Impact of metformin use on the recurrence of hepatocellular carcinoma after initial liver resection in diabetic patients

Background Metformin is proposed to have chemopreventive effect of various cancer currently. However, the anti-cancer effect of metformin for diabetic patients with hepatocellular carcinoma (HCC) undergoing liver resection remains unclear. The aim of our cohort study was to assess whether metformin influence the recurrence of HCC. Methods We retrospectively enrolled 857 HCC patients who received primary resection from April 2001 to June 2016. 222 patients were diagnosed with diabetes mellitus (DM) from medical record. Factors influence the overall survival (OS) and recurrence-free survival (RFS) were analyzed by multivariate analysis. Results During the follow-up period (mean, 75 months), 471 (54.9%) patients experienced recurrence, and 158 (18.4%) patients died. Multivariate analysis revealed that DM (p = 0.015), elevated AST (p = 0.006), hypoalbuminemia (p = 0.003), tumor number (p = 0.001), tumor size (p < 0.001), vascular invasion (p <0.001), high Ishak fibrosis score (p <0.001), hepatitis B (p = 0.014), hepatitis C (p = 0.001) were independent predictors for RFS. In diabetic patients, only HbA1c>9% (p = 0.033), hypoalbuminemia (p = 0.030) and vascular invasion (p = 0.001) were independent risk factors for HCC recurrence; but the metformin use revealed no significance on recurrence. DM is a risk factor of HCC recurrence after resection. Adequate DM control can reduce the recurrence of HCC. However, the use of metformin does not reduce the risk of HCC recurrence in diabetic patient after initial resection. Hence, metformin may not have protective influences on HCC recurrence in diabetic patients who undergo initial liver resection.