Immunotherapy, also referred to as biological therapy, is based on the theory that it is possible to mobilize the body's own immune defenses against cancerous cells. Another name often applies to this therapy, biological response modifiers (BRMs), and is described in overview article on the subject.
For an up-to-date scientific discussion about immunotherapy, Science Magazine published a special issue on the topic of immunotherapy (see www.sciencemag.org to find articles from the issue July 9, 2004; vol. 305). There were also some positive results from immunotherapy treatment of malignant mesothelioma patients in a recent French study (see: "Malignant mesothelioma. Medical oncology: standards, new trends, trials - the French experience;" Lung Cancer. 2004 V 45 suppl. 1:S129-31).
Gene Therapy:
This a new treatment which is currently in clinical trials. Using an adenovirus for delivery, a "suicide gene" is inserted directly into the tumor. This gene makes the cells sensitive to a normally ineffective drug, such as glanciclovir. Treatment with the drug then destroys those cells that are rapidly dividing - which are the cancer cells - leaving the healthy cells unharmed.
In theory, this approach allows treatment to target the tumor specifically, as opposed to treatments such as chemotherapy which also kill healthy cells. (See: "Gene Therapy in Cancer Patients," by E.A. Armandola, PhD; Medscape General Medicine 4(4), 2002).
Gene therapy for mesothelioma is being researched at the University of Pennsylvania, with Dr. Steven Albelda as the principal investigator. This treatment is not without risk, as became apparent in the death of Jesse Gelsinger, a University of Pennsylvania gene therapy trial participant. (Note that Mr. Gelsinger was not a participant in the mesothelioma trial.)
For a more recent assessment of gene therapy, see "Genetic Therapy for Pleural Malignancies," from the Conference Report from the 7th Annual Meeting of the American Society of Gene Therapy (2004).
Cytokines - Interferons (IFN) and Interleukins (IL):
Cytokines are small proteins that occur naturally in the human body. They are similar to hormones and have specific effects on the behavior of other cells.
In 1976 Dr. Robert Gallo (later head of the National Cancer Institute, and famous for his work on HIV) isolated a cytokine protein molecule called interleukin-2 (IL2) which is capable of stimulating the growth of immune system cells called T-cells. T-cells are sometimes called "killer cells" because they search out malignant or virally infected cells and kill them. Using IL2 as a treatment for pleural mesothelioma is still in the experimental stages, but researchers hope that injecting IL2 intrapleurally will promote a significant anti-tumor response.
Interferons are also naturally occuring cytokine proteins, but they inhibit the growth of malignant cells as well as enhance the immune system. Like interleukins, these immune system promoters are being tested to see if they help increase the body's response to what is often an extremely resistant malignancy, mesothelioma.
Search for clinical trials using Interferon for mesothelioma, on the NCI web site.
Further Resources
- Biological Therapies for Cancer: Using the Immune System To Treat Cancer
- Immunotherapy: Past, Present and Future, by T. A. Waldmann; Nat Med 9(3):269-277, 2003
- Gene Therapy for Cancer
- The DNA Files: Gene Therapy - Medicine for your Genes. This NPR program is about mesothelioma and gene therapy. To listen to it on the web you must have RealAudio on your computer; it can be downloaded for free.
- Steven M. Albelda, MD, et al. - "Gene Therapy for Lung Disease: Hype or Hope?" in Annals of Internal Medicine, 18 April 2000. 132: 649-660.
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