Despite interdisciplinary approach to gastric cancer the outcome of patients remains poor. Even after curative resection most patients suffer from progression of disease and metastasizing course. Adjuvant treatment like chemotherapy or radiation can not improve survival substantialy. This is discussed to be due to dissemination of tumor cells, which are not affected by most treatment options. The new concept of tumor specific antibody therapy with a monoclonal antibody is discussed as an effective treatment especially to fight disseminated tumor cells and thus might help to improve the outcome in stomach cancer.