Tumour Risk with Once-Weekly Glucagon-Like Peptide-1 Receptor Agonists in Type 2 Diabetes Mellitus Patients: A Systematic Review.

BACKGROUND AND OBJECTIVE: Once-weekly glucagon-like peptide-1 receptor agonists (GLP-1RAs) are a novel class of injectable antidiabetic drugs. Previous studies indicated that GLP-1RAs (exenatide and liraglutide) might increase the incidence of pancreatitis and pancreatic cancer. Here, we evaluated the clinical safety of once-weekly GLP-1RAs with respect to tumour risk. METHODS: Relevant studies were selected from ClinicalTrials.gov. Randomized controlled trials that reported the incidences of neoplasms were included in our research. Outcomes were calculated as the risk ratio using the Mantel-Haenszel method and fixed-effects model. RESULTS: Our analysis included 26 randomized controlled trials with 16,090 patients. Once-weekly GLP-1RAs did not increase the risk for tumours compared with other antidiabetic drugs [risk ratio (RR), 1.02; 95 % confidence interval (CI), 0.74-1.41; p = 0.91]; this finding was independent of the type of GLP-1RA administered (albiglutide, exenatide extended-release and dulaglutide) and duration of the trials (limited to ≥52 weeks). Subgroup analyses revealed that once-weekly GLP-1RAs did not increase tumour risk compared with placebos, exenatide and liraglutide, insulin or oral drugs. Additionally, once-weekly GLP-1RAs did not increase tumour risk in any tissue. CONCLUSIONS: Compared with other antidiabetic drugs, once-weekly GLP-1RAs did not increase the risk for any tumour, and this finding was independent of the type of GLP-1RA administered and treatment duration. However, our study had many limitations, and further longer term trials with larger samples should be conducted in future to confirm our results.