GLP-1 drugs and lung cancer: what the ASCO 2026 evidence shows, and what it does not

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Written By Web Team
A person self-injecting into their upper arm with a blue pen injector, the way GLP-1 medicines are given.

New research presented at the 2026 ASCO Annual Meeting in Chicago has renewed interest in whether GLP-1 drugs, the medicines used for type 2 diabetes and weight management and known by brand names such as Ozempic, Wegovy and Mounjaro, could have a role in cancer. The early signal for lung cancer is about slower progression in people who are already diagnosed. It is not evidence that these drugs prevent lung cancer.

This article sets out what the data shows, where the limits are, and what it means for people living with lung cancer today.

What the study found

The most discussed analysis is ASCO Abstract 3143, led by Mark David Orland at the Cleveland Clinic. It used real-world health records to compare two groups of people who started a diabetes medication after a cancer diagnosis. One group started a GLP-1 drug, such as semaglutide, tirzepatide, liraglutide or dulaglutide. The other started a DPP-4 inhibitor, an older class of diabetes drug also known as a gliptin.

The propensity-matched group included 12,112 people across seven cancer types, all at stage 1, 2 or 3. The data came from the TriNetX Global Health Research Network. The researchers matched the two groups for factors such as body mass index, smoking, other health conditions, cancer screening frequency and cancer treatment. They then tracked who went on to develop stage 4 disease.

For non-small cell lung cancer, progression to stage 4 occurred in 10% of the GLP-1 group, compared with 22% of the gliptin group. Lung cancer was one of four types where the reduction was statistically significant. The others were breast, colorectal and liver cancer, with reductions of 38% to 50% in the likelihood of advanced disease. For prostate, pancreatic and kidney cancer, the GLP-1 group had fewer metastases, but the difference was not statistically significant.

A possible biological signal

The same research group also examined tumour samples. People whose tumours showed high GLP-1 receptor expression had a 33% lower risk of death overall, and a 45% lower risk in breast cancer. This points to a possible biological role rather than a coincidence. It remains a hypothesis that further study will need to test.

Progression is not the same as prevention

This is the distinction to hold onto. The lung cancer findings describe slower progression in people who already have the disease. They do not show that GLP-1 drugs reduce the risk of developing lung cancer in the first place.

A separate analysis presented at the same meeting did look at prevention, but in breast cancer rather than lung.

Led by Elizabeth McDonald at the University of Pennsylvania and published in JCO Oncology Practice, it was a retrospective review of health records from 111,646 women aged 45 to 80 who were overweight and were having breast screening. The women taking GLP-1 drugs were around 30% less likely to be diagnosed with breast cancer.

That figure needs care. In the matched comparison, 1.62% of GLP-1 users were diagnosed during the study period, against 2.31% of non-users. That is a relative reduction of about 30%, but an absolute difference of less than one percentage point, or roughly seven fewer cases for every 1,000 women. Looking back at records like this cannot show cause and effect, and it cannot separate the drug from weight loss. GLP-1 drugs cause people to lose weight, and excess weight is itself linked to breast cancer risk, so the lower rate may reflect the weight loss rather than the drug.

Looking back at records like this cannot show cause and effect, and it cannot separate the drug from weight loss. GLP-1 drugs cause people to lose weight, and excess weight is itself linked to breast cancer risk, so the lower rate may reflect the weight loss rather than the drug. McDonald was clear that the findings do not confirm GLP-1 drugs prevent breast cancer.

For lung cancer specifically, the prevention question has not been answered. The evidence so far is about progression.

Why caution is needed

These are early findings, and the analysis was observational. It cannot prove that GLP-1 drugs directly slowed cancer progression.

The study drew on a real-world health records network. The researchers matched the two groups for many factors, including body mass index, smoking and other health conditions. Even so, this kind of analysis cannot account for everything that influences cancer outcomes, such as diet or physical activity, and it cannot establish cause and effect.

The findings also describe a specific group: people with cancer who were also taking a diabetes medication. They cannot be read across to the general population.

The investigators said randomised controlled trials are now needed. Marcin Chwistek, an ASCO expert in supportive care at Fox Chase Cancer Center, said the consistency across tumour types is what stands out, and that data on this scale warrants a prospective randomised trial. On safety, the researchers reported similar rates of side effects between the two groups, with no increase in pancreatitis among people taking GLP-1 drugs.

What this means for people living with lung cancer

Nothing about current treatment changes on the strength of this research. No one should start or stop any medication based on these findings. Decisions about GLP-1 drugs should be made with a clinical team, in the context of a person's full medical history.

The early data is encouraging and there is currently a lot of interest in this subject. But, the honest position is that this is a question worth studying, not a treatment recommendation.

Common questions

  • No. The 2026 ASCO evidence is about slower progression in people who already have early-stage cancer, not prevention. No study has shown that GLP-1 drugs stop lung cancer from developing.

  • They are not a lung cancer treatment. The data is early and observational. It shows an association with slower progression, not proof that the drugs cause it. Randomised controlled trials are needed before any conclusion can be drawn.

  • No one should start or stop any medication based on these findings. Decisions about GLP-1 drugs should be made with a clinical team, in the context of a person's full medical history.

Sources

Author disclosures for both studies are available at coi.asco.org. The progression study had no external funding. The breast cancer study was supported by the American College of Radiology Center for Research and Innovation, the Pennsylvania Breast Cancer Coalition, and the Abramson Cancer Center.

Web Team
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