Low prevalence of reporting of participant race and ethnicity in gastroenterology research publications.

BACKGROUND: Empirical information on the evolution of reporting race and ethnicity information in gastroenterology research is lacking. To facilitate understanding of where improvements are needed to increase diversity, equity, and inclusion in gastroenterology research, we aimed to evaluate reporting and representation by race and ethnicity in studies published in flagship United States-based gastroenterology journals over 20 years. METHODS: We manually reviewed reporting and representation by race and ethnicity in all original research articles published in the American Journal of Gastroenterology and Gastroenterology in 2000, 2010, and 2020. RESULTS: Of 1,168 publications, 24% reported information on race/ethnicity, significantly more commonly reported in US-based studies vs non-US based studies. While reporting significantly increased over time, reporting rates were still low as of 2020 (37% overall; 54% with US samples). CONCLUSIONS: We recommend that gastroenterology journals create standard reporting requirements for sociodemographic information, including information on race, ethnicity, and/or cultural background.

Aspirin Use and Incidence of Colorectal Cancer According to Lifestyle Risk.

Importance: Aspirin reduces the risk of colorectal cancer (CRC). Identifying individuals more likely to benefit from regular aspirin use for CRC prevention is a high priority. Objective: To assess whether aspirin use is associated with the risk of CRC across different lifestyle risk factors. Design, Setting, and Participants: A prospective cohort study among women in the Nurses' Health Study (1980-2018) and men in the Health Professionals Follow-Up Study (1986-2018) was conducted. Data analysis was performed from October 1, 2021, to May 22, 2023. Exposures: A healthy lifestyle score was calculated based on body mass index, alcohol intake, physical activity, diet, and smoking with scores ranging from 0 to 5 (higher values corresponding to a healthier lifestyle). Regular aspirin use was defined as 2 or more standard tablets (325 mg) per week. Main Outcome and Measures: Outcomes included multivariable-adjusted 10-year cumulative incidence of CRC, absolute risk reduction (ARR), and number needed to treat associated with regular aspirin use by lifestyle score and multivariable-adjusted hazard ratios for incident CRC across lifestyle scores. Results: The mean (SD) baseline age of the 107 655 study participants (63 957 women from the Nurses' Health Study and 43 698 men from the Health Professionals Follow-Up Study) was 49.4 (9.0) years. During 3 038 215 person-years of follow-up, 2544 incident cases of CRC were documented. The 10-year cumulative CRC incidence was 1.98% (95% CI, 1.44%-2.51%) among participants who regularly used aspirin compared with 2.95% (95% CI, 2.31%-3.58%) among those who did not use aspirin, corresponding to an ARR of 0.97%. The ARR associated with aspirin use was greatest among those with the unhealthiest lifestyle scores and progressively decreased with healthier lifestyle scores (P < .001 for additive interaction). The 10-year ARR for lifestyle scores 0 to 1 (unhealthiest) was 1.28%. In contrast, the 10-year ARR for lifestyle scores 4 to 5 (healthiest) was 0.11%. The 10-year number needed to treat with aspirin was 78 for participants with lifestyle scores 0 to 1, 164 for score 2, 154 for score 3, and 909 for scores 4 to 5. Among the components of the healthy lifestyle score, the greatest differences in ARR associated with aspirin use were observed for body mass index and smoking. Conclusions and Relevance: In this cohort study, aspirin use was associated with a greater absolute reduction in risk of CRC among individuals with less healthy lifestyles. The findings of the study suggest that lifestyle risk factors may be useful to identify individuals who may have a more favorable risk-benefit profile for cancer prevention with aspirin.

Maladaptive weight control and eating behaviours in female adolescents/young adults are associated with increased risk of irritable bowel syndrome in adulthood: Results from the Growing Up Today Study (GUTS).

