Summary
Doctors usually find lung cancer with a scan, after a tumor has already started growing. A new study suggests a simple blood test might spot the danger years earlier.
Scientists at University College London (UCL) and the Francis Crick Institute studied blood samples from more than 48,000 people. Using a computer program, they looked for patterns linked to future lung cancer. The team found a group of 14 proteins in the blood that showed up in people who later developed lung cancer, sometimes more than five years before doctors found a tumor.
Lung cancer screening today is only offered to certain groups, mainly older adults with a smoking history. That leaves out people who never smoked or who breathed in a lot of air pollution over the years. The new blood signature picked up risk in these groups too.
The proteins appear to be tied to inflammation. As people age, their cells can pick up small genetic changes. On its own, that usually isn’t enough to cause cancer. But something else, like long term pollution exposure, can push those cells toward becoming cancerous. Researchers believe this blood signature is picking up on that inflammatory tipping point.
The same signature also showed up in people who developed other lung conditions, like COPD or pulmonary fibrosis, suggesting it may reflect a broader pattern of lung inflammation rather than lung cancer alone.
This isn’t a test available at your doctor’s office yet, but it’s an early sign that blood-based screening tools could someday reach people that today’s guidelines miss entirely. Researchers say the next step is figuring out how a signature like this could guide who receives extra monitoring before cancer takes hold.
