title: Coexistence of HER2 over-expression and p53 protein accumulation is a strong prognostic molecular marker in breast cancer.
abstract: BACKGROUND
  Many laboratories are currently evaluating the usefulness of determination of HER2, p53, and Ki67 proliferation indices using immunohistochemical techniques in cancer. Although the available studies suggest that these factors might indeed be helpful in making treatment decisions in cancer patients, their clinical usefulness is still controversial.
  
  
  METHODS
  Expression of HER2, p53, and Ki67 was examined by immunohistochemistry in samples of breast tissue from 506 patients with invasive ductal carcinoma, obtained between 1981 and 1999 (median follow up period 82 months), and their significance for prognosis was analyzed.
  
  
  RESULTS
  Of the 506 carcinoma tissue samples, 20.1%, 29.0%, and 53.6% were positive for HER2 over-expression, p53 protein accumulation, and Ki67 expression, respectively. Over-expression of HER2 significantly reduced disease free (P = 0.02) and overall survival (P = 0.005). Accumulation of p53 protein significantly decreased disease free (P = 0.01) and overall survival (P = 0.01). Patients with tumors that were positive for both HER2 and p53 relapsed and died within a significantly shorter period of time after surgery (P = 0.0001 and P < 0.0001, respectively). In multivariate analysis, patients with both HER2 and p53 positive tumors had considerably decreased overall survival (P = 0.04), as did patients with larger tumor size and positive lymph node status.
  
  
  CONCLUSIONS
  The findings of the present study indicate that the coexistence of HER2 over-expression and p53 protein accumulation is a strong prognostic molecular marker in breast cancer.
authors.affiliation: Breast and Endocrine Surgery, Nagoya City University Hospital, Nagoya, Japan. hirokoy@med.nagoya-cu.ac.jp
authors.forename: Hiroko
authors.initials: H
authors.lastname: Yamashita
authors.forename: Mariko
authors.initials: M
authors.lastname: Nishio
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Toyama
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sugiura
authors.forename: Zhenhuan
authors.initials: Z
authors.lastname: Zhang
authors.forename: Shunzo
authors.initials: S
authors.lastname: Kobayashi
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Iwase
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis*; D001943:Breast Neoplasms / Q000378:metabolism / Q000473:pathology*; D018270:Carcinoma, Ductal, Breast / Q000378:metabolism / Q000473:pathology*; D016009:Chi-Square Distribution; D018572:Disease-Free Survival; D006801:Humans; D007150:Immunohistochemistry; D019394:Ki-67 Antigen / Q000032:analysis; D008875:Middle Aged; D011379:Prognosis; D016016:Proportional Hazards Models; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000096:biosynthesis*; D016019:Survival Analysis; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*
chemical_list: D014408:Biomarkers, Tumor; D019394:Ki-67 Antigen; D018719:Erb-b2 Receptor Tyrosine Kinases; D016159:Tumor Suppressor Protein p53