Nasopharyngeal Carcinoma and Head and Neck Cancer in Patients with Type-2 Diabetes Mellitus receiving SGLT2I, DPP4I or GLP1a: A population-based cohort study

IntroductionNasopharyngeal carcinoma (NPC) remains endemic in Asian regions, which risk factors were distinct from other head and neck (H&N) cancers. Anti-diabetic drugs has been proposed to reduce the risk of NPC. The associations between sodium glucose cotransporter 2 inhibitors (SGLT2I) versus dipeptidyl peptidase-4 inhibitors (DPP4I) and the risks of NPC and H&N cancer amongst type-2 diabetes mellitus (T2DM) patients remains unknown. MethodThis was a retrospective population-based cohort study including T2DM patients treated with either SGLT2I or DPP4I between 1st January 2015 and 31st December 2019 in Hong Kong. The primary outcome was new-onset NPC and other H&N cancer. The secondary outcome was cancer-related mortality. Propensity score matching (1:1 ratio) was performed using the nearest neighbour search. Multivariable Cox regression was applied to identify significant predictors. ResultsThis cohort included 75,884 patients with T2DM, amongst whom 28,778 patients were on SGLT2I and 47,106 patients were on DPP4I. After matching (57556 patients), 106 patients developed NPC (0.18%), and 50 patients developed H&N cancer (0.08%). Compared to DPP4I, SGLT2I was associated with significantly lower risks of NPC (Hazard ratio [HR]: 0.41; 95% Confidence interval [CI]: 0.21-0.81) but not H&N cancer (HR: 1.00; 95% CI: 0.26-3.92) after adjustments. The result remained significant regardless of demographics and obesity. The association remained consistent in different risk models, matching approaches, and the sensitivity analysis. ConclusionThis study provides real-world evidence that SGLT2I was associated with lower risks of NPC, but not H&N cancer compared to DPP4I after adjustments amongst T2DM patients.