An Introduction to Mesothelioma

An Introduction to Mesothelioma

Mesothelioma is a rare, asbestos-related cancer that primarily develops in the protective lining of the lungs and abdomen.

Doctors diagnose an estimated 3,000 cases of mesothelioma in the U.S. each year. It is even more uncommon in India, where the first cases were detected in Rajasthan in 2015.

The cancer's unusually long latency period — or the amount of time before symptoms appear — makes it unique.

It can take anywhere from 20 to 50 years after asbestos exposure for symptoms to appear. There is currently no cure for mesothelioma. Once diagnosed, survival outlook is generally poor, but continued research and improved treatment options are extending life expectancy and easing symptoms.

Causes and Awareness

Mesothelioma typically develops after prolonged exposure to asbestos in the workplace, generally industrial settings or old buildings.

Last year, 15 mesothelioma cases were detected in Ajmer. All 15 cases involved mine workers. 

Although asbestos is no longer mined in India, the dangerous mineral is not banned. The country remains the top importer of Canadian asbestos. Experts predict a dramatic rise in mesothelioma and other asbestos-related diseases in the future, similar to what has developed in the U.S. over the past 50 years.  

Mesothelioma develops after inhaling microscopic asbestos fibers that become lodged in the mesothelium, a membrane that surrounds the lungs, stomach and abdominal cavity.

Most commonly, asbestos fibers will get trapped in the lining of the lungs, called the pleura. These fibers can also collect in the abdominal cavity (peritoneum), and in rare cases, the heart (pericardium) and the lining of the testes (tunica vaginalis).

The four types of mesothelioma are named for the affected linings — pleural, peritoneal, pericardial and testicular. Pleural mesothelioma (lungs) is by far the most common form, representing 75 percent of all cases. Peritoneal (abdomen) is next with 10-20 percent of all cases, while pericardial (heart) and testicular mesothelioma represent less than 2 percent of all cases.

Over decades, trapped asbestos fibers can cause health complications, triggering biological changes that cause inflammation, scarring and genetic damage. Once the damage is done, the decades-long latency period sets the stage for the development of malignant mesothelioma.

Asbestos is the leading cause of mesothelioma, with 70-80 percent of people developing the disease from occupational exposure to asbestos. It usually takes long-term asbestos exposure for mesothelioma to develop, but some cases have occurred after short-term or even one-time exposure.

Diagnosing Mesothelioma and Challenges

Mesothelioma can be difficult to detect because of its long latency period and common, flu-like symptoms such as fever, muscle weakness, dry cough, respiratory complications, and pain in the chest or abdomen.

However, it usually isn’t difficult for doctors to distinguish between the four types of mesothelioma, because the tumors grow directly into specific body structures. All four forms are fast-spreading.

Oncologists diagnose mesothelioma using several methods, including blood tests, imaging tests such as MRIs, CT scans, PET scans, X-rays and biopsies.

The key is to recognize symptoms early and alert your doctor of any history with asbestos exposure.

This is the first of a series of posts on mesothelioma from Asbestos.com.