Background: Dipeptidyl peptidase-4 inhibitors (DPP-4Is) are increasingly used in patients with type 2 diabetes (T2DM). However, the effects of DPP-4s on malignant tumours have not been confirmed.
Objectives: To review systematically the effects of DPP-4Is on malignant tumours in patients with T2DM.
Methods: The Cochrane Library, Embase, MEDLINE and Clinical Trials were searched from inception through to November 2015 to identify randomized controlled trials (RCTs) that assessed the safety of DPP-4Is versus placebo or other anti-diabetic drugs in T2DM. Odds ratios (ORs) with 95% confidence intervals (CIs) were estimated through network meta-analysis.
Results: Sixty RCTs were included, which included 14 treatments: six DPP-4Is (alogliptin, linagliptin, saxagliptin, sitagliptin, teneligliptin, vildagliptin), two glucagon-like peptide-1 (GLP-1s) (dulaglutide, exenatide), two sodium/glucose cotransporter 2 (SGLT-2s) (canagliflozin, empagliflozin), placebo and three traditional anti-diabetic drugs. Although there were no statistically significant increases in effects on malignant tumours when DPP-4Is were compared with GLP-1s, SGLT-2s, sulfonylureas, biguanides, or thiazolidinediones, there is a trend for increasing of malignant tumours when DPP-4Is versus GLP-1s, sulfonylureas, and thiazolidinediones (with a range of ORs: 1.14 (95% CI 0.50 to 2.32), 1.17 (95% CI 0.81 to 1.88), 1.49 (95% CI 0.34 to 9.89)).
Conclusions: There is no evidence that DPP-4Is were associated with increasing effect on malignant tumours. Studies with more patients and longer durations of follow-up need to be done to identify the relationship between DPP-4Is and malignant tumours.
PROSPERO register: CRD42015020401