In transplant recipients, hepatocellular carcinomas vary considerably in their pattern and kinetics of metastases. Tumor cells may persist in a dormant state for long time periods before giving rise to clinical metastases. Surgical treatment of recurrence should be considered whenever possible.

Resection remains the treatment of choice in liver cancer. In order to avoid liver transplantation in conventionally unresectable tumors ex-situ ("bench" procedure), in-situ and ante-situm resection technique should be preferred whenever feasible. Despite the deficiency of donor organs, a single center experience with 198 patients reveals that liver transplantation continues its role as a therapeutic option for selected patients. At present "favorable" indications for transplantation are International Union against Cancer (UICC) - stage II hepatocellular carcinoma as well as the subtype fibrolamellar carcinoma, uncommon tumors such as epitheloid hemangioendothelioma, hepatoblastoma, and liver metastases from neuroendocrine tumors. Due to unsatisfying results, intrahepatic bile duct-, stage III and IV hepatocellular carcinoma, hemangiosarcoma, and liver metastases from nonendocrine primaries should be excluded from liver transplantation alone. For these advanced tumors, especially in cases of extrahepatic involvement, a combination of liver transplantation and multivisceral resection has been proven feasible. However, a significant improvement in patient survival may only be expected only by currently investigated multimodality treatment protocols which will require further randomized studies.

Thirty patients with advanced colorectal carcinoma (CRC) were treated with alum-precipitated polyclonal goat anti-idiotypic antibodies (Ab2) to monoclonal anti-CRC antibody C017-4A (Abl) in doses between 0.5 and 4 mg per injection. All patients developed anti-anti-idiotypic antibodies (Ab3) with binding specificities on the surfaces of cultured tumor cells similar to the specificity of Abl.