BACKGROUND: Irritable bowel syndrome (IBS) is common among individuals with eating disorders. The relationship between these conditions is likely bidirectional. However, data on the risk of IBS among those with prior eating disorders is largely limited to cross-sectional studies. AIM: To prospectively evaluate the association between maladaptive weight control/eating behaviours in females during adolescence/young adulthood with subsequent IBS using the Growing Up Today Study (GUTS). METHODS: Starting in 1996 (age: 9-14) and during follow-up, participants reported frequency of maladaptive eating/weight control behaviours during the past year to lose weight: self-induced vomiting (n = 5740), laxative use (n = 5438), and fasting (n = 5522) in addition to reporting binge eating (n = 4459). Starting in 2001 and during follow-up, participants reported if they had ever been diagnosed with an eating disorder (n = 5316). Incident IBS cases were identified from four questionnaire cycles (2013, 2014, 2016, 2019), with participants specifying the year of diagnosis if occurring before the questionnaire date. Multivariable logistic regressions adjusting for age, body mass index, and depressive symptoms estimated the associations of interest. RESULTS: Maladaptive weight control/eating behaviours were associated with increased IBS risk [ORs (95% CIs) for laxatives to lose weight = 3.67 (2.52-5.35), vomiting to lose weight = 1.83 (1.29-2.60), fasting to lose weight = 2.62 (1.86-3.70), and bingeing = 2.25 (1.54-3.28)] as was history of eating disorder diagnosis [OR (95% CI) = 3.42 (2.38-4.90)]. The magnitude of IBS risk increased with the frequency of maladaptive behaviours. CONCLUSIONS: There is evidence for the potential role of early maladaptive weight control/eating behaviours in the development of adult IBS among females.

An Empirical Dietary Pattern Associated with the Gut Microbial Features in Relation to Colorectal Cancer Risk.

BACKGROUND & AIMS: Epidemiologic evidence for dietary influence on colorectal cancer (CRC) risk through the gut microbiome remains limited. METHODS: Leveraging 307 men and 212 women with stool metagenomes and dietary data, we characterized and validated a sex-specific dietary pattern associated with the CRC-related gut microbial signature (CRC Microbial Dietary Score [CMDS]). We evaluated the associations of CMDS with CRC risk according to Fusobacterium nucleatum, pks+Escherichia coli, and enterotoxigenic Bacteroides fragilis (ETBF) status in tumor tissue using Cox proportional hazards regression in the Health Professionals Follow-up Study (1986-2018), Nurses' Health Study (NHS) (1984-2020), and NHS II (1991-2019). RESULTS: The CMDS was characterized by high industrially processed foods and low unprocessed fiber-rich foods intakes. In 259,200 participants, we documented 3,854 incident CRC cases over 6,467,378 person-years of follow-up. CMDS was associated with a higher risk of CRC (Ptrend<0.001), with a multivariable hazard ratio (HRQ5vs.Q1) of 1.25 (95%CI, 1.13-1.39). The association remained after adjusting for previously established dietary patterns, e.g., the Western and prudent diets. Notably, the association was stronger for tumoral F. nucleatum-positive (HRQ5vs.Q1, 2.51; 95%CI, 1.68-3.75; Ptrend<0.001) (Pheterogeneity=0.03, positivity vs. negativity), pks+E. coli-positive (HRQ5vs.Q1, 1.68; 95%CI, 0.84-3.38; Ptrend=0.005) (Pheterogeneity=0.01, positivity vs. negativity), and ETBF-positive CRC (HRQ5vs.Q1, 2.06; 95%CI, 1.10-3.88; Ptrend=0.016) (Pheterogeneity=0.06, positivity vs. negativity), compared with their negative counterparts. CONCLUSIONS: CMDS was associated with increased CRC risk, especially for tumors with detectable F. nucleatum, pks+E. coli, and ETBF in tissue. Our findings support a potential role of the gut microbiome underlying the dietary effects on CRC.

Optimizing single-cell RNA sequencing methods for human colon biopsies: droplet-based vs. picowell-based platforms.

