Cancer Treatment’s Catch-22
May 23, 2025
Radiation Was Meant to Kill Cancer. Could it also be helping it spread?
A global team has uncovered a hidden risk of radiation therapy—one that could reshape cancer treatment.
Nearly everyone has a cancer story. If you don’t, you’re one of a fortunate few.
In my home, it was my mother-in-law. A breast cancer survivor, she found another lump in her 70s. This time, it wasn’t just a recurrence—it was a different, more aggressive cancer. That’s when we first heard what some oncologists had begun quietly saying: cancer can return after radiation. Sometimes worse. Bigger. Meaner. This was all of them.
Last week, a paper in Nature caught my eye. It confirmed what patients and families like ours have long feared, and what many doctors are now beginning to track. Radiation therapy, while lifesaving, might sometimes help metastatic cancer—cancer that spreads from where it started, to other parts of the body —come back stronger. Not always. But often enough to matter.
That’s a revelation with consequences.
Why this matters for you:
• One in five people globally will be diagnosed with cancer.
• Radiation is used in over 50%-60% of all cancer treatments & contributes to about 40% of curative cancer treatments.
• Yet, some patients—especially those with metastatic cancers—aren’t responding the way they should.
This study may explain why. And more importantly, it could change how we treat cancer in the future.
Yet, you likely didn’t hear about it. No snappy headlines (bar one or two - literally.. that’s it!). No Hollywood PSA. No pharma PR push. Just a team of scientists across three continents trying to change the playbook on cancer treatment.
Let’s break it down—without the PhD. The full study is linked here. If you want more, the team at the University of Chicago is worth reaching out to.
A Hidden Accomplice: The Biochemist Behind the Breakthrough
Video features Study leads: Kaiting Yang, András Piffkó, Arpit Panda, Janna Heide
Radiation has long been central to cancer treatment, often used alone or alongside surgery and chemotherapy. It’s increasingly used in cases with limited spread. Yet many patients receiving radiation as part of immunotherapy don’t respond—often because of cancer progression elsewhere in the body.
When biochemist Kaiting Yang began investigating the side effects of radiation therapy, she and her international team (including András Piffkó, Arpit Panda, Janna Heide, and others) weren’t expecting to uncover a protein that may actually help cancer spread.
But they did. And what they found could radically shift how we think about treating advanced cancer.
Here’s the crux: radiation triggers a protein called ‘amphiregulin’, especially in aggressive cancers. Instead of helping, it suppresses the immune system and may allow tumors to grow in new places doctors aren’t targeting.
(I dare you to say amphiregulin five times fast.)
“High amounts of amphiregulin weaken the immune system’s ability to fight cancer and make cancer cells better at protecting themselves,” the researchers found.
This doesn’t mean radiation is bad. It’s still a vital tool. But it raises critical questions—especially when treating cancers that have already spread.
THE SCIENCE: What the Team Found?
“Our lab postulated that high doses of radiation might actually promote tumour growth at unirradiated sites under certain conditions, potentially accounting for some of these failures,” says Ralph Weichselbaum, MD, Chair and Daniel K. Ludwig Distinguished Service Professor of Radiation and Cellular Oncology at UChicago Medicine.
Here’s what the team discovered - in simple terms:
Radiation triggers amphiregulin
Radiation increases amphiregulin production, especially in aggressive, metastatic tumours. This protein then tells immune cells to stand down, dulling your body’s natural defences.
Immune suppression = tumour growth
With your body’s defences shutdown, the radiation meant to kill one tumour creates an immunosuppressive environment which might, under certain conditions, help other tumours grow elsewhere.
Blocking the protein works
In animal models, scientists could reduce cancer’s spread by blocking amphiregulin or using drugs that override its effect, like CD47 blockers.
(CD47 is a protein that tells immune cells “don’t eat me.” Blocking it reactivates the immune system’s attack on cancer. Read more at NIH.)
WHO WAS STUDIED?
This wasn’t a narrow trial. It had its clinical and experimental segments and no gender breakdown was reported, but both men and women were included in the study.
The research included:
• Clinical: Patients with metastatic solid tumours undergoing Stereotactic Body Radiotherapy (SBRT), sometimes alongside immunotherapy
• Experimental: Animal models (mice with lung and breast cancer) to track immune response and protein changes before and after radiation
WHY IT MATTERS?
1. A Paradigm Shift in Understanding Radiation
The research challenges a core assumption: that radiation only affects the tumour it targets. In reality, it may unintentionally signal other tumours to grow, especially in metastatic cancers.
2. Personalised Treatment Ahead
There’s growing reason to screen patients for amphiregulin levels post-radiation—and block its effects using targeted therapies like CD47 blockers.
3. Clinical Trials in Progress
The team is already planning trials to test whether combining radiation with amphiregulin or CD47 blockers can improve survival. In animal models, the combination improved metastatic control significantly.
WHO’S BEHIND THE BREAKTHROUGH?
This was a global effort, across top institutions:
• University of Chicago, USA
• Ludwig Center for Metastasis Research, USA
• South China University of Technology, China
• University Medical Center Hamburg-Eppendorf, Germany
• Chinese Academy of Sciences, China
• Weill Cornell Medicine, USA
• Temple University, USA
• University of Regensburg, Germany
Biochemist Kaiting Yang led much of the experimental work, analysing immune response in animal models and patient samples. She co-authored the study with collaborators across continents.
IN SIMPLE TERMS: What Patients Should Know?
• Radiation is still critical—it shrinks and destroys tumours, often saving lives
• But in some metastatic cases, it might help cancer spread by triggering a protein that confuses the immune system
• Scientists have shown they can block this protein in animal models, and now plan to test the approach in humans
• This could lead to more tailored, more effective, and safer cancer care
If you or a loved one is undergoing radiation and you’re concerned, the advice remains unchanged: talk to your doctor. They’ll help you understand whether this research applies to your specific case.
THE CHIEF BRIEF TAKE
Science isn’t just about new discoveries. It’s about questioning the familiar. This study, with its global expertise — challenges the way we see cancer and radiation, and in doing so, might save lives in ways we hadn’t imagined.
For millions of families like mine, science like this isn’t abstract.
It’s personal. And it’s hope.