[268] Breast Scar Gene Expression Profiles Overlap with Tumor Stroma Response Signatures

LL Pate, RB West, M van de Rijn. Stanford University Medical Center, Stanford, CA

Background: The stroma surrounding cancer cells has emerged as an important factor in the development and subsequent behavior of breast tumors. We have previously demonstrated specific, unique stromal gene expression signatures derived from soft tissue tumors: desmoid-type fibromatosis (DTF), solitary fibrous tumors (SFT) (West RB, et al. 2005 PLoS Biol. 3(6):e187), and tenosynovial giant cell tumor (TGCT). We hypothesize that these tumor-associated stromal patterns are also present in normal, physiologic responses, like wound response. The goal of this study was to identify expression profiles associated with scar formation in breast tissue and to determine the overlap, if any, between breast scar formation and SFT, DFT, and TGCT (CSF1 response) signatures.
Design: We searched recent Stanford Pathology archives for formalin-fixed paraffin-embedded (FFPE) breast tissue for biopsy site change following core biopsy or lumpectomy. We chose 14 cases with post-procedure intervals ranging from 7 to 51 days. We isolated and amplified the RNA, and then performed gene expression profiling on 44K element oligonucleotide arrays (HEEBO) for each sample. We then compared the gene expression profiles of the 14 breast scar cases with a list of genes previously shown to comprise the breast cancer stromal signature associated with the DTF, SFT, and TGCT (CSF1 response) signatures.
Results: Gene expression profiles of breast scars show overexpression of a common set of genes. Breast scar expression profiles demonstrate significant overlap with the DTF and TGCT (CSF1 response) stromal signatures.
Conclusions: RNA derived from FFPE tissue can be amplified and used to identify gene expression profiles for scar tissue. Stromal responses to wound healing and stromal responses to tumor share some elements in their expression profiles. Breast scar gene expression profiles may be useful for identifying new activation states for fibroblasts, myofibroblasts, and other stromal elements.
Category: Breast

Monday, March 9, 2009 2:45 PM

Platform Session: Section B, Monday Afternoon