Current trends and future directions in the genetic therapy of human neoplastic disease.

All of these initiatives are exciting and may provide therapy that is not as destructive to normal tissues as most existing modalities of therapy, because the therapy is directed to particular molecular defects in the tumor cells. Possibly, this therapy can be individualized for the defects present within the cancer cell that result in disease. Such therapy could reduce treatment costs, because it will be less toxic and, therefore, more cost-effective. We are making the transition to therapy directed to molecular targets and specific for each patient. The potential rewards of this new direction are great in terms of improvement of the therapeutic outcome and reduction of toxicity and cost. Let us hope that the systematic study of these principles of therapy, which is now underway in many medical centers, will alter the unfavorable natural history that characterizes many of the most commonly encountered neoplastic diseases in humans.