title: The neu-oncogene product in serum and tissue of patients with breast carcinoma.
abstract: BACKGROUND
  A soluble 105 kD neu-related protein is detectable in conditioned medium from breast cancer cells expressing the neu-oncogene product and in serum of nude mice bearing tumors that overexpress neu-oncogene.
  
  
  METHODS
  In 100 patients with primary (n = 33) relapse-free (n = 6) and metastatic (n = 61) breast carcinoma the serum levels of the soluble neu-related protein were investigated by ELISA techniques. Median age was 57 years, range 26-89 years.
  
  
  RESULTS
  The neu-protein serum levels were below 40 HNU/ml (human neu-antigen unit) in 72 patients and 40 or more HNU/ml in 28 patients. In 30 patients with primary breast carcinoma, tested before mastectomy, all serum-neu-protein samples were negative. However, 26 of 61 metastasized patients (43%) were serum-neu-protein-positivity. In disseminated disease (n = 61), serum-neu-protein-positivity was more likely to be seen in patients with visceral metastases (18/33 = 54%), than in patients with nonvisceral metastases (8/28 = 28%). Furthermore, monitoring of the serum-neu-protein levels reflected clinical course. For 53 patients original paraffin-embedded tumor material was available for studying immunohistochemical neu-protein expression. In 39/53 (73%) patients immunohistochemical and ELISA data showed corresponding results. In 27/30 (90%) patients, from whom sera and tissue could be obtained at the same time at primary mastectomy, results of immunohistochemistry in primary tumor and serum ELISA were negative and mutually confirmatory. However, the other three patients were positive for immunohistochemical neu-protein expression in primary tumor but negative for serum-neu-protein expression.
  
  
  CONCLUSIONS
  Our results suggest that patients with advanced breast cancer and an elevated serum-neu-protein level may have a poor clinical outcome. This test might be a useful tool for monitoring patients with advanced breast carcinoma, but not those with early disease. Further prospective studies are warranted to elucidate the question of whether this test can contribute to determining prognosis and treatment strategies.
authors.affiliation: Department of Internal Medicine (Cancer Research), West German Cancer Center Essen, University of Essen Medical School.
authors.forename: R
authors.initials: R
authors.lastname: Kath
authors.forename: K
authors.initials: K
authors.lastname: Höffken
authors.forename: C
authors.initials: C
authors.lastname: Otte
authors.forename: K
authors.initials: K
authors.lastname: Metz
authors.forename: M E
authors.initials: ME
authors.lastname: Scheulen
authors.forename: F
authors.initials: F
authors.lastname: Hülskamp
authors.forename: S
authors.initials: S
authors.lastname: Seeber
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis* / Q000097:blood; D001943:Breast Neoplasms / Q000097:blood / Q000737:chemistry*; D002277:Carcinoma / Q000097:blood / Q000737:chemistry* / Q000556:secondary*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008875:Middle Aged; D009856:Oncogene Proteins, Viral / Q000032:analysis* / Q000097:blood; D018719:Erb-b2 Receptor Tyrosine Kinases
chemical_list: D014408:Biomarkers, Tumor; D009856:Oncogene Proteins, Viral; D018719:Erb-b2 Receptor Tyrosine Kinases