A landmark new study has changed how scientists understand the way lung cancer spreads

Lung cancer's secondaries are starting their own fires

A study just published in Nature (29 April 2026) has fundamentally changed how scientists understand the way lung cancer spreads through the body, and the findings have profound implications for how we diagnose, treat and ultimately fight this disease.

The research, led by teams at University College London and the Francis Crick Institute as part of the TRACERx lung study and PEACE autopsy programme, tracked 24 people with non-small cell lung cancer from diagnosis all the way to death. Using detailed genetic sequencing of 501 tumour samples - collected at surgery, during treatment, and at autopsy - scientists were able to reconstruct, for the first time in such detail, the complete evolutionary history of how each person's cancer spread.

The spark that starts new fires

Think of lung cancer like a burning ember. You start with one source of heat. But as sparks fly off in different directions and land elsewhere, new fires begin to burn - and those new fires start throwing their own sparks. The original ember almost becomes beside the point.

That is precisely what this study found. More than half of all secondary tumours - metastases - were not seeded directly by the original lung tumour. They were seeded by other metastases. In 88% of people, both the primary tumour and existing metastases were active sources of further spread, creating a cascade of new disease that scientists had previously underestimated.

The researchers also found that the longer a secondary tumour had been growing, the more dangerous it became - not just in itself, but because it was more likely to seed further spread. Metastases detected at the first relapse scan were twice as likely to go on to seed other metastases compared to those found only at autopsy. Early metastases, given enough time, become launchpads.

This is a significant shift in scientific thinking. Until now, the working assumption in many treatment approaches has been that secondary tumours originate from the primary site. This research suggests that by the time many people are diagnosed with advanced disease, the cascade is already well underway, and increasingly driven by the metastases themselves.

The study also identified that cancer cells which spread beyond the chest cavity - to the brain, liver, bones and other distant sites - tended to carry higher levels of chromosomal instability: genetic disruption that may give certain cells a greater capacity for distant spread. Understanding which tumours carry this characteristic could, in future, help identify who is at greatest risk of widespread metastatic disease.

Why this research was only possible because of patients

It is worth pausing on how this science happened at all.

Studies like this require something extraordinary: people consenting, during their lifetime, to donate their bodies to research after death. Every tumour sample collected at autopsy, every data point that made these findings possible, exists because people living with lung cancer chose to contribute to science that they knew would not save them - but might save others.

At Lung Cancer Europe, we believe that people with lived experience must be partners in research and innovation - not just subjects of it. This study is a powerful example of what becomes possible when that partnership is real. As our 2026-2030 Charter sets out, high-quality, longitudinal data collection is essential to improving care and outcomes. Research like this shows exactly why.

What it means for treatment - and where Europe falls short

The study's authors suggest that aggressively treating existing metastases early - before they have time to seed further spread - could potentially interrupt the cascade. Local consolidative therapy, which uses targeted radiotherapy or surgery to treat individual metastases, is already used in some settings, and this research offers a biological rationale for considering it in carefully selected patients.

It is important to note that the science here is still developing. A major clinical trial published in 2024 - NRG-LU002 - did not show a survival benefit from this approach in those treated primarily with immunotherapy, highlighting that identifying who might benefit remains an open and urgent question. The authors themselves are careful on this point. But the biological picture this study provides is an important step towards answering it.

What is not in question is the European access gap that surrounds any potential advance. Across Europe, access to advanced diagnostics, clinical trials and new treatment approaches remains deeply unequal. People in lower-income European countries can wait over 600 days for access to new medicines. In some countries, fewer than half of people with lung cancer are discussed at a multidisciplinary team meeting - the basic standard of care that makes nuanced, personalised treatment decisions possible at all.

The science is moving fast. The systems that should deliver its benefits to patients are not keeping pace.

The bigger picture

This study also reinforces something Lung Cancer Europe has long advocated for: that a single biopsy taken at diagnosis gives an incomplete, and potentially misleading, picture of a person's disease. As cancer evolves and spreads, the genetic landscape of metastases can look very different from the original tumour. The researchers found that individual metastases were consistently less genetically complex than the primary tumour, but that taken together across the body, the total diversity was comparable. This means that treating based on one sample, from one site, at one point in time, risks missing a large part of what is actually happening.

Better diagnostics, including access to repeat biomarker testing, are not a luxury. They are a clinical necessity, and they remain out of reach for too many people across Europe.

Lung cancer remains the leading cause of cancer death in Europe, with 484,000 new cases and 376,000 deaths every year. Research of this depth and ambition gives genuine cause for hope. But translating that hope into better outcomes for people with lung cancer across all of Europe - regardless of where they live or what resources their health system has - remains the urgent, unfinished work.