Working in collaboration, researchers at University Hospitals of North Midlands NHS Trust (UHNM), Keele University, and Loughborough University identified circulating tumor cells (CTCs) in blood samples, in real time, using Fourier Transform Infrared (FTIR) microspectroscopy and machine learning. CTCs — cancer cells that break away from a tumor and travel in the bloodstream — can provide clues about how the disease is progressing and how well treatment is working. The new approach to CTC detection, performed with a simple test on blood from a lung cancer patient, could offer a reliable, cost-effective method to help stratify cancer patients and optimize treatment plans. “This approach has the potential to help patients receive earlier diagnoses, personalized treatments, and fewer invasive procedures, and it could eventually be applied to many types of cancer beyond lung cancer,” professor Josep Sulé-Suso said. This figure shows how the technique identifies a single circulating tumor cell (CTC) in a lung cancer patient’s blood sample. The sample is first viewed under a microscope (a), and, after being tested, the cancer cell is stained (b) so the researchers can confirm it is a cancer cell. The Fourier Transform Infrared (FTIR) microspectroscopy technique produces a color-coded map (c) distinguishing the CTC (red) from surrounding blood cells (blue/green). Courtesy of Loughborough University. Using FTIR spectral data, the researchers identified a single CTC based on biochemical composition, specifically within the fingerprint region (1800 cm-1 to 1350 cm cm-1). The researchers used immunohistochemistry to confirm that FTIR, used with a random forest classifier, reliably detected a single CTC in the blood of a lung cancer patient. “Our team was able to detect a single lung cancer cell in a patient’s blood by combining advanced infrared scanning technology with computer analysis, focusing on the unique chemical fingerprint of cancer cells,” Sulé-Suso said. FTIR microspectroscopy is a label-free approach to sample analysis. It does not rely on predefined surface markers or cell morphology. According to the researchers, it is more reliable than existing CTC isolation methods, which sometimes miss cancer cells completely, as the cells often change their characteristics while circulating in the blood. FTIR microsprectroscopy uses standard glass slides, just like those routinely used in pathology labs, to prepare blood samples. This makes the technique easy to integrate into everyday clinical practices, and more affordable for labs than specialized, IR-transparent substrates. By enhancing precision and accessibility in CTC identification, FTIR microspectroscopy has the potential to redefine the techniques used for cancer diagnostics. Although further validation in larger, multi-cancer patient cohorts is required, the initial findings show that cancer diagnostics, and possibly treatment monitoring, can be performed successfully through blood-based testing with FTIR microspectroscopy. “Contributing to research with the potential to transform early cancer detection is both a professional privilege and a deeply personal motivation,” professor Paul Roach said. “Professionally, it offers the chance to translate fundamental spectroscopy into meaningful medical impact. Personally, it resonates strongly: cancer has affected my own family and claimed the lives of friends, and helping to expand the tools available to fight this disease gives me a powerful sense of purpose.” The team plans to test FTIR microspectroscopy in larger patient groups, with the goal of developing a rapid, automated blood test that can be integrated into NHS cancer care pathways. The team welcomes collaborations with clinical, healthcare, and industry colleagues to support the validation, refinement, and eventual adoption of FTIR-based diagnostic tools. It is also interested in working with research groups that are developing analytical technologies, data interrogation methods, or advanced computational tools, all of which play an important role in accelerating cancer diagnostics and treatments. “The possibility that our work could one day influence clinical practice, reduce diagnostic delays, and improve patient outcomes is a constant driving force behind this research,” Roach said. The research was published in Applied Spectroscopy (www.doi.org/10.1177/00037028251390565).