Blood Test Shows Early Promise in Predicting Immunotherapy Success for Advanced Lung Cancer
Early Detection Through Plasma and White‑Blood‑Cell Genomics
Researchers at the Johns Hopkins Kimmel Cancer Center and its Bloomberg‑Kimmel Institute announced a blood‑based assay that can forecast immunotherapy benefit for patients with advanced lung cancer. The findings appeared in the 2026 issue of Clinical Cancer Research and involve participants treated at the center between 2023 and 2025.
The new test examines genetic variants in both plasma and white‑blood‑cell DNA, assigning each mutation to its tumor origin. By detecting these signals before radiographic changes, clinicians can decide sooner whether immunotherapy is likely to work. Early identification may spare patients from ineffective treatment and its side effects.
The assay combines circulating tumor DNA analysis with white‑blood‑cell sequencing to separate tumor‑derived mutations from background genetic noise. In a cohort of 112 patients, the test correctly identified responders with an accuracy exceeding 80 percent, according to the study’s lead author, Dr. Emily Hart. „We wanted a minimally invasive tool that could tell us within weeks whether a patient would benefit,” Hart explained. The researchers emphasize that the method captures tumor evolution in real time, offering a dynamic view that static tissue biopsies cannot provide.
Can This Test Replace Tissue Biopsies for Treatment Decisions?
While the blood test shows strong predictive power, experts caution that it is not yet a full substitute for tissue sampling. Tissue biopsies still deliver essential information about tumor histology and protein expression, which the blood assay cannot assess. Ongoing trials aim to determine whether the assay can reliably guide therapy without a concurrent biopsy. Dr. Michael Lee, a co‑author, noted, „Our goal is to complement, not replace, existing diagnostic pathways until the data are robust enough for standalone use.”
If validated in larger studies, the test could reshape lung‑cancer care by shortening the time to effective treatment and reducing exposure to costly, ineffective drugs. Health systems may adopt the assay as part of routine monitoring, and regulatory approval could follow within the next few years. The promise of a simple blood draw guiding complex immunotherapy choices marks a significant step toward personalized oncology.
Frequently Asked Questions
How does the blood test determine likely benefit from immunotherapy? It sequences DNA fragments circulating in plasma and compares them with mutations found in white‑blood‑cell DNA, isolating tumor‑specific changes that correlate with treatment response.
Which patients are eligible for this assay? The study focused on adults with stage III or IV non‑small‑cell lung cancer who were candidates for checkpoint inhibitor therapy. Similar criteria are expected for future clinical use.
When might clinicians be able to use this test in practice? If ongoing validation trials confirm its accuracy, the assay could enter clinical guidelines by 2028, pending regulatory clearance and insurance coverage decisions.