title: Genomic differences between pure ductal carcinoma in situ of the breast and that associated with invasive disease: a calibrated aCGH study.
abstract: OBJECTIVE
  In the quest for new targets, genomes of ductal carcinoma in situ (DCIS) and infiltrating duct carcinoma (IDC) have been compared previously; however, genomic alterations associated with cancer progression were difficult to identify. We hypothesized that significant events can be detected by comparing lesions with a broader range of behavior: from pure DCIS to IDC associated with lymph node metastasis.
  
  
  METHODS
  Array comparative genomic hybridization, calibrated by self-self hybridization tests, was used to study 6 cases of pure DCIS and 17 cases of DCIS paired with IDC where 8 tumors had spread to the local lymph nodes.
  
  
  RESULTS
  Pure DCIS exhibited a marginally higher degree of genomic complexity than DCIS and IDC components of invasive tumors. The latter two showed similarity between tumors and between components of the same tumor with several regions detected preferentially compared with pure DCIS. IDC associated with lymph node metastases showed similarity of genomic profiles as a group. Gain on 17q22-24.2 was associated with higher histologic grade, large IDC size, lymphatic/vascular invasion, and lymph node metastasis (P < 0.05).
  
  
  CONCLUSIONS
  Our findings suggest that DCIS and IDC are associated with specific genomic events. DCIS associated with IDC is genomically similar to the invasive component and therefore may represent either a clone with high invasive potential or invasive cancer spreading through the ducts. Specifically, gain on 17q22-24.2 is a candidate region for further testing as a predictor of invasion when detected in DCIS and predictor of nodal metastasis when detected in DCIS or IDC.
authors.affiliation: Division of Applied Medical Oncology, Toronto, Ontario, Canada.
authors.forename: Vladimir V
authors.initials: VV
authors.lastname: Iakovlev
authors.forename: Nona C R
authors.initials: NC
authors.lastname: Arneson
authors.forename: Vietty
authors.initials: V
authors.lastname: Wong
authors.forename: Chunjie
authors.initials: C
authors.lastname: Wang
authors.forename: Stephanie
authors.initials: S
authors.lastname: Leung
authors.forename: Gaiane
authors.initials: G
authors.lastname: Iakovleva
authors.forename: Keisha
authors.initials: K
authors.lastname: Warren
authors.forename: Melania
authors.initials: M
authors.lastname: Pintilie
authors.forename: Susan J
authors.initials: SJ
authors.lastname: Done
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000235:genetics* / Q000473:pathology; D018270:Carcinoma, Ductal, Breast / Q000235:genetics* / Q000473:pathology; D002285:Carcinoma, Intraductal, Noninfiltrating / Q000235:genetics* / Q000473:pathology; D002886:Chromosomes, Human, Pair 17 / Q000235:genetics*; D005260:Female; D006801:Humans; D008875:Middle Aged; D020411:Oligonucleotide Array Sequence Analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction