Higher Risk Of Colorectal Cancer Research Articles

Whole Exome-Wide Association Identifies Rare Variants in APC Associated with High-Risk Colorectal Cancer in the Middle East.

Background: Colorectal cancer (CRC) displays a complex pattern of inheritance. It is postulated that much of the missing heritability of CRC is enriched in high-impact rare alleles, which might play a crucial role in the etiology and susceptibility of CRC. Methods: In this study, an exome-wide association analysis was performed in 146 patients with high-risk CRC in the Middle East and 1395 healthy controls. The aim was to identify rare germline variants in coding regions and their splicing sites associated with high-risk CRC in the Middle Eastern population. Results: Rare inactivating variants (RIVs) in APC had the strongest association with high-risk CRC (6/146 in cases vs. 1/1395 in controls, OR = 59.7, p = 5.13 × 10-12), whereas RIVs in RIMS1, an RAS superfamily member, were significantly associated with high-risk CRC (5/146 case vs. 2/1395 controls, OR = 24.7, p = 2.03 × 10-8). Rare damaging variants in 17 genes were associated with high-risk CRC at the exome-wide threshold (p < 2.5 × 10-6). Based on the sequence kernel association test, nonsynonymous variants in six genes (TNXB, TAP2, GPSM3, ADGRG4, TMEM229A, and ANKRD33B) had a significant association with high-risk CRC. RIVs in APC-the most common high-penetrance genetic factor-were associated with patients with high-risk CRC in the Middle East. Individuals who inherited APC RIVs had an approximate 60-fold increased risk of developing CRC and were likely to develop the disease earlier. Conclusions: We identified new potential CRC predisposition variants in other genes that could play a role in CRC inheritance. However, large collaborative studies are needed to confirm the association of these variants with high-risk CRC. These results provide information for counseling patients with high-risk CRC and their families in our population.

Disparities in Colorectal Cancer Screening Before and After the Onset of the COVID Pandemic.

Colorectal cancer (CRC) screening is underutilized among those with lower socioeconomic status and in racial and ethnic minoritized populations who have been disproportionately impacted by COVID. To compare disparities in CRC screening before and after the onset of the COVID pandemic among privately insured individuals. Retrospective cohort study using deidentified claims data from the USA between January 1, 2017, and December 31, 2022. Blue Cross Blue Shield beneficiaries aged 50-75years with average risk of CRC. Mean screening use was compared by demographic and area-level socioeconomic factors between the periods preceding (January 1,2017 to February 28,2020) and following (July 1,2020 to December 31,2022) the onset of the COVID pandemic. Difference-in-differences analysis was used to evaluate changes in screening differences. Our study included 21,724,223 beneficiaries. Compared to males, females had higher screening in both periods (p < 0.05), and this sex difference in screening increased 1.63% (95% confidence interval [CI]: 1.32%, 1.94%) following the onset of the pandemic. Compared to residents in areas with high socioeconomic status (SES), low SES area residents had lower screening (p < 0.001) during both periods. Furthermore, this difference grew 4.32% (95% CI, 3.76%, 4.88%) during the post-onset period. Metropolitan area residents had higher screening than non-metropolitan area residents during both periods (p < 0.001); however, this difference decreased 0.77% (95% CI, 0.34%, 1.20%) during the post-onset period. Among beneficiaries with high risk of CRC, the difference in screening based on social deprivation index and metropolitan area status increased 6.99% (95% CI, 5.77%, 8.20%) and 1.82% (95% CI, 0.88%, 2.74%), respectively. Among privately insured individuals, CRC screening after the COVID pandemic recovered unevenly based on sex, area-level socioeconomic measures, and metropolitan area status, with pre-pandemic disparities persisting and even worsening for some of the factors.

Dye-based chromoendoscopy detects more neoplasia than white light endoscopy in patients with primary sclerosing cholangitis and IBD.

