Cancer morbidity and mortality in immunosuppressed organ transplant recipients is increasingly recognized. This recognition is appropriate because of the stark realization that cancer tends to develop in transplant patients over time, thus reducing life quality and overall survival. The problem has brought a heightened awareness from our perception that many recipients benefiting from the success of immunosuppressive drug therapy are just now entering the long-term phase of their organ replacement treatment, where they are most at risk for cancer.
Until recently, it has been widely suggested that immunosuppressive drug treatment is a one-way path toward the promotion of cancer development in transplant patients. However, new studies indicate that not all immunosuppressive agents necessarily promote cancer and may, in fact, actually be used to treat cancer. In particular, mammalian target of rapamycin inhibitors are one class of drugs with recently demonstrated anticancer properties while also being capable of maintaining safe levels of transplant immunosuppression. Other immunosuppressive substances discussed in this review might also prove to be useful in reducing the problem of cancer in transplant recipients.
One research goal in organ transplantation should be to address the problem of cancer in this high-risk population. Therefore, we must better understand the balance of immunosuppressive and tumorigenic effects of substances being used in the clinic. In an age where we continue to need immunosuppressive agents to achieve long-term organ allograft survival, we must now learn to deal with serious side effects, including cancer.
Department of Surgery, University of Regensburg, Regensburg, Germany
Tumor-transplant studies supported by a grant from the Roche Organ Transplant Research Foundation
Correspondence to Edward K. Geissler, University of Regensburg, Department of Surgery, Franz-Josef-Strauss-Allee 11, 93053 Regensburg, Germany
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