Studies show that Hispanic individuals have higher incidence rates of developing liver cancer and higher mortality rates—by 50% or more—than non-Hispanic White individuals for several cancers, including liver cancer. A new study investigating hepatocellular carcinoma among successive generations of United States residents of Mexican descent living in Los Angeles has found that second- and third-generation individuals had a 35% and 61% higher risk, respectively, than those born in Mexico. The study by Acuna et al was presented during the 15th American Association for Cancer Research (AACR) Conference on the Science of Cancer Health Disparities in racial/Ethnic Minorities and the Medically Underserved (Abstract C110).

Study Methodology

The researchers analyzed data from the Multiethnic Cohort study, a large population-based study of risk factors for cancer and other chronic diseases among more than 215,000 participants from five United States racial/ethnic groups in Los Angeles and Hawaii to study how generational status impacted the risk of hepatocellular carcinoma among individuals of Mexican descent living in Los Angeles. Their analysis focused on self-identified Mexican individuals for whom information on parental birthplace was available. The generation status was categorized as first generation for those born in Mexico with both parents also born in Mexico; second generation for those born in the U.S. with at least one parent born in Mexico; and third generation for those born in the U.S. with both parents also born in the U.S.

Hepatocellular carcinoma risk was assessed after adjusting for age, sex, body mass index (BMI), smoking status, alcohol use, history of diabetes, and daily coffee consumption.

Results

After an average follow-up time of 23.4 years, the researchers found there were a total of 220  incident cases of hepatocellular carcinoma. With successive generations, U.S. residents of Mexican descent were more likely to be current smokers, have a greater intake of alcohol, consume more coffee, and have an elevated BMI.

In addition, there was an increase in age-adjusted hepatocellular carcinoma incidence rates (per 100,000) with each increasing generation (first-generation: 20.9, second-generation: 27.5, third- generation: 34.7). In the multivariable model, second- and third-generation individuals had a 35% (95% confidence interval [CI] = 1.00%–1.84%) and 61% (95% CI = 1.10%–2.36%) increased risk of developing hepatocellular carcinoma, respectively, compared to first-generation individuals (P trend = .009). While the researchers did not observe significant heterogeneity by diabetes status (P heterogeneity = .41), those who did not have diabetes and were third-generation individuals had an 82% (95% CI = 1.17%–2.84%) increased risk of hepatocellular carcinoma compared to first-generation individuals who also did not have diabetes. There was also no heterogeneity by BMI status (P heterogeneity = .92) and alcohol intake (P heterogeneity = .46) for the association between generational status and hepatocellular carcinoma risk. Among those diagnosed with hepatocellular carcinoma, similar distributions of tumor grade or stage at diagnosis were observed across generations.

Second- and third-generation individuals of Mexican descent have a significantly higher risk of developing hepatocellular carcinoma compared to first-generation individuals, concluded the study authors.

Mitigating Increased Risk

“Interventions targeting acculturation and adoption of negative lifestyle behaviors, such as increased alcohol intake, unhealthy diet, and cigarette smoking, among U.S.-born Mexican individuals are needed to mitigate the increased risk of hepatocellular carcinoma in this population,” said lead author of the study Nicholas Acuna, MPH, a PhD student in epidemiology in the Department of Population & Public Health Sciences at the Keck School of Medicine at the University of Southern California.

Disclosure: Funding for this study was provided by the National Cancer Institute.