Background and study aims Patients with primary sclerosing cholangitis and inflammatory bowel disease (IBD) have a high risk of colorectal cancer. There is no agreement on the best technique for surveillance for colorectal neoplasia. We aimed to assess whether chromoendoscopy and/or high-definition endoscopy is associated with increased detection of neoplasia in patients with primary sclerosing cholangitis undergoing surveillance compared with when they were not used. Patients and methods This was a single-center, retrospective, observational study designed to analyze differences in the detection of neoplasia (adenomatous and serrated) among patients with primary sclerosing cholangitis and IBD who underwent annual surveillance between 2010 and 2020. Multilevel logistic regression was used to adjust for confounders. Results Ninety-one patients were identified, resulting in 359 colonoscopies with 360 person-years of follow up. Over the study period, 22 of 91 patients (24%) had at least one neoplastic lesion identified; however, the mean neoplastic lesion rate was 0.87 (54/63) for the primary sclerosing cholangitis-ulcerative colitis subgroup compared with 0.24 (4/17) for the primary sclerosing cholangitis-Crohn's disease subgroup. Chromoendoscopy was associated with a significantly higher detection rate for neoplasia (odds ratio [OR] 5.58, 95% confidence interval [CI] 2.08-14.9, P =0.001), and this association remained after adjusting for confounders, including high-definition endoscopy. High-definition endoscopes had a higher rate of neoplasia detection, but the significance was lost after adjustment for confounders, including chromoendoscopy (OR 1.93, 95% CI 0.69-5.40, P =0.21). Conclusions Chromoendoscopy is associated with a higher detection rate for neoplasia in patients with primary sclerosing cholangitis and IBD even with high-definition colonoscopes.

Novel metabolomic predictors of incident colorectal cancer in men and women.

Metabolomic profiles may influence colorectal cancer (CRC) development. Few studies have performed pre-diagnostic metabolome-wide analyses with CRC risk. We conducted a nested case-control study among women (Nurses' Health Study (NHS)) and men (Health Professionals Follow-up Study (HPFS)) who provided blood between 1989 and 1995. Over 22.9 years, 684 (409 NHS, 275 HPFS) incident CRC cases occurred and were matched 1:1 to controls. Liquid chromatography-mass spectrometry (LC-MS) identified 255 plasma metabolites after quality control. Cohort-specific and combined metabolite association analyses were performed using conditional logistic regression. Metabolite set enrichment analysis (MSEA) was used to identify differential abundance in metabolite classes. Weighted Correlation Network Analysis (WGCNA) provided modules of covarying metabolites, which were tested for CRC association. MSEA identified specific acylcarnitines associated with higher CRC risk and triacylglycerols with lower CRC risk among women and men. Further, phosphatidylcholines were associated with a higher risk of CRC among men. In an analysis restricted to CRC cases diagnosed two years after blood draw, myristoleic acid (OR = 1.37; 95%CI = 1.15-1.62; FDR = 0.072) and C60:12 triacylglycerol (OR = 0.75; 95%CI = 0.64-0.88; FDR = 0.072 were associated with CRC risk in women. WGCNA identified amino acids associated with CRC in men, fatty acid esters (carnitines) with distal CRC in men, and triradylcglycerols inversely associated with CRC in women. We identified pre-diagnostic CRC-associated metabolites with distinct sex-specific profiles. These results provide insight into CRC etiopathogenesis and have implications for risk prediction strategies.

Guidelines for the Prophylaxis and Treatment of Peritoneal Metastases From Colorectal Cancer: A GRADE-Approach for Evidence Evaluation and Recommendations.

Colorectal peritoneal metastases (CPM) are common in colorectal cancer patients. This article aims to provide GRADE guidelines for the use of hyperthermic intraperitoneal chemotherapy (HIPEC) in two clinical situations: (1) To determine the value of adjuvant HIPEC for the prevention of CPM in high-risk colorectal cancer patients; (2) to determine the impact on survival of cytoreductive surgery and HIPEC followed by adjuvant systemic chemotherapy as compared to systemic chemotherapy alone in patients with CPM.

Screening participants with inflammatory bowel disease or high colorectal cancer risk in Denmark: a cohort study.

