Mesothelioma is a form of cancer that develops in the lining around the lungs (the “pleura”), abdomen (the “peritoneum”) or heart (the “pericardium”). In contrast, lung cancer refers to a malignancy of the lung itself. And, unlike lung cancer, which may have other causes as well as asbestos exposure, mesothelioma is virtually always the result of exposure to asbestos. It generally does not appear until decades after the asbestos exposure.
Diagnosis of mesothelioma can be very difficult because its symptoms may not appear for decades after exposure to asbestos. Unfortunately, this lengthy time delay not only prevents diagnosis, but also complicates treatment efforts, given that mesothelioma is usually detected in the late stages, after serious side effects begin to present themselves.
The common symptoms of mesothelioma vary according to the cancer’s location. Because of the similarity of the diseases, however, many of the symptoms are overlapping. Most mesothelioma patients experience shortness of breath and generalized fatigue, but more acute pain will likely be more apparent in the chest for pleural and pericardial mesothelioma patients and in the abdominal region for peritoneal patients.
Learn more about the specific symptoms associated with three kinds of asbestos-related malignant mesothelioma:
- Pleural Mesothelioma, which affects the lining of the lungs;
- Peritoneal Mesothelioma, which attacks the membrane surrounding the abdominal cavity; and
- Pericardial Mesothelioma, which invades the membrane around the heart.
- Cell Types of Mesothelioma
Many of the symptoms of mesothelioma mirror those of other more common physical conditions. In fact, this is another factor that contributes to the difficulty in diagnosing mesothelioma; its symptoms are often mistaken for the flu, bronchitis, pneumonia or heart disease. Still, patients with any of the symptoms discussed below and a history of asbestos exposure should see a physician. If symptoms persist, you should ask your doctor for a thorough evaluation.
Finally, this discussion is not intended as a tool for self-diagnosis, nor is it intended to be a substitute for consulting with a doctor who specializes in the diagnosis and treatment of mesothelioma. This information is designed to help you learn about mesothelioma.
Pericardial mesothelioma is an extremely rare malignant mesothelioma that affects the lining that protects the heart. Like other types of malignant mesothelioma, , e.g., peritoneal mesothelioma, pleural mesothelioma, and testicular mesothelioma, pericardial mesothelioma is caused by exposure to toxic asbestos fibers, although how the fibers end up in the heart lining, or pericardial sac, is unknown. The prevailing theory is that the asbestos fibers are inhaled and travel through the bloodstream until they reach the heart, where they lodge in the spaces in the pericardial covering. So few cases are documented that the correlation between asbestos exposure and pericardial mesothelioma has not been verified with certainty, but a significant number of patients have confirmed exposure to asbestos, and all other types of malignant mesothelioma have been unquestionably linked to asbestos.
Several decades may pass before malignant mesothelioma tumors begin to develop and symptoms appear. Pericardial mesothelioma symptoms do not manifest until the end stages of the disease, and early detection is very unlikely. Generally, the only opportunity for early detection is another problem that requires careful examination of the heart. Even then, pericardial mesothelioma is unexpected, easy to miss, and difficult to identify.
When a patient is diagnosed with pericardial mesothelioma, the prognosis is almost always grim. The proximity to the heart, coupled with the average age of malignant mesothelioma patients – over 55 – and the advanced stage of the cancer, severely limits treatments and rules out most opportunities for surgery. By the time symptoms are evident, the average patient has six months or less to live.
Pericardial Mesothelioma Symptoms
Pericardial mesothelioma is the least common type of malignant mesothelioma, totaling about 5% of malignant mesothelioma cases. The following symptoms are common:
- Heart palpitations or irregular heartbeat (arrhythmia)
- Chest pain
- Heart murmurs
- Dry cough
- Difficulty drawing a breath, even at rest
- Orthopnea (struggling to breathe when lying down)
- Fatigue
- Fever
- Night sweats
How Pericardial Mesothelioma Symptoms Develop:
Pericardial mesothelioma attacks the protective sac that covers the heart, called the pericardium. The membrane that makes up the pericardium is made up of an inner and outer layer of mesothelial cells. These specialized cells secrete a fluid that acts as a lubricant to prevent friction as the organs move within the body.
The outer layer of the pericardium is the parietal layer, also known as the parietal sac. The inner layer is the visceral layer, also known as the epicardium. The outer parietal layer is part of the membrane that protects the entire chest cavity. The visceral layer surrounds only the heart.
When asbestos fibers lodge in the pericardial tissues, the cells eventually become inflamed. This causes the cells to swell and produce extra fluid. At the same time, malignant mesothelioma tumors begin to grow. Pericardial mesothelioma tumors are diffuse and tend to spread until they cover the entire heart. The excess fluid is trapped and puts pressure on the heart, which results in the symptoms.
