title: Expression of oestrogen receptor and loss of E-cadherin are diagnostic for gastric metastasis of breast carcinoma.
abstract: OBJECTIVE
  To investigate whether immunohistochemical staining for oestrogen receptor (ER)alpha, progesterone receptor (PgR) and E-cadherin might be useful to differentiate between metastatic breast carcinoma and primary gastric carcinoma.
  
  
  METHODS
  Gastric biopsies of 75 patients containing adenocarcinoma were stained for ERalpha, PgR and E-cadherin. Included were: Group A, 28 patients with primary gastric cancer; Group B, 28 patients with an adenocarcinoma containing gastric biopsy and a clinical diagnosis of metastatic breast carcinoma; Group C, all consecutive patients with a positive gastric biopsy in 2001 (n = 19) without clinical history of breast carcinoma and not followed by gastric resection (control group).
  
  
  RESULTS
  All ERalpha+ or PgR+ carcinomas (n = 20) were of patients with a previous or concurrent history of breast carcinoma: 19 in group B, one in group C. In addition, absence of E-cadherin staining was seen significantly more often in patients with metastatic breast carcinoma than in patients with primary gastric cancer (P < 0.001).
  
  
  CONCLUSIONS
  Positive immunohistochemical staining for ERalpha or PgR of an adenocarcinoma in a gastric biopsy is diagnostic for metastatic breast carcinoma. Moreover, when carcinoma in a gastric biopsy is negative for E-cadherin staining, metastatic breast carcinoma should be considered.
authors.affiliation: Department of Pathology, Netherlands Cancer Institute, Amsterdam, Netherlands. m.v.velthuysen@nki.nl
authors.forename: M-L F
authors.initials: ML
authors.lastname: van Velthuysen
authors.forename: B G
authors.initials: BG
authors.lastname: Taal
authors.forename: J J M
authors.initials: JJ
authors.lastname: van der Hoeven
authors.forename: J L
authors.initials: JL
authors.lastname: Peterse
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis / Q000378:metabolism / Q000556:secondary; D001943:Breast Neoplasms / Q000378:metabolism / Q000473:pathology*; D015820:Cadherins / Q000032:analysis*; D047628:Estrogen Receptor alpha / Q000096:biosynthesis*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D011980:Receptors, Progesterone / Q000032:analysis; D013274:Stomach Neoplasms / Q000175:diagnosis / Q000378:metabolism / Q000556:secondary*
chemical_list: D015820:Cadherins; D047628:Estrogen Receptor alpha; D011980:Receptors, Progesterone