[Molecular biology and immunohistochemical studies of Her2/neu oncogene in stomach cancer]. / Molekularbiologische und immunhistochemische Untersuchungen zum Her2/neu-Onkogen beim Magencarcinom.

ABSTRACT

In 58 gastric carcinomas the expression of the Her2/neu gene product p185 was immunohistochemically analyzed. Fresh tumor tissue for molecular studies was available in 25 cases. The results were correlated with various pathohistological and prognostic factors. A 16-32fold Her2/neu amplification was found in 20% of the tumors (n = 5). The oncogene product p185 was detected at the basement membrane in 38% of the tumors (n = 22). Amplification and p185 overexpression occurred in intestinal, but not diffuse type carcinomas (p < 0.001). p185 expression was independent from tumor site and tumor stage, but correlated with pT-stage (p < 0.001). Overall prognosis was influenced by tumor stage and R-classification, but not by p185 expression. Multivariate analysis, however, defined patients with stage IIIA/B and IV and R0-resection who had a poorer survival in case of p185 expression (p < 0.05). Her2/neu amplification and p185 overexpression appear to be characteristic molecular events in intestinal type gastric carcinogenesis and may help in identifying a subgroup of patients at increased risk for shorter survival.