Background & Aims: Single-cell RNA sequencing (scRNA) has empowered many insights into gastrointestinal microenvironments. However, profiling human biopsies using droplet-based scRNA (D-scRNA) is challenging since it requires immediate processing to minimize epithelial cell damage. In contrast, picowell-based (P-scRNA) platforms permit short-term frozen storage before sequencing. We compared P- and D-scRNA platforms on cells derived from human colon biopsies. Methods: Endoscopic rectosigmoid mucosal biopsies were obtained from two adults and conducted D-scRNA (10X Chromium) and P-scRNA (Honeycomb HIVE) in parallel using an individual's pool of single cells (> 10,000 cells/participant). Three experiments were performed to evaluate 1) P-scRNA with cells under specific storage conditions (immediately processed [fresh], vs. frozen at -20C vs. -80C [2 weeks]); 2) fresh P-scRNA versus fresh D-scRNA; and 3) P-scRNA stored at -80C with fresh D-scRNA. Results: Significant recovery of loaded cells was achieved for fresh (80.9%) and -80C (48.5%) P-scRNA and D-scRNA (76.6%), but not -20C P-scRNA (3.7%). However, D-scRNA captures more typeable cells among recovered cells (71.5% vs. 15.8% Fresh and 18.4% -80C P-scRNA), and these cells exhibit higher gene coverage at the expense of higher mitochondrial read fractions across most cell types. Cells profiled using D-scRNA demonstrated more consistent gene expression profiles among the same cell type than those profiled using P-scRNA. Significant intra-cell-type differences were observed in profiled gene classes across platforms. Conclusions: Our results highlight non-overlapping advantages of P-scRNA and D-scRNA and underscore the need for innovation to enable high-fidelity capture of colonic epithelial cells. The platform-specific variation highlights the challenges of maintaining rigor and reproducibility across studies that use different platforms.

Intestinal Blastocystis is linked to healthier diets and more favorable cardiometabolic outcomes in 56,989 individuals from 32 countries.

Diet impacts human health, influencing body adiposity and the risk of developing cardiometabolic diseases. The gut microbiome is a key player in the diet-health axis, but while its bacterial fraction is widely studied, the role of micro-eukaryotes, including Blastocystis, is underexplored. We performed a global-scale analysis on 56,989 metagenomes and showed that human Blastocystis exhibits distinct prevalence patterns linked to geography, lifestyle, and dietary habits. Blastocystis presence defined a specific bacterial signature and was positively associated with more favorable cardiometabolic profiles and negatively with obesity (p < 1e-16) and disorders linked to altered gut ecology (p < 1e-8). In a diet intervention study involving 1,124 individuals, improvements in dietary quality were linked to weight loss and increases in Blastocystis prevalence (p = 0.003) and abundance (p < 1e-7). Our findings suggest a potentially beneficial role for Blastocystis, which may help explain personalized host responses to diet and downstream disease etiopathogenesis.

Short- and long-term impact of aspirin cessation in older adults: a target trial emulation.

