title: [Analysis of associations between molecular subtypes and responses to neoadjuvant chemotherapy in primary breast cancer patients].
abstract: OBJECTIVE
  To explore the correlations between molecular subtypes and responses to neoadjuvant chemotherapy in primary breast cancer patients.
  
  
  METHODS
  The core-needle biopsy specimens were collected from 563 patients undergoing 4-8 cycles of neoadjuvant chemotherapy between January 2001 to January 2009. And immunohistochemical assays were employed to detect the levels of estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2) and Ki-67 proliferation index simultaneously. Molecular subtypes were divided on the basis of immunohistochemical results. And the associations between molecular subtypes and responses to neoadjuvant chemotherapy were analyzed in 563 patients.
  
  
  RESULTS
  The pathological complete response (pCR) rates of patients with hormone receptor-negative/HER2-negative subtype (HR-/HER2-) , HER2-positive subtype (HER2+) and hormone receptor-positive/HER2-negative subtype (HR+/HER2-) were 38.9%, 17.9% and 8.3% respectively. In univariate analysis, there were significant differences in pCR rates among the groups (P < 0.001) . In multivariate analysis, the patients with HER2+ subtype had a significantly higher pCR rate than those with HR+/HER2- subtype (OR = 0.344, P = 0.002) . Whereas the patients with HER2+ subtype had a significantly lower pCR rate than those with HR-/HER2- subtype (OR = 2.453, P = 0.007) . Among HR+/HER2-subtypes, a higher pCR rate was observed in the group of high expression level of Ki-67 proliferation index (Ki-67 ≥ 20%) (P = 0.004) . But no significant differences existed in pCR rates between the group of high expression level of hormone receptor and the group of non-high expression level (P = 0.256) .
  
  
  CONCLUSIONS
  There were correlations between molecular subtypes and responses to neoadjuvant chemotherapy in primary breast cancer patients. Patients of HER2+and HR-/HER2- subtype are more likely to respond to neoadjuvant chemotherapy. Among HR+/HER2-subtypes, those with a high level of Ki-67 proliferation index tend to benefit from neoadjuvant chemotherapy.
authors.affiliation: Breast Cancer Prevention & Treatment Center, Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Peking University Cancer Hospital & Institute, Beijing 100142, China.
authors.forename: Yi-jun
authors.initials: YJ
authors.lastname: Zhou
authors.forename: Min
authors.initials: M
authors.lastname: Ying
authors.forename: Ying-jian
authors.initials: YJ
authors.lastname: He
authors.forename: Yi-qiang
authors.initials: YQ
authors.lastname: Liu
authors.forename: Zhao-qing
authors.initials: ZQ
authors.lastname: Fan
authors.forename: Tie
authors.initials: T
authors.lastname: Fan
authors.forename: Jin-feng
authors.initials: JF
authors.lastname: Li
authors.forename: Tian-feng
authors.initials: TF
authors.lastname: Wang
authors.forename: Yun-tao
authors.initials: YT
authors.lastname: Xie
authors.forename: Ai-ping
authors.initials: AP
authors.lastname: Lu
authors.forename: Tao
authors.initials: T
authors.lastname: Ouyang
mesh_terms: D001943:Breast Neoplasms / Q000145:classification* / Q000473:pathology / Q000628:therapy*; D005260:Female; D006801:Humans; D016130:Immunophenotyping; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism; D011960:Receptors, Estrogen / Q000378:metabolism; D011980:Receptors, Progesterone / Q000378:metabolism
chemical_list: D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; C508053:ERBB2 protein, human