GLP-1 Drugs May Distort Cancer Imaging Results
New findings show GLP-1 receptor agonists like Ozempic and Wegovy can alter PET-CT scans, prompting caution among doctors interpreting cancer tests.
Researchers have identified that GLP-1 receptor agonists may influence the results of fluorodeoxyglucose (FDG) PET-CT scans used in cancer diagnosis, potentially leading to misinterpretation if clinicians are unaware of a patient’s medication history.
Study Details:
A retrospective review led by Peter Strouhal, MBBS, at Alliance Medical in Warwick, England, analyzed oncologic FDG PET-CT scans of patients using GLP-1 receptor agonists such as semaglutide (Ozempic, Wegovy). The study, presented at the European Association of Nuclear Medicine Congress in Barcelona, found atypical imaging patterns in patients taking these drugs, raising diagnostic concerns.
Methodology:
The research team conducted a retrospective case series across multiple imaging centers, examining PET-CT scans in patients known to be on GLP-1 therapy. These scans use the radiotracer FDG, which highlights areas of high glucose metabolism to detect cancerous tissue. The team compared tracer uptake patterns in GLP-1 users against expected physiological norms.
Key Findings:
Altered imaging patterns were observed in the stomach and pancreas, regions where GLP-1 drugs act directly.
These patterns could mimic cancer activity, potentially leading to false positives if medication history is not considered.
No formal guidance currently exists in the U.K. or internationally regarding management of GLP-1 users before PET-CT imaging.
Given the long half-life of GLP-1s, researchers estimate a patient would need to pause therapy for up to a month to eliminate potential scan interference though this is not yet recommended.
Implications for Practice:
For patients, this finding underscores the need to inform clinicians of all medications, including GLP-1s prescribed for diabetes or weight management.
For clinicians, particularly radiologists and oncologists, awareness is essential. Misinterpreting these tracer uptake patterns could complicate cancer staging or monitoring. Instead of discontinuing treatment pre-scan, experts recommend integrating medication context into imaging analysis.
As GLP-1 drugs continue expanding beyond diabetes into obesity and cardiovascular care, understanding their full systemic effects including how they interact with diagnostic tools becomes increasingly important.