BACKGROUND: The net benefit of aspirin cessation in older adults remains uncertain. This study aimed to use observational data to emulate a randomized trial of aspirin cessation versus continuation in older adults without cardiovascular disease (CVD). METHODS: Post hoc analysis using a target trial emulation framework applied to the immediate post-trial period (2017-2021) of a study of low-dose aspirin initiation in adults aged ≥ 70 years (ASPREE; NCT01038583). Participants from Australia and the USA were included if they were free of CVD at the start of the post-trial intervention period (time zero, T0) and had been taking open-label or randomized aspirin immediately before T0. The two groups in the target trial were as follows: aspirin cessation (participants who were taking randomized aspirin immediately before T0; assumed to have stopped at T0 as instructed) versus aspirin continuation (participants on open-label aspirin at T0 regardless of their randomized treatment; assumed to have continued at T0). The outcomes after T0 were incident CVD, major adverse cardiovascular events (MACE), all-cause mortality, and major bleeding during 3, 6, and 12 months (short-term) and 48 months (long-term) follow-up. Hazard ratios (HRs) comparing aspirin cessation to continuation were estimated from propensity-score (PS) adjusted Cox proportional-hazards regression models. RESULTS: We included 6103 CVD-free participants (cessation: 5427, continuation: 676). Over both short- and long-term follow-up, aspirin cessation versus continuation was not associated with elevated risk of CVD, MACE, and all-cause mortality (HRs, at 3 and 48 months respectively, were 1.23 and 0.73 for CVD, 1.11 and 0.84 for MACE, and 0.23 and 0.79 for all-cause mortality, p > 0.05), but cessation had a reduced risk of incident major bleeding events (HRs at 3 and 48 months, 0.16 and 0.63, p < 0.05). Similar findings were seen for all outcomes at 6 and 12 months, except for a lowered risk of all-cause mortality in the cessation group at 12 months. CONCLUSIONS: Our findings suggest that deprescribing prophylactic aspirin might be safe in healthy older adults with no known CVD.

Ultraprocessed food consumption and risk of gallstone disease: analysis of 3 prospective cohorts.

BACKGROUND: Majority of dietary intake in United States adults comes from ultraprocessed foods (UPFs), which have been linked to several adverse health outcomes. Gallstone disease is highly prevalent and constitutes a significant burden to the United States health system but remains understudied. OBJECTIVES: This study aimed to investigate the association between UPF consumption and incident gallstone disease risk. METHODS: In this analysis, 44,149 males in the Health Professionals' Follow-up Study (HPFS: 1986-2022), 71,145 females in the Nurses' Health Study (NHS: 1986-2021), and 90,932 females in the NHS II (1991-2021) were prospectively followed. Dietary intake was quadrennially assessed with semiquantitative food frequency questionnaires and used to identify UPFs. The primary outcome was defined as cholecystectomy. Cox proportional hazards model was used to estimate adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs). RESULTS: Baseline median age was 54 y in HPFS, 53 y in NHS, and 36 y in NHS II. We identified 32,374 incident gallstone disease cases over 5,077,059 person-years. Participants in the highest UPF quintile had a higher incidence of gallstone disease than those in the lowest quintile (aHR: 1.29; 95% CI: 1.24, 1.36; P < 0.001). Incremental risk of incident gallstone disease was 2.8% per daily serving (95% CI: 2.4%, 3.2%; P < 0.001). This risk was driven by sugar-sweetened beverages and artificially sweetened beverages on UPF subgroup analyses. The proportion of risk mediated by obesity was 12.8% (95% CI: 7.7%, 20.5%; P < 0.001) in HPFS, 14.3% (95% CI: 10.4%, 19.4%; P < 0.001) in NHS, and 39.4% (95% CI: 31.2%, 48.1%; P < 0.001) in NHS II. The partial population attributable risk was estimated at 15.9% (95% CI: 13.4%, 18.3%). CONCLUSIONS: UPF consumption is associated with a higher risk of gallstone disease, particularly consumption of sugar-sweetened beverages and artificially sweetened beverages. A substantial proportion of this risk is potentially mediated by obesity in younger females.

Community collaboration to advance racial/ethnic equity in colorectal Cancer screening: Protocol for a multilevel intervention to improve screening and follow-up in community Health centers.

