Many people have treated mesothelioma as a passing phenomenon that will disappear along with the use of asbestos. However, even though asbestos use has decreased dramatically in United States since the 1970s, the period for contracting mesothelioma is between 15 and 50 years. Asbestos is also still used in other countries like Asia, Europe, Great Britain, Australia, and South America. People who work in mining and manufacturing are also at risk for mesothelioma.
There are three main types of mesothelioma. The most common is the epithelial type and most easily treated. The other two less common types are called mixed/biphasic and sarcomatoid. About three-fourths of mesotheliomas begin in the chest cavity and another 10 to 20 percent begin in the abdomen.
Symptoms may not appear for 30 to 50 years after exposure to asbestos. Nearly 60 percent of patients report chest pain; the pain is often times severe enough to require strong pain medications. The other most common symptom is shortness of breath, usually secondary to large fluid accumulation around the lung in the pleural sac. Other less frequent symptoms include cough, fever, sweating, trouble swallowing, tiredness, and weight loss. Symptoms of mesothelioma in the abdomen can include pain or swelling, weight loss, nausea, and vomiting. Many patients with mesothelioma can have symptoms for six months before seeking medical help. Some have even had symptoms for up to two years. But most have symptoms from between two and three months.
Diagnosing mesothelioma is often difficult because the symptoms are similar to many other conditions.
After a review of your medical history, your doctor may order an X-ray, a computed tomography (CT) scan of the chest or abdomen, or a magnetic resonance imaging (MRI) scan.
To diagnose pleural mesothelioma, the doctor may use a thoracoscope, or a pleuroscope to look inside the chest cavity.
To diagnose peritoneal mesothelioma, a doctor may use a peritoneoscope, or laparascope to look inside the abdomen.
If fluid is present in the pleural (chest) or peritoneal (abdomen) cavity, a sample of the fluid may be obtained by thoracentesis (chest) or paracentesis (abdomen), and analyzed under a microscope. These procedures are usually performed in the doctor's office or clinic, or in the radiology department.
If there is no fluid, or if the fluid does not give the diagnosis, biopsies of the pleural or abdominal lining may be required. This is usually performed during the thoracoscopy or laparoscopy.
If malignant mesothelioma is found, more tests will be performed to learn the extent of the cancer and to find out if the cancer cells have metastasized (spread) to other parts of the body. This process is called staging. It is important to know the stage of the disease in order to plan the best treatment.
There are three systems for staging mesothelioma.
- The Butchart System is based primarily on the extent of the primary tumor mass. It divides mesotheliomas into four stages.
- The TNM system considers variables in the tumor, lymph node involvement, and metastasis.
- The Brigham System, the newest system, stages mesothelioma according to the ability to surgically remove the tumor, and the extent of lymph node involvement.
Mesothelioma mainly attacks people who have worked around asbestos. Men in their 50s, 60s, and 70s are the most likely to be affected due to the long latency period between exposure to asbestos and the development of a tumor.