Why Does Liver Cancer Occur? Causes and Treatment Pathways as of 2026

Liver cancer is a cancer that mostly develops on top of existing liver damage—chronic hepatitis or cirrhosis—and liver function status influences the treatment direction just as much as the cancer stage does. Risk is known to rise with long-standing hepatitis B or C infection or with cirrhosis.

Key Takeaways

• Liver cancer typically develops on top of chronic hepatitis (hepatitis B or C) or cirrhosis, and alongside cancer stage, liver function grade (Child-Pugh) is a core factor determining treatment.
• Korea's 5-year relative survival rate for liver cancer is 40.4% (National Cancer Registration Statistics 2019–2023, National Cancer Center Korea's Central Cancer Registry).
• In the United States, the SEER 5-year relative survival rate for liver and intrahepatic bile duct cancer is 21.9% (2016–2022); this reflects nationwide statistics for each country, not the performance of any single hospital.
• Korea runs a national screening program offering ultrasound and blood tests every 6 months for people with hepatitis B or cirrhosis, which tends to result in a relatively high proportion of cases being caught at a small size.
• In many cases, diagnosis is possible without a biopsy, based on the characteristic blood-flow pattern on contrast-enhanced CT or MRI together with tumor markers such as AFP.

What exactly causes liver cancer?

• Liver cancer is a cancer that mainly arises in a liver already damaged by chronic hepatitis or cirrhosis, rather than in a healthy liver. In patients with cirrhosis or chronic hepatitis, diagnosis is often made when contrast-enhanced CT or MRI shows a characteristic blood-flow pattern (strong enhancement in the arterial phase followed by washout).
• People with hepatitis B, hepatitis C, or cirrhosis are classified as high-risk for liver cancer, and in Korea this group undergoes a national screening program with ultrasound and blood tests every 6 months. As a result, Korea has a relatively high rate of detecting liver cancer at a small size.
• For patients with hepatitis B, it is standard practice to continue taking antiviral medication without interruption before and after liver cancer treatment.

Why is liver function so important in treatment decisions?

• Liver cancer treatment is not decided by TNM stage alone. Staging systems such as BCLC combine the number and size of tumors, whether blood vessels are invaded, liver function (the Child-Pugh grade, which combines bilirubin, albumin, clotting values, ascites, and jaundice), and the patient's overall general condition.
• Even for tumors of the same size, the treatments available can differ depending on liver function. When liver function is significantly impaired, chemotherapy can actually further damage the liver, so the focus shifts to symptom control, preserving liver function, and evaluating the possibility of a liver transplant.

How does treatment differ by stage?

• Stage 1, very early/early stage (small, few tumors, good liver function) — Liver resection is the first-choice treatment. If resection is not feasible due to tumor location or liver function, radiofrequency ablation is used. If liver function is significantly reduced but the tumor meets size/number criteria, a liver transplant is considered.
• Stage 2, intermediate stage (multiple tumors within the liver) — Transarterial chemoembolization (TACE) is central, sometimes combined with radioembolization, stereotactic radiotherapy, particle therapy, or systemic drug therapy.
• Stage 3, advanced stage (vascular invasion or spread outside the liver) — Systemic drug therapy is central. A combination of an immune checkpoint inhibitor and an angiogenesis inhibitor is now part of the first-line standard of care, and oral targeted therapy is used depending on the patient's condition.
• Stage 4, significantly impaired liver function — Because chemotherapy can place a heavy burden on the liver, symptom control and preservation of liver function take priority.

FAQ — Can liver cancer be diagnosed without a biopsy?

Yes. Unlike many other cancers, liver cancer is often diagnosed through imaging findings (blood-flow patterns on contrast-enhanced CT or MRI), tumor markers (such as AFP), and hepatitis status, making a biopsy unnecessary in many cases. A biopsy is performed only when imaging findings are ambiguous or metastasis from another cancer is suspected.

FAQ — Can the survival rate figures be trusted?

Korea's 5-year relative survival rate of 40.4% and the U.S. SEER figure of 21.9% are both nationwide statistics, not the results of any particular hospital. They represent population averages and are not numbers that predict an individual outcome. Because the two countries' screening systems and timing of detection differ, simple comparisons between them have limitations.

Sources and Notes

• This article was written based on National Cancer Registration Statistics 2019–2023 (National Cancer Center Korea) and SEER 2016–2022 (U.S. National Cancer Institute).
• This content is intended to provide general medical information, and actual diagnosis, treatment methods, and outcomes may vary depending on the individual's condition. Accurate diagnosis and treatment should always be determined through consultation with a medical professional.