A group of researchers have developed a blood test that may be able to more quickly diagnose patients with brain cancer, thereby allowing them to seek treatment earlier and possibly increasing their chance for survival.
“This is the first publication of data from our clinical feasibility study and it is the first demonstration that our blood test works in the clinic,” said lead study author Dr. Matthew J. Baker, reader in the University of Strathclyde’s Department of Pure and Applied Chemistry and chief scientific officer of ClinSpec Diagnostics, in a press release. “Earlier detection of brain [tumors] in the diagnostic pathway brings the potential to significantly improve patient quality of life and survival, whilst also providing savings to the health services.”
Making a timely diagnosis of brain tumors is difficult because symptoms often mirror those of much less serious conditions, with one of the main symptoms being headache, the study authors note. By the time they are diagnosed, most patients have already had several visits with their general practitioner.
In this new method, the researchers analyzed blood serum using attenuated total reflectance–Fourier transform infrared (ATR-FTIR) spectroscopy. The serum sample is deposited onto the surface of an internal reflection element (IRE). Infrared (IR) light then enters the IRE, and this internal reflection forms an evanescent wave at the IRE-sample interface. “It is this wave that interrogates the samples at a defined penetration depth (calculable dependent upon refractive indices of the IRE and sample, the wavelength of IR beam, and the angle of incidence),” the authors described.
The drawback of IRE is that it is typically an expensive, inflexible option that does not allow for batch processing. The researchers therefore proposed that silicone IREs would be a viable option.
“The technical considerations inherent in applying this test in real-time in the clinic have been explored in great detail, including the examination of sample, preparation, and an investigation into the mechanisms of serum deposition patterns that may influence the spectral response. The integration of the test into a clinical pathway has also been assessed,” the study authors wrote.
This new method is not intended to be an absolute diagnostic tool, but rather one tool that general practitioners can use in guiding their decision of whether to refer a patient to a specialist.
The researchers tested their technology in a retrospective cohort with good outcomes: “On a per patient basis, and averaged over 51 randomised training and test set splits, the sensitivity and specificity of the approach computed for the test set is 93.2% and 92.0% respectively, indicating potential to detect both cancer and control patients effectively.”
They therefore employed the test in a prospective cohort, which included 104 test patients; here, the reported sensitivity and specificity were 83.3% and 87.0%, respectively—which, while lower than the retrospective outcomes, is still higher than the cost-effectiveness thresholds.
Study partner Dr. Paul Brennan, senior clinical lecturer and consultant neurosurgeon at the University of Edinburgh, said, “With this new test, we have shown that we can help doctors quickly identify which patients with these non-specific symptoms should be [prioritized] for urgent brain imaging. This means a more rapid diagnosis for people with a brain [tumor], and quicker access to treatment.”