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Background and Aims: Self-expandable metal stents (SEMS) are effective in alleviating malignant colorectal obstruction. However, bowel perforation following SEMS placement remains a significant concern, as it can adversely affect oncological outcomes. This study aimed to evaluate the recurrence and overall survival rates associated with SEMS-related bowel perforations., Methods: This multicenter, retrospective analysis included patients with obstructive colorectal cancer who underwent SEMS placement as a bridge to surgery. The data collection period spanned from January 2008 to May 2019, with patient matching in a 1:5 ratio based on age, sex, tumor location, pathological stage, and achievement of curative resection., Results: Among the 412 patients who received SEMS placement, 25 (6.1%) patients experienced SEMS-related perforations (perforation group), with 21 instances classified as overt and four as silent perforations. Compared with 125 matched controls (non-perforation group), the perforation group showed elevated rates of emergent surgery, open surgery, and stoma formation, as well as a reduced interval from SEMS placement to surgery. The 5-year recurrence rate was notably higher in the perforation group than in the no-perforation group (47.4% vs. 21.5%, p < 0.001), whereas the 5-year survival rate was not significantly different between groups (63.8% vs. 80.0%, p = 0.330)., Conclusions: SEMS-related perforation led to less favorable surgical outcomes and a higher rate of recurrence, although no notable impact on overall survival was observed. Considering the risk of perforation, these findings support the cautious use of SEMS as a bridge to surgery., Competing Interests: Declarations. Disclosures: Han Hee Lee, Dong Hyun Kim, Hyun Lim, Jung-Wook Kim, Yunho Jung, Hyun-Soo Kim, Hyung-Hoon Oh, Jin Won Kim, Kwang Bum Cho, Young-Eun Joo, and Bo-In Lee have no conflicts of interest or financial ties to disclose., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Prostaglandin E 2 (PGE 2 ) interacts with four specific G protein-coupled receptors, namely EP1, EP2, EP3, and EP4, playing a pivotal role in determining the fate of cells. Our previous findings highlighted that stimulating the EP4 receptor with its agonist, CAY10598, triggers apoptosis in colon cancer HCT116 cells via the production of reactive oxygen species (ROS). This process also reduces the phosphorylation of the oncogenic protein JAK2 and leads to its degradation in these cells. In this study, our goal was to explore the pathways through which CAY10598 leads to JAK2 degradation. We focused on Hsp90, a heat shock protein family member known for its role as a molecular chaperone maintaining the stability of several key proteins including EGFR, MET, Akt, and JAK2. Our results show that CAY10598 decreases the levels of client proteins of Hsp90 in HCT116 cells, an effect reversible by pretreatment with the ROS scavenger N -acetyl cysteine (NAC) or the proteasome inhibitor MG132, indicating that the degradation is likely driven by ROS. Furthermore, we observed that CAY10598 cleaves both α and β isoforms of Hsp90, the process inhibited by NAC. Inhibition of EP4 with the antagonist GW627368x not only prevented the degradation of Hsp90 client proteins but also the cleavage of Hsp90 itself in CAY10598-treated HCT116 cells. Additionally, CAY10598 suppressed the growth of HCT116 cells implanted in mice. Our findings reveal that CAY10598 induces apoptosis in cancer cells by a novel mechanism involving the ROS-dependent cleavage of Hsp90, thereby inhibiting the function of crucial Hsp90 client proteins.

