Circulating tumor cells, disease progression, and survival in metastatic breast cancer.
Cristofanilli M, Budd GT, Ellis MJ, Stopeck A, Matera J, Miller MC, Reuben JM, Doyle GV, Allard WJ, Terstappen LW, et al. N Engl J Med. 2004 Aug 19; 351(8):781-91.