A large real-world cohort study published in The Journal of Clinical Endocrinology & Metabolism evaluated whether exposure to GLP-1 receptor agonists increases cancer risk among patients with endogenous Cushing’s syndrome. Using two decades of data from Israel’s Clalit Health Services, investigators analyzed 609 patients with endogenous Cushing’s syndrome diagnosed between 2000 and 2023. Over an average follow-up of 14.7 years, the study found no statistically significant association between GLP-1 exposure and new malignancies, providing evidence for the oncologic safety of these agents in this high-risk endocrine population.
Endogenous Cushing’s syndrome is characterized by chronic hypercortisolism driven by the body’s overproduction of cortisol. This hormonal excess commonly disrupts glucose metabolism and contributes to severe insulin resistance, obesity, and type 2 diabetes — conditions reported in roughly one-third of patients with Cushing’s syndrome in the source article. GLP-1 receptor agonists, a drug class that includes widely used agents such as semaglutide and liraglutide, have become standard therapies for weight management and glucose control. Prior to this study, safety data specifically addressing cancer risk in patients with endogenous Cushing’s syndrome were limited, and clinicians had expressed caution because this population already has an elevated baseline risk of malignancy.
Investigators conducted a nationwide analysis using Israel’s Clalit Health Services database. The cohort included 609 patients diagnosed with endogenous Cushing’s syndrome from 2000 through 2023. The analysis excluded patients with ectopic forms of Cushing’s syndrome and those with adrenal carcinoma. The mean follow-up time for the cohort was reported as 14.7 years, during which incident cancers and deaths were ascertained.
Within the cohort, 137 patients (22.5%) were prescribed and consistently used GLP-1 receptor agonists during the study window. Across all 609 patients, 116 individuals developed cancer during follow-up, and 141 died. The study applied a time-varying analytical framework to capture the precise timing of medication initiation relative to cancer outcomes, which reduces bias related to immortal time and allows exposure status to change over time.
Using time-varying models, the crude hazard ratio for malignancy associated with GLP-1 exposure was reported as 1.65. After adjusting for confounding health variables, the hazard ratio was reduced to 1.22 and was described as not statistically significant. The investigators therefore did not find evidence that GLP-1 receptor agonist exposure increased the probability of developing cancer among patients with endogenous Cushing’s syndrome.
To test the robustness of their findings, the research team performed secondary sensitivity analyses. These included a conservative 12-month lag period after initiation of GLP-1 therapy to reduce the likelihood that pre-existing, undiagnosed cancers biased the association. The investigators also stratified analyses by the remission status of the patient’s Cushing’s syndrome. The source article reports that both the lagged analyses and the stratified analyses produced results consistent with the primary finding of no increased malignancy risk associated with GLP-1 exposure.
The authors concluded that the findings provide important evidence supporting the oncologic safety of GLP-1 receptor agonists in patients with endogenous Cushing’s syndrome. Given the high prevalence of severe metabolic complications such as obesity, insulin resistance, and type 2 diabetes in this population, the study offers reassurance that endocrinologists can more confidently consider GLP-1 therapies to address those conditions without an observed increased risk of cancer in this dataset.
The source article summarizes cohort size, follow-up duration, numbers of exposed patients, incident cancers, deaths, and the reported crude and adjusted hazard ratios. The article does not report the full list of covariates included in the adjusted model, nor does it provide detailed numeric confidence intervals or p values in the summary text. Specifics about GLP-1 agents used (beyond class examples), dosing, adherence measures, or cancer types and staging were not detailed in the source summary. Those methodological and granular outcome details were not reported in the source article’s public summary.
Overall, the nationwide, long-term, time-varying analysis reported in The Journal of Clinical Endocrinology & Metabolism found no statistically significant association between GLP-1 receptor agonist exposure and incident malignancy in patients with endogenous Cushing’s syndrome, and secondary sensitivity checks supported the primary conclusion. Clinicians should refer to the full study publication for comprehensive methodological information and subgroup data that were not included in the article summary.