The Translational Research Program in Cancer Differences across Populations.

Background: Cancer incidence and mortality vary substantially across populations. The Translational Research Program in Cancer Differences across Populations (TRPCDP) was established in 2020 to address differences in cancer incidence and mortality rates within the United States, with a particular focus on colorectal cancer.

Methods: The TRPCDP centralized data acquisition and harmonization across three sites in the United States to create a well-annotated resource of colorectal cancer tumors across four populations: African American/Black, Alaska Native, Hispanic/Latino/Latina, and non-Hispanic White.

Red meat intake interacts with a TGF-β-pathway-based polygenic risk score to impact colorectal cancer risk: Application of a novel approach for polygenic risk score construction.

Background: High intake of red and/or processed meat are established colorectal cancer (CRC) risk factors. Genome-wide association studies (GWAS) have reported 204 variants (G) associated with CRC risk. We used functional annotation data to identify subsets of variants within known pathways and constructed pathway-based Polygenic Risk Scores (pPRS) to model pPRS x environment (E) interactions.

Associations between Calcium Intake and T-cell Infiltration in Colorectal Tumors.

Unlabelled: Higher T-cell infiltration in colorectal tumors has been associated with better prognosis. Evidence indicates that calcium signaling is essential for T-cell functioning. However, as it is unknown whether calcium intake influences T-cell infiltration, we investigated the association of calcium intake with T-cell subsets in the tumor microenvironment of colorectal cancer.

Density of T-cell Subsets in Colorectal Cancer in Relation to Disease-Specific Survival.

Background: Prior studies have demonstrated that the overall density of T cells in colorectal tumors is favorably associated with colorectal cancer survival; however, few studies have considered the potentially distinct roles of heterogeneous T-cell subsets in different tissue regions in relation to colorectal cancer outcomes.

Methods: Including 1,113 colorectal cancer tumors from three observational studies, we conducted in situ T-cell profiling using a customized nine-plex [CD3, CD4, CD8, CD45RA, CD45RO, FOXP3, KRT (keratin), MKI67 (Ki-67), and DAPI] multispectral immunofluorescence assay. Multivariable-adjusted Cox proportional hazards models were used to estimate HRs and 95% confidence intervals for the associations of T-cell subset densities in both epithelial and stromal tissue areas in colorectal cancer with disease-specific survival.

Waist Circumference, a Body Shape Index, and Molecular Subtypes of Colorectal Cancer: A Pooled Analysis of Four Cohort Studies.

Background: Waist circumference (WC) and its allometric counterpart, "a body shape index" (ABSI), are risk factors for colorectal cancer; however, it is uncertain whether associations with these body measurements are limited to specific molecular subtypes of the disease.

Methods: Data from 2,772 colorectal cancer cases and 3,521 controls were pooled from four cohort studies within the Genetics and Epidemiology of Colorectal Cancer Consortium. Four molecular markers (BRAF mutation, KRAS mutation, CpG island methylator phenotype, and microsatellite instability) were analyzed individually and in combination (Jass types).

Functional variants in the cystic fibrosis transmembrane conductance regulator (CFTR) gene are associated with increased risk of colorectal cancer.

Background: Individuals with cystic fibrosis (CF; a recessive disorder) have an increased risk of colorectal cancer (CRC). Evidence suggests individuals with a single CFTR variant may also have increased CRC risk.

Methods: Using population-based studies (GECCO, CORECT, CCFR, and ARIC; 53 785 CRC cases and 58 010 controls), we tested for an association between the most common CFTR variant (Phe508del) and CRC risk.

Association between somatic microsatellite instability, hypermutation status, and specific T cell subsets in colorectal cancer tumors.

Background: Microsatellite instability-high (MSI-high) tumors comprise ~15% of sporadic colorectal cancers (CRC) and are associated with elevated T cell infiltration. However, the universality of this response across T cell subtypes with distinct functions is unknown.

Methods: Including 1,236 CRC tumors from three observational studies, we conducted T cell profiling using a customized 9-plex (CD3, CD4, CD8, CD45RA, CD45RO, FOXP3, KRT, MKI67, and DAPI) multispectral immunofluorescence assay.

Associations of blood lipids and LDL cholesterol lowering drug-targets with colorectal cancer risk: a Mendelian randomisation study.

Background: Whether blood lipids are causally associated with colorectal cancer (CRC) risk remains unclear.

Methods: Using two-sample Mendelian randomisation (MR), our study examined the associations of genetically-predicted blood concentrations of lipids and lipoproteins (primary: LDL-C, HDL-C, triglycerides, and total cholesterol), and genetically-proxied inhibition of HMGCR, NPC1L1, and PCSK9 (which mimic therapeutic effects of LDL-lowering drugs), with risks of CRC and its subsites. Genetic associations with lipids were obtained from the Global Lipids Genetics Consortium (n = 1,320,016), while genetic associations with CRC were obtained from the largest existing CRC consortium (n = 58,221 cases and 67,694 controls).

Fine-mapping analysis including over 254,000 East Asian and European descendants identifies 136 putative colorectal cancer susceptibility genes.

Genome-wide association studies (GWAS) have identified more than 200 common genetic variants independently associated with colorectal cancer (CRC) risk, but the causal variants and target genes are mostly unknown. We sought to fine-map all known CRC risk loci using GWAS data from 100,204 cases and 154,587 controls of East Asian and European ancestry. Our stepwise conditional analyses revealed 238 independent association signals of CRC risk, each with a set of credible causal variants (CCVs), of which 28 signals had a single CCV.

Unveiling challenges in Mendelian randomization for gene-environment interaction.

Gene-environment (GxE) interactions play a crucial role in understanding the complex etiology of various traits, but assessing them using observational data can be challenging due to unmeasured confounders for lifestyle and environmental risk factors. Mendelian randomization (MR) has emerged as a valuable method for assessing causal relationships based on observational data. This approach utilizes genetic variants as instrumental variables (IVs) with the aim of providing a valid statistical test and estimation of causal effects in the presence of unmeasured confounders.