INTRODUCTION: Colorectal cancer (CRC) screening utilization is low among low-income, uninsured, and minority populations that receive care in community health centers (CHCs). There is a need for evidence-based interventions to increase screening and follow-up care in these settings. METHODS: A multilevel, multi-component pragmatic cluster randomized controlled trial is being conducted at 8 CHCs in two metropolitan areas (Boston and Los Angeles), with two arms: (1) Mailed FIT outreach with text reminders, and (2) Mailed FIT-DNA with patient support. We also include an additional CHC in Rapid City (South Dakota) that follows a parallel protocol for FIT-DNA but is not randomized due to lack of a comparison group. Eligible individuals in participating clinics are primary care patients ages 45-75, at average-risk for CRC, and overdue for CRC screening. Participants with abnormal screening results are offered navigation for follow-up colonoscopy and CRC risk assessment. RESULTS: The primary outcome is the completion rate of CRC screening at 90 days. Secondary outcomes include the screening completion rate at 180 days and the rate of colonoscopy completion within 6 months among participants with an abnormal result. Additional goals are to enhance our understanding of facilitators and barriers to CRC risk assessment in CHC settings. CONCLUSIONS: This study assesses the effectiveness of two multilevel interventions to increase screening participation and follow-up after abnormal screening in under-resourced clinical settings, informing future efforts to address CRC disparities. TRIAL REGISTRATION: NCT05714644.

Folate intake and colorectal cancer risk according to genetic subtypes defined by targeted tumor sequencing.

BACKGROUND: Folate is involved in multiple genetic, epigenetic, and metabolic processes, and inadequate folate intake has been associated with an increased risk of cancer. OBJECTIVE: We examined whether folate intake is differentially associated with colorectal cancer (CRC) risk according to somatic mutations in genes linked to CRC using targeted sequencing. DESIGN: Participants within 2 large CRC consortia with available information on dietary folate, supplemental folic acid, and total folate intake were included. Colorectal tumor samples from cases were sequenced for the presence of nonsilent mutations in 105 genes and 6 signaling pathways (IGF2/PI3K, MMR, RTK/RAS, TGF-ß, WNT, and TP53/ATM). Multinomial logistic regression models were analyzed comparing mutated/nonmutated CRC cases to controls to compute multivariable-adjusted odds ratios (ORs) with 95% confidence interval (CI). Heterogeneity of associations of mutated compared with nonmutated CRC cases was tested in case-only analyses using logistic regression. Analyses were performed separately in hypermutated and nonhypermutated tumors, because they exhibit different clinical behaviors. RESULTS: We included 4339 CRC cases (702 hypermutated tumors, 16.2%) and 11,767 controls. Total folate intake was inversely associated with CRC risk (OR = 0.93; 95% CI: 0.90, 0.96). Among hypermutated tumors, 12 genes (AXIN2, B2M, BCOR, CHD1, DOCK3, FBLN2, MAP3K21, POLD1, RYR1, TET2, UTP20, and ZNF521) showed nominal statistical significance (P < 0.05) for heterogeneity by mutation status, but none remained significant after multiple testing correction. Among these genetic subtypes, the associations between folate variables and CRC were mostly inverse or toward the null, except for tumors mutated for DOCK3 (supplemental folic acid), CHD1 (total folate), and ZNF521 (dietary folate) that showed positive associations. We did not observe differential associations in analyses among nonhypermutated tumors, or according to the signaling pathways. CONCLUSIONS: Folate intake was not differentially associated with CRC risk according to mutations in the genes explored. The nominally significant differential mutation effects observed in a few genes warrants further investigation.

Strain-specific gut microbial signatures in type 2 diabetes identified in a cross-cohort analysis of 8,117 metagenomes.

The association of gut microbial features with type 2 diabetes (T2D) has been inconsistent due in part to the complexity of this disease and variation in study design. Even in cases in which individual microbial species have been associated with T2D, mechanisms have been unable to be attributed to these associations based on specific microbial strains. We conducted a comprehensive study of the T2D microbiome, analyzing 8,117 shotgun metagenomes from 10 cohorts of individuals with T2D, prediabetes, and normoglycemic status in the United States, Europe, Israel and China. Dysbiosis in 19 phylogenetically diverse species was associated with T2D (false discovery rate < 0.10), for example, enriched Clostridium bolteae and depleted Butyrivibrio crossotus. These microorganisms also contributed to community-level functional changes potentially underlying T2D pathogenesis, for example, perturbations in glucose metabolism. Our study identifies within-species phylogenetic diversity for strains of 27 species that explain inter-individual differences in T2D risk, such as Eubacterium rectale. In some cases, these were explained by strain-specific gene carriage, including loci involved in various mechanisms of horizontal gene transfer and novel biological processes underlying metabolic risk, for example, quorum sensing. In summary, our study provides robust cross-cohort microbial signatures in a strain-resolved manner and offers new mechanistic insights into T2D.

