A difficult-to-treat cancer mostly caused by exposure to asbestos
While we generally think of cancer as a disease primarily driven by genetic and lifestyle factors, there are some types of cancer that are caused by environmental exposure to hazardous materials. One of these is mesothelioma, a relatively rare type of cancer that is difficult to treat and unlikely to be curable.1-4
That’s why it is so important to raise awareness about the need for more research and support for people with this rare and deadly cancer, generally caused by breathing in asbestos dust, which once diagnosed currently gives individuals on average just 12 months to live, if treated.1,3-5
Mesothelioma accounts for less than 1% of all cancer cases worldwide and only around 14,000 people a year are diagnosed with the condition.3,4 The number of cases is on the rise however, especially in the elderly, because the illness tends to develop decades after exposure to asbestos.1 The majority of all cases of mesothelioma are traced to men who had exposure to asbestos through working in the shipbuilding, construction or automotive industries.1
What is asbestos?
Asbestos is a naturally occurring type of mineral that readily separates into thin fibres, and was widely used for insulation of water and combustion pipes, materials used for house construction and shipbuilding, car brakes and gaskets, even toys, jewellery and cigarette filters.1 Research findings linking exposure to asbestos to both pleural (around the lungs) and peritoneal (within the body cavity) mesothelioma resulted in the banning of asbestos production and import in several European countries after 1970.1
While it is still used today, in many countries only small amounts of asbestos are allowed to be present in certain types of product (e.g. brake pads, automobile clutches, roofing materials) and there are strict regulations that control its use and manage its removal from older buildings.1,6 Prior to controls on the use of asbestos, exposure to asbestos fibres was common when chipping, demolishing or fitting asbestos products.7
When microscopic asbestos fibres are inhaled, it is difficult for our bodies to exhale them.1,7 The trapped fibres can enter the lining of the lung and chest wall, which over time causes damage that can lead to the development of a particular type of cancer called malignant pleural mesothelioma.1 In a small number of cases, the cancer can also form around the lining of other parts of the body, such as the abdomen or heart.1,8
It can take anywhere from 20 to 40 years after asbestos exposure before mesothelioma is diagnosed.1,2 This is because the main symptoms associated with this type of cancer are often ambiguous (shortness of breath, cough and pain in the chest) and are attributed to less serious conditions such as flu or a cold.9
This means that a definitive diagnosis is generally only made when patients have advanced disease.9 While there's no cure for advanced mesothelioma and the outlook is generally poor, researchers including those at Roche are committed to helping improve the outcome of patients with this deadly disease.1,6,10
Find out more about mesothelioma on our Mesothelioma Infographic.
An unusual cancer in shipbuilders started the hunt for the cause of mesothelioma
Some of the earliest reported cases of mesothelioma can be traced back to a shipyard in Belfast, Northern Ireland where the ill-fated Titanic was built.11,12
Using modern techniques, samples analysed from three cases of an unusual cancer diagnosed in men working at the world famous, high-output Harland & Wolff shipyard in 1935 became recognised as cases of mesothelioma.12
The characteristics and relatively higher incidence of the Belfast ship workers’ cancer prompted a number of dedicated experts to begin a search for an environmental cause, and they eventually confirmed the link to asbestos.1,12
1. Røe OD, et al. Eur Respir Rev. 2015;24:115-31.
2. Bianchi C, et al. Ind Health. 2007;45:379-87.
3. Park E-K, et al. Environ Health Perspect. 2011;119:514-8.
4. GLOBOCAN 2012. Estimated cancer incidence, mortality and prevalence worldwide in 2012. Available at http://globocan.iarc.fr. Last accessed September 2016.
5. Vogelzang NJ, et al. J Clin Oncol. 2003;21:2636-44.
6. Environmental Protection Agency. U.S. Federal Bans on Asbestos. Available at https://www.epa.gov/asbestos/us-federal-bans-asbestos. Last accessed September 2016.
7. Mesothelioma Cancer Alliance. What is Asbestos? Available at http://www.mesothelioma.com/asbestos-exposure/what-is-asbestos.htm. Last accessed September 2016.
8. Hassan R, et al. Hematol Oncol Clin North Am. 2005;19:1067-87.
9. National Comprehensive Cancer Network (NCCN). NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines). Malignant Pleural Mesothelioma. Version 3.2016.
10 .Zalcman G, et al. Lancet 2016;387:1405-14.
11. Campbell SB & Young JS. Ulster Med J. 1935;4:36-34.8.
12. Morrison PJ. Ulster Med J. 2008;77:145.
13. Rare Diseases Europe. About Rare Diseases. Available at http://www.eurordis.org/about-rare-diseases. Last accessed September 2016.
14. Rare Disease Day. Key Figures. Available at http://www.rarediseaseday.org/article/what-is-a-rare-disease. Last accessed September 2016.