title: Overexpression of her-2/neu in malignant mammary tumors; translation of clinicopathological features from dog to human.
abstract: BACKGROUND
  Canine mammary gland tumors (CMGTs) are the most common tumor found in bitches. Changes in HER-2/neu genes in human breast cancer (HBC) lead to decrease in disease-free survival (DFS) and overall survival rate (OSR). Previous studies have demonstrated that the biological behavior of malignant mammary gland tumors (MMGTs) is similar to that of HBC. The present study aimed at evaluating the relationship between overexpression of HER-2/neu and clinicopathological features in MMGTs to represent a model of prognostic factors for HBC.
  
  
  METHODS
  The clinicopathological data of 35 MMGTs were obtained. Immunohistochemical staining with HER-2, Ki-67 and CD34 markers was conducted with sections from paraffin-embedded blocks. According to standard protocols, histological type, grade, margin status, lymphovascular invasion (LVI), HER-2/ neu score, proliferation rate and microvessel density (MVD) of tumors were determined and the association of HER-2/neu overexpression with these parameters was assessed statistically.
  
  
  RESULTS
  The IHC results showed that 12 (34.3%) cases were HER-2/neu positive. Statistical analyses indicated a significant relationship between HER-2 positivity and tumor grade (p=0.043), which also was demonstrated with cancer stage (p=0.035), tumor margin involvement (p=0.016), proliferation index (p=0.001) and MVD (p=0.001); however, there was no statistical relationship between LVI and tumor size. Overexpression of the HER-2/neu gene in MMGTs results in similar biological behavior as that of HBC; as a result, these tumors have can be considered to have important similarities in clinicopathological characteristics.
  
  
  CONCLUSIONS
  MMGTs can be regarded as an HBC animal model. Further studies in this field would result in new treatments that could be beneficial for both dogs and humans.
authors: Department of Pathology, Faculty of Specialized Veterinary Sciences, Science Research Branch, Islamic Azad University, Tehran, Iran. mohamadnajad@yahoo.com
authors: Ahad
authors: A
authors: Muhammadnejad
authors: Elahe
authors: E
authors: Keyhani
authors: Pejman
authors: P
authors: Mortazavi
authors: Farkhondeh
authors: F
authors: Behjati
authors: Iraj Sohrabi
authors: IS
authors: Haghdoost
mesh_terms: D000818:Animals; D018952:Antigens, CD34 / Q000235:genetics; D001943:Breast Neoplasms / Q000235:genetics* / Q000473:pathology*; D049109:Cell Proliferation; D004285:Dogs; D005260:Female; D006801:Humans; D019394:Ki-67 Antigen / Q000235:genetics; D008207:Lymphatic Metastasis / Q000235:genetics / Q000473:pathology; D015674:Mammary Neoplasms, Animal / Q000235:genetics* / Q000473:pathology*; D009367:Neoplasm Staging; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000235:genetics*
chemical_list: D018952:Antigens, CD34; D019394:Ki-67 Antigen; D018719:Erb-b2 Receptor Tyrosine Kinases