Metformin modifies disparity in hepatocellular carcinoma incidence in men with type 2 diabetes but without chronic liver diseases

Meeting at the Crossroad between Obesity and Hepatic Carcinogenesis: Unique Pathophysiological Pathways Raise Expectations for Innovative Therapeutic Approaches

The escalating global prevalence of obesity and its intricate association with the development of hepatocellular carcinoma (HCC) pose a substantial challenge to public health. Obesity, acknowledged as a pervasive epidemic, is linked to an array of chronic diseases, including HCC, catalyzing the need for a comprehensive understanding of its molecular underpinnings. Notably, HCC has emerged as a leading malignancy with rising incidence and mortality. The transition from viral etiologies to the prominence of metabolic dysfunction-associated fatty liver disease (MAFLD)-related HCC underscores the urgent need to explore the intricate molecular pathways linking obesity and hepatic carcinogenesis. This review delves into the interwoven landscape of molecular carcinogenesis in the context of obesity-driven HCC while also navigating using the current therapeutic strategies and future prospects for combating obesity-related HCC. We underscore the pivotal role of obesity as a risk factor and propose an integrated approach encompassing lifestyle interventions, pharmacotherapy, and the exploration of emerging targeted therapies. As the obesity-HCC nexus continues to challenge healthcare systems globally, a comprehensive understanding of the intricate molecular mechanisms and innovative therapeutic strategies is imperative to alleviate the rising burden of this dual menace.

Metformin reduces hepatocellular carcinoma incidence after successful antiviral therapy in patients with diabetes and chronic hepatitis C in Taiwan

BACKGROUND & AIMS

Diabetes mellitus (DM) is known to increase the risk of hepatocellular carcinoma (HCC) among individuals with chronic hepatitis C (CHC). We aimed to evaluate whether metformin reduces HCC risk among individuals with DM and CHC after successful antiviral therapy.

METHODS

Individuals with CHC who achieved a sustained virological response (SVR) after interferon-based therapy were enrolled in a large-scale, multicenter cohort in Taiwan (T-COACH). Cases of HCC at least 1 year after SVR were identified through linkage to the catastrophic illness and cancer registry databases.

RESULTS

Of 7,249 individuals with CHC enrolled in the study, 781 (10.8%) had diabetes and 647 (82.8%) were metformin users. During a median follow-up of 4.4 years, 227 patients developed new-onset HCC. The 5-year cumulative HCC incidence was 10.9% in non-metformin users and 2.6% in metformin users, compared to 3.0% in individuals without DM (adjusted hazard ratio [aHR] 2.83; 95% CI 1.57-5.08 and aHR 1.46; 95% CI 0.98-2.19, respectively). Cirrhosis was the most important factor significantly associated with higher HCC risk in Cox regression analysis, followed by DM non-metformin use, older age, male sex, and obesity; whereas hyperlipidemia with statin use was associated with a lower HCC risk. Using the two most crucial risk factors, cirrhosis and DM non-metformin use, we constructed a simple risk model that could predict HCC risk among individuals with CHC after SVR. Metformin use was shown to reduce the risk of all liver-related complications.

CONCLUSIONS

Metformin use greatly reduced HCC risk after successful antiviral therapy in individuals with diabetes and CHC. A simple risk stratification model comprising cirrhosis and DM non-metformin use could predict long-term outcomes in individuals with CHC after SVR.

IMPACT AND IMPLICATIONS

The current study provides evidence that metformin could reduce hepatocellular carcinoma (HCC) incidence after successful antiviral therapy among those with diabetes and chronic hepatitis C in a large-scale nationwide cohort study. Although successful antiviral therapy greatly reduces HCC risk in individuals with chronic hepatitis C, those with cirrhosis, diabetes, obesity, and the elderly remain at high risk of HCC development. We demonstrated that a simple risk model composed of two crucial unfavorable factors, cirrhosis and diabetes without metformin use, predicts the risk of HCC and major liver-related complications after successful antiviral therapy in individuals with chronic hepatitis C. Metformin use is highly recommended for individuals with diabetes and chronic hepatitis C after viral eradication to reduce the risk of HCC.

Metformin: A promising drug for human cancers

Small-molecule chemical drugs are of great significance for tumor-targeted and individualized therapies. However, the development of new small-molecule drugs, from basic experimental research and clinical trials to final application in clinical practice, is a long process that has a high cost. It takes at least 5 years for most drugs to be developed in the laboratory to prove their effectiveness and safety. Compared with the development of new drugs, repurposing traditional non-tumor drugs can be a shortcut. Metformin is a good model for a new use of an old drug. In recent years, the antitumor efficacy of metformin has attracted much attention. Epidemiological data and in vivo, and in vitro experiments have shown that metformin can reduce the incidence of cancer in patients with diabetes and has a strong antagonistic effect on metabolism-related tumors. Recent studies have shown that metformin can induce autophagy in esophageal cancer cells, mainly by inhibiting inflammatory signaling pathways. In recent years, studies have shown that the antitumor functions and mechanisms of metformin are multifaceted. The present study aims to review the application of metformin in tumor prevention and treatment.

