6-52634, 2010.

C. Paoletti, M. Connelly, D. Chianese, M. Brown, M. Muñiz et al., P4-07-16: Development of Circulating Tumor Cell-Endocrine Therapy Index in Metastatic Breast Cancer Patients., Proceedings of the San Antonio Breast Cancer Symposium), 2011.
DOI : 10.1158/0008-5472.SABCS11-P4-07-16

C. Paoletti, M. Connelly, D. Chianese, M. Brown, M. Muñiz et al., Multiparameter molecular characterization of circulating tumor cells (CTC): Development of a CTC-Endocrine Therapy Index (CTC-ETI). . Proc Am Assoc Cancer Res HER-2 as a target for breast cancer therapy, Ignatiadis M Clin Cancer Res, vol.1715, issue.6, pp.1848-52, 2009.

S. Paik, C. Kim, and N. Wolmark, Status and Benefit from Adjuvant Trastuzumab in Breast Cancer, New England Journal of Medicine, vol.358, issue.13, pp.1409-1420, 2008.
DOI : 10.1056/NEJMc0801440

V. Georgoulias, V. Bozionelou, S. Agelaki, M. Perraki, S. Apostolaki et al., Four-year follow-up of trastuzumab plus adjuvant chemotherapy for operable human epidermal growth factor receptor 2-positive breast cancer: joint analysis of data from NCCTG N9831 and NSABP B-31, J Clin Oncol, vol.29, issue.20, pp.3366-73, 2011.

T. Fehm, V. Muller, B. Aktas, W. Janni, A. Schneeweiss et al., Trastuzumab decreases the incidence of clinical relapses in patients with early breast cancer presenting chemotherapy-resistant CK19 mRNA-positive circulating tumor cells: results of a randomized phase II study HER2 status of circulating tumor cells in patients with metastatic breast cancer: a prospective, multicenter trial, Ann Oncol Breast Cancer Res Treat, vol.21124, issue.2, pp.403-415, 2010.

S. Meng, D. Tripathy, S. Shete, R. Ashfaq, B. Haley et al., HER-2 gene amplification can be acquired as breast cancer progresses, Proceedings of the National Academy of Sciences, vol.101, issue.25, pp.9393-9401, 2004.
DOI : 10.1073/pnas.0402993101
URL : http://www.ncbi.nlm.nih.gov/pmc/articles/PMC438987

T. Fehm, S. Becker, S. Duerr-stoerzer, K. Sotlar, V. Mueller et al., Determination of HER2 status using both serum HER2 levels and circulating tumor cells in patients with recurrent breast cancer whose primary tumor was HER2 negative or of unknown HER2 status Study of the biologic effects of lapatinib, a reversible inhibitor of ErbB1 and ErbB2 tyrosine kinases, on tumor growth and survival pathways in patients with advanced malignancies, R74. 24. Spector NL, pp.2502-2514, 2005.

E. A. Eisenhauer, P. Therasse, J. Bogaerts, L. H. Schwartz, D. Sargent et al., New response evaluation criteria in solid tumours: Revised RECIST guideline (version 1.1), European Journal of Cancer, vol.45, issue.2, pp.228-247, 2009.
DOI : 10.1016/j.ejca.2008.10.026

W. Janni, Unrestricted educational and research grants from Veridex