Individuals with inflammatory bowel disease (IBC) and high-risk individuals are advised to discuss participation with their doctor and not to participate in colorectal cancer (CRC) screening. Yet a substantial proportion still participate in the Danish faecal immunochemical test (FIT) screening and have a higher positive FIT rate than the average-risk population. We estimated the risk of false-positive screening among individuals with inflammatory bowel disease and high-risk individuals to improve recommendations regarding screening participation. We included 71,871 FIT-positive participants (2014-2017) who had a subsequent colonoscopy within 3 months. Screening outcome within 180 days was established by using registers. We determined that 26,591 of the included participants had a false-positive screening. Participants with IBC or high CRC risk had a significantly higher risk of getting a false-positive screening than the average risk population, resulting in too many screening-related colonoscopies being performed among these individuals, indicating a need to update the screening protocols.

Efficacy of ColonFlag as a Complete Blood Count-Based Machine Learning Algorithm for Early Detection of Colorectal Cancer: A Systematic Review.

Colorectal cancer (CRC) screening is essential to reduce incidence and mortality rates. However, participation in screening remains suboptimal. ColonFlag, a machine learning algorithm using complete blood count (CBC), identifies individuals at high CRC risk using routinely performed tests. This study aims to review the existing literature assessing the efficacy of ColonFlag across diverse populations in multiple countries. The Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) were followed in reporting this systematic review. Searches were conducted on PubMed, Cochrane, ScienceDirect, and Google Scholar for English articles, using keywords related to CBC, machine learning, ColonFlag, and CRC, covering the first development study from 2016 to August 2023. The Cochrane Prediction Model Risk of Bias Assessment Tool (PROBAST) was used to assess the risk of bias. A total of 949 articles were identified during the literature search. Ten studies were found to be eligible. ColonFlag yielded Area Under the Curve (AUC) values ranging from 0.736 to 0.82. The sensitivity and specificity ranged from 3.91% to 35.4% and 82.73% to 94%, respectively. The positive predictive values ranged between 2.6% and 9.1%, while the negative predictive values ranged from 97.6% to 99.9%. ColonFlag performed better in shorter time windows, tumors located more proximally, in advanced stages, and in cases of CRC compared to adenoma. While ColonFlag exhibits low sensitivity compared to established screening methods such as the fecal immunochemical test (FIT) or colonoscopy, its potential to detect CRC before clinical diagnosis suggests an opportunity for identifying more cases than regular screening alone.

Uptake of Aspirin Chemoprevention in Patients With Lynch Syndrome.

Individuals with Lynch syndrome (LS) are at a high lifetime risk of colorectal cancer (CRC) and other cancers. Aspirin (ASA), a nonsteroidal anti-inflammatory drug (NSAID), has proven chemopreventive benefits in LS, with the CAPP2 randomized double-blind placebo-controlled trial demonstrating a 60% relative risk reduction for CRC among participants who adhered to ASA for 2 years or more. This study sought to characterize uptake of ASA/NSAIDs among individuals with LS and to understand factors associated with use. Individuals with LS were invited (June 2020-August 2022) to complete a one-time electronic survey about LS screening behaviors, uptake of ASA/NSAIDs, and current/emerging cancer prevention options. Participants were recruited from the Fox Chase Cancer Center (FCCC) Risk Assessment Program Registry and through a research invitation posted to two patient-facing LS advocacy websites. Two hundred and ninety-six participants completed the survey including 116 (39.2%) from FCCC and 180 (60.8%) recruited via the Internet, including 14.9% non-US based individuals. Uptake of regular ASA or NSAIDs was modest at 34.8% and was even lower (25.7%) when focusing on individuals taking ASA or NSAIDs solely for chemoprevention of LS. More than half (55%) were taking <100 mg ASA daily. In multivariable modeling, lower perceived threat of LS (odds ratio [OR], 0.84 [95% CI, 0.72 to 0.98]), lower concern for side effects (OR, 0.86 [95% CI, 0.76 to 0.99]), and higher likelihood of recommending ASA/NSAIDs to family or a friend were all associated with ASA/NSAIDs use (OR, 1.70 [95% CI, 1.37 to 2.10]). Uptake of ASA/NSAIDs chemoprevention is modest among individuals with LS. Patient perceptions of the pros and cons of ASA, more so than demographic and disease-related factors, were associated with chemoprevention uptake.