Background/aim: Endoscopic submucosal dissection (ESD) is a valuable technique for treating colorectal neoplasms. However, there are insufficient data concerning the treatment outcomes in relation to the size of colorectal neoplasms., Patients and Methods: The data on ESD for colorectal epithelial neoplasms between January 2015 and December 2020 were retrospectively collected from five tertiary medical centers. Colorectal neoplasms were stratified into groups based on their longitudinal diameter: <20 mm as Group 1, 20-39 mm as Group 2, 40-59 mm as Group 3, and 60 mm or more as Group 4., Results: Of the 1,446 patients, 132 patients were in Group 1 (<20 mm), 1,022 in Group 2 (20-39 mm), 249 in Group 3 (40-59 mm), and 43 in Group 4 (≥60 mm). There was an observed trend of increasing age from Group 1 to Group 4, accompanied by a corresponding increase in the Charlson Comorbidity Index. Procedure time also exhibited a gradual increase from Group 1 to Group 4. Similarly, the length of hospital stay tended to increase from Group 1 to Group 4. The predictive model, using restricted cubic spline curves, revealed that as the size of lesion exceeded 30 mm, complete resection steadily decreased, and major complications notably increased., Conclusion: As the size of colorectal neoplasms increases, the rate of complete resection decreases and the rate of complications increases., (Copyright © 2024, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

A positive resection margin after colorectal endoscopic submucosal dissection (ESD) is associated with an increased risk of recurrence. We aimed to identify the clinical significance of positive resection margins in colorectal neoplasms after ESD. We reviewed 632 patients who had en bloc colorectal ESD at two hospitals between 2015 and 2020. The recurrence rates and presence of residual tumor after surgery were evaluated. The rate of additional surgery after ESD and recurrence rate were significantly higher in patients with incomplete resection (n = 75) compared to patients with complete resection (n = 557). When focusing solely on non-invasive lesions, no significant differences in recurrence rates were observed between the groups with complete and incomplete resection (0.2% vs. 1.9%, p = 0.057). Among 84 patients with submucosal invasive carcinoma, 39 patients underwent additional surgery due to non-curative resection. Positive vertical margin and lymphovascular invasion were associated with residual tumor. Lymphovascular invasion was associated with lymph node metastasis. However, no residual tumor nor lymph node metastases were found in patients with only one unfavorable histological factor. In conclusion, a positive resection margin in non-invasive colorectal lesions, did not significantly impact the recurrence rate. Also, in T1 colorectal cancer with a positive vertical resection margin, salvage surgery can be considered in selected patients with additional risk factors., (© 2024. The Author(s).)

Background/aim: The aging population has been growing gradually; therefore, the proportion of elderly patients undergoing colorectal endoscopic submucosal dissection (ESD) has also been increasing. However, there is a lack of large-scale studies on the efficacy and safety of colorectal ESD in elderly patients., Patients and Methods: This retrospective analysis evaluated colorectal ESDs performed at five tertiary medical institutions between January 2015 and December 2020. Patients were categorized into the following four age groups: Middle-aged (<65 years), young-elderly (≥65 to <75 years), mid-elderly (≥75 to <85 years), and very elderly (≥85 years). Of the 1,446 patients included, 668 (46.2%), 466 (32.2%), 293 (20.3%), and 19 (1.3%) were in the middle-aged, young-elderly, mid-elderly, and very-elderly groups, respectively., Results: Compared to younger patients, more older patients used aspirin, clopidogrel, and anti-thrombotic agents. Additionally, the Charlson comorbidity index increased significantly with increasing age. However, no significant differences were observed in the complete resection rates nor the rates of complications, such as perforation, bleeding, and post-ESD coagulation syndrome, among the different age groups. A restricted cubic spline curve was used to construct predictive models for complete resection and major complications based on age and showed that the need for complete resection did not decrease with increasing age. Furthermore, major complications did not significantly differ with age progression., Conclusion: Colorectal ESD should be actively considered as a relatively safe and effective treatment method for elderly patients., (Copyright © 2024, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Colorectal endoscopic submucosal dissection (ESD) is a promising but challenging procedure. It is not widely performed due to its technical difficulty. We aimed to find the predictive factors associated with technical difficulty in colorectal ESD before the procedure. Clinical data from patients who underwent ESD for colorectal tumors in 5 hospitals in Honam province of South Korea between 2015 and 2020 were reviewed retrospectively. Technically difficult colorectal ESD procedure was defined in 3 points. Long procedure time (longer than 60 minutes), occurrence of perforation, and failure of en bloc resection. Factors associated with technically difficult ESD were included as main outcome measure. 1446 patients were identified and their data were analyzed. Median procedure time was 30.0 minutes and median long axis of the tumor was 20.1 mm. Technically difficult procedures including long procedure time were 231 cases (16.0%), perforation occurred in 34 cases (2.3%), and en bloc resection was done in 1292 cases (89.3%). Tumor size larger than 35 mm (odd ratio [OR]: 1.474, P = .047), central depression or ulceration in the lesion (OR: 1.474, P = .013), previous endoscopic mucosal resection (EMR) or polypectomy procedure (OR: 2.428, P = .020) were associated with technically difficult ESD. Descending colon-located tumor (OR: 5.355, P < .001), and use of IT knife (OR: 4.157, P = .003) were associated with perforation. Recognizing factors associated with technically difficult ESD can help in planning the ESD procedure beforehand., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2024 the Author(s). Published by Wolters Kluwer Health, Inc.)

