ABSTRACT
The possibility to direct immunotherapy against defined molecular targets was the key feature for all antibody treatment concepts. The role of relative lymphocyte count in the context of intraperitoneal (i.p.) immunotherapy was discussed as a rapid and simple marker of the balance between antitumor immune activity and tumor-induced immunosuppression. Catumaxomab was also shown to induce relevant activity against tumor stem cells after i.p. immunotherapy in patients with malignant ascites. Peritoneal carcinomatosis represents a far advanced tumor disease, the distribution of single cells or tumor cell clusters on an extended surface of the peritoneum is another attractive point for locally administered immunotherapy. Peritoneal carcinomatosis is characterized by diffuse tumor spread of malignant cells found either in the cavity or directly at the peritoneum. Since the peritoneal cavity is easily accessible by interventional catheters, a locoregional immune therapy is able to induce an effect directly at the site of proposed tumor growth.
