The Effect Of Metformin On The Prognosis Of Hepatocellular Carcinoma With Diabetes Mellitus And Its Potential Mechanism

Background:Hepatocellular carcinoma(HCC)is the fifth most frequently diagnosed cancer worldwide,and yet it was the third most common cause of cancer death.Recent epidemiological studies suggest that diabetes mellitus(DM)increases the risk of HCC and associated with significantly poor prognosis.With the arrival of aging population and the increased incidence of obesity,the number of HCC patients with DM showed an upward trend,and HCC patients with DM has become a hot spot in the field of medicine.However,several deficient still exist in overseas and domestic research status,such as lack of data summary and prognosis analysis of HBV related-HCC patients with DM,little is known about the role of metformin in survival of HBV-related HCC patients with DM after radical resection,and the synergistic benefit with liver kinase 1(LKB1)in the anti-cancer mechanisms still remains unknow.Objective:To summarize the characteristics of HBV-related HCC patients with DM,and to assess the association of metformin with overall survival of HBV-related HCC patients with DM after radical resection by propensity score matching analysis,and the correlation between metformin and LKB1 in the anti-cancer mechanisms.We hope that the present study can provide a certain theoretical basis for metformin usage in the prevention and treatment of HCC.Three specific contents are as follows:Part I Clinical characteristics of HBV-related HCC patients with DMObjective:To analyze the clinicopathologic characteristics and prognosis of HBV-related HCC patients with DM after radical resection.Patients and Methods:Using data from the First Affiliated Hospital of Nanchang University and theEastern Hepatobiliary Surgery Hospital in China,we identified 250 HBV-related HCC patients 30-78 years of age diagnosed with DM between 2000 and 2013,and analyzed the clinical characteristics and prognostic risk factors of these patients.The inclusion criteria were: ⑴ received redical liver resection;⑵ Child-Pugh A-B;⑶ patients between 18 and 80 years;⑷ have a pathological diagnosis as HCC;⑸Hepatitis B surface antigen positive.The exclusion criteria were: ⑴ underwent transarterial chemoembolization or other antitumor therapies before surgery;⑵ the combination of the main hepatic vein tumor thrombus,inferior vena cava tumor thrombus,portal vein and its secondary branch tumor thrombus,the main hepatic duct tumor thrombus;⑶ extrahepatic metastasis of hepatocellular carcinoma;⑷ a co-existing malignancy or concomitant severe heart,lung and kidney diseases;⑸rupture of liver cancer.The content of questionnaire is as follows:age,gender,duration of DM,antiviral therapy,therapy after recurrence,hypoglycemic agents,body mass index,hemoglobin,platelet count,prothrombin time,fasting plasma glucose,albumin,total bilirubin,albumin,alanine aminotransferase,aspartate aminotransferase,hepatitis B surface antigen,hepatitis B virus DNA,type of liver cancer,pathological grading,tumor diameter,tumor size,tumor capsule,macrovascular invasion,liver cirrhosis,postoperative complications.Results:These patients including male 230 cases(92%)and female 20 cases(8%),were diagnosed to have HCC at a mean±SD of 53.15±8.73 years.The median duration from the time of confirmed DM to a diagnosis of HCC was 36 months,and the percentage of patients with diabetes who had a course of more than 5 years was 42%(105/250).Edmondson grade III is the main Edmondson grade of hepatocellular carcinoma,accounting for 65.6%.The multivariate Cox proportional hazards model revealed that number of tumors,hemoglobin levels and therapy after recurrence were the factors influencing the survival of HBV-related HCC patients with DM,and metformin was the factor increasing the DFS of HCC patients(P=0.031).Conclusions:People should strengthen the detection and follow-up of the overweight or obese male patients who have HBV related-liver cirrhosis and longer history of diabetes.Comprehensive treatment after recurrence is helpful to the prognosis of HCC,and metformin may be associated with higher overall survival.Part II Effect of metformin on the prognosis of hepatocellularcarcinoma patients with diabetes mellitus: a propensity scorematching analysisObjective:To assess the association of metformin with prognosis of HBV-related HCC patients with DM after radical resection.Patients and Methods:A total of 250 HCC patients,aged 30-78 years old and diagnosed with DM were selected between 2000 and 2013 from the First Affiliated Hospital of Nanchang University and the Eastern Hepatobiliary Surgery Hospital in China.Patients were divided into the metformin group(n=66)and the non-metformin group(n=184).We used propensity score matching(PSM)methods to assess the association of metformin use with the overall survival(OS)of patients while controlling the potential confounders.Results:In the propensity score-matched cohort(n=176),the overall survival of the metformin group at 1,3,and 5 years was significantly higher than that of the non-metformin group(P=0.002),and the same was true also for disease-free survival(DFS)(P=0.030).The Cox proportional hazards model revealed that metformin use was associated with a statistically significant improvement in survival(HR: 0.551,95%CI: 0.381-0.798).Conclusions:Metformin is found to be associated with a better clinical outcome among HBV-related HCC patients with DM after radical resection,suggesting a potential anticancer effect for metformin.Further research is needed to further verify the effectand explore the possible mechanisms of metformin with prospective clinical trials.Part III The expression of LKB1 in hepatocellular carcinoma andits relationship with metforminObjective:To explore the relationship between the expression of the proteins associated with tumor suppression,LKB1 proteins and metformin in the HBV-related HCC tissues with DM.Patients and Methods:A total of 60 HCC patients and 20 patients with traumatic liver rupture in the First Affiliated Hospital of Nanchang University and the Eastern Hepatobiliary Surgery Hospital were enrolled in this study between 2007 and 2013.HCC patients were divided into the metformin group(n=30)and the non-metformin group(n=30),after controlling for potential confounders.LKB1 expression was detected by immunohistochemistry.Results:LKB1 expression was decreased in the HCC samples(41.7%),especially in the HCC tissues of non-metformin group(23.3%).Loss of LKB1 expression in HCC was significantly related to live cirrhosis(P =0.02),Serum glucose(P=0.01)and duration of DM(P=0.04).The positive expression of LKB1 protein associated with metformin(r =0.372,P=0.004).Patients showing positive LKB1 expression had a significantly better overall survival than those with negative expression(P =0.012).Multivariate Cox regression analysis indicated that the positive expression of LKB1 was an independent factor of survival(P = 0.00).Conclusions:Metformin is a potential drug for the treatment of HCC,in particular to those with incomplete LKB1 expression.Metformin may enhance LKB1 tumor suppression,inhibit cell growth,and reduce tumor cell viability via the activation of LKB1-AMPK-mTOR signaling.