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. Our cis-eQTL/mQTL and colocalization analyses using colorectal tissue-specific transcriptome and methylome data separately from 1299 and 321 individuals, along with functional genomic investigation, uncovered 136 putative CRC susceptibility genes, including 56 genes not previously reported. Analyses of single-cell RNA-seq data from colorectal tissues revealed 17 putative CRC susceptibility genes with distinct expression patterns in specific cell types. Analyses of whole exome sequencing data provided additional support for several target genes identified in this study as CRC susceptibility genes. Enrichment analyses of the 136 genes uncover pathways not previously linked to CRC risk. Our study substantially expanded association signals for CRC and provided additional insight into the biological mechanisms underlying CRC development., (© 2024. The Author(s).)

Transcriptome-wide association studies (TWAS) have identified many putative susceptibility genes for colorectal cancer (CRC) risk. However, susceptibility miRNAs, critical dysregulators of gene expression, remain unexplored. We genotyped DNA samples from 313 CRC East Asian patients and performed small RNA sequencing in their normal colon tissues distant from tumors to build genetic models for predicting miRNA expression. We applied these models and data from genome-wide association studies (GWAS) including 23 942 cases and 217 267 controls of East Asian ancestry to investigate associations of predicted miRNA expression with CRC risk. Perturbation experiments separately by promoting and inhibiting miRNAs expressions and further in vitro assays in both SW480 and HCT116 cells were conducted. At a Bonferroni-corrected threshold of P < 4.5 × 10-4, we identified two putative susceptibility miRNAs, miR-1307-5p and miR-192-3p, located in regions more than 500 kb away from any GWAS-identified risk variants in CRC. We observed that a high predicted expression of miR-1307-5p was associated with increased CRC risk, while a low predicted expression of miR-192-3p was associated with increased CRC risk. Our experimental results further provide strong evidence of their susceptible roles by showing that miR-1307-5p and miR-192-3p play a regulatory role, respectively, in promoting and inhibiting CRC cell proliferation, migration, and invasion, which was consistently observed in both SW480 and HCT116 cells. Our study provides additional insights into the biological mechanisms underlying CRC development., (© The Author(s) 2023. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Introduction: Delayed bleeding is an important adverse event following colorectal endoscopic submucosal dissection (ESD). However, whether anticoagulants are risk factors for delayed bleeding after colorectal ESD remains debatable., Methods: We retrospectively analyzed 1,708 patients who underwent colorectal ESDs between January 2015 and December 2020 at five academic medical centers in South Korea. We aimed to identify the risk factors for delayed bleeding in patients after colorectal ESD and, in particular, to evaluate the effect of anticoagulants., Results: Delayed bleeding occurred in 40 of 1,708 patients (2.3%). The risk factors for delayed bleeding were antithrombotic agents (odds ratio [OR], 6.155; 95% confidence interval [CI], 3.201-11.825; p &lt; 0.001), antiplatelet agents (OR, 4.609; 95% CI, 2.200-9.658; p &lt; 0.001), anticoagulants (OR, 8.286; 95% CI, 2.934-23.402; p &lt; 0.001), and tumor location in the rectum (OR, 2.055; 95% CI, 1.085-3.897; p = 0.027). In the analysis that excluded patients taking antiplatelet agents, the delayed bleeding rate was higher in patients taking anticoagulants (1.6% no antithrombotic agents vs. 12.5% taking anticoagulants, p &lt; 0.001). There was no difference in the delayed bleeding rate (4.2% direct oral anticoagulants vs. 25.0% warfarin, p = 0.138) or clinical outcomes according to the type of anticoagulant used., Conclusions: Anticoagulants use was a risk factor for delayed bleeding after colorectal ESD, and there was no difference in the risk of delayed bleeding based on the type of anticoagulant used. Colorectal ESD in patients receiving anticoagulants requires careful observation and management for delayed bleeding., (© 2024 S. Karger AG, Basel.)

