MESOTHELIOMA CANCER BACKGROUND

 Mesothelioma Background

On this page you can find:
» Key Statistics
» Causes of Mesothelioma
» History of Mesothelioma

• Key Statistics

Approximately 2000 new cases of mesothelioma are diagnosed in the U.S. each year, according to the National Cancer Institute. Internationally, the incidence is approximately 9 cases per every 1 million persons.

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.

Mortality

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 median survival for patients with malignant mesothelioma is 11 months. 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.

• Causes of Mesothelioma

The most common risk factor for mesothelioma is exposure to asbestos. Over 50 percent of the patients have a history of asbestos exposure. This exposure can occur while directly handling the fibrous material, or through environmental (indirect) exposure.

Asbestos exposure is by far one of the most common causes of mesothelioma. Over 50% of the patients have a history of asbestos exposure. This exposure could occur while directly handling the fibrous material, or it could occur through just environmental exposure.

There are numerous documented cases where patients contracted the disease due to living close to the asbestos mines or by coming in contact with asbestos when some of the fibers became airborne. Persons most commonly afflicted include shipyard workers, construction workers, automobile mechanics (particularly those working on brake linings), insulation workers, pipe and heater installation and flooring workers and roofers. 

Erionite

Erionite is a mineral that has a long, thin rod-like amphiboles structure. Exposure to this mineral has been associated with increased incidence of mesothelioma. Erionite exposure has a high mortality rate due to mesothelioma in Anatolia, Turkey.

Exposure to asbestos is the primary cause for malignant mesothelioma in most patients. If you or a loved one has been exposed to asbestos, then you are at risk. There is no minimum level of exposure that is deemed safe. Insure that during your routine health care, you advise your doctor of previous asbestos exposure, particularly if you experience any chest pressure, shortness of breath, chest pain or coughing. While these symptoms do not indicate the presence of the disease, they are the most common symptoms and should be further investigated if you have had asbestos exposure.

• History of Mesothelioma

Mesothelioma is a deadly disease that affects the lining of several organs in the body, most commonly the lungs. It is now known that exposure to asbestos is the primary cause for this disease; however, for more than 100 years of asbestos mining and production, the link between asbestos and mesothelioma remained obscured. Learn more about the history of mesothelioma.

The history of mesothelioma started in the early 1900s. Mesothelioma history, just as in the discoveries of other major diseases, has a combination of science, politics, medical research and courage. Mesothelioma is a deadly disease that affects the lining of several organs in the body, most commonly the lungs. It is now known that asbestos exposure is the primary cause for this disease; however, for more than 100 years of asbestos mining and production, the link between asbestos and mesothelioma remained obscured. 

In the early 1900s workers at asbestos factories in Britain were experiencing an alarmingly high incidence rate of lung disease. The first reported case of asbestosis in a British asbestos worker occurred in 1906. By the late 1920s, the lung disease problems associated with asbestos mining and production were becoming well known, so much so that the British government commissioned a study in 1930. The study results showed that asbestosis was an occupational disease and was associated with asbestos exposure.

Mesothelioma and Asbestos

The link between lung cancer and asbestos was slower to emerge. While many asbestos workers were dying of lung cancer in the 1930s and 1940s, there was also high growth rate of tobacco use and a high incidence of tuberculosis. Unless an autopsy was performed, it was difficult to determine the exact type of lung cancer that caused death. During this time period, it appears that the asbestos industry officials made little effort to establish the link between asbestos and mesothelioma, even though considerable evidence suggested this link.

The South African Asbestos Mines

After World War II, asbestos mining in South Africa was growing rapidly. South Africa had plenty of cheap labor, and new technology was making asbestos mining much more efficient. Although a well known South African medical researcher noted in 1928 that asbestos exposure could cause danger, he attributed the dangers to asbestos processing, not mining. (South Africa did little processing of asbestos at that time.)

In 1948, South Africa commissioned the first chest and infectious disease hospital in the area of the asbestos mines. The hospital's first medical superintendent, Chris Sleggs, was the first physician anywhere in the world to see a significant number of malignant mesothelioma cases. He noted the presence of atypical cases of lung disease in the wards. Most cases of tuberculosis recovered with treatment, but a few of the cases appeared to be resistant to the drugs. He began to investigate.

Chris Wagner, a medical researcher, became aware of the atypical lung disease in the mid 1950s. He started a research project to better understand the occupational hazards associated with the asbestos mining. Due to the efforts of Drs. Sleggs and Wagner, along with a third researcher, Ian Webster, by the late 1950s, the connection between mesothelioma and asbestos was well documented.

In 1959, these three researchers attended an international conference in Johannesburg, South Africa. They presented papers, based on their research, showing the connection between mesothelioma and asbestos. After the conference, they combined their data and submitted it to a prestigious British medical journal. Their data showed that of the 33 cases of pleural mesothelioma investigated by them, 32 had proven exposure to asbestos mining.

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