Mesothelioma is an aggressive cancer that is primarily caused by exposure to asbestos. Although we now know that asbestos is a carcinogen, its widespread presence started during the Industrial Revolution and lasted until the substance was banned in the late 1980s. Thus, many individuals were exposed to the material, meaning that more and more people will be diagnosed with this disorder, peaking in about 2016.
To try to understand the widespread impact of asbestos, it is important to know why it was considered so beneficial. A member of the silicate family, asbestos has incredible insulating properties. It resists heat, flame, electricity, chemicals, and even biodegradation. On its own, this material has high tensile strength and flexibility. Thus, it was easily added to everything from vinyl flooring to ceiling tiles to brake pads.
It was not until the late 1950s that doctors and researchers proved a definite link between asbestos exposure and mesothelioma. Mesothelioma is different from lung cancer in that it attacks the linings of the body, including the lungs, rather than the lung tissue itself. The linings susceptible to mesothelioma include that of the lungs, heart, abdomen, and testes. Besides these four main categories of this cancer, there are also three subtypes of the disease: epithelioid, sarcomatoid, and biphasic.
The subtypes of mesothelioma refer to their different shapes. When examined under a microscope, the cancerous tissue comes in different shapes that also give physicians a clue as to how aggressive the cancer will be.
The least aggressive form of mesothelioma, which affects 50-70% of mesothelioma patients, is epithelioid. When viewed under a microscope, the cells have a uniform, tubular shape. Because this is a fairly common shape of cancerous cells, it may be confused with adenocarcinoma. However, adenocarcinoma starts in the lining of the organs rather than the lining of an entire body cavity.
Next, the most aggressive subtype of mesothelioma is sarcomatoid. Thankfully, this only accounts for 10-15% of mesothelioma cases each year because the outlook is grim. Sarcomatoid cancer cells are more irregular than those of epithelioid, and they tend to be more oval in shape. Like epithelioid cells, sarcomatoid cells can also be confused with other diseases, such as sarcoma and sarcomatoid carcinoma.
Lastly, biphasic mesothelioma contains a mix of epithelioid and sarcomatoid cells, and it affects 46-63% of mesothelioma sufferers.