Early Stages of Malignant Mesothelioma:
In the early stages of malignant mesothelioma, there may be no detectable symptoms. The cancer itself is painless and develops slowly over a long period of time. This makes it very difficult to detect without extensive testing, and many victims are unaware they were at risk. Malignant mesothelioma is usually a result of exposure to asbestos that happened years, or even decades, before. It is thought to be caused by prolonged exposure, most commonly in a work environment, but it is unknown whether any level of exposure to asbestos can be considered safe.
Symptoms develop in the late stages of the cancer, when the tumors grow large enough to put pressure on a nerve or other body organ, or block the flow of air to the lungs. One reason for the relatively low survival rate of malignant mesothelioma patients is that by the time the symptoms manifest, it is often too late to help the patient.
The most common types of malignant mesothelioma are pleural mesothelioma (lung) or peritoneal mesothelioma (abdomen). The symptoms of these cancers can be attributed to other causes, but if you have any of these symptoms, see a physician, and have tests run. Make sure your doctor knows if you have been exposed to asbestos in the past to help him pinpoint or rule out the problem.
Early Detection:
There is no reliable method of early detection today. Malignant mesothelioma is rare and difficult to detect. For people with known exposure, many doctors recommend regular chest X-rays or CT scans to track lung changes that might indicate signs of malignant mesothelioma or other lung cancers, but it is unknown how reliable these tests are in finding early malignancy.
Recent research efforts reveal that people with malignant mesothelioma may have certain markers that can be detected with a blood test. Indicators such as elevated levels of osteopontin and soluble mesothelin-related peptides may one day be used as a screening tool, but are currently being used only to monitor patients already diagnosed with malignant mesothelioma for research purposes.
Symptoms of Late-Stage Pleural Mesothelioma:
- Pain in the lower back or the side of the chest
- Persistent coughing
- Shortness of breath
- Profound muscle weakness
- Hoarse voice
- Unexplained weight loss higher than 10% of your weight
- Sweating and fevers
- Trouble swallowing
- Swelling of the face and arms
- In very rare cases, some people experience changes in the shape of their fingers and nails called finger clubbing
Symptoms of Late-Stage Peritoneal Mesothelioma:
- Abdominal (stomach) pain
- Swelling or fluid in the abdomen that cases bulging
- Unexplained weight loss higher than 10% of your weight
- Nausea and vomiting
If you have any of these symptoms do not jump to conclusions. Many of these symptoms are also associated with other common, and often temporary, ailments like allergic reactions, pneumonia, flu, or food poisoning. Consult with your doctor to determine what’s really going on.
People at Risk for Malignant Mesothelioma
Typical occupations most at risk for asbestos exposure are shipyard workers, automobile factory and repair workers, Navy personnel, construction workers, mine workers, heavy machine operators, and people who work with air conditioning and heating systems. Since asbestos dust sticks to clothing, the families of these workers are also at risk. People who live near mines are at greatest risk. Your doctor should know if you were ever at risk of asbestos exposure even if you have no reason to suspect asbestos cancer, malignant mesothelioma or another related disease, asbestosis.
While asbestos was commonly used in nearly everything built before the late 1970s, people who live in houses with asbestos tiles or insulation are not generally at risk. Most asbestos is bound to another material and can not float in the air to be inhaled. The danger is during manufacturing and mining, when materials are sawn or ground, filling the air with deadly asbestos dust. If you have an old house you wish to remodel, it’s best to hire a professional hazardous materials certified contractor to handle the repairs. Few people under the age of 30 in the United States are at risk for asbestos cancer or malignant mesothelioma today. Between 1940 and 1970, when asbestos was heavily in use, approximately 27.5 million people were exposed to toxic asbestos fibers at work.
Mesothelioma is a rare form of cancer caused by exposure to asbestos. Asbestos is a naturally-occurring fiber that, when released into the air, can be inhaled or swallowed. Asbestos has no smell or taste, and asbestos fibers are so small that they are not visible to the naked eye. Asbestos fibers can “stick” in the lung, abdomen and other body tissues and over time, lead to the development of asbestos-related diseases like mesothelioma. There is a long latency period between asbestos exposure and the development of mesothelioma; in other words, decades may pass after a person’s first exposure to asbestos before he or she becomes ill. A person who has been diagnosed with asbestosis (a non-cancerous scarring of the lungs) is at an increased risk of developing mesothelioma in the future.
Millions of people in the U.S. have been exposed to asbestos, and it is estimated that approximately 3,000 people are diagnosed with mesothelioma each year. In these pages, you will read about asbestos, cancer support and the common ways for occupational and environmental asbestos exposure.
