From the Guidelines
Current evidence does not show a clear association between GLP-1 receptor agonists and increased cancer risk. In fact, large clinical trials and post-marketing surveillance have not identified cancer as a significant safety concern with these medications, as noted in a 2021 study published in Diabetes Care 1. Some early animal studies raised theoretical concerns about medullary thyroid cancer and pancreatic cancer, which is why these medications carry precautionary warnings. However, human data has been reassuring, with no consistent signal for increased cancer risk in real-world use, as reported in a 2021 study in The Lancet Diabetes and Endocrinology 2. The FDA requires monitoring for these theoretical risks, which is why patients with personal or family history of medullary thyroid cancer or Multiple Endocrine Neoplasia syndrome type 2 should not use these medications. The biological mechanism of GLP-1 drugs primarily affects insulin secretion, glucose metabolism, and appetite regulation rather than cellular proliferation pathways typically associated with cancer development. Ongoing surveillance continues, but current evidence suggests that for most patients, the benefits of GLP-1 medications for diabetes management and weight loss outweigh any theoretical cancer risks.
Key points to consider:
- GLP-1 receptor agonists have been shown to reduce the risk of major adverse cardiovascular events and have beneficial effects on kidney disease outcomes, as reported in a 2022 study published in Kidney International 3.
- The incidence of acute pancreatitis, pancreatic cancer, medullary thyroid carcinoma, and serious adverse events did not differ significantly between GLP-1 receptor agonist and placebo groups in clinical trials, as noted in a 2021 study published in Diabetes Care 1.
- Meta-analyses of trial results demonstrate a reduction in cardiovascular events and kidney disease outcomes with GLP-1 receptor agonist use, as reported in a 2021 study in The Lancet Diabetes and Endocrinology 2.
Overall, the available evidence suggests that GLP-1 receptor agonists are safe and effective medications for the treatment of type 2 diabetes, with no clear association with increased cancer risk.
From the FDA Drug Label
Glucagon-like peptide-1 (GLP-1) receptor agonists have induced thyroid C-cell adenomas and carcinomas in mice and rats at clinically relevant exposures. It is unknown whether TRULICITY will cause thyroid C-cell tumors, including medullary thyroid carcinoma (MTC), in humans, as the human relevance of dulaglutide-induced rodent thyroid C-cell tumors has not been determined One case of MTC was reported in a patient treated with TRULICITY in a clinical trial. This patient had pretreatment calcitonin levels approximately 8 times the upper limit of normal (ULN). An additional case of C-cell hyperplasia with elevated calcitonin levels following treatment was reported in the cardiovascular outcomes trial (REWIND) Cases of MTC in patients treated with liraglutide, another GLP-1 receptor agonist, have been reported in the postmarketing period; the data in these reports are insufficient to establish or exclude a causal relationship between MTC and GLP-1 receptor agonist use in humans.
There is an association between GLP-1 use and an increased risk of thyroid C-cell tumors, including medullary thyroid carcinoma (MTC), in animal studies. However, the human relevance of this association is unknown. Some cases of MTC have been reported in patients treated with GLP-1 receptor agonists, including dulaglutide, but the data is insufficient to establish a causal relationship 4.
From the Research
Association between Cancer and GLP-1 Use
There is no direct evidence in the provided studies to suggest a significant association between cancer and GLP-1 use.
- The studies primarily focus on the efficacy and safety of GLP-1 receptor agonists in the treatment of type 2 diabetes, highlighting their benefits in reducing hemoglobin A1c levels, body weight, and cardiovascular risk factors 5, 6, 7, 8, 9.
- None of the studies explicitly investigate the relationship between GLP-1 receptor agonist use and cancer risk.
- However, it is worth noting that some studies mention the potential for GLP-1 receptor agonists to be used in the treatment of other diseases, such as neurodegenerative diseases and psoriasis, but do not discuss cancer specifically 5, 9.
Key Findings on GLP-1 Receptor Agonists
- GLP-1 receptor agonists have been shown to be effective in reducing hemoglobin A1c levels, body weight, and cardiovascular risk factors in patients with type 2 diabetes 5, 6, 7, 8.
- The choice of GLP-1 receptor agonist depends on patient preferences, potential adverse effects, and cost 6, 8.
- GLP-1 receptor agonists may have benefits beyond glycemic control, including weight loss and cardiovascular protection 5, 7, 9.