Breath Test for Mesothelioma Might Identify Subtypes

Researchers in the UK say a breath test for mesothelioma might be able to distinguish between mesothelioma subtypes.

There are three major subtypes of mesothelioma. It is important to know which kind of person has. A patient’s subtype can impact their prognosis and even their mesothelioma treatment choice. 

Right now, the only way to tell the mesothelioma subtypes apart is to look at the cells under the microscope. But scientists at Sheffield Hallam University have identified volatile organic compounds (VOCs) in the rarest and the most common mesothelioma subtypes. 

These VOCs could be used to develop a mesothelioma breath test that could tell the subtypes apart. 

The Advantages of Breath Testing

Breath testing is a way of measuring VOCs in a person’s exhaled breath. By analyzing these compounds, doctors may be able to tell if a patient has cancer or another illness. Scientists are still working on a breath test for mesothelioma.

There are several advantages of breath analysis over other kinds of tests. For one thing, a breath test is non-invasive. Other kinds of mesothelioma tests require a biopsy or at least the extraction of blood or lung fluid. 

No scalpels or needles are needed for a breath test. This kind of test is also less expensive than other tests and the results are faster. With a biopsy, a pathologist has to use a microscope to look at mesothelioma cells.  But breath testing does not require a pathologist. If it leads to earlier diagnosis and treatment, such a test could even save lives. 

Three Different Cell Types Tested

There are limits to the mesothelioma VOC tests that have been tested so far. One big one is that a breath test for mesothelioma cannot tell the different subtypes apart. This can only be done by looking at the cells. 

But the new research at Sheffield Hallam University could help change that. The scientists focused on three types of cells – biphasic, epithelioid, and non-malignant mesothelial. 

Biphasic is the rarest mesothelioma subtype. Epithelioid is the most common. Mesothelial cells come from the membrane where mesothelioma tumors start. The researchers used them as a control group.

VOCs Key to a Breath Test for Mesothelioma

The new study used a headspace analyzer to measure the VOCs released by each type of cell. Headspace gas chromatography is a way of separating VOCs from a liquid or solid for analysis.  

“2-ethyl-1-hexanol was significantly increased in both MSTO-211H [biphasic] and NCI-H28 [epithelioid] cells compared to MET-5A [healthy cell] controls,” writes study author Liam David Little. “In addition, ethyl propionate and cyclohexanol were significantly increased in MSTO-211H cells and dodecane was significantly increased in NCI-H28 cells.”

A breath test for mesothelioma that measures these VOCs might be able to distinguish one subtype from another. This is the first study to consider the impact of mesothelioma subtype on VOC profile. 

The report concludes, “Current results further highlight the potential for a diagnostic mesothelioma breath test as well as providing proof of concept for the differentiation between biphasic and epithelioid mesothelioma based on VOC profiles.”

No one knows yet if breath testing can really detect mesothelioma. None of the previous studies have been big enough for the technique to be universally recommended. 

Source: 

Little, LD, et al, “Headspace analysis of mesothelioma cell lines differentiates biphasic and epithelioid sub-types”, July 30, 2020, Journal of Breath Research, Epub ahead of print, https://iopscience.iop.org/article/10.1088/1752-7163/abaaff