title: Clinical significance of subtype classification in metastatic lymph nodes of breast cancer patients undergoing neoadjuvant chemotherapy.
abstract: BACKGROUND
  Neoadjuvant chemotherapy has been increasingly utilized in the treatment of breast cancer patients. However, there are no established surrogate markers predicting the response to subsequent adjuvant therapy and clinical outcome of patients. In particular, whether primary or lymph nodes metastasis should be evaluated for these analyses has remained unknown. Therefore, in this study, we first evaluated the differences in biomarkers between primary and metastatic cancer tissues in the patients undergoing neoadjuvant chemotherapy. We then correlated the findings with the clinical outcomes of these patients.
  
  
  METHODS
  We examined 49 patients receiving neoadjuvant chemotherapy and subsequent surgery with lymph node metastasis. Estrogen receptor (ER), progesterone receptor (PgR), human epidermal growth factor receptor 2 (HER2) and Ki-67 were all immunohistochemically evaluated in core needle biopsy samples from primary and metastatic tumors following chemotherapy.
  
  
  RESULTS
  No statistically significant differences in these markers were detected between the primary tumor and metastatic lymph nodes following therapy, but the Ki-67 labeling index was significantly higher in metastatic lymph nodes than in primary tumor (p = 0.017). The patients associated with luminal A type carcinoma in their lymph nodes following chemotherapy demonstrated significantly better clinical outcomes (disease-free survival: p = 0.0045, overall survival: p = 0.0006) than those who were not.
  
  
  CONCLUSIONS
  These data indicate that subtype classification following chemotherapy, in the metastatic lymph nodes rather than primary tumor could predict long-term outcomes of patients undergoing neoadjuvant chemotherapy.
authors.affiliation: 1 Division of Surgical Oncology, Tohoku University Graduate School of Medicine, Sendai, Miyagi - Japan.
authors.forename: Noriko
authors.initials: N
authors.lastname: Nemoto
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Shibahara
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Tada
authors.forename: Keiko
authors.initials: K
authors.lastname: Uchida
authors.forename: Keely M
authors.initials: KM
authors.lastname: McNamara
authors.forename: Monica S M
authors.initials: MS
authors.lastname: Chan
authors.forename: Mika
authors.initials: M
authors.lastname: Watanabe
authors.forename: Kentaro
authors.initials: K
authors.lastname: Tamaki
authors.forename: Minoru
authors.initials: M
authors.lastname: Miyashita
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Miki
authors.forename: Kohsuke
authors.initials: K
authors.lastname: Gonda
authors.forename: Takanori
authors.initials: T
authors.lastname: Ishida
authors.forename: Noriaki
authors.initials: N
authors.lastname: Ohuchi
authors.forename: Hironobu
authors.initials: H
authors.lastname: Sasano
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000473:pathology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis / Q000473:pathology*; D008875:Middle Aged; D020360:Neoadjuvant Therapy / Q000379:methods*; D016896:Treatment Outcome