Onkologie. 2010:4(2):115-119

HER-2/neu testing in gastric carcinoma - new challenge and hope?

Aleš Ryška, Tomáš Rozkoš, Jan Laco

Fingerlandův ústav patologie LF UK a FN, Hradec Králové

Gastric carcinoma is the second cause of cancer related death worldwide. Prognosis significantly varies among patients within the same

stage, therefore oncologists urge for identification of new prognostic and predictive markers, such as HER-2/neu (HER2). Stimulation

of HER2 triggers molecular pathway resulting in increased proliferation, blocked apoptosis, loss of differentiation and increased tumor

invasion. HER2 is a negative prognostic factor, associated with increased invasiveness, serosal involvement, lymph-node metastases

and shorter survival, as well as a negative predictive marker and target for trastuzumab treatment.

There are two methods of HER2 detection – immunohistochemistry (IHC) and in situ hybridisation (ISH). Positivity of HER2 in gastric

cancer ranges from 6,8 to 34 % (mean 17,6 %) in IHC detection, and 7,1–42,6 % (mean 19,2 %) in ISH detection, respectively. HER2 is more

often positive in intestinal than in diffuse type.

HER2 detection in gastric carcinoma shows certain specific features – positive cells show either complete or incomplete basolateral (Ushaped)

membranous expression. Due to more frequent inhomogenity of tumor population, the threshold has been set at 10 % of positive

cells in resection specimens, but even one cohesive cluster of positive (2+ or 3+) neoplastic cells is sufficient in biopsy samples.

Keywords: gastric carcinoma, HER-2/neu, c-erbB-2, immunohistochemistry, in situ hybridization

Published: May 1, 2010  Show citation