The risk of dying from mesothelioma rises and gradually falls in the decades after exposure for most, but not all, types of asbestos cancer. New research shows those peaks and valleys can vary based on a number of factors.
Public health researchers from across Italy recently published their findings on asbestos workers’ risk of dying from mesothelioma.
They suggest that the lifetime risk of dying from peritoneal mesothelioma stays high, even after the risk of death from pleural mesothelioma and lung cancer begins to drop off.
Quantifying the Risk of Dying from Mesothelioma
Asbestos is the primary cause of all three types of mesothelioma: pleural, peritoneal, and pericardial. Pleural mesothelioma is the most common asbestos-related cancer. Pleural tumors start on the lining around the lungs.
About a fifth of the 2,500 annual cases of mesothelioma in the US are peritoneal mesothelioma. These tumors grow on the lining of the abdomen. Pericardial mesothelioma is the rarest type. These tumors start on the lining around the heart.
Although mesothelioma mortality is low in people who have never been exposed to asbestos, the risk of dying from mesothelioma is much higher among asbestos-exposed people. Asbestos-exposed people also face a higher risk of death from lung cancer.
Differing Timelines for Mesothelioma Mortality
The new study focuses on the risk of dying from mesothelioma among asbestos cement workers in Bari, Italy.
Some of these workers died of mesothelioma and others died of lung cancer. When researchers compared all the deaths from asbestos-related cancers, they found important differences.
The risk of dying from mesothelioma varied by type, cumulative exposure, and time since last exposure.
Researchers first looked at cancer deaths based on cumulative asbestos exposure. They saw a rise and then a decrease in the number of deaths among people with lung cancer and pleural mesothelioma.
But deaths did not taper off among patients with peritoneal mesothelioma. Instead, the numbers just kept rising with higher asbestos exposure levels.
Then researchers separated the cancer deaths by how long it had been since each patient’s last asbestos exposure. In these groups, the risk of dying from pleural mesothelioma peaked between 20 and 29 years after exposure and then declined.
But the risk of dying from mesothelioma of the peritoneum plateaued at 20 years and stayed the same. It did not decrease over time. The risk of dying from lung cancer also remained high in each group.
Cuccaro, F, et al, “Mortality for Mesothelioma and Lung Cancer in a Cohort of Asbestos Cement Workers in BARI (Italy): Time Related Aspects of Exposure”, March 6, 2019, Journal of Occupational and Environmental Medicine, Epub ahead of print, https://www.ncbi.nlm.nih.gov/pubmed/30870398