Hepatitis B and hepatitis C are the two forms of hepatitis that cause liver cancer. Together, they account for at least 60% of hepatocellular carcinoma cases worldwide. No other primary hepatitis virus directly causes liver cancer, though hepatitis D (which only occurs alongside hepatitis B) can amplify the risk.
Hepatitis B: The Leading Cause Globally
Hepatitis B is the dominant driver of liver cancer in regions where the virus is most common, particularly Southeast Asia and sub-Saharan Africa. An estimated 360 million people worldwide live with chronic hepatitis B infection, and a meaningful fraction of them will develop liver cancer over the course of decades.
What makes hepatitis B uniquely dangerous is its ability to insert its own genetic material directly into the DNA of liver cells. Once embedded, viral genes can disrupt the normal controls on cell growth. One frequent target is a gene called TERT, which helps cells divide indefinitely, a hallmark of cancer. About one-third of the genes that hepatitis B preferentially inserts itself near are cancer-related, essentially flipping switches that push liver cells toward uncontrolled growth.
This direct DNA integration means hepatitis B can cause liver cancer even without cirrhosis (severe liver scarring). Annual liver cancer rates range from 0.01% to 1.4% in hepatitis B patients who don’t have cirrhosis, compared to 0.9% to 5.4% in those who do. That’s a critical distinction: most liver cancers from other causes develop only after cirrhosis, but hepatitis B doesn’t always follow that pattern.
Hepatitis C: Dominant in Europe, Japan, and the Americas
Hepatitis C takes a different path to liver cancer. More than 170 million people are infected globally, and roughly 80% of them develop chronic infection. In countries like Japan, Pakistan, and across Southern Europe and North Africa, hepatitis C overtakes hepatitis B as the primary cause of liver cancer.
Unlike hepatitis B, hepatitis C doesn’t insert itself into your DNA. Instead, it causes cancer indirectly through years of chronic inflammation. The immune system’s ongoing attempt to fight virus-infected liver cells damages healthy tissue in the process. That damage triggers constant repair and cell division. At the same time, the inflammation generates reactive oxygen species, molecules that cause random mutations in DNA. When you combine a high rate of cell turnover with accumulating DNA errors, the odds of a cancerous transformation climb steadily.
Hepatitis C also promotes fat buildup in the liver, insulin resistance, and progressive scarring (fibrosis). These overlapping processes create an environment where cancer is far more likely to take hold. Nearly all hepatitis C-related liver cancers arise in patients who have already developed cirrhosis, making the progression from infection to scarring to cancer more predictable than with hepatitis B.
How Hepatitis D Fits In
Hepatitis D can only infect people who already have hepatitis B, because it relies on hepatitis B’s surface proteins to replicate. A meta-analysis of 21 studies found that people co-infected with both viruses have roughly double the risk of liver cancer compared to those with hepatitis B alone (odds ratio of 2.08). In patients without additional infections like HIV or hepatitis C, the added risk was even higher, about four times that of hepatitis B alone. Still, there’s ongoing debate about whether hepatitis D is independently carcinogenic or simply accelerates the liver damage that hepatitis B initiates.
The Timeline From Infection to Cancer
Liver cancer from hepatitis doesn’t happen quickly. The typical progression spans decades. Research tracking patients over time found that cirrhosis generally develops about 14 years before a liver cancer diagnosis, with fibrosis scores crossing into the severe range roughly 7 years before cancer is detected. For hepatitis C patients who cleared the virus with treatment, cirrhosis still appeared about 7 years before any cancer showed up, meaning the scarring that had already occurred continued to carry risk.
This long timeline is both the challenge and the opportunity. The slow progression means regular screening can catch cancer early, but it also means many people live with chronic hepatitis for years without symptoms, unaware their risk is building.
Factors That Multiply the Risk
Hepatitis alone doesn’t tell the whole story. Alcohol consumption and exposure to aflatoxin (a toxin produced by mold on improperly stored grains and peanuts, common in tropical regions) can dramatically increase cancer risk in people already infected.
In one large study, people with both hepatitis C and high aflatoxin exposure had 20 times the liver cancer risk of people with neither factor. That’s far greater than the risk from hepatitis C alone (about 6 times baseline) or aflatoxin alone (about 2 times baseline). The likely explanation is that chronic inflammation from the virus makes liver cells more vulnerable to the DNA damage aflatoxin causes. A similar pattern holds for heavy alcohol use combined with hepatitis C, where the compounding damage to liver tissue accelerates the path to cancer.
How Treatment Changes the Outlook
Treating the underlying hepatitis infection substantially lowers liver cancer risk, though it doesn’t eliminate it entirely. For hepatitis B, long-term antiviral therapy reduces cancer risk by about 70%. In one study, the 15-year cumulative cancer incidence was 9% in treated patients compared to 19% in untreated patients.
For hepatitis C, modern antiviral treatments cure the infection in over 95% of cases. Clearing the virus halts the cycle of inflammation and reduces (but does not erase) the cancer risk, particularly in patients who already had significant scarring before treatment. That’s why screening recommendations typically continue even after successful treatment in people who had advanced fibrosis or cirrhosis.
Geographic Patterns Worth Knowing
Where you live shapes which virus poses the greater threat. In East Asia and sub-Saharan Africa, hepatitis B is highly endemic and drives most liver cancer cases. In Japan, Southern Europe, Egypt, and Pakistan, hepatitis C is the primary culprit. In Northern Europe and the United States, a growing share of liver cancer cases are tied to non-viral causes like alcohol-related liver disease and fatty liver disease, though hepatitis C still contributes significantly. Across virtually all regions, hepatitis B and C together remain the leading causes, with hepatitis C’s share growing in many countries as screening and vaccination efforts shift the landscape.