Pre-diagnostic plasma inflammatory proteins and risk of hepatocellular carcinoma in three population-based cohort studies from the United States and the United Kingdom.

Previous studies suggest a role for inflammation in hepatocarcinogenesis. However, no study has comprehensively evaluated associations between circulating inflammatory proteins and risk of hepatocellular carcinoma (HCC) among the general population. We conducted a nested case-control study in the Nurses' Health Study (NHS) and the Health Professionals Follow-up Study (HPFS) with 56 pairs of incident HCC cases and controls. External validation was performed in the UK Biobank (34 HCC cases and 48,471 non-HCC controls). Inflammatory protein levels were measured in pre-diagnostic plasma using the Olink® Inflammation Panel. We used conditional logistic regression to calculate multivariable odds ratios (ORs) with 95% confidence intervals (CIs) for associations between a 1-standard deviation (SD) increase in biomarker levels and HCC risk, considering a statistically significant threshold of false discovery rate (FDR)-adjusted p < .05. In the NHS/HPFS, among 70 analyzed proteins with call rates >80%, 15 proteins had significant associations with HCC risk (pFDR < .05). Two proteins (stem cell factor, OR per SD = 0.31, 95% CI = 0.16-0.58; tumor necrosis factor superfamily member 12, OR per SD = 0.51, 95% CI = 0.31-0.85) were inversely associated whereas 13 proteins were positively associated with risk of HCC; positive ORs per SD ranged from 1.73 for interleukin (IL)-10 to 2.35 for C-C motif chemokine-19. A total of 11 proteins were further replicated in the UK Biobank. Seven of the eight selected positively associated proteins also showed positive associations with HCC risk by enzyme-linked immunosorbent assay, with ORs ranging from 1.56 for IL-10 to 2.72 for hepatocyte growth factor. More studies are warranted to further investigate the roles of these observed inflammatory proteins in HCC etiology, early detection, risk stratification, and disease treatment.

Genome-wide interaction study of dietary intake of fibre, fruits, and vegetables with risk of colorectal cancer.

BACKGROUND: Consumption of fibre, fruits and vegetables have been linked with lower colorectal cancer (CRC) risk. A genome-wide gene-environment (G × E) analysis was performed to test whether genetic variants modify these associations. METHODS: A pooled sample of 45 studies including up to 69,734 participants (cases: 29,896; controls: 39,838) of European ancestry were included. To identify G × E interactions, we used the traditional 1--degree-of-freedom (DF) G × E test and to improve power a 2-step procedure and a 3DF joint test that investigates the association between a genetic variant and dietary exposure, CRC risk and G × E interaction simultaneously. FINDINGS: The 3-DF joint test revealed two significant loci with p-value <5 × 10-8. Rs4730274 close to the SLC26A3 gene showed an association with fibre (p-value: 2.4 × 10-3) and G × fibre interaction with CRC (OR per quartile of fibre increase = 0.87, 0.80, and 0.75 for CC, TC, and TT genotype, respectively; G × E p-value: 1.8 × 10-7). Rs1620977 in the NEGR1 gene showed an association with fruit intake (p-value: 1.0 × 10-8) and G × fruit interaction with CRC (OR per quartile of fruit increase = 0.75, 0.65, and 0.56 for AA, AG, and GG genotype, respectively; G × E -p-value: 0.029). INTERPRETATION: We identified 2 loci associated with fibre and fruit intake that also modify the association of these dietary factors with CRC risk. Potential mechanisms include chronic inflammatory intestinal disorders, and gut function. However, further studies are needed for mechanistic validation and replication of findings. FUNDING: National Institutes of Health, National Cancer Institute. Full funding details for the individual consortia are provided in acknowledgments.

