title: Reliance on hormone receptor assays of surgical specimens may compromise outcome in patients with breast cancer.
abstract: OBJECTIVE
  To assess the concordance of breast cancer immunohistochemical receptor assays on core biopsy and surgical specimens.
  
  
  METHODS
  We identified 100 patients whose core biopsy and definitive surgical specimens were processed in our hospital. New sections, with core and surgical specimens on the same slides, were stained for estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER-2) immunohistochemistry (IHC). Two pathologists assessed the sections independently. Raw scores and clinically significant groupings were compared.
  
  
  RESULTS
  Concordance for ER, PR, overall hormone receptor (HR), and HER-2 status was seen in 86%, 83%, 90%, and 80% of patients, respectively. The core was positive, while the surgical specimen was negative in 13%, 11%, 9%, and 1% of patients, respectively. Using a log-linear model, differences in ER, PR, and HER-2 staining were all in the direction of stronger staining in the cores, and were statistically significant. Nine percent (95% CI, 4.2% to 16.4%) of women in this group would have had endocrine therapy inappropriately withheld if management decisions were based on surgical specimen results alone.
  
  
  CONCLUSIONS
  ER and PR assays on core biopsy specimens are more reliable than assays on surgical specimens. Receptor IHC should be performed on core biopsy specimens to avoid patients with HR positive cancers not receiving appropriate hormonal therapy and being overtreated with systemic chemotherapy. Biopsy should be considered in patients with "receptor negative" cancer and recurrent disease.
authors.affiliation: Department of Surgery, The Royal Melbourne Hospital, The University of Melbourne, Parkville 3050, Australia. bruce.mann@mh.org.au
authors.forename: G Bruce
authors.initials: GB
authors.lastname: Mann
authors.forename: Vanessa D
authors.initials: VD
authors.lastname: Fahey
authors.forename: Frank
authors.initials: F
authors.lastname: Feleppa
authors.forename: Malcolm R
authors.initials: MR
authors.lastname: Buchanan
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D001943:Breast Neoplasms / Q000473:pathology* / Q000601:surgery / Q000628:therapy; D066246:ErbB Receptors / Q000032:analysis; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008875:Middle Aged; D010347:Patient Care Planning; D011237:Predictive Value of Tests; D011379:Prognosis; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000032:analysis; D011960:Receptors, Estrogen / Q000032:analysis*; D011980:Receptors, Progesterone / Q000032:analysis*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
chemical_list: D066246:ErbB Receptors; D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone