title: Comparison of nuclear grade and immunohistochemical features in situ and invasive components of ductal carcinoma of breast.
abstract: OBJECTIVE
  To compare the prognostic and predictive features between in situ and invasive components of ductal breast carcinomas.
  
  
  METHODS
  We selected 146 consecutive breast samples with ductal carcinoma in situ (DCIS) associated with adjacent invasive breast carcinoma (IBC). We evaluated nuclear grade and immunohistochemical expression of estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2), cytokeratin 5/6 (CK5/6), and epidermal growth factor receptor (EGFR) in both components, in situ and invasive, and the Ki-67 percentage of cells in the invasive part. The DCIS and IBC were classified in molecular surrogate types determined by the immunohistochemical profile as luminal (RE/PR-positive/ HER2-negative), triple-positive (RE/RP/HER2-positive), HER2-enriched (ER/PR-negative/HER2-positive), and triple-negative (RE/RP/HER2-negative). Discrimination between luminal A and luminal B was not performed due to statistical purposes. Correlations between the categories in the two groups were made using the Spearman correlation method.
  
  
  RESULTS
  There was a significant correlation between nuclear grade (p<0.0001), expression of RE/RP (p<0.0001), overexpression of HER2 (p<0.0001), expression of EGFR (p<0.0001), and molecular profile (p<0.0001) between components in situ and IBC. CK 5/6 showed different distribution in DCIS and IBC, presenting a significant association with the triple-negative phenotype in IBC, but a negative association among DCIS.
  
  
  CONCLUSIONS
  Our results suggest that classical prognostic and predictive features of IBC are already determined in the preinvasive stage of the disease. However the role of CK5/6 in invasive carcinoma may be different from the precursor lesions.
authors.affiliation: Instituto do Câncer do Estado de São Paulo, São Paulo, SP, Brazil.
authors.forename: Fernando Nalesso
authors.initials: FN
authors.lastname: Aguiar
authors.forename: Henrique Nogueira
authors.initials: HN
authors.lastname: Mendes
authors.forename: Carlos E
authors.initials: CE
authors.lastname: Bacchi
authors.forename: Filomena Marino
authors.initials: FM
authors.lastname: Carvalho
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000473:pathology*; D018270:Carcinoma, Ductal, Breast / Q000473:pathology*; D002285:Carcinoma, Intraductal, Noninfiltrating / Q000473:pathology*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008875:Middle Aged; D060787:Neoplasm Grading; D009361:Neoplasm Invasiveness; D011237:Predictive Value of Tests; D011379:Prognosis