title: [Ki-67 expression and significance of different molecular subtypes of breast invasive ductal carcinoma].
abstract: OBJECTIVE
  To analyze Ki-67 expression and explore its significance in different molecular subtypes of breast invasive ductal carcinoma (IDC).
  
  
  METHODS
  The expressions of estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor-2 (HER-2) and Ki-67 were detected in 126 cases of IDC by immunohistochemical staining. Then the molecular subtype of each case of IDC was determined.Statistical analysis was performed to determine the relationship between Ki-67 expression and the molecular subtypes with clinicopathological features of IDC.
  
  
  RESULTS
  There was no statistically significant difference of Ki-67 expression in age and tumor size (P > 0.05).However, significant difference existed in histological grading and lymph node metastasis (P < 0.05). The expression level of Ki-67 was negatively correlated with ER expression (r = -0.273, P = 0.002) and PR expression (r = -0.242, P = 0.007) and positively with HER-2 expression (r = 0.245, P = 0.006) . A low expression of Ki-67 was in LumianlA subtype (17/17) and high expression in other molecular subtypes. Moreover, the rate of high expression (Ki-67 LI>50%) in each subtype progressively increased with the degree of molecular typing and Ki-67 expression in different molecular subtypes showed significant difference (P < 0.05).
  
  
  CONCLUSIONS
  The expression level of Ki-67 is correlated with histological grading and molecular type of IDC. High expression of Ki-67 carries poor prognosis. Thus it is necessary to perform a variety of routine clinicopathological examinations, such as Ki-67, ER, PR and HER-2.
authors.affiliation: Email:zsuj@163.com.
authors.forename: Su-juan
authors.initials: SJ
authors.lastname: Zhou
authors.forename: Hua
authors.initials: H
authors.lastname: Guo
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000378:metabolism* / Q000473:pathology; D018270:Carcinoma, Ductal, Breast / Q000378:metabolism* / Q000473:pathology; D005260:Female; D006801:Humans; D019394:Ki-67 Antigen / Q000235:genetics / Q000378:metabolism*; D008875:Middle Aged; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism; D011960:Receptors, Estrogen / Q000378:metabolism; D011980:Receptors, Progesterone / Q000378:metabolism
chemical_list: D019394:Ki-67 Antigen; D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; C508053:ERBB2 protein, human