Clinical Trials
The medical community in the United States is actively seeking new
treatments and better ways to use current treatments. The National Cancer
Institute (NCI) is sponsoring clinical trials (research studies with people)
that are designed to find these new treatments. Before any new treatment can
be recommended for general use, doctors conduct clinical trials to find out
whether the treatment is safe for patients and effective against the
disease. Participation in clinical trials is an important treatment option
for many patients with mesothelioma, giving people access to the latest treatments in a carefully monitored environment.
People interested in taking part in a clinical trial should talk with their
doctor. Information about clinical trials is available from the Cancer
Information Service (CIS) or at 1-800-4-CANCER. Outlined below are some of
the new treatments being developed for asbestos-related disease and cancers:
New Treatments
Photodynamic Therapy
This form of treatment uses highly focused light to kill cancer cells. The
patient receives a drug called a photosensitizer which builds up in
cancerous cells but not in healthy cells. The photosensitizer drug causes
cells to be sensitive to light of specific wavelengths. Once the cancer
cells have become sensitized, surgery is performed in order to place
fiberoptic cables in the body. This enables the focusing of light of the
correct frequency on the tumor. This process causes the photosensitizer drug
to produce toxic oxygen molecules which kill the cancerous cells.
This treatment has been used successfully to combat other types of cancer
and, hopefully, it will be just as successful in the fight against
mesothelioma.
Immunotherapy
Immunotherapy utilizes the body's immune defense system to combat cancer
cells. There are various therapies currently being tested that fall into
this category.
Gene Therapy
This is a new therapy that is being tested at the University of
Pennsylvania's Institute for Human Gene Therapy. www.med.upenn.edu/~nihgt. A "suicide gene" is implanted inside the tumor, making the cancer cells
sensitive to drugs that are normally ineffective in fighting cancer. When
administered, the drugs kill only the cancer cells, and the healthy cells
are not harmed. This allows doctors to concentrate the treatment on the
tumor only, as opposed to treatments like chemotherapy that kill cancerous
and healthy cells alike.
Cytokines
Cytokines are proteins that effect the behavior of other cells. One type of
cytokine molecule is called interleukin - 2 (IL2). IL2 causes immune system
cells to grow. These cells, called T-cells, are also referred to as killer
cells because they kill cancerous cells. Scientists theorize that injecting
IL2 into the pleura of the lung will result in the death of the cancerous
cells in the pleura. This treatment is now in the experimental stage but
provides hope for the future.
Interferons
Interferons are cytokine proteins that act to enhance the body's immune
system. Interferons stop the rapid growth of cancerous cells and, at the
same time, increase the body's ability to fight off the malignant cells.
Experiments are currently being conducted to see if interferons will combat
the aggressive mesothelioma tumors.
Experimental Chemotherapy
L-NDDP
This is a new chemotherapy protocol that is being tested at the New York
University Kaplan Cancer Center in New York City. (212) 263-8043
kccc-www.med.nyu.edu/mesoletter. Chemotherapy involves the use of toxic
chemicals to kill cancer cells. L-NDDP is a compound that is administered
directly into the pleura of the lung. The compound is cleared very slowly
from the pleural cavity and, therefore, has more time to unleash its toxic
effects on the tumor. This agent has also been found to effectively
penetrate tumors by virtue of its creamy composition. L-NDDP has been found
to be less toxic to the body than conventional chemotherapy drugs. Clinical
trials with L-NDDP are currently being conducted at the Kaplan Cancer Center
on patients with mesothelioma and the early results have been promising.
Onconase
Onconase is a new chemotherapy drug that is currently being tested in
clinical trials. Onconase is a ribonuclease protein that promotes the
anti-cancer effects of traditional chemotherapy. With conventional
chemotherapy drugs, the body removes the drug from cancer cells. This
results in the administration of high doses of the drugs in order to kill
the cancer cells. Experiments have shown that Onconase causes cancer cells
to be more susceptible to lower doses of toxic drugs. The administration of
lower doses of toxic drugs that are still effective has the benefit of
reducing the side effects of the treatment.
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