Treating Mesothelioma - Photodynamic Therapy

Treating mesothelioma has to be just as aggressive as the disease, which is one of the reasons why there are so many different treatment options and techniques available today. Treating mesothelioma also depends greatly on a variety of factors such as the overall health and age of the patient as well as the heart and lung health, the type of mesothelioma cancer cells and how they appear under a microscope, the stage of the mesothelioma, the size of the tumor, the amount of fluid in the abdomen or chest, and whether or not the mesothelioma has been diagnosed recently or if it has recurred.

These and other factors can be tested using a wide range of procedures that will bring the physician a step closer to creating the most effective treatment combination to help manage the disease. Diagnostic methods and procedures for detecting mesothelioma include: physical examination, chest x-ray, complete blood count or CBC, sedimentation rate, bronchoscopy, or a cytologic exam. A biopsy can also be performed. The different types of biopsy methods are: fine needle aspiration biopsy or FNA, thoracoscopy, laparotomy, or thoracotomy.

Once the type of mesothelioma, stage, and overall health of the patient have been determined, the doctor will explore various treatment methods. The treatments and methods used for treating mesothelioma are divided into two types: traditional mesothelioma treatments and new mesothelioma treatments. New mesothelioma treatments include photodynamic therapy or PDT, gene therapy, immunotherapy, intensity modulated radiation therapy or IMRT and the development of new chemotherapy agents. Traditional mesothelioma treatments include: surgery, chemotherapy, and radiation therapy or radiotherapy. In many cases a trimodality approach is employed, which means several treatments are combined for the best outcomes, for a better chance at long-term survival, and/or a better quality of life.

Photodynamic therapy or PDT destroys cancerous cells by using fixed frequency light to activate certain photosensitive drugs, which have accumulated in the body tissues. These photosensitizing drugs are administered to patients intravenously and they take only a few days to absorb into the diseased cells – which are referred to as “treated cancer cells” at this point. The treated cancer cells are exposed to the laser light, which is delivered to the cancer site by a physician using a fiberoptic device. Once the agent in the treated cancer cells absorbs the laser light, surrounding cancer cells are destroyed by a kinetic form of oxygen. Side effects of photodynamic therapy are not unlike symptoms of chemotherapy. They can include nausea and vomiting as well as a metallic taste on the palette. The main side effect of photodynamic therapy is skin sensitivity as well as eye sensitivity to light.

Gene therapy may be used in treating mesothelioma in an attempt to correct cancer at the DNA level. It is typically used to treat fatal and disabling diseases and there are several types including replacement gene therapy and knockout gene therapy. Replacement gene therapy replaces a missing or mutated gene with a healthy clone of the gene. This helps to manage cell growth and division. It should be noted that the p53 gene is the most common gene mutated in cancer. This gene is at the center of gene replacement. While other newer methods have met with little success, p53 gene replacement shows promise in treating aggressive forms of cancer. It inhibits cell growth, it inhibits the development of the tumor’s blood supply (angiogenesis), and it induces cell death or apoptosis.

Knockout gene therapy literally attacks the genes that cause tumors to form and prevents them from forming.

Immunotherapy is also called biological therapy and immune augmentative therapy. This type of approach to treating mesothelioma involves the body’s immune system. Immunotherapy works with the body’s immune system to help fight cancer and to also help control how the patient’s body reacts to certain cancer drugs. While doctors are not entirely sure how immunotherapy helps the immune system fight cancer, they are confident that it does keep cancer from spreading to other parts of the body, that is stops or slows the growth of deadly cancer cells, and that it makes it easier for the immune system to destroy cancer cells. Immunotherapy may be used depending on the type of cancer and the stage of the cancer. It may also be based on any treatments that may have already been used. In some cases, immunotherapy is the very best option for treating mesothelioma or other types of cancer.

Immunotherapy may be used alone or in combination with chemotherapy and radiation.
Treatment may come in the form of pills or shots that the patient can self-administer at home. In some cases, patients may have to stay at the hospital or clinic to receive immunotherapy via IV. Depending on the delivery method, treating mesothelioma with immunotherapy may take place once a day or several times a day. In some cases, it may occur weekly or once a month. Immunotherapy may have similar side effects as other forms of cancer treatments such as loss of appetite, fatigue, nausea, vomiting, fever muscle aches, chills, low blood pressure, bone pain, and swelling or rashes at the injection site.

Also referred to as radical forms of treating mesothelioma, there are several other new mesothelioma treatments including angiogenesis therapies, antineoplaston therapy, mesothelioma clinical trials, interferon and interleukin therapy, and radiofrequency ablation. A wide variety of complementary and alternative mesothelioma treatments are also currently being explored including: herbal products, special diets, homeopathic medicine, acupuncture, therapeutic massage, high dose vitamin C, laetrile (amygdalin, extracted from fruit pits), and Eastern medicines.

New mesothelioma treatments such as photodynamic therapy (PDT), gene therapy, and immunotherapy offer new hope for doctors and mesothelioma patients. Doctors, scientists, and researchers are attempting to further develop these new treatment modalities, with the hope that they will be successful where traditional treatments have failed. To date, these new treatments for mesothelioma have not quite measured up to traditional methods, but they are currently being used in conjunction with traditional methods and they are, of course, constantly being monitored and assessed.

 

'Treating Mesothelioma - Photodynamic Therapy' Resources:
  1. “Types of Complementary and Alternative Medicine (CAM)” (online article) 6/8/05
    Accessed: 3/6/08.
  2. “Mesothelioma Treatments Non-traditional Mesothelioma Treatment Options” (online article) 2007
    Accessed: 3/6/08.
  3. “Gene Therapy for Cancer: Questions & Answers” (online fact sheet) 8/31/06
    Accessed: 3/6/08.