The state of an asbestos-exposed person’s immune system might give doctors clues about how likely they are to develop malignant mesothelioma.
It’s a fear for any person who has worked around asbestos – that one day they may develop the asbestos-linked cancer, mesothelioma. Pleural mesothelioma can take decades to develop, causes few symptoms at first, and is extremely hard to treat. Right now, there is no definitive way to screen for it. Even making a mesothelioma diagnosis is a challenge.
Now, a team of occupational medicine experts in Japan and China have released an article in Environmental Health and Preventive Medicine detailing a list of biomarkers they believe may indicate asbestos-induced immune changes that could result in mesothelioma.
How Asbestos Causes Malignant Mesothelioma
When shards of asbestos dust are inhaled, they tend to stay in the lungs, working their way deep into the tissues and into the pleural lining that surrounds the lungs.
Over time, the chronic inflammation caused by this foreign substance in the tissue appears to trigger DNA changes that can lead to malignant mesothelioma.
But before that happens, the conditions for the development of cancer have to be just right, including alterations in the immune system.
A healthy immune system is continually rooting out potentially cancerous cells and destroying them. But the Japanese and Chinese scientists say asbestos can change the situation in definable, measurable ways, making it more feasible to assess mesothelioma risk.
Immune System Cells and Mesothelioma Development
According to the new research, asbestos has an has an immunological effect on a number of different lymphocytes including T cells (Treg), responder CD4+ T helper cells (Tresp), CD8+ cytotoxic T lymphocytes (CTL), and natural killer (NK) cells.
“Results show that asbestos exposure impairs antitumor immunity through enhancement of regulatory T cell function and volume, reduction of CXCR3 chemokine receptor in responder CD4+ T helper cells, and impairment of the killing activities of CD8+ cytotoxic T lymphocytes (CTL) and NK cells,” writes lead author Hidenori Matsuzaki with Japan’s Kawasaki Medical School.
The researchers say there are other unexplored molecules that can be found in the blood that may also be helpful in assessing malignant mesothelioma risk, but they say the cells they have laid out in their new report are a good place to start.
“Biomarkers based on immunological alterations may be helpful in clinical situations to screen the high-risk population exposed to asbestos and susceptible to asbestos-related cancers such as mesothelioma,” concludes the report.
Other Biomarkers for Mesothelioma
Although there is no definitive screening test for mesothelioma or mesothelioma risk, previous studies have identified a number of proteins in the blood that may indicate the early stages of the disease.
The most well-known of these is the MESOMARK test for Soluble Mesothelin-Related Peptides (SMRP). The manufacturer of the test says that SMRP can be elevated years before an actual mesothelioma diagnosis is made.
Other possible mesothelioma biomarkers include the protein fibulin-3, plasma osteopontin, and the ratio of neutrophils to lymphocytes in the blood.
Because there is no way to know who will develop this rare cancer, it is important for people who have worked around asbestos to communicate this to their doctor, know the symptoms, and have regular physical exams to monitor their health.
Matsuzaki, H, et al, “Search for biomarkers of asbestos exposure and asbestos-induced cancers in investigations of the immunological effects of asbestos”, December 2017, Environmental Health and Preventive Medicine