Overall, cancer incidence in the United States has decreased, but liver cancer is one of the exceptions. Each year, about 25,000 men and 11,000 women get liver cancer — an increase of 48 percent since 2000, according to research.
Now a new analysis of liver cancer, published September 5 in Clinical Gastroenterology and Hepatology, provides insights into emerging trends and racial and ethnic differences. “Since 2015, there’s been a decline in liver cancer from hepatitis C — likely due to the advent of direct-acting antivirals — but an increasing incidence of liver cancer from fatty-liver disease, reflecting rising rates of obesity and diabetes in the general population,” says a corresponding author of the new study, Paulo Pinheiro, MD, PhD, an epidemiologist at the Sylvester Comprehensive Cancer Center in Miami.
There’s a false notion that rates are stable, when in reality, certain risks are actually rising and need to be addressed to improve prevention efforts, says Dr. Pinheiro. This is especially important because liver cancer is highly fatal, with a five-year survival rate of only 18 percent.
The study found that race and birthplace influence the causes of liver cancer, with clear differences for various groups and even within some groups who are often “lumped” together, and the disparity appears to be tied to socioeconomic factors, the authors wrote.
“Information by subgroup allows us to identify which patient groups are at greatest risk of developing HCC [hepatocellular carcinoma, the most common type of primary liver cancer], which is an important step in our efforts to address disparities in HCC care,” says Nicole Kim, MD, an assistant professor and hepatologist at UW Medicine in Seattle who was not involved in the research.
Liver Cancer Disproportionately Impacts People With Lower Incomes and Less Education
Previous research performed by Pinheiro and colleagues have shown that an estimated 90 percent of all liver cancers are caused by hepatitis B or hepatitis C viral infections, fatty-liver disease, and alcohol-related liver disease. But the limitations or focus of those earlier studies didn’t allow for a deeper dive into the most common causes specific to racial-ethnic groups — and that information is necessary to develop effective prevention and control efforts for those most vulnerable, according to the authors.
Liver cancer disproportionately affects people of low socioeconomic status, as well as immigrants, veterans, and incarcerated populations — groups which are rarely included in clinical studies because they have limited access to healthcare, notes Pinheiro.
For this trial, investigators took advantage of Florida’s rich ethnic diversity, which allowed them to uncover patterns in detailed racial-ethnic groups, such as Central Americans, Cubans, Dominicans, Mexicans, Puerto Ricans, and South Americans, instead of Hispanic/Latino only. Researchers were similarly able to look at differences between African Americans, Haitians, and West Indians, instead of simply non-Hispanic Black people.
Significant Differences in Causes of Liver Cancer Found Within Racial Groups
The study included 14,420 confirmed cases of hepatocellular carcinoma diagnosed between 2010 and 2018. The data was gathered from Florida’s statewide cancer registry and two other public sources. By using three independent sources, researchers sought to reduce potential biases.
Researchers found that race and birth country were correlated with different causes of liver cancer, with clear differences for various groups that appeared to be connected to socioeconomic factors such as income and education.
Pinheiro and his team were somewhat surprised by the different patterns within each broad racial or ethnic group. “We tend to characterize everyone as Blacks, Hispanics, Asians, etc., but for liver cancer these broad umbrellas fall short,” he says.
There were significant differences in the causes of liver cancer for specific groups, such as Haitian versus African American, Cuban versus Puerto Rican, and Filipino versus Chinese, says Pinheiro.
Other key findings included:
- A threefold difference in liver cancer rates between Puerto Rican and Cuban men, with Puerto Rican men being higher — which authors cited as proof that grouping all Hispanics together can obscure major differences across ethnicity.
- Filipinos have higher rates of fatty-liver-related cancer, similar to Hispanics.
- Liver cancer from hepatitis B infection is the leading cause of liver cancer among Asians and Haitian-born Black men.
- Liver cancer causes that are increasing (fatty liver and alcohol-related), are both more prevalent in the Hispanic population.
- The causes that are declining, primarily hepatitis C, are more prevalent in U.S.-born white and Black populations.
- For men and women combined in 2018, hepatitis C infection and fatty-liver disease accounted for 36 percent and 35 percent of all liver cancers, respectively.
Identifying different causes among and within different races matters because different causes have different implications for prevention of liver cancer, says Pinheiro.
Dr. Kim agrees, pointing out that in this study, Puerto Rican men had the highest HCC rate, while West Indian–born Black men had the lowest HCC rate of all studied groups.
“Without the detailed data, these differences may not have been as clear. As nonalcoholic fatty liver disease … and alcoholic liver disease-related HCC rates are on the rise, it will also be especially important to focus on patient subgroups at greatest risk for these conditions to minimize further disparities in care,” she says.
Although the data presented is limited to Florida, this study offers a model for evaluating other state or national level data on liver cancer, adds Kim.
Findings Highlight the Importance of Screening for Hep B and Hep C
The findings should be used to raise awareness of liver cancer and hepatocellular carcinoma among primary care physicians, says Pinheiro. “All providers should be following the recommendations of the CDC to screen all asymptomatic adult populations in the United States for hepatitis C and hepatitis B. Unfortunately, that is not always the case, and even when screening is done, the specific recommended tests are not always prescribed,” he says.
“If a patient screening results in a positive, they can be referred to a liver specialist and treated for hepatitis C, for which a cure exists, or their hepatitis B can be controlled in a way that lowers the odds of getting liver cancer in the future,” says Pinheiro.
These findings could also be used to raise awareness about the specific risks for certain groups who are more likely to develop different precursors of liver cancer — about hepatitis C for Puerto Ricans, hepatitis B for Haitians, and fatty-liver disease for Hispanics, he adds.
Interested in getting tested for hep B, hep C, or both? Ask your doctor or health department for details. At-home testing kits are also available.