The most appropriate mesothelioma treatment for each individual is determined by issues such as the location and stage of the disease, the age and general health of a patient and his or her wishes. Surgery, chemotherapy and radiation are established treatments for mesothelioma. However, they often have limited effectiveness. A range of experimental therapies or treatments are also under development. Treatments that are experimental are, by definition, still being evaluated. Neither their effectiveness nor their risks are fully understood, but in some cases they have more impact than established therapies. Those who have exhausted traditional therapies or who seek a more aggressive approach may choose to try an experimental treatment.
Typically, a patient will enroll in a clinical trial to receive an experimental therapy. Clinical trials are offered around the globe, targeting different phases of the disease. For instance, the pharmaceutical company Eli Lilly conducted a clinical trial that involved treating 1200 people with malignant mesothelioma with an experimental drug called Alimta™ (see below).
Physicians and patients can work together to determine whether experimental therapies are advisable and to review available clinical trials. Clinical trials are listed with the National Institute of Health, the National Cancer Institute and Center Watch leading experimental therapies are described here:
Angiogenesis Inhibition Therapy: Angiogenesis is a process in the body through which blood is delivered to tumors by blood vessels and capillaries. This blood supply allows tumors to grow. In the case of the asbestos cancer mesothelioma, tumors are located near blood rich tissue, which enables them to grow more aggressively. Angiogenesis Inhibition therapy involves administering medications called angiogenic inhibitors that inhibit the proteins that allow angiogenesis to occur. Thus, tumor growth may be slowed. One example of this type of drug, Bevacizumab, is described below.
Drug Therapy: This type of therapy includes experimental chemotherapy drugs such as Bevacizumab, a vaccine that slows the growth of tumors by stopping the development of new blood vessels in the tumor. This drug was shown to increase survival for individuals with lung cancer in one trial and has been approved for treating colon cancer. Its effects on mesothelioma are still being evaluated, however.
Alimta™ is the first drug to be approved by the Food and Drug Administration to treat mesothelioma for patients when surgery is not an option. Alimta™, which is being tested in clinical trials, is often administered with a drug called Cisplatin™. Early results show that it extends the length of survival and reduces the symptoms of mesothelioma. Its side effects are similar to those of other chemotherapy drugs, and include nausea and vomiting.
Gene Therapy: This therapy changes the genetic composition of living cells in order to fight disease. Genes are inserted into cells using viruses that are no longer able to replicate. Typically, cells are taken out of a patient’s body and then, in a laboratory, exposed to a virus that carries a gene that can slow or stop tumor growth, or otherwise fight the cancer. The cells are then injected back into a patient’s body and the inserted gene goes to work.
Armed with growing knowledge about genetics, scientists are testing more forms of gene therapy and there are currently many clinical trials underway. This approach has had significant effects when tested on animals, but has not yet demonstrated the same effects on humans. One risk of this approach is that a virus could impact cells other than the targeted ones.
Immunotherapy (or Biologic Therapy): When a person is healthy, his or her immune system recognizes “foreign” cells and fights them off. However, for those with a mesothelioma diagnosis, cancerous cells are not recognized as “foreign” and the body does not fight them off. Immunotherapy attempts to “trick” the body into recognizing that cancer cells are not normal by introducing drugs called biological response modifiers into the body. This approach, which has similarities to gene therapy, has been shown to reduce the size of tumors in patients in early stages of mesothelioma.
Immunotherapies used to treat mesothelioma include: Interferon; antiangiogenics (see above); monoclonal antibodies; and Interleukin2. One example of immunotherapy is a multi-step process that involves 1) removing cells from patients, 2) exposing the cells to cytokines, which are proteins that can stimulate cells in the immune system, and then 3) reintroducing these treated cells into the body.
Photodynamic Therapy: This therapy combines medication with surgery. First, a drug is administered to cancer cells that causes them to be sensitive to a particular wavelength of light. Then, during surgery, these cells are exposed to laser light, causing them to die. While this therapy has worked in treating some types of cancers, it has caused serious complications in treating mesothelioma. For this reason, it is not widely regarded as a safe or effective treatment.
Multimodality Therapy: This approach involves combinations of surgery, radiation therapy and chemotherapy, with a goal of realizing the benefits of, and compensating for the weaknesses of, each type of therapy. For example, this approach might involve using multiple chemotherapy drugs, or combining surgery and radiation. This therapy may prove more effective than a single therapy alone. However, the risk of this approach is that patients may experience more severe side effects, and more types of side effects. This therapy can also be more expensive than other approaches .
In addition to established and experimental therapies, some patients and physicians also draw on holistic medicine to promote wellness in the entire body. People may change their diet, for instance, to boost their immune system. Specific examples of holistic approaches include altering the diet to include more “healthy fats,” like those found in fish oil; taking Melatonin every day; practicing yoga and breathing techniques to aid in relaxation and recovery; and adding enzymes to the diet to counteract the side effects of chemotherapy.
In short, there is no single approach to the treatment of mesothelioma. Patient advocacy groups and physicians recommend that each individual works closely with his/her physician to choose the therapy, or combination of therapies, that is best suited to his or her needs.