title: The expression of the cytoskeletal focal adhesion protein paxillin in breast cancer correlates with HER2 overexpression and may help predict response to chemotherapy: a retrospective immunohistochemical study.
abstract: Paxillin, a cytoskeletal focal adhesion adaptor protein, has been shown to be transcriptionally up-regulated and phosphorylated by human epidermal growth factor receptor-2 (HER2) signaling in vitro. Paxillin expression may also correlate with HER2 amplification in breast cancer patients. In the current study, we sought to explore the relationship further between paxillin expression and clinicopathologic features and clinical outcome in breast cancer. A total of 314 primary invasive breast carcinomas were assessed for paxillin expression via immunohistochemistry. Paxillin immunoreactivity was compared with estrogen receptor/progesterone receptor status, HER2 status by silver in situ hybridization, age, tumor size, stage, Bloom-Richardson grade, nodal status, disease-free survival (DFS), and overall survival (OS). Paxillin expression was identified in 27.7% of breast carcinomas as diffuse cytoplasmic staining and the expression correlated with HER2 overexpression (p < 0.001). The influence of paxillin on clinical outcome, in particular the response to chemotherapy, appeared to differ depending on the HER2 status of the tumor. For the subset of HER2 nonamplified cases treated with chemotherapy, patients whose tumor showed a loss of paxillin expression demonstrated a significantly lengthened DFS and OS. In contrast, loss of paxillin expression in the HER2 amplified subset of patients who received chemotherapy correlated with a significantly worse outcome. These data suggest that paxillin up-regulation may be a part of the HER2 pathway in some breast cancers and, furthermore, paxillin expression may also influence the clinical response to chemotherapy, depending upon the HER2 status of a given patient's tumor. Further study of a role for paxillin expression in predicting response to cytotoxic regimens or targeted treatments is warranted.
authors.affiliation: Department of Anatomic and Clinical Pathology L25, Cleveland, Ohio, USA.
authors.forename: Sarah M
authors.initials: SM
authors.lastname: Short
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Yoder
authors.forename: Shannon M
authors.initials: SM
authors.lastname: Tarr
authors.forename: Nichole L
authors.initials: NL
authors.lastname: Prescott
authors.forename: Simas
authors.initials: S
authors.lastname: Laniauskas
authors.forename: Kara A
authors.initials: KA
authors.lastname: Coleman
authors.forename: Erinn
authors.initials: E
authors.lastname: Downs-Kelly
authors.forename: James D
authors.initials: JD
authors.lastname: Pettay
authors.forename: Toni K
authors.initials: TK
authors.lastname: Choueiri
authors.forename: Joseph P
authors.initials: JP
authors.lastname: Crowe
authors.forename: Raymond R
authors.initials: RR
authors.lastname: Tubbs
authors.forename: Thomas G
authors.initials: TG
authors.lastname: Budd
authors.forename: David G
authors.initials: DG
authors.lastname: Hicks
mesh_terms: D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism* / Q000401:mortality; D018270:Carcinoma, Ductal, Breast / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism* / Q000401:mortality; D005260:Female; D015870:Gene Expression; D018734:Genes, erbB-2; D006801:Humans; D007150:Immunohistochemistry; D017403:In Situ Hybridization / Q000379:methods; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000235:genetics / Q000378:metabolism; D051419:Paxillin / Q000378:metabolism*; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism*; D012189:Retrospective Studies
chemical_list: D051419:Paxillin; D018719:Erb-b2 Receptor Tyrosine Kinases