Innovative Blood Test Uses Immune Protein Changes for Early Tumor Detection and Personalized Treatment Guidance

A groundbreaking blood test developed by researchers at the Spanish National Cancer Research Centre (CNIO) offers a new approach to early cancer detection and treatment planning. Unlike traditional methods that rely on identifying tumor-specific biomarkers, this innovative test focuses on the immune system's response to early-stage tumors. It detects subtle changes in blood proteins caused by the body's immune reaction to cancer cells, enabling detection before tumors become advanced.

Led by Gonçalo Bernardes, the research team concentrated on analyzing blood proteins derived from immune system disruptions rather than tumor-produced markers. This approach stems from the understanding that immune responses are more pronounced during the initial stages of cancer, although they have rarely been harnessed for diagnostic purposes. By focusing on these early immune responses, the test provides a window into tumor presence at an incipient phase.

To overcome the complexity of human blood, which contains over 5,000 proteins, the team narrowed their focus to five amino acids—lysine, tryptophan, tyrosine, cysteine, and cysteine not bound to disulfide bonds. The concentrations of these amino acids are measured using fluorogenic reactions that emit fluorescence upon light exposure. Using machine learning, an artificial intelligence tool, the researchers identified distinct patterns in amino acid levels that correlate with the presence of cancer.

The study, published in Nature Communications, showed promising results: testing samples from 170 patients yielded a detection accuracy of 78%, with zero false positives. The test requires only a small blood sample and simple reagents available in any hospital setting, making it a practical tool for early screening.

Beyond detecting cancer, the test also distinguishes signals from other diseases, such as COVID-19, and can identify different types and stages of cancer. Moreover, it offers insights into how patients may respond to specific treatments, adding a layer of precision medicine. For instance, it predicted with 100% accuracy whether a patient would not respond to anti-metastatic therapy and was correct in 87% of cases predicting response.

While the initial results are encouraging, the researchers acknowledge that larger clinical trials are necessary to bring this diagnostic tool into widespread clinical practice. Currently, two trials are underway in the UK to validate and refine the assay for potential commercial use.

This innovative approach exemplifies how analyzing the immune system's early reaction to cancer might revolutionize cancer diagnostics, making early detection more accessible and personalized, ultimately improving patient outcomes.

source: https://medicalxpress.com/news/2025-07-blood-immune-protein-early-stage.html