Mesothelioma is a rare type of asbestos cancer that affects the mesothelium, a membrane that covers many of the body’s internal organs, such as the heart and lungs. There are several known causes for mesothelioma, including exposure to asbestos, exposure to mineral called Zeolite, and exposure to thorium dioxide (which was formerly used in performing certain types of x-rays). By far, the most common cause of mesothelioma is exposure to asbestos, a term which refers to a group of six naturally occurring minerals. Asbestos was widely used in industrial and construction processes, and in the production of many common household products, from the late 1800s through the late 20th Century. Its use in the United States was largely banned by the Environmental Protection Agency in 1989.
Asbestos is dangerous because its fibers can become embedded in tissue and, many years later, lead to cancer. Mesothelioma can develop anywhere from 15 to 50 years after the initial asbestos exposure occurs. Those who were exposed to asbestos or feel that they are at risk for developing mesothelioma are urged to closely monitor their health for any signs or symptoms of mesothelioma, or other respiratory conditions that can result from exposure.
Types of Mesothelioma Mesothelioma occurs in several parts of the body: pleural mesothelioma, which affects the lining of the chest wall; peritoneal mesothelioma, which affects the lining of the abdomen; pericardial mesothelioma, which affects the sac surrounding the heart; and the rarest form, tunica vaginalis mesothelioma, which affects the tissue surrounding the testes in males. It is helpful to understand the different parts of the body that can be affected by mesothelioma in order to better understand the disease’s symptoms.
Unfortunately, the earliest mesothelioma symptoms are often ignored because they feel like common or minor health issues. In fact, it is not uncommon for an individual to experience symptoms for up to three months before seeking treatment and being diagnosed with mesothelioma.
Pleural mesothelioma is the most common form of the diseases. Lower back pain and/or discomfort in the side of the chest are very common early symptoms of this type of malignant mesothelioma. Some people may experience cough, sweating, fever, exhaustion, weight loss and difficulty swallowing. People may also cough up blood and experience swelling of the face and arms, hoarseness, and weakness.
Symptoms of peritoneal mesothelioma are pain or discomfort in the abdomen, vomiting, nausea and weight loss. Fluid may build up in the abdomen, or a mass may be detected (1).
The less common forms of mesothelioma—pericardial mesothelioma and tunica vaginalis mesothelioma—are harder to detect. In fact, tunica vaginalis mesothelioma is often misdiagnosed as a hernia, and not detected as cancer until the corrective surgical procedure is performed.
It is strongly recommended that individuals seek medical attention as soon as symptoms are detected. Once an individual sees a doctor, a series of tests will be performed to determine the cause of the symptoms. The first step in this process is conducting a thorough medical history to identify risks and to document all symptoms. People will be asked questions about their work history and their family’s medical history.
Pleural Effusion Those who have mesothelioma often develop fluid in the affected area. In the lungs, such fluid buildup is called pleural effusion. In the abdomen, it is called ascites, and in the pericardium, it is called pericardial effusion. A physician will be able to diagnose fluid buildup when an exam is conducted, or through the use of diagnostic imaging. If there is fluid buildup, a sample of this fluid may be taken to test it for the presence of cancerous cells, and then to determine the type of cancer cells. This procedure is called an aspiration.
Imaging, such as an x-ray, Computed Tomography (CT) scan, Positron Emission Tomography (PET) scan, or Magnetic Resonance Imaging (MRI) scan, is often performed during the diagnostic process. These imaging techniques allow physicians to determine the size and location of the cancer, and if and where it has spread, or metastasized. If a tumor is detected through imaging, tissue samples may also be taken using a procedure called a thoracoscopy, a bronchoscopy, or a mediastinoscopy, depending on the location of the tumor.
Chest x-rays can help physicians detect the effects of asbestos exposure, but this is not considered a way to detect mesothelioma. Research is currently being conducted into a blood test that assesses the amount of osteopontin in the blood Osteopontin is a protein that occurs in higher levels in people whose lungs have been damaged by asbestos. Once a person develops mesothelioma, levels of this protein are even higher (2).
When a diagnosis of mesothelioma occurs, the next step is for a physician to “stage” the disease to classify the area(s) of the body that are affected and how advanced the cancer is. There are several staging systems that are used, including the Butchart System, the TNM System and the Brigham System (3).
Next, the patient will work with his/her physician to determine the type of mesothelioma treatment that will be pursued. The most common forms of treatment are chemotherapy, surgery, radiation, experimental therapies such as immunotherapy, or some combination of the above. Some individuals also choose to pursue holistic therapies related to changes in diet and breathing and movement techniques. Factors such as age, weight, general health and a patient’s wishes will determine the course of treatment.
Mesothelioma Survival Rate Depending on the type of mesothelioma and whether or not it has spread beyond the primary site, treatments may be used to slow the progress or growth of the disease and/or to alleviate symptoms such as shortness of breath. Treatments are not considered curative (that is, they do not get rid of the cancer permanently), but they may extend an individual’s lifespan for up to several years, and some individuals have lived with mesothelioma for many years.
Patient advocacy groups, such as the American Cancer Society, recommend that individuals and their families, or support systems, take time to learn more about the disease and the range of treatment options before deciding on a treatment path.