The FOLFOX regimen (combination of leucovorin, 5-fluorouracil, and oxaliplatin) is the first-line treatment for high-risk stage 2 and 3 colorectal cancer patients. While hypersensitivity reactions (HSRs) caused by oxaliplatin are commonly reported, HSRs due to leucovorin have been infrequently reported. This report aims to investigate the clinical presentation, diagnosis, and management of leucovorin induced HSRs. A 60-year-old female developed generalized edema, dyspnea, and facial redness during cetuximab plus FOLFOX chemotherapy administered for management of metastatic colorectal cancer. Because HSRs induced by oxaliplatin are commonly reported, we initially presumed an oxaliplatin-induced HSR. However, despite undergoing oxaliplatin desensitization, HSRs persisted, and they were still observed when leucovorin was administered without oxaliplatin. The patient was diagnosed with leucovorin-induced HSR and underwent leucovorin desensitization. However, the reactions recurred within 30 minutes of the initiating the desensitization. Considering unsuccessful leucovorin desensitization, leucovorin was excluded. The patient received cetuximab and oxaliplatin chemotherapy without leucovorin to date without any adverse effects. While leucovorin-induced HSRs are infrequently reported, they should still be regarded as potential adverse effects.

Background and Aims: The natural history of small polyps is not well established and rests on limited evidence from barium enema studies decades ago. Patients with one or two small polyps (6-9 mm) at screening CT colonography (CTC) are offered CTC surveillance at 3 years but may elect immediate colonoscopy. This practice allows direct observation of the growth of subcentimetre polyps, with histopathological correlation in patients undergoing subsequent polypectomy., Design: Of 11 165 asymptomatic patients screened by CTC over a period of 16.4 years, 1067 had one or two 6-9 mm polyps detected (with no polyps ≥10 mm). Of these, 314 (mean age, 57.4 years; M:F, 141:173; 375 total polyps) elected immediate colonoscopic polypectomy, and 382 (mean age 57.0 years; M:F, 217:165; 481 total polyps) elected CTC surveillance over a mean of 4.7 years. Volumetric polyp growth was analysed, with histopathological correlation for resected polyps. Polyp growth and regression were defined as volume change of ±20% per year, with rapid growth defined as +100% per year (annual volume doubling). Regression analysis was performed to evaluate predictors of advanced histology, defined as the presence of cancer, high-grade dysplasia (HGD) or villous components., Results: Of the 314 patients who underwent immediate polypectomy, 67.8% (213/314) harboured adenomas, 2.2% (7/314) with advanced histology; no polyps contained cancer or HGD. Of 382 patients who underwent CTC surveillance, 24.9% (95/382) had polyps that grew, while 62.0% (237/382) remained stable and 13.1% (50/382) regressed in size. Of the 58.6% (224/382) CTC surveillance patients who ultimately underwent colonoscopic resection, 87.1% (195/224) harboured adenomas, 12.9% (29/224) with advanced histology. Of CTC surveillance patients with growing polyps who underwent resection, 23.2% (19/82) harboured advanced histology vs 7.0% (10/142) with stable or regressing polyps (OR: 4.0; p<0.001), with even greater risk of advanced histology in those with rapid growth (63.6%, 14/22, OR: 25.4; p<0.001). Polyp growth, but not patient age/sex or polyp morphology/location were significant predictors of advanced histology., Conclusion: Small 6-9 mm polyps present overall low risk to patients, with polyp growth strongly associated with higher risk lesions. Most patients (75%) with small 6-9 mm polyps will see polyp stability or regression, with advanced histology seen in only 7%. The minority of patients (25%) with small polyps that do grow have a 3-fold increased risk of advanced histology., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2023. No commercial re-use. See rights and permissions. Published by BMJ.)

