GLP-1 receptor agonists and risk of cancer in type 2 diabetes: an updated meta-analysis of randomized controlled trials

Purpose Some preliminary studies reported a link between GLP-1 receptor agonists (GLP-1RAs) and thyroid/pancreatic neoplasms, while its human relevance remained undetermined. The present meta-analysis was performed to collect information on cancers associated with GLP-1RAs in patients with type 2 diabetes mellitus (T2DM). Methods Medline, Embase, the Cochrane Central Register of Controlled Trials (CENTRAL), Web of Science and ClinicalTrials.gov were extensively searched to identify randomized controlled trials that reported cancer events in T2DM patients treated with GLP-1RAs for at least 52 weeks, up to March 18, 2019. Odds ratio (OR) with 95% Confidence Interval (CI) was calculated for overall cancer (primary outcome), thyroid and pancreatic cancer. Results A total of 37 eligible trials were identified. The OR for overall cancer associated with GLP-1RAs was 1.03 (95% CI 0.95-1.12; p = 0.41) compared with comparators. Subgroup analyses showed that treatment with albiglutide was associated with a lower risk of overall cancer (OR 0.76 [95% CI 0.60-0.97]; p = 0.03), and no elevated risk of overall cancer was identified for other GLP-1RAs. No significant differences in the risks of thyroid nor pancreatic cancer were disclosed between GLP-1RAs and comparators. Conclusions This meta-analysis did not suggest any increased risk of cancers associated with GLP-1RAs use in T2DM. The reduction in the risk of overall cancer associated with albiglutide needs to be examined further.