Association of Metformin Treatment with Risk for Death in Diabetic Patients with Concomitant Gastric Cancer.

importanceDespite the existing guideline's recommendation of metformin therapy as the initial approach for managing diabetes mellitus (DM), there remains a scarcity of comprehensive documentation regarding metformin's impact on outcomes that are important for patients.

objectivesThe objective of this study was to assess the potential impact of metformin treatment on the risk of death in individuals diagnosed with both gastric cancer and pre-existing diabetes mellitus (DM); Design, Setting, and Participants: The study made use of a dataset encompassing nationwide health insurance claims, allowing for a retrospective analysis of all patients with a history of gastric cancer diagnosis (classified under International Classification of Diseases 10th Revision code: C16.X) spanning from 1 January 2002 to 31 December 2012. The primary objective was to observe death within a 5-year follow-up period. The study population comprised 63,664 individuals who fell into two categories: those treated with metformin (n = 29,548) and those who did not receive metformin treatment (n = 34,116). This classification was based on the initial treatment allocation following the diagnosis of gastric cancer. EXPOSURES: Metformin treatment, comorbidities, concurrent medication, and procedural information. OUTCOMES: All-cause death, disease-specific death, cardiovascular death.

resultsDuring the 5-year follow-up period, the metformin treatment group exhibited a lower cumulative incidence of all-cause death (27.5%) in comparison to the group not receiving metformin treatment (32.8%). Furthermore, the relative hazards for all-cause death were significantly reduced in the metformin treatment group (HR: 0.80, 95% CI 0.78-0.82), indicating a lower risk of death when compared to the non-metformin group. In addition, metformin treatment was associated with lower occurrences of disease-specific death (related to gastric cancer) and cardiovascular death when compared to the group not undergoing metformin treatment.

conclusionsThe findings demonstrated that the use of metformin was effective at improving prognosis among gastric cancer patients documented with prior DM. In this population-based cohort study, metformin treatment was associated with reduced risk of mortality.