Polygenic risk scores (PRS) have great potential to guide precision colorectal cancer (CRC) prevention by identifying those at higher risk to undertake targeted screening. However, current PRS using European ancestry data have sub-optimal performance in non-European ancestry populations, limiting their utility among these populations. Towards addressing this deficiency, we expand PRS development for CRC by incorporating Asian ancestry data (21,731 cases; 47,444 controls) into European ancestry training datasets (78,473 cases; 107,143 controls). The AUC estimates (95% CI) of PRS are 0.63(0.62-0.64), 0.59(0.57-0.61), 0.62(0.60-0.63), and 0.65(0.63-0.66) in independent datasets including 1681-3651 cases and 8696-115,105 controls of Asian, Black/African American, Latinx/Hispanic, and non-Hispanic White, respectively. They are significantly better than the European-centric PRS in all four major US racial and ethnic groups (p-values < 0.05). Further inclusion of non-European ancestry populations, especially Black/African American and Latinx/Hispanic, is needed to improve the risk prediction and enhance equity in applying PRS in clinical practice., (© 2023. Springer Nature Limited.)

Radiologic imaging, especially MRI, has long been the mainstay for rectal cancer staging and patient selection for neoadjuvant therapy prior to surgical resection. In contrast, colonoscopy and CT have been the standard for colon cancer diagnosis and metastasis staging with T and N staging often performed at the time of surgical resection. With recent clinical trials exploring the expansion of the use of neoadjuvant therapy beyond the anorectum to the remainder of the colon, the current and future state of colon cancer treatment is evolving with a renewed interest in evaluating the role radiology may play in the primary T staging of colon cancer. The performance of CT, CT colonography, MRI, and FDG PET-CT for colon cancer staging will be reviewed. N staging will also be briefly discussed. It is expected that accurate radiologic T staging will significantly impact future clinical decisions regarding the neoadjuvant versus surgical management of colon cancer., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Development of colorectal cancer (CRC) is regulated by a series of genetic and microenvironmental alterations. Olfactomedin 4 (OLFM4) is a secreted glycoprotein that is highly expressed in the gastrointestinal tract and modulates inflammation. However, the role of OLFM4 in CRC is uncertain. Here we aimed to explore the function of OLFM4 in CRC in vivo and in vitro. The mRNA expression of OLFM4 was up-regulated in precursor lesions with dysplasia or ulcerative colitis but was reduced in CRC. OLFM4 neutralizing antibody suppressed inflammation-mediated early-stage CRC formation in an AOM/DSS colitis-associated cancer model. OLFM4 knockdown cells exhibited increased cell proliferation and motility in vitro and in vivo. Ablation of OLFM4 increased tumor growth and metastasis in xenograft experiments. In addition, OLFM4 knockdown cells showed elevated expression of colon cancer stem cell markers including CD133, resulting in increased metastasis via epithelial-mesenchymal transition signaling. This study demonstrated that OLFM4 regulates inflammation and cancer progression differently; ablation of OLFM4 promotes cancer metastasis via stemness and epithelial-mesenchymal transition. These results suggest a new route for controlling cancer progression and metastasis., (© 2022. The Author(s), under exclusive licence to Springer Nature America, Inc.)