S511 Direct Genetic Screening Approach in Hereditary Nonpolyposis Colorectal Cancer: A Health Economics Analysis in High-risk Colorectal Cancer Population; Perspective from Middle-Income Country

S511 Direct Genetic Screening Approach in Hereditary Nonpolyposis Colorectal Cancer: A Health Economics Analysis in High-risk Colorectal Cancer Population; Perspective from Middle-Income Country

Clinical features, surgical treatment strategy, and feasibility of minimally invasive surgery for synchronous and metachronous multiple colorectal cancers: A 14-year single-center experience.

Patients with a history of colorectal cancer (CRC) are at increased risk of developing secondary synchronous/metachronous CRCs. The role of minimally invasive surgery (MIS) for multiple CRCs remains unclear. This study aimed to evaluate the short-term outcomes of MIS in patients with multiple CRCs and elucidate their clinical characteristics. This retrospective study reviewed CRC patients who underwent MIS between 2010 and 2023. Multiple CRC cases were categorized into synchronous and metachronous cohorts. Demographics, pathological findings, and perioperative outcomes were analyzed. Propensity score matching (PSM) analysis was performed as appropriate. A total of 1,272 patients met the inclusion criteria, with 99 (7.8%) having multiple CRCs (75 synchronous and 24 metachronous). Multiple CRC patients had a higher prevalence of strong family history (8.1% vs. 1.0%, P < 0.001) and right-sided colon cancer (55.6% vs. 34.4%, P < 0.001) compared to solitary CRC patients. MSI-high/MMR-deficient status, including Lynch syndrome, was frequently observed among patients with multiple CRCs. Synchronous CRCs requiring double-anastomosis were associated with longer operation times (P = 0.03) and increased blood loss (P = 0.03) compared to those with a single-anastomosis. In the metachronous cohort, repeat operation patterns were categorized based on tumor location and sacrificed arteries. Preservation of the left-colic artery avoided extended colectomy in some patients. Patients with multiple CRC involving rectal cancer had a higher anastomotic leakage (AL) rate (17.6% vs. 5.7%, P < 0.01); however, this difference in AL rate disappeared after PSM (8.8% vs. 8.8%, P = 1.0). In patients with multiple CRCs, AL has not been observed ever since the indocyanine green fluorescence imaging was implemented. MIS is feasible for multiple CRCs, with perioperative outcomes comparable to those for solitary CRCs. Preservation of critical arteries may benefit patients at high risk of secondary CRCs, particularly those with a strong family history of CRC, right-sided tumors, or MSI-high/MMR-deficient profiles, including Lynch syndrome.

Predicting Regression of Barrett's Esophagus-Can All the King's Men Put It Together Again?

The primary pre-neoplastic lesion of the lower esophagus in the vicinity of the gastroesophageal junction (GEJ) is any Barrett's esophageal lesions (BE), and esophageal neoplasia has increased in the US population with predispositions (Caucasian males, truncal obesity, age, and GERD). The responses to BE are endoscopic and screening cytologic programs with endoscopic ablation of various forms. The former have not been proven to be cost-effective and there are mixed results for eradication. A fresh approach is sorely needed. We prospectively followed 2229 mostly male veterans at high risk for colorectal cancer in a 27-year longitudinal long-term study, collecting data on colorectal neoplasia development and other preneoplastic lesions, including BE and spontaneous regression (SR). Another cross-sectional BE study at a similar time period investigated antigenic changes at the GEJ in both BE glandular and squamous mucosa immunohistochemistry and the role of inflammation. Ten of the prospective cohort (21.7%) experienced SR out of a total of forty-six BE patients. Significant differences between SR and stable BE were younger age (p < 0.007); lower platelet levels (p < 0.02); rectal p87 elevation in SR (p < 0.049); a reduced innate immune system (InImS) FEREFF ratio (ferritin: p87 colonic washings) (p < 0.04). Ancillary testing showed a broad range of neoplasia biomarkers. InImS markers may be susceptible to intervention using commonplace and safe medical interventions and encourage SR.

Family history and genetic risk score combined to guide cancer risk stratification: A prospective cohort study.

