Mesothelioma Diagnosis May Be More Likely Among Family Members

Italian researchers indicate that there appears to be a genetic component to the risk of developing mesothelioma following exposure to asbestos, after examining clusters of the deadly lung cancer among multiple members of the same family.  

In a study published last month in the medical journal Cancer Epidemiology, researchers from the Sapienza University and the Lazio Regional Health Service in Rome looked at clusters of mesothelioma diagnosis among family members, finding that familial cases accounted for about 3.4% of all cases of the rare cancer.

Mesothelioma is only known to be caused by exposure to asbestos, and the life expectancy following diagnosis is very short. The cancer is often not diagnosed until decades after exposure to asbestos fibers, by which time it is often at a very advanced stage.

The study looked at 997 cases involving individuals who received a mesothelioma diagnosis over a 32-year period from data collected by the Italian National Mesothelioma Register network. Researchers found 13 clusters and 34 cases with familial links. The data found that the most common clusters were those that affected siblings, but did not affect parents.

“The results suggest potential genetic recessive effects in mesothelioma that interact with asbestos exposure,” the researchers concluded, “but it is not possible to estimate the specific proportion attributable to each of these components.”

Although asbestos has been banned for more than 30 years, new cases of mesothelioma continue to be diagnosed given the long latency period of 20 to 40 years between exposure and the development of symptoms.

Asbestos use peaked in 1973, and previous reports by the U.S. Centers for Disease Control and Prevention (CDC) suggest that the number of diagnosed cases of mesothelioma are just now peaking.

In addition to workers and others directly exposed to asbestos fibers, a growing number of cases have been diagnosed in recent years involving mesothelioma from secondary asbestos exposure, such as among wives, children and other family members who breathed fibers that were carried home in the hair or on the clothing of individuals who worked directly with the materials.

More than 600,000 people in the United States have pursued asbestos lawsuits against more than 6,000 different defendants after receiving a diagnosis of mesothelioma, asbestosis, lung cancer or other injuries that were allegedly caused by inhaling the asbestos fibers. The complaints all involve similar allegations that companies that manufactured or used asbestos-based products failed to adequately warn about the health risks for workers or to take adequate steps to protect them from exposure.