title: Biologic subtype is a more important prognostic factor than nodal involvement in patients with stages I and II breast carcinoma.
abstract: OBJECTIVE
  Nodal infiltration has been one of the most important prognostic factors in breast cancer. In recent decades, risk stratification has greatly changed, and is applied in accordance with hormone receptor and human epidermal growth factor receptor 2 (HER2) status. We compared the prognostic power of tumor subtype to nodal involvement in early breast cancer.
  
  
  METHODS
  We reviewed the medical records of 505 patients who had curative surgery for stage I or II breast cancer. We analyzed clinicopathologic factors according to tumor subtype and nodal involvement. Tumors were classified into 4 subtypes according to immunohistochemical status of estrogen receptor, progesterone receptor, HER2, and Ki67 labeling index. Disease-free survival (DFS) and overall survival were analyzed.
  
  
  RESULTS
  There were 363 node-negative patients (71.9%) and 142 node-positive patients (28.1%). Luminal A, Luminal B, HER2, and triple-negative breast cancer subtypes were composed of 207 (41.0%), 147 (29.1%), 42 (8.3%), and 109 patients (21.6%), respectively. The median follow-up period was 89.5 months. Node negative-luminal A subtype showed the best prognosis with regard to 5-year DFS, and the pN1-triple negative subtype was associated with the shortest DFS (95.1% vs. 67.8%; hazard ratio, 9.554; P < 0.001). However, the node negative-triple negative subtype was associated with a worse 5-year DFS than the pN1-luminal A subtype ([86.4%; hazard ratio, 2.647; P = 0.048] vs. [93.2%; hazard ratio, 2.061; P = 0.194]).
  
  
  CONCLUSIONS
  Node negative-triple negative breast cancer was associated with a poorer prognosis than pN1-luminal A subtype. Tumor subtype has greater prognostic power compared to nodal status in early breast cancer.
authors.affiliation: Department of Surgery, Keimyung University School of Medicine, Daegu, Korea.
authors.forename: Hyosun
authors.initials: H
authors.lastname: Kim
authors.affiliation: Department of Surgery, Keimyung University School of Medicine, Daegu, Korea.
authors.forename: Jihyoung
authors.initials: J
authors.lastname: Cho
authors.affiliation: Department of Pathology, Keimyung University School of Medicine, Daegu, Korea.
authors.forename: Sun Young
authors.initials: SY
authors.lastname: Kwon
authors.affiliation: Department of Surgery, Keimyung University School of Medicine, Daegu, Korea.
authors.forename: Sun Hee
authors.initials: SH
authors.lastname: Kang
keywords: Breast neoplasms; Lymphatic metastasis; Prognosis; Triple negative breast neoplasms