title: Overexpression of the HER2/neu Gene: A New Therapeutic Possibility for Patients With Advanced Gallbladder Cancer.
abstract: BACKGROUND
  The HER2/neu gene is a proto-oncogene that can predict the response to treatment with trastuzumab, pertuzumab, and lapatinib. This study was conducted to determine the frequency of HER2/neu overexpression and to identify a subgroup of patients with gallbladder cancer who would benefit from targeted therapy.
  
  
  METHODS
  Patients with gallbladder cancer (n = 187; 165 women and 22 men) with a recorded follow-up of at least 5 years were included, along with control subjects (n = 75). An automated immunohistochemical technique was used with an anti-ErbB2 antibody. Scoring was conducted according to the CAP/ASCO (College of American Pathologists/American Society of Clinical Oncology) criteria for breast cancer.
  
  
  RESULTS
  Overexpression of HER2/neu was observed in 12.8% of the cases. Of those, 0% were mucosal, 14.3% muscular, 12.8% subserosal, and 10.6% serosal. In 20% of the cases, equivocal staining was observed. Overexpression was more frequent in the advanced cancers and in the better differentiated tumors (13.8% and 17.4%, respectively), but the difference was nonsignificant. The patients with overexpression of HER2/neu had a worse overall survival, when compared with those who had no expression at 5 years (34% vs. 41%).
  
  
  CONCLUSIONS
  This is the single largest study of HER2/neu expression in gallbladder cancer to use commonly accepted scoring criteria. The results indicate that HER2/neu overexpression occurred in 14% of the advanced gallbladder cancer cases. This subgroup may benefit from inhibitors of the HER2/neu pathway.
authors.affiliation: Creative Bioscience Santiago, Chile.
authors.forename: Iván
authors.initials: I
authors.lastname: Roa
authors.affiliation: Pathology Service Puerto Montt Hospital Puerto Montt, Chile.
authors.forename: Gonzalo
authors.initials: G
authors.lastname: de Toro
authors.affiliation: Pathology Department Faculty of Medicine Yale University New Haven, CT.
authors.forename: Kurt
authors.initials: K
authors.lastname: Schalper
authors.affiliation: Surgery Department Clínica Alemana Santiago, Chile.
authors.forename: Xabier
authors.initials: X
authors.lastname: de Aretxabala
authors.affiliation: Gastrointestinal Medical Oncology UT-MD Anderson Cancer Center Houston, TX.
authors.forename: Chaitanya
authors.initials: C
authors.lastname: Churi
authors.affiliation: Gastrointestinal Medical Oncology UT-MD Anderson Cancer Center Houston, TX.
authors.forename: Milind
authors.initials: M
authors.lastname: Javle