title: Beta-catenin expression patterns in matched pre- and post-neoadjuvant chemotherapy-resistant breast cancer.
abstract: BACKGROUND
  β-catenin is a critical component of the cadherin cell-to-cell adhesion pathway and a key participant in the Wnt signaling pathway. Activation of β-catenin signaling in the Wnt pathway is a known contributor to tumor cancer progression and metastasis and may result in resistance to chemotherapeutic agents. The aim of this study is to evaluate the patterns of expression of β-catenin in breast carcinoma cells before and after neoadjuvant chemotherapy. Discovery of the molecular mechanisms responsible for resistance to chemotherapy treatment could result in more effective therapy, and improve outcome and survival.
  
  
  METHODS
  Twenty-nine matched pre-treatment and post-neoadjuvant chemotherapy breast carcinomas were subjected to immunohistochemical study using anti-β-catenin antibody. Normal staining was defined as crisp membrane staining in >90% tumor cells; aberrant expression was nuclear staining in >5% tumor cells.
  
  
  RESULTS
  Of the 29 included cases, five cases of invasive lobular carcinoma lacked β-catenin immunoreactivity pre- and post-treatment. Mildly reduced membranous staining was seen in two post-treatment samples. One case of triple-negative ductal carcinoma had reduced pre- and post-treatment staining. All other cases showed normal pre- and post-treatment β-catenin expression. No aberrant staining was identified.
  
  
  CONCLUSIONS
  In our study, there was no difference in the expression of β-catenin in pre- and post-neoadjuvant chemotherapy specimens. These results do not suggest that β-catenin plays a role in conferring neoadjuvant chemotherapy resistance.
authors.affiliation: Departments of Anatomic Pathology and Women's Oncology, H. Lee Moffitt Cancer Center & Research Institute, Tampa, FL, USA marilin.rosa@moffitt.org.
authors.forename: Marilin
authors.initials: M
authors.lastname: Rosa
authors.affiliation: Women's Oncology, H. Lee Moffitt Cancer Center & Research Institute, Tampa, FL, USA.
authors.forename: Hyo Sook
authors.initials: HS
authors.lastname: Han
authors.affiliation: Women's Oncology, H. Lee Moffitt Cancer Center & Research Institute, Tampa, FL, USA.
authors.forename: Roohi
authors.initials: R
authors.lastname: Ismail-Khan
authors.affiliation: Women's Oncology, H. Lee Moffitt Cancer Center & Research Institute, Tampa, FL, USA.
authors.forename: Pushpa
authors.initials: P
authors.lastname: Allam-Nandyala
authors.affiliation: Departments of Anatomic Pathology and Women's Oncology, H. Lee Moffitt Cancer Center & Research Institute, Tampa, FL, USA.
authors.forename: Marilyn M
authors.initials: MM
authors.lastname: Bui
mesh_terms: D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000378:metabolism* / Q000473:pathology; D018270:Carcinoma, Ductal, Breast / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology; D019008:Drug Resistance, Neoplasm; D005260:Female; D006801:Humans; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D055815:Young Adult; D051176:beta Catenin / Q000378:metabolism*
chemical_list: D000970:Antineoplastic Agents; D051176:beta Catenin