Study finds increased risk of liver cancer among Mexican Americans in later generations

In the United States, liver cancer rates have more than tripled since 1980. Some groups, including Latinos, face an even higher risk than the general population, but researchers don’t fully understand why.

A study from the Keck School of Medicine of USC, funded by the National Cancer Institute, has shed new light on those disparities. Researchers found that among Mexican Americans, the risk of liver cancer increases the longer a person’s family has lived in the U.S. That increased risk primarily affected men. The findings have just been published in the journal. Cancer.

With each subsequent generation, we see an increased risk of liver cancer. When we take a closer look at this trend, the numbers are significant.”

Veronica Wendy Setiawan, PhD, senior author, professor of population sciences and public health and Jane and Kris Popovich Chair in Cancer Research at the Keck School of Medicine

Setiawan and his colleagues analyzed data on first-, second-, and third-generation Mexican Americans. Compared to the first generation, second-generation Mexican Americans were 37% more likely to develop liver cancer and third-generation Mexican Americans were 66% more likely to develop the disease.

Metabolic syndrome (including obesity and diabetes) and lifestyle factors, such as increased alcohol consumption and smoking in later generations, may explain some, but not all, of the increased risk. More research is needed to understand what other factors are linked to the increase in liver cancer cases.

“The Mexican-American population is growing, but there is very little research focusing on this group,” said Setiawan, who is also co-director of the Cancer Epidemiology Program at the USC Norris Comprehensive Cancer Center. “So there’s a lot we still don’t know.”

Unexplained disparities

Researchers studied 31,377 Mexican Americans who were part of the Multi-Ethnic Cohort Study, a collaboration between USC and the University of Hawaii Cancer Center. First-generation participants were born in Mexico; second-generation participants were born in the US with one or both parents born in Mexico; and third-generation participants were born in the US along with both of their parents.

Across all generations, 213 participants developed liver cancer. Compared to the first generation, second- and third-generation Mexican Americans faced a 37% and 66% higher risk, respectively. Researchers believe the increased risk may primarily affect men because they tend to have more risk factors related to the disease than women.

The researchers looked at a number of factors that could influence a person’s risk of developing liver cancer, including higher rates of alcohol and cigarette consumption, as well as a higher average body mass index. They also took into account neighborhood-level factors that may influence cancer risk, including socioeconomic status and living in an “ethnic enclave,” a geographic area with many residents of a single ethnicity.

“After adjusting for factors that are different between generations, we still see these higher risks,” Setiawan said. “That tells us that this is an important population to study further.”

A continuous search for answers

Additional research on lifestyle and neighborhood factors, including data on diet, education, and environmental exposures, may help researchers continue to explain ethnic disparities in liver cancer risk. That knowledge can ultimately support targeted prevention efforts to protect high-risk populations from developing the disease, Setiawan said.

She and her colleagues also received funding from the National Institutes of Health to recruit approximately 2,000 Latino participants nationwide in Los Angeles with fatty liver disease, a possible precursor to liver cancer. They will perform ultrasounds to track liver health over time and collect detailed information about diet and other aspects of health to get a clearer picture of how the disease progresses.