A new report on asbestos and lung cancer says asbestos could be to blame for the cancer, even if the patient is a heavy smoker.
In smokers, lung cancer is usually attributed to tobacco use. But cancer researchers in Australia and Finland say that is not always right, especially if the patient has been exposed to asbestos.
They propose new criteria for establishing the cause of lung cancer in asbestos-exposed people. The criteria would apply to both smokers and non-smokers.
Mesothelioma is Not the Only Cancer Linked to Exposure
Malignant mesothelioma is the cancer most often associated with asbestos exposure. Mesothelioma is a rare but fast-growing and treatment-resistant cancer. Asbestos exposure is the only known cause of mesothelioma. Smoking increases the risk.
But mesothelioma is not the only cancer caused by asbestos. There is also a strong link between asbestos and lung cancer, ovarian cancer, and laryngeal cancer.
Other asbestos-related cancers may show up sooner than pleural mesothelioma does. Like mesothelioma, they can be very hard to treat.
The Link Between Asbestos and Lung Cancer
The World Health Organization and the US government say asbestos is a carcinogen. Most people who get sick came in contact with it on the job. Once they inhale or swallow asbestos fibers, the fibers stay in the body indefinitely. They may cause mesothelioma, lung cancer, or another illness years later.
If a smoker develops lung cancer after asbestos exposure, doctors do not always recognize the cause. They may attribute the cancer solely to smoking.
Researchers at Flinders University in Adelaide, the University of Sydney, and The University of Finland acknowledge that such cases are tricky. They reviewed years of research on asbestos and lung cancer in smokers and non-smokers. These included both human and animal studies as well as lab studies of cells.
“We conclude that the mechanism of lung cancer causation induced by the interdependent coaction of asbestos fibers and tobacco smoke at a biological level is a multistage stochastic [random] process with both agents acting conjointly at all times,” writes lead author Sonja Klebe.
In other words, tobacco and asbestos interact to cause lung cancer. The researchers say this is proof of synergy between the two cancer-causing agents. They say doctors should change how they decide what caused a patient’s lung cancer.
“Any asbestos exposure, even in a heavy smoker, contributes to causation,” they write.
Many negligent employers have had to provide compensation to employees who contracted mesothelioma. New causation criteria could open the door to fairer compensation for lung cancer patients.
Klebe, S, et al, “Asbestos, Smoking and Lung Cancer: An Update”, December 30, 2019, International Journal of Environmental Research and Public Health, https://www.mdpi.com/1660-4601/17/1/258