Family history (FH) of cancer and polygenic risk scores (PRS) are pivotal for cancer risk assessment, yet their combined impact remains unclear. Participants in the UK Biobank (UKB) were recruited between 2006 and 2010, with complete follow-up data updated until February 2020 for Scotland and January 2021 for England and Wales. Using UKB data (N = 442,399), we constructed PRS and incidence-weighted overall cancer PRS (CPRS). FH was assessed through self-reported standardized questions. Among 202,801 men (34.6% with FH) and 239,598 women (42.0% with FH), Cox regression was used to examine the associations between FH, PRS, and cancer risk. We found a significant dose-response relationship between FH of cancer and corresponding cancer risk (Ptrend < .05), with over 10 significant pairs of cross-cancer effects of FH. FH and PRS are positively correlated and independent. Joint effects of FH of cancer (multiple cancers) and PRS (CPRS) on corresponding cancer risk were observed: for instance, compared with participants with no FH of cancer and low PRS, men with FH of cancer and high PRS had the highest risk of colorectal cancer (hazard ratio [HR]: 3.69, 95% confidence interval [CI]: 3.01-4.52). Additive interactions were observed in prostate and overall cancer risk for men and breast cancer for women, with the most significant result being a relative excess risk of interaction (RERI) of 2.98, accounting for ~34% of the prostate cancer risk. In conclusion, FH and PRS collectively contribute to cancer risk, supporting their combined application in personalized risk assessment and early intervention strategies.

Null polymorphism of the GSTM1 and GSTT1 genes in susceptibility to colorectal tumorigenesis: systematic review with meta-analysis

Objective: To assess if GSTT1 and GSTM1 null polymorphisms increase susceptibility to colorectal cancer. Methods: A search was conducted in PubMed, SciELO, BVS, and Medline databases. Forty articles were selected, totaling 12,698 cases and 19,517 controls. Odds ratios with 95% confidence intervals were used, and p-values &lt;0.05 were considered significant. The Dersimonian-Laird method was applied for p-values &lt;0.05, and the Mantel-Haenszel method was used otherwise. All p-values were two-tailed with an alpha value of 0.05 determined a priori. STATA 16.0 software was utilized. Result: A higher risk of colorectal cancer was shown in the general population for the GSTM1 null genotype (OR=1.11; 95%CI [1.03, 1.19]; P&lt;0.01). No significant risk was observed for GSTT1 or the GSTM1/GSTT1 null combination (OR=1.09; 95%CI [0.98, 1.22]; P&lt;0.01 and OR=1.13; 95%CI [0.89, 1.43]; P&lt;0.01, respectively). In subgroup analysis, increased colorectal cancer risk was found for Asians with the GSTM1 null genotype (OR=1.10; 95%CI [1.02, 1.20]; P=0.02) and GSTM1/GSTT1 null combination (OR=1.49; 95%CI [1.03, 2.15]; P&lt;0.01). Conclusion: The findings suggest that the GSTM1 null polymorphism and the GSTM1/GSTT1 null combination are potential susceptibility factors for colorectal cancer, particularly in the Asian population.

Impact of Ascending HPV Infection on Colorectal Cancer Risk: Evidence from a Nationwide Study.

Colorectal cancer (CRC) is a prevalent and escalating health issue in Taiwan. This nationwide study delves into the relationship between Human Papillomavirus (HPV) infection and CRC risk, employing population datasets from 2007 to 2017. Cox regression analyses revealed a statistically significant hazard ratio (HR) of 1.73 (95% CI: 1.63-1.83) for CRC in HPV-positive patients, indicating a considerably elevated risk compared to non-infected individuals. Further, stratification by sex showed males with HPV have a higher CRC risk (HR = 1.49, 95% CI: 1.40-1.58) compared to females. Age-related analysis uncovered a progressive increase in CRC risk with advancing age (HR = 34.69 for over 80 years). The study of specific CRC subtypes showed varying risks: HR = 1.74 for the colon, HR = 1.64 for the rectum, and a notably higher HR = 4.72 for the anus. Comorbid conditions such as hypertension (HR = 1.26), diabetes mellitus (HR = 1.32), and abnormal liver function (HR = 1.18) also correlate with significantly increased CRC risks. These findings suggest that HPV is a significant risk factor for CRC, with disparities in risk based on anatomical location, demographic characteristics, and comorbidities, highlighting the need for intervention strategies and targeted prevention.

A Stool DNA-Based SDC2 Methylation Test for the Early Detection of Colorectal Cancer in an Asymptomatic, High-Risk Population: A Multicenter Prospective Randomized Trial.

