Mesothelioma is a tumor of the mesothelium. Mesothelium is a thin membrane that encompasses the body’s internal organs such as the lungs, stomach, and heart. The primary cause of Mesothelioma is exposure to asbestos. Smoking also increases the risk for those who have been exposed. Mesothelioma is the most serious of the asbestos-related diseases. Three types of the cancer exist. Pleural mesothelioma affects the protective lining of the lungs in the chest cavity, and accounts for about 3/4th of patients with the disease. The second most common is peritoneal mesothelioma, which affects the abdominal cavity. The most rare type is called pericardinal mesothelioma, and affects the cardiac cavity. Symptoms of the disease include coughing, shortness of breath, and chest pain. Instances of mesothelioma are still rare, with only about 2500-3000 in the U.S. per year. Diagnosing the disease often requires surgery or several body scans such as MRIs, CT scans, or PET scans.
Conventionally, three methods are used to treat Mesothelioma. These methods include surgery, chemotherapy, and radiation therapy. About 1 in every 5 patients with pleural mesothelioma undergoes surgery. Two types of surgery exist for this form of the cancer. First, there is an operation referred to as a pleurectomy, in which the surgeon removes as much of the tumor from around the lung as possible. The other operation is called an extrapleural pneumonectomy, in which the lung itself is removed. Most long-term survivors of the disease have had some form of surgery, and studies have shown that surgery combined with radiation has prevented tumor recurrence in the chest in 80-85% of patients. Chemotherapy is used to prevent cancer cells from growing and multiplying.It is used both before and after surgery, and by those who choose not to undergo surgery. The most common chemotherapy drugs are cisplatin combined pemetrexed or raltitrexed. Radiation therapy is used to target and shrink tumors. It is often combined with other forms of therapy in order to make them more effective. Because Mesothelioma affects an area so close to the heart and lungs, it is difficult to use the kind of high-dose, intensive radiation therapy that is usually needed to shrink tumors. However, a new option called Intensity-Modulated Radiotherapy (IMRT) may be able to help.
Several treatment options for Mesothelioma are still in the experimental stage. Gene therapy is one example. It has shown promising results in animal trials, but unfortunately results in humans have so far been disappointing. Immunotherapy is a treatment option in which a patient uses his or her own immune system to fight cancer. One approach to immunotherapy is to stimulate the patient’s immune system in an attempt to make it work harder and “smarter” in fighting cancer cells. The other approach is to introduce man-made immune system proteins to boost the patient’s immune system. The four main types of immunotherapy include: monoclonal antibodies, immune checkpoint inhibitors, cancer vaccines, and nonspecific immunotherapies. Pembrolizumab has also been showing promising results. Photodynamic therapy involves the use of a drug that makes cancer cells sensitive to a certain wavelength of light. It is usually used before a patient undergoes surgery. Unfortunately, it has seen disappointing results so far. Multimodality therapy is the combination of surgery, radiation therapy, and chemotherapy, and may provide the best option for patient treatment. Palliative treatment is a process in which the symptoms of Mesothelioma are treated in order to ease a patient’s pain and ensure their relative comfort.