Identification of potential mediators of the relationship between body mass index and colorectal cancer: a Mendelian randomization analysis.

BACKGROUND: Colorectal cancer (CRC) is the third-most-common cancer worldwide and its rates are increasing. Elevated body mass index (BMI) is an established risk factor for CRC, although the molecular mechanisms behind this association remain unclear. Using the Mendelian randomization (MR) framework, we aimed to investigate the mediating effects of putative biomarkers and other CRC risk factors in the association between BMI and CRC. METHODS: We selected as mediators biomarkers of established cancer-related mechanisms and other CRC risk factors for which a plausible association with obesity exists, such as inflammatory biomarkers, glucose homeostasis traits, lipids, adipokines, insulin-like growth factor 1 (IGF1), sex hormones, 25-hydroxy-vitamin D, smoking, physical activity (PA) and alcohol consumption. We used inverse-variance weighted MR in the main univariable analyses and performed sensitivity analyses (weighted-median, MR-Egger, Contamination Mixture). We used multivariable MR for the mediation analyses. RESULTS: Genetically predicted BMI was positively associated with CRC risk [odds ratio per SD (5 kg/m2) = 1.17, 95% CI: 1.08-1.24, P-value = 1.4 × 10-5] and robustly associated with nearly all potential mediators. Genetically predicted IGF1, fasting insulin, low-density lipoprotein cholesterol, smoking, PA and alcohol were associated with CRC risk. Evidence for attenuation was found for IGF1 [explained 7% (95% CI: 2-13%) of the association], smoking (31%, 4-57%) and PA (7%, 2-11%). There was little evidence for pleiotropy, although smoking was bidirectionally associated with BMI and instruments were weak for PA. CONCLUSIONS: The effect of BMI on CRC risk is possibly partly mediated through plasma IGF1, whereas the attenuation of the BMI-CRC association by smoking and PA may reflect confounding and shared underlying mechanisms rather than mediation.

Appendectomy and Long-term Colorectal Cancer Incidence, Overall and by Tumor Fusobacterium nucleatum Status.

OBJECTIVE: To test hypotheses that appendectomy history might lower long-term colorectal cancer risk and that the risk reduction might be strong for tumors enriched with Fusobacterium nucleatum, bacterial species implicated in colorectal carcinogenesis. BACKGROUND: The absence of the appendix, an immune system organ and a possible reservoir of certain pathogenic microbes, may affect the intestinal microbiome, thereby altering long-term colorectal cancer risk. METHODS: Utilizing databases of prospective cohort studies, namely the Nurses' Health Study and the Health Professionals Follow-up Study, we examined the association of appendectomy history with colorectal cancer incidence overall and subclassified by the amount of tumor tissue Fusobacterium nucleatum​​ (Fusobacterium animalis). We used an inverse probability weighted multivariable-adjusted duplication-method Cox proportional hazards regression model. RESULTS: During the follow-up of 139,406 participants (2,894,060 person-years), we documented 2811 incident colorectal cancer cases, of which 1065 cases provided tissue F. nucleatum analysis data. The multivariable-adjusted hazard ratio of appendectomy for overall colorectal cancer incidence was 0.92 (95% CI, 0.84-1.01). Appendectomy was associated with lower F. nucleatum-positive cancer incidence (multivariable-adjusted hazard ratio, 0.53; 95% CI, 0.33-0.85; P=0.0079), but not F. nucleatum-negative cancer incidence (multivariable-adjusted hazard ratio, 0.98; 95% CI, 0.83-1.14), suggesting a differential association by F. nucleatum status (Pheterogeneity=0.015). This differential association appeared to persist in various participant/patient strata including tumor location and microsatellite instability status. CONCLUSIONS: Appendectomy likely lowers the future long-term incidence of F. nucleatum-positive (but not F. nucleatum-negative) colorectal cancer. Our findings do not support the existing hypothesis that appendectomy may increase colorectal cancer risk.

