Abstract C110: The role of generation on hepatocellular carcinoma risk among US Mexicans in Los Angeles

Abstract Background. Incidence of hepatocellular carcinoma (HCC) is nearly twice as likely to occur among Hispanics/Latinos compared to their Non-Hispanic White counterparts. Studies show that birthplace may play a role specifically where US-born Hispanic/Latinos are at a greater risk of developing HCC compared to foreign-born Hispanic/Latinos, which may be due to acculturation. Given this information, we looked at how generations in the US impact HCC risk among US Mexicans. Methods. The Multiethnic Cohort (MEC), a prospective study with over 215,000 participants in Los Angeles, CA and Hawaii. The MEC regularly performs linkages with the Surveillance, Epidemiology, End Results (SEER) Program. International Classification of Diseases for Oncology, Third Edition (ICD-O-3) codes C.22 and histology codes 8170-8175 to identify HCC cases up until December 31st, 2017. We subset our sample to self-identified Mexicans with information on parental birthplace (n=32,239). Generation status was categorized by 1st generation as born in the Mexico with both parents born in Mexico; 2nd generation as US-born with at least one parent born in Mexico; and 3rd generation as US-born with both parents also born in the US. To assess HCC risk, we performed multivariable Cox models adjusting for age, sex, body mass index (BMI), smoking status, alcohol intake, history of diabetes, and daily coffee consumption. Results. After an average follow-up time of 23.4 years there were a total of 220 HCC incident cases. With successive generation, US-Mexicans 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 HCC incidence rates (per 100,000) with each increasing generation (1st generation: 20.9, 2nd generation: 27.5, 3rd generation: 34.7). In the multivariable model, 2nd and 3rd generation US Mexicans had a 35% (95% CI: 1.00-1.84) and 61% (95% CI: 1.10-2.36) increased risk of HCC compared to 1st generation US Mexicans, respectively (Ptrend=0.009). While we did not observe significant heterogeneity by diabetes status (Pheterogeneity=0.41); those who did not have diabetes and were 3rd generation had an 82% (95% CI: 1.17-2.84) increased risk of HCC compared to a 1st generation US Mexicans who also did not have diabetes. There was also no heterogeneity by BMI status (Pheterogeneity=0.92) and alcohol intake (Pheterogeneity=0.46) for the association between generation status and HCC risk. Among HCC cases, similar distributions of tumor grade or stage at diagnosis were observed across generations. Conclusions. 2nd and 3rd generation US Mexicans have a significantly higher risk of HCC compared to 1st generation US Mexicans. Targeted interventions focusing on healthier lifestyle behaviors are much needed for US-born Mexicans reduce HCC risk. Citation Format: Nicholas Acuna, Kali Zhou, Paulo Pinheiro, Tiffany Lim, Lynne Wilkens, Loic Le Marchand, Veronica Wendy Setiawan. The role of generation on hepatocellular carcinoma risk among US Mexicans in Los Angeles [abstract]. In: Proceedings of the 15th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2022 Sep 16-19; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2022;31(1 Suppl):Abstract nr C110.