Can a Breath Test Diagnose Mesothelioma in the Early Stages?
Much of mesothelioma research centers on identifying new and noninvasive biomarkers for earlier detection of the asbestos-related cancer.
Progress has been made in finding biomarkers in blood and pleural effusions, but researchers in Belgium now believe the next breakthrough in early diagnosis for mesothelioma cancer may be a breath test.
Researchers at Ghent University Hospital and Antwerp University Hospital recently highlighted the potential of breath analysis, called breathomics, as a noninvasive screening tool for malignant pleural mesothelioma. The Oncotarget medical journal published the study in May.
Breath tests or electronic noses are not a new innovation, but the science behind them — especially as an early detection device for cancer — is improving.
The tool uses spectrometric, chromatographic and sensor techniques to identify organic molecules in breath as biomarkers. There are still challenges, including improving effectiveness and ease-of-use, lowering test-related costs and shortening the time for achieving an analytical result.
There is also a need for more clinical studies with larger patient cohorts.
But breath tests seem to be the most promising avenue for early detection. Current mesothelioma screening tools generally detect the cancer in advance stages.
“We believe a breathomics-based biomarker approach should be further explored to improve the follow-up and management of asbestos exposed individuals,” lead researcher Sabrina Lagniau wrote in the study. “We aim to develop breath analysis as a point-of-care biomarker test that meets these requirements.”
Switching Focus to High-Risk Individuals
Mesothelioma, much like other cancers, is best treated in the early stage.
But the rarity of the cancer, along with symptoms that mirror less serious conditions, makes early detection difficult. Most diagnoses occur after symptoms become severe, when the cancer has progressed so much that treatments usually focus on improving a patient’s quality of life rather than substantially extending it.
In the recent study, Lagniau and her team highlight shortcomings of blood and fluid based biomarkers.
“Studies addressing the accuracy in mesothelioma patients versus healthy controls are redundant, as are studies restricted to pleural effusions, as the latter are obtained in patients who have already a high likelihood of [malignant pleural mesothelioma],” Lagniau wrote.
Lagniau’s team believes the focus should turn to people with a history of asbestos exposure with no signs of asbestos-related health conditions.
High-risk individuals can be monitored with breathomics, and if they are later diagnosed with mesothelioma or another asbestos-related disease, researchers can better determine the biological changes that occurred.
While this won’t prevent the development of mesothelioma, it could potentially lead to detection before symptoms appear, when the cancer is localized and more life-extending treatment options are possible.
It could revolutionize the diagnostic process, which now relies on imaging tests and biopsies.
“Cancer is a disease that affects people in every layer of society and we, scientists, have the obligation to use our knowledge on human health in exploring new ways to improve cancer management,” Lagniau wrote. “Therefore, future studies should focus on the at-risk population, consisting of people being [occupationally] exposed to asbestos with a latency time of at least 20 years after exposure.”
Challenges Facing the Future of Breathomics
There is still no “gold standard” for breath analysis in regard to early detection of malignancies.
Currently, the best option is gas chromatography-mass spectrometry (GC-MS), known for its high sensitivity and ability to identify and quantify individual compounds.
But downsides of GC-MS, as Lagniau points out, include its relative cost, requirement for expert operation and the amount of time it takes to get a result.
Other breath analysis tools such as electronic noses (e-noses) or selected ion flow tube mass spectrometry allow for real-time results, but also come with shortcomings, including decreased sensitivity.
Volatile organic compounds (VOCs) may be used as a potential diagnostic biomarker to screen mesothelioma and other cancers. The Belgian research team believes if cancer-specific VOCs can be identified, e-noses can be refined to detect them.
“With this strategy, the specificity of an e-nose will be higher than that of the standard, more complex technologies,” Lagniau wrote.
There is still plenty of work to be done, but Lagniau feels research is moving in the right direction.
“Research that focuses on breath biomarkers in [malignant pleural mesothelioma] is in its early days, but the few studies that have been performed show promising results.”