Although mesothelioma is described as a rare form of cancer, we tend to hear so much about it online and on the news these days that you can be forgiven for thinking it’s not rare at all, it seems quite common. It’s a cancer that usually starts in the lining of the lungs (pleural mesothelioma) but may also start in the abdomen (peritoneal mesothelioma). The disease gets its name from the mesothelium, a sac-like membrane that protects the body’s internal organs. The mesothelium is divided into two layers, the visceral layer (which surround the organ directly) and the parietal (a sac around the body cavity). The mesothelium releases a lubricating fluid which allows the organs to move freely within the body cavity (for example when the lungs contract and expand during breathing).
More than two thirds of mesothelioma cases begin in the pleura (lung) region and spread through the chest cavity, sometimes developing in the lungs as well. This leads to a build up of excess fluids inside the chest cavity known as pleural effusion. The excess fluid increases pressure on the lungs and restricts breathing. Malignant cells may cause the pleural lining to thicken which will restrict breathing even more.
Peritoneal mesothelioma is the second most common form of this deadly disease and accounts for nearly 30% of all cases. Malignant cells begin to form in the peritoneum and affect the abdomen, bowel, liver and spleen. Again, there is a build up of excess fluid which obstructs normal bodily functions such as digestion.
While mesothelioma is relatively uncommon in the USA with approximately 2.500 new cases reported per year, the incidence rates are much higher in Western Europe where more than 5,000 cases are reported annually. These numbers are predicted to increase dramatically in the coming 20 years.
Approximately 80% of all mesothelioma patients have a history of asbestos exposure, with most of these having been employed in an industry that involved the use of asbestos in some form. In addition to the occupational exposure to asbestos, household exposure also occurs. This is where the individual who is exposed to asbestos at work carries the asbestos particles on clothing, skin and in their hair when they return home. With asbestos fibres being released into the atmosphere, especially during cleaning and laundry procedures, this leads to what’s known as paraoccupational exposure (second hand exposure) of family members.
Although there is plenty of information available nowadays on mesothelioma, the harsh fact is that this disease is on the increase with more cases being diagnosed on an annual basis. Although the dangers associated with asbestos are well known in the 21st Century, this was not always the case. Because asbestos was still in use in the UK (especially in the construction industry) until the total ban in 1999 and symptoms can typically take up to 20 years or more to present themselves, we’re sure to see more cases being diagnosed for many years to come.