Association of tea and coffee consumption and biliary tract cancer risk: The Biliary Tract Cancers Pooling Project.

BACKGROUND AND AIMS: Tea and coffee are widely consumed beverages worldwide. We evaluated their association with biliary tract cancer (BTC) incidence. APPROACH AND RESULTS: We pooled data from 15 studies in the Biliary Tract Cancers Pooling Project to evaluate associations between tea and coffee consumption and biliary tract cancer development. We categorized participants as nondrinkers (0 cup/day), moderate drinkers (>0 and <3 cups/day), and heavy drinkers (≥3 cups/day). We estimated multivariable HRs and 95% CIs using Cox models. During 29,911,744 person-years of follow-up, 851 gallbladder, 588 intrahepatic bile duct, 753 extrahepatic bile duct, and 458 ampulla of Vater cancer cases were diagnosed. Individuals who drank tea showed a statistically significantly lower incidence rate of gallbladder cancer (GBC) relative to tea nondrinkers (HR=0.77; 95% CI, 0.64-0.91), and intrahepatic bile duct cancer (IHBDC) had an inverse association (HR=0.81; 95% CI, 0.66-1.00). However, no associations were observed for extrahepatic bile duct cancer (EHBDC) or ampulla of Vater cancer (AVC). In contrast, coffee consumption was positively associated with GBC, with a higher incidence rate for individuals consuming more coffee (HR<3 cups/day =1.29; 95% CI, 1.01-1.66; HR≥3 cups/day =1.49; 95% CI, 1.11-1.99, Ptrend=0.01) relative to coffee nondrinkers. However, there was no association between coffee consumption and GBC when restricted to coffee drinkers. There was little evidence of associations between coffee consumption and other biliary tract cancers. CONCLUSIONS: Tea consumption was associated with a lower incidence of GBC and possibly IHBDC. Further research is warranted to replicate the observed positive association between coffee and GBC.

Identifying modifiable risk factors to prevent aggressive colorectal cancer.

It remains unclear if pre-diagnostic factors influence the developmental pathways of colorectal cancer (CRC) that could enhance tumor aggressiveness. This study used prospective data from 205,489 cancer-free US health professionals to investigate the associations of 31 known or putative risk factors with the risk of aggressive CRC. Tumor aggressiveness was characterized by three endpoints: aggressive CRC (cancer that causes death within 5 years of diagnosis), fatal CRC, and tumor stage at diagnosis. The data augmentation method was used to assess the difference in the associations between risk factors and endpoints. We documented 3201 CRC cases, of which 899 were aggressive. The protective associations of undergoing lower endoscopy (hazard ratios [HR] 0.43, 95% confidence interval (CI) 0.37, 0.49 for aggressive versus HR 0.61, 95% CI 0.56, 0.67 for non-aggressive) and regular use of aspirin (HR 0.70, 95% CI 0.61, 0.81 versus HR 0.84, 95% CI 0.77, 0.92) were stronger for aggressive than non-aggressive CRC (pHeterogeneity <0.05). Lower intake of whole grains or cereal fiber and greater dietary inflammatory potential were associated with a higher risk of aggressive but not non-aggressive CRC. The remaining risk factors showed comparable associations with aggressive CRC and non-aggressive CRC. Aggressive cases were more likely to have KRAS-mutated tumors but less likely to have distal or MSI-high tumors (p < .007). Similar results were observed for fatal CRC and advanced tumor stages at diagnosis. These findings provide initial evidence for the role of pre-diagnostic risk factors in the pathogenesis of aggressive CRC and suggest research priorities for preventive interventions.