1386-P: Dipeptidyl Peptidase-4 Inhibitors and the Risk of Skin Cancer among Patients with Type 2 Diabetes—Population-Based Cohort Study

Introduction: The dipeptidyl peptidase-4 (DPP-4) enzyme influences carcinogenic pathways in the skin, although its exact role remains uncertain. The objective of this study was to determine whether DPP-4 inhibitors are associated with the incidence of melanoma and nonmelanoma skin cancer, compared with sulfonylureas.

Research Design and Methods: Using the United Kingdom Clinical Practice Research Datalink, we assembled two new-user active comparator cohorts for each skin cancer outcome from 2007 to 2019. For melanoma, the cohort included 96,739 DPP-4 inhibitor users and 209,341 sulfonylurea users, and 96,411 DPP-4 inhibitor users and 208,626 sulfonylurea users for nonmelanoma skin cancer. Propensity score fine stratification weighted Cox proportional hazards models were to estimate hazard ratios (HRs) with 95% confidence intervals (CIs) of melanoma and nonmelanoma skin cancer, separately.

Results: Overall, DPP-4 inhibitors were associated with a 23% decreased risk of melanoma compared with sulfonylureas (49.7 vs. 65.3 per 100,000 person-years, respectively; HR 0.77, 95% CI 0.61-0.96). The HR progressively reduced with increasing cumulative duration of use (0-2 years HR 1.14, 95% CI 0.84-1.54; 2.1-5 years HR 0.44, 95% CI 0.29-0.66; >5 years HR 0.33, 95% CI 0.14-0.74). In contrast, these drugs were not associated with the incidence of nonmelanoma skin cancer, compared with sulfonylureas (448.1 vs. 426.1 per 100,000 person-years, respectively; HR 1.06, 95% CI 0.98-1.15).

Conclusions: In this large, population-based cohort study, DPP-4 inhibitors were associated with a reduced risk of melanoma but not nonmelanoma skin cancer, compared with sulfonylureas.