If you have been exposed to asbestos, whether at work or in the home, you may never outlive your risk of developing malignant mesothelioma. That unsettling finding comes from a recently-published medical stud conducted by researchers in Australia and Italy.
Mesothelioma has a particularly long latency period, meaning it is not uncommon for it to take decades for this aggressive cancer to develop. To determine if asbestos-exposed individuals can ever consider themselves out of danger, the researchers compiled and analyzed data from eight separate previous studies on the relationship between asbestos exposure and mesothelioma development. Six of the studies focused on people with occupational exposure to the deadly toxin and the remaining two included people with residential asbestos exposure.
Among the more than 22,000 asbestos-exposed individuals included in the studies, 707 eventually developed pleural mesothelioma (around the lungs) while another 155 people develop peritoneal (in the abdomen) mesothelioma. One-hundred and sixty-five of the pleural mesothelioma cases and 32 of the peritoneal cases occurred in women. The median duration of exposure among people who developed pleural mesothelioma was 3.75 years and it took a median of 38.4 years for mesothelioma symptoms to develop.
But, while the risk of developing pleural mesothelioma appeared to decline somewhat after 45 years post-exposure, the risk of peritoneal mesothelioma continued to rise even after 50+ years. Lead author Dr. Alison Reid, Associate Professor in the School of Public Health at Australia’s Curtin University, concludes, “While the rate of increase appears to start to level out after 40 to 50 years, no one survives long enough for the excess risk to disappear.”
This is disturbing news for tens of thousands of people around the world who have lived or worked around asbestos, a once-popular component of many building materials. While there is still no proven way to predict mesothelioma development, some studies have suggested that regular monitoring by a physician and periodic CT scans may increase the chances of catching the cancer earlier, when treatment is likely to be most effective.
Reid, A et al, “Mesothelioma risk after 40 years since first exposure to asbestos: a pooled analysis”, May 9, 2014, Thorax, Epub head of print