title: Estrogen receptor (ER), progesterone receptor (PR), and HER2 expression pre- and post- neoadjuvant chemotherapy in primary breast carcinoma: a single institutional experience.
abstract: BACKGROUND
  The estrogen receptor (ER), progesterone receptor (PR), and HER2 profile of a primary breast carcinoma plays a significant role in patient management and treatment. Because of the increasing utilization of neoadjuvant chemotherapy or hormone therapy, surgically-resected carcinomas often show marked treatment effect. The aim of this study was to compare immunohistochemical (IHC) profiles (ER, PR, HER2, HER2 FISH) of primary breast carcinomas before and after neoadjuvant chemotherapy to assess the subsequent effects on hormone receptor status.
  
  
  METHODS
  Primary breast carcinomas from 38 female patients treated with neoadjuvant therapy after needle core biopsy or fine needle aspiration diagnosis were included. Histologic data was collected for each case, including site, type, grade, tumor size (cm), pre- and post- neoadjuvant treatment IHC panel (ER, PR, HER2), and fluorescence in-situ hybridization (FISH) for HER2.
  
  
  RESULTS
  Of the 38 carcinomas studied, 45 % were positive for ER by IHC both pre- and post- neoadjuvant treatment (P=1.00). IHC studies for PR in these 38 patients showed 37% positivity for PR pre-neoadjuvant therapy and 21% positivity post-treatment (p=0.03). For 37 patients with HER2 IHC, 32% were positive pre-treatment, and 22% were positive post-treatment (P = 0.20). For 7 patients, HER2 FISH was positive in 71% pre-therapy and in 57% post-treatment (P=0.32).
  
  
  CONCLUSIONS
  Profiles for ER, HER2 IHC, and HER2 FISH were not significantly different in primary breast carcinomas before and after neoadjuvant chemotherapy. Further investigation is warranted to assess reproducibility of technique and investigate clinical implications of significant loss of PR status in treated patients.
authors.affiliation: Emory University Department of Anatomic Pathology, Atlanta, GA 30322, USA.
authors.forename: Mary Diane
authors.initials: MD
authors.lastname: Kinsella
authors.forename: Aziza
authors.initials: A
authors.lastname: Nassar
authors.forename: Momin T
authors.initials: MT
authors.lastname: Siddiqui
authors.forename: Cynthia
authors.initials: C
authors.lastname: Cohen
mesh_terms: D000970:Antineoplastic Agents / Q000627:therapeutic use*; D014408:Biomarkers, Tumor / Q000378:metabolism; D062005:Biopsy, Large-Core Needle; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D018270:Carcinoma, Ductal, Breast / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D018275:Carcinoma, Lobular / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D004273:DNA, Neoplasm / Q000032:analysis; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D020360:Neoadjuvant Therapy; D009367:Neoplasm Staging; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000235:genetics / Q000378:metabolism*; D011960:Receptors, Estrogen / Q000378:metabolism*; D011980:Receptors, Progesterone / Q000378:metabolism*
chemical_list: D000970:Antineoplastic Agents; D014408:Biomarkers, Tumor; D004273:DNA, Neoplasm; D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone