PURPOSE:The overall aim of this study was to develop a novel treatment for colorectal cancer based on the use of gene therapy. Genetic modification of T lymphocytes has been used to specifically target and kill tumor cell lines directly. To test the efficacy of this method with clinically relevant materials, this study investigated the potential of T lymphocytes derived from patients with advanced colorectal disease to target autologous primary tumor material.METHODS:T lymphocytes isolated preoperatively were modified genetically with recombinant retroviruses encoding CD3&zgr;‐based chimeric immune receptors and were tested for functional activity against freshly isolated autologous tumor cells harvested from hepatic colorectal metastases.RESULTS:Patient‐derived T cells were successfully transduced, and chimeric immune receptor expression was confirmed. Carcinoembryonic antigen expression on freshly isolated colorectal tumor cells was also demonstrated by molecular and immunohistochemical techniques. T cells expressing the anticarcinoembryonic antigen receptor were specifically activated by coculture with disaggregated or intact, diced tumor, whereas control non‐carcinoembryonic antigen‐targeted T‐cell populations failed to activate.CONCLUSIONS:These results indicate that gene‐targeted primary T lymphocytes depict specific functional activity against autologous colorectal tumor cells. This evidence indicates that chimeric immune receptor‐expressing T cells may be able to circumvent the mechanisms used by tumor cells to avoid immune cell activityin vivo. This study emphasizes the potential of this approach as a therapy for carcinoembryonic antigen‐expressing primary colorectal tumor and its metastases.