title: Circulating tumor cells in patients with breast cancer: possible predictor of micro-metastasis in bone marrow but not in sentinel lymph nodes.
abstract: BACKGROUND
  Blood and lymphatic circulation are the major routes during metastatic spread of breast cancer cells. Despite the predictive and prognostic value of bone marrow (BM) micro-metastasis, repeated and frequent BM aspirations may not be easily accepted by patients. We try to establish the role of circulating tumor cells as a predictor for micro-metastasis in BM and sentinel lymph node (SLN) as well as to identify the association between micro-metastasis in blood and lymphatic circulation. We prospectively studied 47 breast cancer patients without overt metastasis. Bilateral BM samples and blood samples were obtained before surgery and subsequently handled using magnetic-activated cell separation (MACS) followed by immunocytochemistry (ICC). SLN was examined by hematoxylin and eosin (H and E) staining and ICC.
  
  
  RESULTS
  Blood and BM micro-metastasis were detected in 16 (35%) and 25 (54%) of 47 patients. SLN micro-metastasis were detected in 13 (27.7%) and 22 (46.8%) patients using H and E and ICC, respectively. All the patients with circulating tumor cells had micro-metastasis in BM, whereas 9 of 25 (36%) patients with micro-metastasis in BM had no circulating tumor cells (P < 0.001). On the other hand, there is no correlation between circulating tumor cells and micro-metastasis in SLNs detected by either H and E (P = 0.52) or ICC (P = 0.36). We found that the presence of circulating tumor cells might predict BM micro-metastasis but not SLN micro-metastasis. It is also interesting to find that the presence of SLN micro-metastasis does not necessarily correlate with the presence of micro-metastasis in BM and blood.
authors.affiliation: Hung Chao Hong Integrated Center for Breast Diseases, Department of Surgery, Queen Mary Hospital, The University of Hong Kong, Pokfulam, China.
authors.forename: L
authors.initials: L
authors.lastname: Zhu
authors.forename: W T Y
authors.initials: WT
authors.lastname: Loo
authors.forename: L W C
authors.initials: LW
authors.lastname: Chow
mesh_terms: D000328:Adult; D019046:Bone Marrow Neoplasms / Q000556:secondary*; D001943:Breast Neoplasms / Q000473:pathology*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008198:Lymph Nodes / Q000473:pathology; D008207:Lymphatic Metastasis / Q000473:pathology*; D008875:Middle Aged; D009360:Neoplastic Cells, Circulating / Q000473:pathology*; D011237:Predictive Value of Tests; D011446:Prospective Studies