Effects of Metformin Exposure on Survival in a Large National Cohort of Patients With Diabetes and Cirrhosis

BACKGROUND & AIMS

Type II diabetes mellitus worsens the prognosis of cirrhosis. Multiple medications including metformin and statins often are co-administered to manage patients with diabetes. The aim of this study was to assess the impact of metformin exposure on mortality, hepatic decompensation, and hepatocellular carcinoma in individuals with diabetes and cirrhosis, controlling for multiple concomitant exposures.

METHODS

We performed a retrospective cohort study of patients with cirrhosis diagnosed between January 1, 2008, through June 30, 2016, in the Veterans Health administration. Marginal structural models and propensity-matching approaches were implemented to quantify the treatment effect of metformin in patients with pre-existing diabetes with or without prior metformin exposure.

RESULTS

Among 74,984 patients with cirrhosis, diabetes mellitus was present before the diagnosis of cirrhosis in 53.8%, and was diagnosed during follow-up evaluation in 4.8%. Before the diagnosis of cirrhosis, 11,114 patients had active utilization of metformin. In these patients, metformin, statin, and angiotensinogen-converting enzyme inhibitor/angiotensin-2-receptor blocker exposure were associated independently with reduced mortality (metformin hazard ratio, 0.68; 95% CI, 0.61-0.75); metformin was not associated with reduced hepatocellular carcinoma or hepatic decompensation after adjustment for concomitant statin exposure. For patients with diabetes before a diagnosis of cirrhosis but no prior metformin exposure, metformin similarly was associated with reduced mortality (hazard ratio, 0.72; 95% CI, 0.35-0.97), but not with reduced hepatocellular carcinoma or hepatic decompensation.

CONCLUSIONS

Metformin use in patients with cirrhosis and diabetes appears safe and is associated independently with reduced overall, but not liver-related, mortality, hepatocellular carcinoma, or decompensation after adjusting for concomitant statin and angiotensinogen-converting enzyme inhibitor/angiotensin-2-receptor blocker exposure.

The Clinical Value of Postoperative Transarterial Chemoembolization for Resectable Patients with Intermediate Hepatocellular Carcinoma After Radical Hepatectomy: a Propensity Score-Matching Study

BACKGROUND AND AIMS

Surgical resection for patients with intermediate hepatocellular carcinoma (HCC) is preferred in China, but the prognosis remains far from satisfactory. Postoperative transarterial chemoembolization (p-TACE) has been conducted prevalently to prevent recurrence, but its efficacy remains controversial. Hence, we collected the data from primary liver cancer big data (PLCBD) to investigate the clinical value of p-TACE for patients with intermediate HCC and identify the potential beneficiaries.

METHODS

Patients who were diagnosed with intermediate HCC between December 2012 and December 2015 were identified through the PLCBD. Disease-free survival (DFS) of patients who received p-TACE or not following radical resection was evaluated using Kaplan-Meier survival curves before and after 1:1 propensity scoring match (PSM). Subgroup analysis was conducted stratified by risk factors associated with recurrence.

RESULTS

A total of 325 intermediate HCC patients receiving radical resection were eligible in this study, including 123 patients in the p-TACE group and 202 in the non-TACE group. Median DFS in the p-TACE group was significantly longer than in the non-TACE group (23.3 months vs. 18.0 months, P = 0.016) in the whole cohort with no severe complicates, which was confirmed in a well-matched cohort (17.4 months vs. 23.3 months, P = 0.012). In addition, p-TACE was identified as an independent risk factors of DFS by multivariate Cox regression analysis before and after PSM (both P < 0.05). After adjusting for other prognostic variables, patients were found to significantly benefit from p-TACE in DFS if they were male, or had hepatitis, diabetes, cirrhosis, AFP ≤ 400 ng/ml, anatomic hepatectomy, no severe surgical complication, no intraoperative transfusion, tumor number = 2, differentiation grading III, capsule, or had no transfusion (all P < 0.05).