Noninvasive stool DNA-based methylation testing has emerged as an effective strategy for the early colorectal cancer (CRC) detection. Syndecan-2 (SDC2) methylation frequently occurs in all stages of CRC; therefore, the aim of this study was to evaluate the clinical performance of a stool DNA-based SDC2 methylation test for detecting CRC in asymptomatic or high-risk CRC populations. This multicenter prospective study was conducted to determine the clinical performance of the SDC2 methylation test on stool DNA using real-time polymerase chain reaction. Stool samples were collected from asymptomatic individuals before colonoscopy, and the test results were independently analyzed through comparison with colonoscopic findings and pathological outcomes as reference standards. Of the 1,124 evaluable participants, 20 had CRC, 73 had advanced adenomatous polyps (≥1.0 cm), 469 had nonadvanced adenomatous polyps (<1.0 cm), 178 had non-neoplastic polyps, and 384 had negative colonoscopy results. The stool SDC2 methylation test had a sensitivity and specificity of 95.0% and 81.5%, respectively, for detecting CRC, while the sensitivity for detecting advanced adenomatous polyps and CRC was 58.1%. The rate of adenoma detection increased with polyp size (P < 0.01), and sensitivity was not associated with CRC stage (P = 0.864). The stool DNA-based SDC2 methylation test attained a high sensitivity for CRC detection in an asymptomatic high-risk population. Further large-scale clinical studies are required to validate the clinical utility of this test as a population-based CRC screening tool.

Triglyceride-Glucose Index, Modifiable Lifestyle, and Risk of Colorectal Cancer: A Prospective Analysis of the Korean Genome and Epidemiology Study.

Insulin-mediated pathways plausibly explain the pathogenesis of colorectal cancer (CRC). The triglyceride-glucose index (TyG) is a surrogate of insulin resistance (IR), but its association with CRC in the Korean population has not been evaluated. From the 2004-2013 Korean Genome and Epidemiology Study, 98,800 participants aged 40-69 years were followed through 2020. Data on CRC incidence were obtained from the Korean National Cancer Center registry. Cox regression models and restricted cubic splines were fitted to examine the association between the TyG; In [(triglycerides) × (fasting glucose)/2] and CRC incidence. Joint effects of modifiable lifestyle factors and TyG on CRC risk were also investigated. Median follow-up time was 10.6 years, and 699 CRC cases were observed. A unit-increment in TyG was associated with increased risk of CRC combined (hazard ratio, HR: 1.28, and 95% confidence interval, CI: 1.12-1.46), colon (1.29, 1.10-1.54), and rectal cancer (1.24, 1.01-1.52). Associations were dose-dependent, with linear associations observed for CRC and colon, but non-linear associations were observed for rectal cancer. A high TyG index (above 8.4) combined with overweight/obesity was linked to an increased risk of CRC (1.31, 1.07-1.61) and colon cancer (1.33, 1.03-1.72). When combined with low fruit and vegetable intake, the risks were higher for CRC (1.40, 1.12-1.74) and colon cancer (1.57, 1.18-2.09). Combined with high red meat consumption, the risks were elevated for CRC (1.32, 1.05-1.65) and colon cancer (1.52, 1.15-2.02). A high TyG index was associated with a higher risk of colorectal cancer, and the risk was highest among participants with a high BMI, low fruit and vegetable intake, and high intake of red meat, suggesting a role of both insulin resistance and modifiable lifestyle in colorectal cancer development.

Management of T1 colorectal cancer.

Approximately 10% of patients with submucosal invasive (T1) colorectal cancer (CRC) have lymph node metastasis (LNM). The risk of LNM can be stratified according to various histopathological factors, such as invasion depth, lymphovascular invasion, histological grade, and tumor budding. T1 CRC with a low risk of LNM can be cured by local excision via endoscopic resection (ER), whereas surgical resection (SR) with lymph node dissection is required for high-risk T1 CRC. Current guidelines raise concern that many patients receive unnecessary SR, even though most patients achieve a radical cure. Novel diagnostic techniques for LNM, such as nomograms, artificial intelligence systems, and genomic analysis, have been recently developed to identify more low-risk T1 CRC cases. Assessing the curability and the necessity of additional treatment, including SR with lymph node dissection and chemoradiotherapy, according to histopathological findings of the specimens resected using ER, is becoming an acceptable strategy for T1 CRC, particularly for rectal cancer. Therefore, complete resection with negative vertical and horizontal margins is necessary for this strategy. Advanced ER methods for resecting the muscle layer or full thickness, which may guarantee complete resection with negative vertical margins, have been developed. Although a necessary SR should not be delayed for T1 CRC given its unfavorable prognosis when SR with lymph node dissection is performed, the optimal treatment method should be chosen based on the risk of LNM and the patient's life expectancy, physical condition, social characteristics, and wishes.

