Gallbladder Adenocarcinoma, Potential Target for Anti-Her-2 Therapy

Abstract

Her-2 (ErbB-2) is an oncogene frequently overexpressed in breast and gastric adenocarcinomas, and anti-Her-2 targeted therapy can be given to such patients. Her-2 overexpression and role of anti-Her-2 targeted therapy in cases of gallbladder adenocarcinomas (GBC) are still debatable. Scoring protocols for Her-2 expression in breast and gastric carcinomas are standardized, however, not for carcinomas arising in other body organs like the gallbladder. This study is conducted to evaluate the expression of Her-2 in patients with GBC, which may benefit from targeted therapy. It is a cross-sectional study conducted on patients with GBC (n=63; 53 women and ten men). An automated immunohistochemical technique was used with an anti-ErbB2 antibody. Scoring was conducted according to the CAP (College of American Pathologists) criteria for breast cancer. Positive (3+) Her-2 staining was observed in 8/63 (12.7%). Nine cases (14.3%) showed equivocal staining (2+) pattern. All of the tumors showing Her-2 overexpression were moderately differentiated. This study indicates that a significant number of GBC cases show Her-2 overexpression. This subgroup may benefit from inhibitors of the Her-2 pathway. Standardization of scoring protocol for Her-2 expression in GBC is needed to better evaluate the predictive potential of Her-2 for the treatment of these tumors.