Genomic biomarker for the top risk factor of gallbladder cancer, cholelithiasis, in a Latinx population.

Abstract

e16326 Background: Cholelithiasis or Gallstone disease (GSD), is one of the most common and costly digestive disorders in adults worldwide, presenting 10-20% of the general population but in greater than 30% of Latina and Hispanic American women aged 40 years or older. Moreover, GSD individuals contribute significantly to the incidence and mortality of gallbladder and other digestive system cancers; specifically, the excessive risk of gallbladder cancer is 3-10-fold. Parallel to gallbladder cancer, an appalling female preponderance of GSD has been documented for decades; thus, precisely defining high-risk populations and properly managing patients with GSD would lead to reduced disease burden from GSD and multiple cancers. Several genome-wide association studies (GWAS) in the past have identified genes associated with GSD but few were focused on Latinx population. Methods: To identify genetic risk factors for GSD in Latinx population, we used the Sangre Por Salud cohort (SPS) where participants are Latinx adult individuals aged 18-85 years who were current patients in the Mountain Park Health Center in Arizona. This sample represents historically underrepresented population with low socioeconomic status that are primarily Spanish-speaking, majority being born outside of the US, with low rates of health insurance coverage. A total of 172 GSD cases were identified, each matched with 6 controls (n = 1032) who were people from the same community but without history of GSD diagnosis; matching variables are age at enrollment to SPS, sex, height and weight, dyslipidemia, and HbA1C level indicative of type 2 diabetes. We characterized genome-wide interrogation for biomarkers predicting GSD and contributing to the observed gender disparity by performing a GWAS using a matched case-control design. Results: We identified several novel loci associated with GSD and validated few loci that were reported in previous GWAS. The top 3 loci (MATN2, GPRIN3, GPC6) were strongly associated with GSD in our overall analysis; follow-up pathway enrichment analysis suggests enrichment of GO terms that are associated with immunological pathways, enzymatic processes in gallbladder, liver and gastrointestinal tract and GSD pathology. In a sex-specific analysis, CDHR3 and RPL31P35-SEC61G were identified for females, which have been associated respectively with rhinovirus C infection and HbA1c level in previous studies. Conclusions: Our findings suggest directions towards better and deeper understanding of sex differences in GSD pathology, biological mechanisms, and disease progression among Latinx people. Knowing approximately 80% of gallbladder cancer patients harbored gallstones, our optimal goal is to provide evidence for an innovative strategy to early detect and effectively intervene the modifiable risk factors to reduce gallbladder cancer burden in high risk populations.