Liver Cancer Causes Differ Markedly by Race/Ethnicity

Hepatocellular carcinoma (HCC) etiologies differ "remarkably" by race/ethnicity, and the variation may warrant specific interventions for different populations, a new review suggests.

HCC represents 78% of liver cancers in the United States and is highly fatal: only 18% of patients survive 5 years, the authors note. Approximately 25,000 new HCC cases are diagnosed annually, and incidence rates have increased 48% since 2000.

The main causes of HCC include chronic hepatitis B virus (HBV) and hepatitis C virus (HCV) infections, nonalcoholic fatty liver disease (NAFLD; now known as metabolic dysfunction–associated steatotic liver disease), and alcohol-related liver disease (ALD), the researchers note.

They sought to determine the distribution of HCC by cause and to identify whether causes differ by race/ethnicity, country of birth, sex, and community income level.

"We were surprised by the heterogeneity of liver cancer patterns by detailed racial/ethnic group," Paulo S. Pinheiro, MD, PhD, of the University of Miami School of Medicine, Florida, told Medscape Medical News. "Simply put, all Blacks are not the same, all Hispanics are not the same, and all Asians are not the same."

For example, among two Caribbean populations ― Puerto Rican males and Cuban males ― there is an almost threefold difference in age-adjusted HCC incidence rates, he noted. It shows that "grouping all Hispanics in the same category may obscure large differences across ethnicity," Pinheiro said.

Primary care physicians, especially those who serve populations more at risk, should follow the latest Centers for Disease Control and Prevention guidelines to screen all asymptomatic adult populations at least once for HBV and HCV, Pinheiro advised.

The study was published online September 5 in Clinical Gastroenterology and Hepatology.

HCC Rates Vary

For the study, 14,420 HCC cases from the Florida statewide cancer registry that were reported from 2010–2018 were individually linked to hospital and discharge data provided by the Florida Agency for Healthcare Administration and to viral hepatitis data from the Florida Department of Health's Department of Sexually Transmitted Diseases and Viral Hepatitis surveillance. The linkages permitted the investigators to determine the etiology of each case.

The diversity of Florida's population enabled examination of HCC incidence and etiology across broad race/ethnicity groups: Hispanic, non-Hispanic White, non-Hispanic Black, and non-Hispanic Asian/Pacific Islander. Etiology was examined across more specific Hispanic groups ― Central American; Cuban; Dominican; Mexican, both US and foreign born; Puerto Rican; and South American ― and more specific non-Hispanic Black populations ― African American, Haitian, and West Indian.

The overall HCC age-adjusted incidence rate (AAIR) for Florida was 9.3 per 100,000 for men, which was 3.8-fold higher than the AAIR among women, which was 2.4 per 100,000.

Among men of all racial/ethnic groups, Puerto Ricans had the highest HCC rate (19.6 per 100,000), largely owing to a high rate of HCV, whereas West Indies–born Black men had the lowest HCC rate (3 per 100,000).

Among women, Mexican women born outside the United States had (5.9 per 100,000), mainly attributable to a high rate of NAFLD. West Indies–born Black women had the lowest rate (1.6 per 100,000).

Leading Causes

Overall, the most prevalent HCC etiology was HCV (46.6%), followed by NAFLD (27.2%), ALD (13%), and HBV (4.4%). The remaining were cryptogenic (7.3%) and other causes (1.5%), including hemochromatosis and autoimmune hepatitis.

The median age at diagnosis for HCV-HCC was 60 years; however, the median age was 71 years for those with NAFLD-HCC.

HCV-HCC proportions were significantly higher among males, US-born individuals, and residents of high-poverty areas.

Although HCV was the main cause of HCC in most populations, HBV was the leading cause among Haitian-born Black men and Asian men. By contrast, NAFLD was the leading cause among Central American, South American, and foreign-born Mexican men and women and among Cuban women.

Since 2017, NAFLD has been the leading cause of HCC among women.

Incidence Rates by Cause

Among men, HCV-HCC AAIRs per 100,000 were especially high among US-born minorities, including Puerto Ricans (10.9), African Americans (8), and US-born Mexican Americans (7.6).

Overall, NAFLD-caused HCC incidence rates were significantly higher among all Hispanic persons in comparison with non-Hispanic White persons. Incidence was lowest among non-Hispanic Black men and women and non-Hispanic White women.

HBV-caused HCC incidence rates were highest among Asian and Haitian-born Black men. They were lower among women in all racial/ethnic groups except Asian women. HBV-HCC also was more prevalent among those born outside the United States; for those patients, the median age was lowest, at 59 years.

ALD-caused HCC rates were low among women of all ethnicities but were high among Puerto Rican, Central American, and Mexican males.

HCV-HCC rates have been declining since 2015 (-9.6% annually), whereas rates are rising for ALD-HCC (+6%) and NAFLD-HCC (+4.3%).

Next Steps

The study provides important data about which groups could benefit from enhanced HCC screening, treatment, and surveillance of underlying liver disease, the researchers write. The information it provides on specific HCC causes could be used to anticipate future HCC burden and to develop targeted outreach and intervention programs, they add.

"The next step is to reinforce the need for HBV and HCV screening tests for all adults in Florida, starting with increased awareness among all medical practitioners," Pinheiro said.

Additionally, surveillance of etiology-specific liver cancer (rather than just all cases of liver cancer combined) should be conducted on data from 2018 onward on a permanent basis in Florida and in states across the country, he said.

The study was supported by the Bankhead Coley Research Program of the State of Florida. Supplemental funding was provided by the Sylvester Comprehensive Cancer Center at the University of Miami Miller School of Medicine. Pinheiro has disclosed no relevant financial relationships.

Clin Gastroenterol Hepatol. Published online September 5, 2023. Abstract

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