GLP-1 Receptor Agonists Show Promise in ASCO 2026 Research

A cluster of 5 real-world studies being presented at the 2026 ASCO Annual Meeting, is poised to reshape how oncology teams think about glucagon-like peptide-1 (GLP-1) receptor agonists in the context of cancer prevention, progression, and immunotherapy outcomes.

For oncology nurses caring for patients who are already taking GLP-1 receptor agonists such as semaglutide (Ozempic/Wegovy), liraglutide (Victoza), or dulaglutide (Trulicity) — or who may begin these medications alongside their cancer treatment — the ASCO 2026 findings may signal an important shift in how these drugs are perceived and monitored in oncology practice.

The emerging evidence spans breast cancer prevention, metastatic progression across multiple tumor types, survival in patients on immune checkpoint inhibitors, and outcomes in patients receiving CDK4/6 inhibitor-based regimens for metastatic breast cancer.

What should oncology nurses know about GLP-1s and cancer prevention?

Two abstracts to be presented focus specifically on breast cancer prevention and incidence. In a real-world analysis of more than 100,000 women who were overweight and eligible for mammogram screening, researchers from the University of Pennsylvania found that those taking GLP-1 receptor agonists were less likely to develop breast cancer compared with those who did not take these medications.¹ The analysis will be presented Tuesday, June 2.

A second prevention-focused study² examined GLP-1 receptor agonists specifically for primary prevention of breast cancer in high-risk women, analyzing both efficacy and safety outcomes in a real-world cohort. Being overweight or obese — particularly after menopause — is a known risk factor for breast cancer, and chronic low-grade inflammation is suspected to play a contributing role; GLP-1 drugs affect both metabolic and inflammatory pathways, which may underpin their potential preventive effect.

For oncology nurses involved in patient education and survivorship care planning, these findings may help guide conversations with patients who ask whether their GLP-1 medications offer any cancer-related benefit — a question that is becoming increasingly common given the widespread use of these agents.

What do the cancer progression findings mean for oncology nursing care?

A large propensity-matched real-world analysis³ compared GLP-1 receptor agonists head-to-head with DPP-4 inhibitors (gliptins) in more than 12,000 patients with 1 of 7 obesity-related cancers at stage I, II, or III. The study found that for 4 of the 7 cancer types — lung, breast, colorectal, and liver cancer — patients taking GLP-1s were 38% to 50% less likely to progress to stage IV disease compared with those taking gliptins.

Specifically, metastatic progression occurred in 10% of the GLP-1 group versus 22% in the gliptin group for lung cancer; 10% versus 20%, respectively, for breast cancer; 13% versus 22% for colorectal cancer; and 19% versus 28% for liver cancer. For prostate, pancreatic, and kidney cancers, fewer metastatic events were seen with GLP-1 use, but the differences did not reach statistical significance. Adverse event (AE) rates in both groups were similar, with no increase in pancreatitis or other GLP-1–associated concerns in the cancer setting.

Additionally, an analysis of tumor GLP-1 receptor expression data from The Cancer Genome Atlas found that high GLP-1 receptor expression on tumors was associated with a 33% lower risk of death overall, and with a 45% lower mortality risk specifically in breast cancer — suggesting that the GLP-1 signaling pathway may itself be biologically active in certain cancers.

For nurses involved in patient education, these findings may help guide conversations with patients who are managing both diabetes or obesity and a cancer diagnosis, and who are asking whether to continue or initiate a GLP-1 medication.

What should oncology nurses monitor in patients taking GLP-1s during immunotherapy?

One of the most clinically actionable findings for oncology nursing practice comes from a multi-institutional real-world analysis⁴ examining the association between GLP-1 receptor agonist use and outcomes in patients with cancer who are also receiving immune checkpoint inhibitors (ICIs). Prior data from a target-trial emulation design — using more than 2,900 propensity-matched patients with type 2 diabetes who started an ICI with or without concurrent GLP-1 receptor agonist use — found that GLP-1 co-exposure was associated with substantially lower all-cause mortality (hazard ratio [HR], 0.55; 36-month absolute risk difference, −16.4%), lower rates of hospitalization (HR, 0.76), and fewer composite immune-related adverse events (irAEs; 43.9% vs. 51.5%).

Importantly for oncology nursing teams monitoring patients during ICI therapy, the data also signaled 2 ophthalmic safety considerations requiring vigilance: diabetic retinopathy progression (HR, 1.75) and non-arteritic anterior ischemic optic neuropathy (HR, 1.51) were both observed at higher rates in the GLP-1 group. Although rates of hypoglycemia, acute kidney injury, and orthostatic hypotension were lower with GLP-1 co-exposure, these ophthalmic signals warrant proactive screening and patient education.

Oncology nurses caring for patients who are concurrently receiving an ICI and a GLP-1 receptor agonist should be aware of the potential for reduced irAE burden but should also incorporate ophthalmology awareness into routine patient education and symptom reporting protocols — particularly for patients with pre-existing diabetes and retinopathy risk factors.

What are the emerging data in metastatic breast cancer and CDK4/6 inhibitor regimens?

A fifth real-world analysis⁵ specifically examines GLP-1 receptor agonist use in patients with breast cancer receiving systemic therapy, including those on combination endocrine therapy and CDK4/6 inhibitor regimens. Preliminary data reported in the ASCO press program indicate that the addition of GLP-1 receptor agonists to combination endocrine therapy and CDK4/6 inhibitors is associated with a 30% reduction in mortality risk in patients with hormone receptor–positive, HER2-negative metastatic breast cancer.

For oncology nurses involved in the management of patients receiving CDK4/6 inhibitors — agents associated with significant monitoring requirements including complete blood count surveillance, assessment for neutropenia, and gastrointestinal toxicity management — awareness of the potential co-benefit of GLP-1 medications that patients may already be taking for metabolic indications is an emerging area of clinical relevance. These findings underscore the importance of medication reconciliation at every visit and of communicating patients' full medication lists across the care team.

As with all retrospective, real-world analyses, these data are hypothesis-generating rather than practice-changing on their own. Randomized controlled trials will be needed to confirm causality and define the patient populations most likely to benefit. However, for oncology nurses, the cumulative picture emerging from these abstracts reinforces the need to remain attentive to GLP-1 use across the care continuum — from prevention counseling to active treatment monitoring.

References

1. McDonald ES, Gillis L, Gabriel P, et al. Association of GLP-1 agonists with breast cancer incidence in women. J Clin Oncol. 2026;44(suppl 16): abstract 10506.
2. Gotera NP, Jones C, Gelfond J, et al. GLP-1 receptor agonists for primary prevention of breast cancer in high-risk women: A real-world analysis of efficacy and safety. J Clin Oncol. 2026;44(suppl 16):abstract 10520.
3. Orland MD, Mandala A, Unlu S, et al. Can GLP-1 receptor agonists mitigate cancer progression? A propensity-matched analysis across seven solid tumors. J Clin Oncol. 2026;44(suppl 16): abstract 3143).
4. Jajja S, Thukral J, Abdalla A, et al. The association of GLP-1 receptor agonist use with survival and immune-related adverse events in patients receiving immune checkpoint inhibitors: A multi-institutional real-world analysis. J Clin Oncol. 2026;44(suppl 16): abstract 11000.
5. Sukumar JS, Niu J, Jackson I, et al. Real-world treatment patterns and mortality associated with GLP1-RAs in breast cancer patients. J Clin Oncol. 2026;44(suppl 16): abstract 629.