MASLD and HCC

Metabolic dysfunction–associated steatotic liver disease (MASLD) and hepatocellular carcinoma (HCC) are closely interconnected, with MASLD emerging as a significant risk factor and contributor to the development of HCC. Below is a detailed explanation of MASLD and its relationship with HCC:

### **Understanding MASLD**

MASLD is the most common chronic liver disease globally, affecting over a billion people. It was previously referred to as non-alcoholic fatty liver disease (NAFLD), but the terminology has been updated to better reflect the metabolic dysfunctions associated with the condition. MASLD is characterized by the accumulation of fat in liver cells (steatosis) in individuals who do not consume excessive alcohol and who have at least one of five cardiometabolic risk factors, such as:

• Obesity
• Type 2 diabetes mellitus (T2DM)
• Hypertension
• Dyslipidemia
• Insulin resistance

MASLD progresses through several stages:

1. **Simple steatosis**: Fat accumulation in the liver without significant inflammation or damage.

2. **Metabolic dysfunction–associated steatohepatitis (MASH)**: A more severe form of MASLD marked by inflammation, liver cell injury (ballooning), and fibrosis. MASH can lead to cirrhosis.

3. **Cirrhosis**: Advanced scarring of the liver, which impairs liver function and increases the risk of complications.

4. **Hepatocellular carcinoma (HCC)**: The most serious complication, MASLD-related liver cancer, which can occur with or without cirrhosis.

### **HCC Overview**

HCC is the most common type of primary liver cancer and represents the fifth most common cancer globally. It is also the second leading cause of cancer-related deaths worldwide. HCC can develop due to chronic liver diseases such as MASLD, viral hepatitis (HBV, HCV), alcoholic liver disease, and autoimmune liver conditions.

### **MASLD as a Driver of HCC**

MASLD is increasingly recognized as a major contributor to HCC due to the global rise in metabolic disorders such as obesity and T2DM. Key aspects include:

1. **Epidemiology**:

• MASLD is rapidly becoming the leading indication for liver transplantation among patients listed for HCC.
• Studies from the USA, Europe, South Korea, and Southeast Asia show that MASLD is the fastest-growing cause of HCC.

2. **Risk Factors**:

• Obesity and T2DM are significant drivers of MASLD progression to HCC.
• Advanced age, male sex, and Latino/Latina ethnicity are associated with higher risks of MASLD progression and HCC development.

3. **Pathogenesis**:

• Chronic inflammation, oxidative stress, and metabolic dysfunction in MASLD contribute to DNA damage, genetic mutations, and liver cell proliferation, which can ultimately lead to HCC.
• Unlike other causes of HCC, MASLD-HCC can develop without cirrhosis in 36.6%–54.0% of cases, complicating early detection and treatment.

### **Challenges in Diagnosis and Management**

1. **Early Detection**:

• Diagnosing MASLD and MASLD-related HCC (MASLD-HCC) in the early stages is challenging, particularly in patients without cirrhosis.
• Current screening strategies for MASLD patients at risk of HCC are still under debate, and there is no universal consensus on optimal approaches.

2. **Risk Evaluation**:

• Assessing the risk of MASLD progression to HCC requires identifying high-risk patients based on metabolic factors, liver fibrosis, and genetic predispositions.
• Advanced imaging techniques and biomarkers are being explored for early detection, but their implementation in clinical practice remains limited.

3. **Therapeutic Challenges**:

• MASLD-HCC treatment is highly complex due to the multifactorial nature of the disease and its pathogenesis.
• While therapies such as liver transplantation, surgical resection, and systemic treatments (e.g., immunotherapy, targeted therapy) are available, their effectiveness can vary depending on the stage of HCC and the presence of underlying metabolic dysfunctions.
• Preventive strategies, including lifestyle modifications (e.g., weight loss, exercise, and dietary changes), are crucial in managing MASLD and reducing the risk of HCC.

### **Current Advancements**

Recent research focuses on improving early detection and risk stratification for MASLD and MASLD-HCC patients. Key advancements include:

• **Biomarkers**: Identifying molecular and genetic markers to predict MASLD progression and HCC risk.
• **Imaging**: Enhanced imaging techniques such as MRI elastography and contrast-enhanced ultrasound for non-invasive liver fibrosis assessment.
• **Therapeutics**: Development of novel drugs targeting metabolic pathways, inflammation, and fibrosis in MASLD, which may help prevent progression to HCC.

### **Conclusion**

MASLD is a rapidly emerging cause of HCC due to the global increase in metabolic disorders such as obesity and T2DM. Early detection, risk evaluation, and effective management of MASLD are critical to preventing progression to HCC and improving patient outcomes. However, challenges remain in diagnosing MASLD-HCC, particularly in patients without cirrhosis, and in developing optimal therapeutic strategies. Continued research and advancements in screening, biomarkers, and targeted therapies are essential to address the growing burden of MASLD-related HCC.