Metformin Does Not Affect Cancer Risk : A Cohort Study in the U.K. Clinical Practice Research Datalink Analyzed Like an Intention-to-Treat Trial
Menée au Royaume-Uni à partir de données portant sur une cohorte de 95 820 patients présentant un diabète sucré de type 2 (durée médiane de suivi : 5,1 ans), cette étude montre que l'utilisation de metformine, un antidiabétique oral, n'affecte pas le risque de cancer
OBJECTIVE : Meta-analyses of epidemiologic studies have suggested that metformin may reduce cancer incidence, but randomized controlled trials did not support this hypothesis. RESEARCH DESIGN AND METHODS : A retrospective cohort study, Clinical Practice Research Datalink, was designed to investigate the association between use of metformin compared with other antidiabetes medications and cancer risk by emulating an intention-to-treat analysis as in a trial. A total of 95,820 participants with type 2 diabetes who started taking metformin and other oral antidiabetes medications within 12 months of their diagnosis (initiators) were followed up for first-incident cancer diagnosis without regard to any subsequent changes in pharmacotherapy. Cox proportional hazards models were used to estimate multivariable-adjusted hazard ratios (HR) and 95% CI. RESULTS : A total of 51,484 individuals (54%) were metformin initiators and 18,264 (19%) were sulfonylurea initiators, and 3,805 first-incident cancers were diagnosed during a median follow-up time of 5.1 years. Compared with initiators of sulfonylurea, initiators of metformin had a similar incidence of total cancer (HR 0.96; 95% CI 0.89–1.04) and colorectal (HR 0.92; 95% CI 0.76–1.13), prostate (HR 1.02; 95% CI 0.83–1.25), lung (HR 0.85; 95% CI 0.68–1.07), or postmenopausal breast (HR 1.03; 95% CI 0.82–1.31) cancer, or any other cancer. CONCLUSIONS : In this large study, individuals with diabetes who used metformin had a similar risk of developing cancer compared with those who used sulfonylureas.
http://care.diabetesjournals.org/content/early/2014/06/02/dc14-0584.abstract