Hurdles and hopes for cancer treatment

Remarkable progress has been achieved in the field of gene therapy over the past decade. The initial excitement in this young field has led to the development of more than 500 gene therapy protocols approved for evaluation in clinical trials. As these clinical trials progress, many obstacles have been identified that investigators in the field will need to overcome. Among the most important areas of investigation in the field of cancer gene therapy are 1) development of novel vectors to improve gene delivery, 2) development of tumor-selective binding to improve specific tumor targeting, and 3) improvement of the therapeutic window to reduce the toxicity of gene therapy administered alone or in combination with conventional agents. The challenge is not to replace current strategies for cancer therapy with gene therapy but to incorporate gene therapy as a more rational, molecularly based approach to increase our therapeutic armamentarium.