Mesothelioma and Asbestos

First, the mesothelium. It's a frictionless monolayer lining that covers the internal organs. The luminal side has lots of microvilli that told fluids and proteins to allow intracoeolmic movement. It also helps leukocytes and other cells of the immune system to travel about in the fluid.

Mesothelium cells, with connective tissues.

How exactly does asbestos cause cancer? Well, it's made up of little tiny fibers that people inhale it. These fibers travel into the lungs and stick to its linings, damaging the membrane.  Intra-pleural inoculation of asbestos in rats have demonstrated that asbestos cause lesions within the lining, recruiting phagocytes and macrophages to the site of the lesion. The macrophages are part of the immune response, and they eat up cells which have asbestos in them. This in turn damages the macrophages and cause oxidative stress. Additionally, it is thought that smaller asbestos fibers can sometimes become entangled within the chromatin itself in the cell, and disrupt with the process of cellular division by interfering the packing and segregation of chromosomes. After many cycles of cellular division, the DNA damage accumulates. The subsequent damage induces the cell to undergo DNA repair, which is often error-prone. This is how asbestos damages the tissues, ultimately causing lesions to develop into a malignant tumor in the mesothelium.

Asbestos may interfere with cell division.

So why was asbestos use so widespread if the link between lung cancer and it was made in the early 19th century? Asbestos is a mineral that is heat-, friction-, and acid-resistant, easily obtained by mining, and easy to modify. These industrial merits are why companies today still incorporate asbestos into their products. Countries all over the world limit the use of asbestos. But whatever countries do to limit the use of asbestos, mesothelioma will still be a problem for years to come, because of there is long latency between asbestos exposure and the development of the disease. For example, the Japanese government expects the peak year for malignant mesothelioma to be in 2025. 

The widespread use of asbestos, the long latency period, the exclusive linkage between asbestos and malignant mesothelioma, and the fact that not all companies have enacted proper safety measures have opened the doors for a whole lot of lawsuits. People are seeking compensation, and in 1999, already 2 billion have been award to people. That's 2,000 million. No wonder there are lawyers and attorneys who specialize in mesothelioma cases.  Why not? Some mesothelioma lawyers have gotten recoveries of 3 million per victim. It's lucrative since not only is the five year survival rate very low (9%, so what's the point of a structured settlement?) and the treatment expensive, so many people were exposed to asbestos because of the American economy's emphasis on manufacturing (where contact with asbestos is most likely) after World War 2. On top of that, many companies that used asbestos were reluctant to get rid of asbestos, even when they knew the occupational hazards.

If you think you may have mesothelioma because you have the symptoms (weight loss, fever, cough, swelling due to fluid buildup) go get an MRI or a thoracoscopy (where they make an incision and put a camera to look into your chest).

Pleural mesothelioma tumor grows and effectively "shrinks" lung capacity. It affects 70% of patients.

Mesothelioma affects people from all walks of life. Steve McQueen died of a heart attack in Juarez, Mexico, after undergoing mesothelioma treatment. He was exposed to asbestos during his time in the United States Navy and during his long career as a race car driver. At the time, asbestos was used to insulate the piping on the boats and was also incorporated into  his racing suits.

Posted in: biology, genetics, mesothelioma