title: Detection of circulating tumor cells in peripheral blood of heavily treated metastatic breast cancer patients.
abstract: BACKGROUND
  Circulating tumor cells (CTCs) are detected in peripheral blood of breast cancer patients, and they may play an important role as a prognostic and predictive marker. We conducted this study to determine the presence of CTCs with the CellSearch System™ and the clinical significance in treatment of metastatic breast cancer (MBC).
  
  
  METHODS
  Twenty-eight MBC patients were enrolled. These patients were followed by assessing CTCs, imaging studies, and serum tumor markers. Blood samples were collected before starting a new treatment and at the treatment evaluation period (2-3 months after starting chemotherapy). The cutoff for CTC level was 5.
  
  
  RESULTS
  At baseline, 9 of 28 patients (32%) had ≥5 CTCs per 7.5 mL of blood. At the evaluation period, 5 of 23 patients (22%) had ≥5 CTCs. The baseline CTC number did not contribute to determine their overall survival (OS); however, CTCs at the evaluation period were available to predict their OS (p < 0.001). In two cases, both CTCs and tumor markers were available as predictors of treatment efficacy. In two other cases, although alterations of tumor markers might not reflect disease condition, CTC alteration corresponded to their condition. One patient who had multiple skeletal metastasis only, experienced a decrease in her CTCs in spite of tumor marker alteration.
  
  
  CONCLUSIONS
  We suggest that monitoring the number of CTCs may be helpful in predicting the efficacy of the treatment and the prognosis. CTCs might be especially useful with patients whose lesions are difficult to assess.
authors.affiliation: Department of Medical Oncology, The Cancer Institute Hospital of Japanese Foundation for Cancer Research, 3-8-31 Ariake, Koto-ku, Tokyo, 135-8550, Japan. nahomi.tokudome@jfcr.or.jp
authors.forename: Nahomi
authors.initials: N
authors.lastname: Tokudome
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Ito
authors.forename: Shunji
authors.initials: S
authors.lastname: Takahashi
authors.forename: Kokoro
authors.initials: K
authors.lastname: Kobayashi
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Taira
authors.forename: Chizuko
authors.initials: C
authors.lastname: Tsutsumi
authors.forename: Masafumi
authors.initials: M
authors.lastname: Oto
authors.forename: Masaru
authors.initials: M
authors.lastname: Oba
authors.forename: Kenichi
authors.initials: K
authors.lastname: Inoue
authors.forename: Akiko
authors.initials: A
authors.lastname: Kuwayama
authors.forename: Kyoko
authors.initials: K
authors.lastname: Masumura
authors.forename: Yoshie
authors.initials: Y
authors.lastname: Nakayama
authors.forename: Chie
authors.initials: C
authors.lastname: Watanabe
authors.forename: Kiyohiko
authors.initials: K
authors.lastname: Hatake
mesh_terms: D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D014408:Biomarkers, Tumor / Q000097:blood; D001943:Breast Neoplasms / Q000097:blood* / Q000188:drug therapy* / Q000401:mortality / Q000473:pathology*; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000556:secondary; D008875:Middle Aged; D009360:Neoplastic Cells, Circulating / Q000187:drug effects; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism; D011960:Receptors, Estrogen / Q000378:metabolism; D016019:Survival Analysis; D016896:Treatment Outcome
chemical_list: D014408:Biomarkers, Tumor; D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; C508053:ERBB2 protein, human