title: The 70-gene prognostic signature for korean breast cancer patients.
abstract: OBJECTIVE
  A 70-gene prognostic signature has prognostic value in patients with node-negative breast cancer in Europe. This diagnostic test known as "MammaPrint™ (70-gene prognostic signature)" was recently validated and implementation was feasible. Therefore, we assessed the 70-gene prognostic signature in Korean patients with breast cancer. We compared the risk predicted by the 70-gene prognostic signature with commonly used clinicopathological guidelines among Korean patients with breast cancer. We also analyzed the 70-gene prognostic signature and clinicopathological feature of the patients in comparison with a previous validation study.
  
  
  METHODS
  Forty-eight eligible patients with breast cancer (clinical T1-2N0M0) were selected from four hospitals in Korea. Fresh tumor samples were analyzed with a customized microarray for the 70-gene prognostic signature. Concordance between the risk predicted by the 70-gene prognostic signature and risk predicted by commonly used clinicopathological guidelines (St. Gallen guidelines, National Institutes of Health [NIH] guideline, and Adjuvant! Online) was evaluated.
  
  
  RESULTS
  Prognosis signatures were assessed in 36 patients. No significant differences were observed in the clinicopathological features of patients compared with previous studies. The 70-gene prognosis signature identified five (13.9%) patients with a low-risk prognosis signature and 31 (86.1%) patients with a high-risk prognosis signature. Clinical risk was concordant with the prognosis signature for 29 patients (80.6%) according to the St. Gallen guidelines; 30 patients (83.4%) according to the NIH guidelines; and 23 patients (63.8%) according to the Adjuvant! Online. Our results were different from previous validation studies in Europe with about a 40% low-risk prognosis and about a 60% high-risk prognosis. The high incidence in the high-risk group was consistent with data in Japan.
  
  
  CONCLUSIONS
  The results of 70-gene prognostic signature of Korean patients with breast cancer were somewhat different from those identified in Europe. This difference should be studied as whether there is a gene disparity between Asians and Europeans. Further large-scale studies with a follow-up evaluation are required to assess whether the use of the 70-gene prognostic signature can predict the prognosis of Korean patients with breast cancer.
authors.affiliation: Department of Surgery, Ajou University School of Medicine, Suwon, Korea.
authors.forename: Kuk Young
authors.initials: KY
authors.lastname: Na
authors.forename: Ku Sang
authors.initials: KS
authors.lastname: Kim
authors.forename: Jeong Eon
authors.initials: JE
authors.lastname: Lee
authors.forename: Hee Jeong
authors.initials: HJ
authors.lastname: Kim
authors.forename: Jung-Hyun
authors.initials: JH
authors.lastname: Yang
authors.forename: Sei-Hyun
authors.initials: SH
authors.lastname: Ahn
authors.forename: Byung-In
authors.initials: BI
authors.lastname: Moon
authors.forename: Ra Mi
authors.initials: RM
authors.lastname: Kim
authors.forename: Si Mon
authors.initials: SM
authors.lastname: Ko
authors.forename: Yong Sik
authors.initials: YS
authors.lastname: Jung