Photodynamic therapy (PDT), a type of cancer treatment, is premised in the theory that single-celled organisms, if first treated with certain photosensitive drugs, will die when exposed to light at a particular frequency. Through PDT, doctors attempt to destroy cancerous cells through the use of fixed frequency light to activate photosensitizing drugs that have accumulated in body tissues.
In PDT, a doctor administers photosensitizing drug intravenously. In a matter of days, the drug selectively concentrates in diseased cells, while rapidly being eliminated from normal cells. Doctors then expose the treated cancer cells to a laser light chosen for its ability to activate the photosensitizing agent. Doctors deliver this laser light to the cancer site, (in the case of mesothelioma, the pleura), through a fiberoptic device that allows the doctor to control the laser light. As the agent in the treated cells absorbs the light, an active form of oxygen destroys the surrounding cancer cells. A doctor must carefully time the light exposure so that it occurs when most of the photosensitizing drug has left the healthy cells, but remains present in cancerous ones.
Skin sensitivity is the major side effect of PDT. Doctors usually advise patients undergoing this type of therapy to avoid direct and even indirect sunlight for at least six weeks. Other side effects may include nausea, vomiting, a metallic taste in the mouth, and eye sensitivity to light.
Immunotherapy is designed to repair, stimulate, or enhance the immune system's natural anticancer function. Through immunotherapy, sometimes called biological therapy, doctors use the body's own immune system to protect against disease. Researchers have found that the immune system may recognize the difference between healthy cells and cancer cells, and eliminate those that become cancerous.
Substances used in immunotherapy, called biological response modifiers (BRMs) alter the interaction between the body's immune defenses and cancer, thereby improving the body's ability to fight disease. Some BRMs, such as cytokines and antibodies, occur naturally in the body, however, pharmaceuticals can now make BRMs in the laboratory that imitate or influence natural immune response agents. These BRMs may enhance the immune system to fight cancer cell growth, eliminate, regulate, or suppress the body's responses that permit cancer growth, make cancer cells more susceptible to destruction by the immune system, alter cancer cell's growth patterns to behave like normal cells, block or reverse the process that changes a normal cell into a cancer cell, and prevent a cancer cell from spreading to other sites. BRMs doctors currently used in cancer treatment include interferons, interleukins, tumor necrosis factor, colony-stimulating factors, monoclonal antibodies, and cancer vaccines.
Specific immunotherapy research has concentrated on the SV40 virus. Some researchers believe that the presence of this virus makes the formation of mesothelioma tumors more likely. Having identified this virus, researchers now hope to develop a vaccine, which could prevent the development of mesothelioma in those a risk by prompting the body to produce antibodies that would attack the SV40 virus.
Gene therapy treats mesothelioma, and other diseases, by manipulating an individual's genes to achieve a therapeutic goal. The premise of gene therapy is based on correcting disease at the DNA level and compensating for the abnormal genes.
Replacement gene therapy replaces a mutated or missing gene, most often a tumor suppressor gene, with a normal copy of that gene to keep cell growth and division under control. The most common gene mutated in cancer has become a prime target for gene replacement. Researchers have met with some success in inhibiting cell growth, inhibiting angiogenesis (the development of a tumor's blood supply), and inducing apoptosis (cell death). Knockout gene therapy targets the products of oncogenes (a gene that can induce tumor formation) in an effort to render them inactive and reduce cell growth.
Complementary and alternative medicine covers a wide range of treatments that conventional medicine does not commonly accept or make available to its patients. Acupuncture, herbs, homeopathy, therapeutic massage, and Far Eastern medicine are among those treatments considered alternative.
Patients can use these therapies alone as an alternative to conventional medicine, or in addition to conventional medicine. Many focus on treating the whole patient physically, mentally, emotionally, and spiritually. These treatments are not generally used in hospitals, and, for the most part, are not covered under insurance policies.