Mesothelioma is an aggressive and hard-to-treat cancer usually caused by exposure to asbestos. It can take decades to develop and, as a result, is usually thought of as a disease of older people. The vast majority of patients are over 70.
However, as a new report in Oncotarget points out, there is a subset of mesothelioma patients under 40 years old. In these patients, mesothelioma can act very differently – and require a different treatment approach – than it does in the older population.
The new study relied on data from Surveillance, Epidemiology and End Results (SEER), a national database of cancer cases. Researchers from the National Cancer Institute focused on mesothelioma cases that occurred between 1990 and 2010.
The study found that about two percent (207) of the 12,345 mesothelioma cases studied occurred in people under 40 years old. While almost 80 percent of the older mesothelioma patients are men, the disease is about equally split between men and women in the younger age group. This group is also more likely to undergo cancer-directly surgery and to live longer afterward, even if they have a type of mesothelioma that is usually considered less survivable.
“Regardless of histologic subtype, young patients with pleural and peritoneal mesothelioma had significantly improved overall survival,” reports Anish Thomas, MD, with the Thoracic and GI Oncology Branch of the National Cancer Institute. Most patients diagnosed with mesothelioma die of the disease within a year of diagnosis.
Another difference between younger and older mesothelioma patients is the frequency of pleural and peritoneal mesothelioma. The two types of mesothelioma are about evenly distributed in the younger patients while 90 percent of older patients have the pleural variety.
Although almost all cases of mesothelioma are associated with asbestos exposure, the authors of the new study say further research is needed to better understand how genetic susceptibility and exposure interact to cause mesothelioma in certain younger people.
Thomas, A, et al “Distinctive clinical characteristics of malignant mesothelioma in young patients”, June 30, 2015, Oncotarget, pp. 16766-73