Early detection has the power to improve the prognosis of thousands of individuals diagnosed with mesothelioma, a rare form of cancer that develops in the lining of the lungs, heart and abdomen.
As the disease typically presents itself 1-5 decades after exposure to asbestos, medical professionals and researchers are working hard to develop effective screening methods for early detection.
What Is Mesothelioma Screening?
Mesothelioma is a relatively uncommon disease, with around 3,000 new cases diagnosed in the United States each year. Screening is the process of testing for cancer in individuals who do not present any symptoms, and due to mesothelioma’s rarity, few screening tests exist for the disease.
Additionally, as mesothelioma can take 10-50 years to develop after exposure to asbestos, it can be tricky to detect the disease in its early stages.
Doctors do not typically screen the general public for mesothelioma. Instead, screening tests are only performed on individuals who have had previous exposure to asbestos.
Regardless of these challenges, medical professionals and researchers are determined to develop and perfect screening methods for mesothelioma. Detecting mesothelioma at an earlier stage can result in prolonged survival and a better prognosis for diagnosed individuals.
How Is Mesothelioma Screened?
The current screening methods used for early detection of mesothelioma include:
- Testing SMRP levels
- Identifying specific genetic risk factors, such as BAP1 gene
- Imaging tests including chest x rays along with CT and PET scans
Testing SMRP Levels
Research has shown that people diagnosed with pleural mesothelioma can have high amounts of osteopontin and soluble mesothelin-related peptides (SMRPs) in their blood—types of proteins and protein byproducts that show up in bloodwork.
This screening method may not be useful in detecting all cell types of mesothelioma, so doctors need to use a combination of screening tests. Research is showing that testing and monitoring SMRP levels may be more effective in measuring patient’s response to treatment as well as relapse management than in actual disease detection.
BAP1 and Genetics Risk Factors
While asbestos exposure causes the majority mesothelioma, research has found that some people can be at a higher risk of developing the disease if they have a specific gene called BAP1 gene.
When screening for mesothelioma, doctors may take a blood sample and test to see if the BAP1 gene is present. Although genetic testing can be helpful in understanding a patient’s risk of developing mesothelioma, it does not mean that patient will develop the disease.
In combination with SMRP levels and genetic testing, doctors may use imaging tests such as chest X-rays along with CT and PET scans to detect mesothelioma at an early stage.
Doctors may use these tests to identify tumor formation, although none of these imaging tests are specific to distinguishing mesothelioma from other forms of cancer and noncancerous masses. Research has shown that imaging tests may not be beneficial in finding early cases of mesothelioma as a tumor needs to reach a certain size before it can be detected.
Challenges to Mesothelioma Screening
Researchers are finding it difficult to develop effective screening methods for mesothelioma due to the rarity of the disease and its multi-decade latency period.
A study conducted in 2008 tested the effectiveness of SMRP levels and imaging tests in early detection of mesothelioma.
The study included 538 individuals who were exposed to asbestos in the past, with no mesothelioma being present in any of the test subjects despite finding elevated SMRP levels in 15 patients.
These individuals were further investigated using CT and PET scans only to detect one case of lung cancer and a suspected cardiac tumor. The showed that the association between elevated SMRP levels and mesothelioma occurrence is low, with imaging tests having little specialization in detecting the disease.
Monitoring Asbestos-Exposed Patients
While the study showed a limited correlation between SMRP levels and detecting mesothelioma, it doesn’t mean there is no hope for effective screening. Researchers are suggesting it may be worthwhile to follow patients exposed to asbestos with high levels of SMRPs or the presence of the BAP1 gene.
Monitoring patients who have a combination of risk factors through the use of imagining tests may lead to early detection and the development of more effective screening tests.
Research will continue to grow around the environmental and genetic risk factors, along with the unique cellular characteristics and biomarkers associated with mesothelioma. As this information develops, so too will the efficiency of screening methods and the cases of early detected mesothelioma.
If there is a chance that you or someone you know has been exposed to asbestos it is important that you discuss potential mesothelioma screening options with your doctor.