Malignant mesothelioma is not only one of the rarest and most difficult-to-treat cancers. It is also among the hardest to diagnose.
The challenge of diagnosing the asbestos cancer can lead to delayed referral and late treatment and can limit mesothelioma patients’ access to clinical trials that might help them.
In an effort to improve the diagnostic process for malignant mesothelioma, a group of researchers in Scotland has launched the Diagnostic and Prognostic Biomarkers in the Rational Assessment of Mesothelioma (DIAPHRAGM) trial. The multi-center clinical trial will compare biomarkers in the blood of mesothelioma patients to see which markers are the most clinically useful.
The DIAPHRAGM Trial
In an explanation of the new trial in the British Medical Journal’s open access online-only journal BMJ Open, the research team detail their plans to recruit up to 120 malignant pleural mesothelioma patients, at least 480 patients with other types of pleural diseases, and 109 people who have been exposed to asbestos but do not have mesothelioma.
Twenty-two recruiting centers across Scotland will perform identical sampling and storage of blood serum and plasma samples from each of the study participants.
These samples will be tested using the SOMAscan proteomic assay, a test that measures a panel of protein biomarkers that can indicate the presence of pleural mesothelioma. The serum samples will also be subjected to an ELISA test for a protein called fibulin-3.
Correlating Markers with Mesothelioma Clinical Characteristics
Once they have each patient’s biomarker levels in hand, the researchers can compare them with their clinical characteristics.
“Blood levels will be compared with paired pleural fluid levels and malignant pleural mesothelioma tumor volume (using MRI) in a nested substudy,” explains researcher Selina Tsim of the Department of Respiratory Medicine at Queen Elizabeth University Hospital in Glasgow.
The goal of the study is to create what the team calls a large “bioresource” of mesothelioma markers which can be used to guide clinicians around the world in their efforts to diagnose and treat mesothelioma.
Right now, a protein called mesothelin remains the primary biomarker for the diagnosis of mesothelioma. But mesothelin is not 100 percent accurate as a mesothelioma biomarker and can also be elevated for reasons other than mesothelioma.
Thoracoscopy, a procedure that uses a thin, flexible viewing tube to obtain a mesothelioma tissue sample, is also valuable for diagnosing mesothelioma but is not available everywhere, which is another reason why reliable biomarkers are critical.
Tsim, S, et al, “Diagnostic and Prognostic Biomarkers in the Rational Assessment of Mesothelioma (DIAPHRAGM) study: protocol of a prospective, multicentre, observational study”, November 24, 2016, BMJ Open,