title: Breast cancer prognosis and isolated tumor cell findings in axillary lymph nodes after core needle biopsy and fine needle aspiration cytology: Biopsy method and breast cancer outcome.
abstract: BACKGROUND
  It is unknown whether performing a core needle biopsy (CNB) to diagnose breast cancer increases the incidence of isolated tumor cells (ITC) in the axillary sentinel lymph nodes.
  
  
  METHODS
  Patients diagnosed with unilateral invasive pT1 breast cancer (≤2 cm in diameter, n = 1525) at a single center between February 2001 and August 2005 were included in this prospective observational cohort study. The patients were categorized into two groups according to the type of the preoperative breast needle biopsy performed, the CNB and the fine needle aspiration cytology (FNAC) groups, and followed up for a median of 9.5 years after breast surgery.
  
  
  RESULTS
  868 (56.9%) patients had FNAC and 657 (43.2%) CNB. In the subset of patients with no axillary metastases (pN0, n = 1005) 70 patients had ITC, 37 (4.3%) out of the 546 patients in FNAC group and 33 (5.0%) out of the 459 patients in the CNB group (p = 0.798). The type of tumor biopsy did not influence breast cancer-specific survival (p = 0.461) or local recurrence-free survival (p = 0.814) in univariable survival analyses. Overall, survival favored the CNB group in a univariable analysis, but no difference in survival emerged in a multivariable analysis (p = 0.718).
  
  
  CONCLUSIONS
  CNB was not associated with a greater incidence of ITC in axillary lymph nodes as compared with FNAC, and did not have an adverse effect on survival outcomes in a patient population treated with modern adjuvant therapies.
authors.affiliation: Helsinki University Central Hospital, Comprehensive Cancer Center, Breast Surgery Unit, P.O. Box 263, FIN-00029 HUS, Finland. Electronic address: jenni.liikanen@helsinki.fi.
authors.forename: J
authors.initials: J
authors.lastname: Liikanen
authors.affiliation: Helsinki University Central Hospital, Comprehensive Cancer Center, Breast Surgery Unit, P.O. Box 263, FIN-00029 HUS, Finland. Electronic address: marjut.leidenius@hus.fi.
authors.forename: M
authors.initials: M
authors.lastname: Leidenius
authors.affiliation: Helsinki University Central Hospital, Comprehensive Cancer Center, Department of Oncology, P.O. Box 180, FI-00029 Helsinki, Finland. Electronic address: heikki.joensuu@hus.fi.
authors.forename: H
authors.initials: H
authors.lastname: Joensuu
authors.affiliation: Helsinki University Central Hospital, Jorvi Hospital, Breast Surgery Unit, P.O. Box 800, FIN-00029 HUS, Finland. Electronic address: jaana.vironen@hus.fi.
authors.forename: J
authors.initials: J
authors.lastname: Vironen
authors.affiliation: Helsinki University Central Hospital, Department of Pathology, P.O. Box 400, FIN-00029 HUS, Finland. Electronic address: paivi.heikkila@hus.fi.
authors.forename: P
authors.initials: P
authors.lastname: Heikkilä
authors.affiliation: Helsinki University Central Hospital, Comprehensive Cancer Center, Breast Surgery Unit, P.O. Box 263, FIN-00029 HUS, Finland. Electronic address: tuomo.meretoja@hus.fi.
authors.forename: T
authors.initials: T
authors.lastname: Meretoja
mesh_terms: D000704:Analysis of Variance; D001365:Axilla; D044963:Biopsy, Fine-Needle / Q000379:methods*; D062005:Biopsy, Large-Core Needle / Q000379:methods*; D001943:Breast Neoplasms / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D015331:Cohort Studies; D005260:Female; D005387:Finland; D006801:Humans; D007150:Immunohistochemistry; D053208:Kaplan-Meier Estimate; D008198:Lymph Nodes / Q000473:pathology*; D009361:Neoplasm Invasiveness / Q000473:pathology; D009364:Neoplasm Recurrence, Local / Q000453:epidemiology* / Q000473:pathology; D009367:Neoplasm Staging; D009360:Neoplastic Cells, Circulating / Q000473:pathology*; D011379:Prognosis; D016016:Proportional Hazards Models; D011446:Prospective Studies; D018570:Risk Assessment; D016019:Survival Analysis
keywords: Breast cancer; Core needle biopsy; Fine needle aspiration cytology; Outcome; Prognosis