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

Background & AimsEpidemiologic evidence for dietary influence on colorectal cancer (CRC) risk through the gut microbiome remains limited. MethodsLeveraging 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). ResultsThe 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. ConclusionsCMDS 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.

Risk of colorectal cancer and adenoma after an appendectomy: results from three large prospective cohort studies and meta-analysis.

The relationship between appendectomy and subsequent colorectal cancer risk remains unclear, and no study has examined its association with colorectal adenoma. We used data from three prospective cohorts: Health Professionals Follow-up Study, Nurses' Health Study (NHS), and NHSII. Appendectomy history was self-reported at baseline. Colorectal cancer risk was analyzed with Cox proportional hazard models among 224,109 participants followed up to 32years. Colorectal adenoma risk was evaluated among 157,490 participants with at least one lower gastrointestinal endoscopy during follow-up with logistic regression models accounting for repeated observations. We also performed a meta-analysis of cohort studies that examined association between appendectomy and colorectal cancer risk. We documented 3,384 colorectal cancers, 13,006 conventional adenomas, and 11,519 serrated polyps during the follow-up period. Compared to participants without appendectomy, those whoreported appendectomy history were not at higher risk of colorectal (HR [95% CI], 0.92 [0.84-1.00]), colon (0.92 [0.83-1.01]), or rectal (0.85 [0.70-1.03]) cancer. Similarly, appendectomy history was not associated with higher risk of conventional adenoma (OR [95% CI], 1.00 [0.97-1.02]), serrated polyp (0.97 [0.94-1.00]), or high-risk adenoma (0.96 [0.92-1.01]). The meta-analysis showed appendectomy was associated with a higher risk of colorectal cancer within a short time after the procedure (1.68 [1.01-2.81]), while the long-term risk was slightly inverse (0.94 [0.90-0.97]). We found no evidence of an association between appendectomy history and long-term risk of colorectal cancer or its precursors. The observed higher risk of colorectal cancer right after appendectomy in the first few years is likely due to reverse causation.

The impact of hysterectomy on subsequent colonoscopy in women with Lynch Syndrome

Background and aims Women with Lynch Syndrome (LS) have a high risk of colorectal and endometrial cancer. They are recommended regular colonoscopies, and some choose prophylactic hysterectomy. The aim of this study was to determine the impact of hysterectomy on subsequent colonoscopy in these women. Materials and methods A total of 219 LS women >30 years of age registered in the clinical registry at Section for Hereditary Cancer, Oslo University Hospital, were included. Data included hysterectomy status, other abdominal surgeries, and time of surgery. For colonoscopies, data were collected on cecal intubation rate, challenges, and level of pain. Observations in women with and without hysterectomy, and pre- and post-hysterectomy were compared. Results Cecal intubation rate was lower in women with hysterectomy than in those without (119/126 = 94.4% vs 88/88 = 100%, p = 0.025). Multivariate regression analysis showed an increased risk of challenging colonoscopies (OR,3.58; CI: 1.52–8.43; p = 0.003), and indicated a higher risk of painful colonoscopy (OR, 3.00; 95%CI: 0.99–17.44, p = 0.052), in women with hysterectomy compared with no hysterectomy. Comparing colonoscopy before and after hysterectomy, we also found higher rates of reported challenging colonoscopies post-hysterectomy (6/69 = 8.7% vs 23/69 = 33.3%, p < 0.001). Conclusions Women with hysterectomy had a lower cecal intubation rate and a higher number of reported challenging colonoscopy than women with no hysterectomy. However, completion rate in the hysterectomy group was still as high as 94.4%. Thus, LS women who consider hysterectomy should not be advised against it.