CONCLUSION

With the current data, we concluded that p-TACE was safe and efficient for the patients with intermediate HCC following radical resection, and male patients with hepatitis, diabetes, cirrhosis, AFP ≤ 400 ng/ml, anatomic hepatectomy, no severe surgical complication, no intraoperative transfusion, tumor number = 2, differentiation grading III, and capsule would benefit more from p-TACE.

Hepatocellular Carcinoma and Obesity, Type 2 Diabetes Mellitus, Cardiovascular Disease: Causing Factors, Molecular Links, and Treatment Options

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer, which will affect more than a million people by the year 2025. However, current treatment options have limited benefits. Nonalcoholic fatty liver disease (NAFLD) is the fastest growing factor that causes HCC in western countries, including the United States. In addition, NAFLD co-morbidities including obesity, type 2 diabetes mellitus (T2DM), and cardiovascular diseases (CVDs) promote HCC development. Alteration of metabolites and inflammation in the tumor microenvironment plays a pivotal role in HCC progression. However, the underlying molecular mechanisms are still not totally clear. Herein, in this review, we explored the latest molecules that are involved in obesity, T2DM, and CVDs-mediated progression of HCC, as they share some common pathologic features. Meanwhile, several therapeutic options by targeting these key factors and molecules were discussed for HCC treatment. Overall, obesity, T2DM, and CVDs as chronic metabolic disease factors are tightly implicated in the development of HCC and its progression. Molecules and factors involved in these NAFLD comorbidities are potential therapeutic targets for HCC treatment.

Assessment of risk factors, and racial and ethnic differences in hepatocellular carcinoma

Despite improved screening and surveillance guidelines, significant race/ethnicity‐specific disparities in hepatocellular carcinoma (HCC) continue to exist and disproportionately affect minority and disadvantaged populations. This trend indicates that social determinants, genetic, and environmental factors are driving the epidemic at the population level. Race and geography had independent associations with risk of mortality among patients with HCC. The present review discusses the risk factors and issues related to disparities in HCC. The underlying etiologies for these disparities are complex and multifactorial. Some of the risk factors for developing HCC include hepatitis B (HBV) and hepatitis C (HCV) viral infection, nonalcoholic fatty liver disease, nonalcoholic steatohepatitis, smoking and alcohol consumption. In addition, population genetics; socioeconomic and health care access; treatment and prevention differences; and genetic, behavioral, and biological influences can contribute to HCC. Acculturation of ethnic minorities, insurance status, and access to health care may further contribute to the observed disparities in HCC. By increasing awareness, better modalities for screening and surveillance, improving access to health care, and adapting targeted preventive and therapeutic interventions, disparities in HCC outcomes can be reduced or eliminated.

Metformin modifies disparity in hepatocellular carcinoma incidence in men with type 2 diabetes but without chronic liver diseases

Background

We assessed racial/ethnic disparity in hepatocellular carcinoma (HCC) incidence among men with type 2 diabetes (T2D) but without chronic liver diseases (CLD), and whether metformin use modified the disparity.

Methods

Study cohort: the nationwide Veterans Administration Health Care System electronic medical records among 40‐89 years old men with T2D; without CLD, cancer, cardiovascular or renal diseases previously; insulin and thiazolidinedione naive. Logistic regression analyses compared HCC incidence between race/ethnicity groups under no metformin use adjusted for covariates and inverse propensity score weights (IPSW) for race/ethnicity. The generalizability technique integrated with IPSW was incorporated to compare covariates adjusted odds ratios (aOR) of HCC associated with metformin use among race/ethnicity groups.

Results

Study cohort: N = 84 433; 79.47% non‐Hispanic white (NHW), 15.5% non‐Hispanic African American (NHAA), 5.03% Hispanics; 36.76% metformin users; follow‐up 6.10 ± 2.87 years; age 67.8 ± 9.8 years, HbA1c 6.57 ± 0.98%; 0.14% HCC cases. Under no metformin use, HCC incidence was lower for NHAA vs NHW (aOR = 0.60 [0.40‐0.92]), similar between NHW and Hispanics. Metformin was associated with reduced HCC risk: aOR = 0.57 (0.40‐0.81) for NHW; aOR = 0.35 (0.25‐0.47) for NHAA; aOR = 0.31 (0.22‐0.43) for Hispanics. Metformin dose >1000 mg/d was neutral for NHW; less effective for NHAA (P = 0.02); more effective for Hispanics (P = 0.002).

Conclusions

In men with T2D but without CLD nor metformin use, HCC incidence was lower for NHAA compared to NHW or Hispanics; similar between NHW and Hispanics. Metformin use reduced HCC risk and modified the race/ethnicity disparity.

Impact

Metformin's heterogeneous HCC prevention effect elucidates potential interventions to modify HCC disparity in patients with T2D.