Continued from: Mesothelioma Background
Approximately 2000 new cases of mesothelioma are diagnosed in the United States each year, according to the National Cancer Institute. Internationally, the incidence is approximately nine cases per every 1 million persons.
In the fall of 2004, the U.S. Centers for Disease Control (CDC) reported a surge in deaths related to asbestos exposure. Even though the use of asbestos has fallen dramatically over the last several decades, the number of asbestos related deaths are rising.
This death rate is expected to continue to increase for at least the next decade, according to statistics developed in a report from the CDC. Asbestosis, which is caused by the inhalation of asbestos, can cause fibrous growths of scar tissue in the lung, and ultimately lead to the inability of the patient to breath. Deaths from asbestosis increased from a recorded 77 in 1986 to 1,493 in 2000. This disease, which is characterized by shortness of breath and incessant cough, and which is linked to a higher risk of mesothelioma, now causes more occupational related deaths than silicosis and black lung disease. It is the deadliest of all work-related respiratory illnesses.
The CDC's assertion that the death toll may continue to rise, despite the reduced use of asbestos, is based on the time lag between initial exposure to asbestos, the development of asbestosis and death. This time lag can be as long as 45 years. In 1998, asbestosis overtook black lung disease as the top killer among work-related respiratory diseases, partially because of the decline in coal mining and partially due to the fact that the incubation period was giving way to the formation of asbestosis among many asbestos workers.
The CDC reached these conclusions by inspecting the death certificates of over 125,000 people who had lung conditions linked to inhaling dust or fibers from minerals such as coal, asbestos and sand.
The average malignant mesothelioma prognosis is 11 months, and it is almost always fatal. The survival rate depends on the type of mesothelioma. Sarcomatoid cancer is the most aggressive with a median survival rate of approximately 9.4 months. Epithelioid cancer and biphasic cancer (or mixed) have somewhat longer survival rates at 12.5 and 11 months, respectively.
Malignant mesothelioma is not linked to race or gender, as asbestos exposure is thought to be the most important risk factor. Asbestos exposure is directly linked to at least 50 percent of mesothelioma cases.
Approximately 8 million people in the U.S. have been exposed to asbestos in the workplace. Family members who have been exposed through residual asbestos dust from work clothing are also at risk. The risk of developing lung cancer is five times greater for those exposed to asbestos. For those who smoke and have had exposure to asbestos, the chance of developing mesothelioma is 55 times greater than normal.
Studies show that mesothelioma is three times more common in men than women, but this is thought to be due to asbestos exposure and not gender. Of men with mesothelioma, a case series study showed that 45 percent had a history of exposure to asbestos and 53 percent had occupational exposure to asbestos. Most of the men were railroad workers, construction workers, naval mechanics and automobile mechanics.
Malignant mesothelioma has a peak incidence about 40 years after asbestos exposure, and it commonly develops when a person is between 50 and 70 years of age.
[Page updated February 2008]