Beneficial Effect of Metformin on the Five-Year Survival in about 40,000 Patients with Head and Neck Cancer

Simple Summary Metformin is well known for its glucose-lowering effect and is mainly prescribed for diabetes type II. Moreover, some studies showed a beneficial effect on the survival of patients with head and neck cancer with metformin medication. Therefore, this study aimed to investigate the effect of metformin medication on five-year survival in such patients using a federated network of more than 80 healthcare organizations. Two cohorts matched by age, gender, BMI, diabetes type 2, and risk factors were built: the patients with head and neck cancer on metformin were assigned to cohort I, and the patients with head and neck cancer not on metformin medication were assigned to cohort II. We found a higher five-year survival rate for cohort I, indicating the beneficial effect of metformin medication on five-year survival. Since this study was conducted retrospectively, further clinical research is required.Abstract Introduction: Even in times of new therapy regimes, the overall survival of patients with head and neck cancer remains low. Since the previous studies showed the beneficial effect of metformin medication on the survival of patients with cancer, our objective was to investigate if-and in which way-metformin medication affects the overall survival of patients with head and neck cancer. Methods: Clinical data pertaining to patients diagnosed with head and neck cancer (International Classification of Diseases 10 codes C00-C14, C31, and C32) were retrospectively retrieved from the TriNetX network (TriNetX, Cambridge, MA, USA). The initial cohort extracted from the network was stratified into two groups: patients on metformin medication (cohort I), and individuals not on metformin medication (cohort II). The matching criteria included age, gender, BMI, type 2 diabetes, and risk factors, such as nicotine and alcohol abuse/dependence. Kaplan-Meier analysis, risk analysis, and the calculation of odds and hazard ratios were conducted. Additionally, the Hemoglobin A1c values were subject to analysis. Results: Following matching, each cohort comprised 20,416 patients. Cohort I exhibited a higher five-year survival rate at 75.3%, in contrast to cohort II, which registered a rate of 69.8%. The odds ratio was 0.79 (95% CI = 0.75-0.83), and the hazard ratio was 0.78 (95% CI = 0.75-0.82). Conclusion: Metformin medication may correlate with improved five-year survival rates in patients with head and neck cancer. Since potentially influencing factors such as comorbidities and the initial tumor stage were not available, the results of our retrospectively conducted study must be interpreted with caution.