Objective: It is unclear whether photodocumentation is associated with colorectal neoplasm (CRN) detection at colonoscopy, despite its ability to take more images with the development of affordable digital imaging systems. This study aimed to investigate whether photodocumentation-related factors could affect the detection rate of CRNs in healthy subjects., Patients and Methods: A total of 2,637 subjects undergoing screening colonoscopy in routine health check-ups at CHA Bundang Medical from January to September 2016 were enrolled in this study. Only the endoscopic image data for observation purposes during colonoscopy withdrawal was used in this analysis. The number of observation images, observation time and the speed of photodocumentation (SPD) defined as the number of observation images per minute were used as quantity measures of photodocumentation. The presence of documented anatomical landmarks such as appendix orifice (AO), ileocecal valve (ICV), anorectal junction was used as quality measures of photodocumentation., Results: Among subject-related factors, the independent factors for CRN detection in the multivariate analysis were age, male sex, waist circumference, and family history of colorectal cancer. In photo-documentation-related factors, SPD [Odds ratio (OR) 0.800; 95% confidence interval (CI), 0.740 to 0.864], observation time over 6 min (OR 1.671; 95% CI, 1.145 to 2.439), clear documentation of appendix orifice (AO) (OR 5.976; 95% CI, 4.548 to 7.852) and ileocecal valve (ICV) (OR 3.826; 95% CI, 2.985 to 4.904), and endoscopists (p < 0.001) were independently significant factors. However, the number of observation images was not associated with the detection of CRNs., Conclusions: Lower SPD and clear documentation of cecal landmarks might be associated with an increased detection rate of CRNs.

Purpose: To evaluate the safety and effectiveness of aflibercept in combination with fluorouracil, leucovorin, and irinotecan (FOLFIRI) in Korean patients with metastatic colorectal cancer (mCRC) who progressed with oxaliplatin-containing regimen., Methods: This was a prospective observational study conducted at 22 sites across Korea between February 2018 and September 2019. Patients aged > 19 years with a diagnosis of mCRC who were prescribed aflibercept plus FOLFIRI, after progression with an oxaliplatin-containing regimen were included. Disease assessment was performed every 6 weeks., Results: A total of 185 patients were included (males, 58.9%; right-sided tumors, 23.8%; and ECOG performance factor ≥ 1, 68.6%). A total of 514 adverse events (AEs) occurred in 134 patients, of which 206 (49.2%; 95% CI 42.0%, 56.4%) events were considered as adverse drug reactions (ADRs), 172 unexpected AEs (49.7%; 95% CI 42.5%, 56.9%), and 53 serious AEs (22.2%; 95% CI16.2%, 28.2%). The most common serious ADR was pneumonia (n = 2, 1.6%). The most common all grade hematological AE and non-hematological AE were neutropenia (21.6%) and nausea (16.2%), respectively. Over a median follow-up of 5.6 months, a total of five grade 5 (1.0%) AEs were reported. Median OS was 9.4 months, and median progression-free survival (PFS) was 7.3 months. The overall response rate was 14.6%. Right-sided tumor location and prior bevacizumab treatment were independent factors of poor PFS in multivariate analysis., Conclusion: Aflibercept in combination with FOLFIRI was effective and showed an acceptable safety profile in Korean patients with mCRC in daily clinical practice., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Colorectal cancer (CRC) is a leading cause of mortality worldwide. We conducted a genome-wide association study meta-analysis of 100,204 CRC cases and 154,587 controls of European and east Asian ancestry, identifying 205 independent risk associations, of which 50 were unreported. We performed integrative genomic, transcriptomic and methylomic analyses across large bowel mucosa and other tissues. Transcriptome- and methylome-wide association studies revealed an additional 53 risk associations. We identified 155 high-confidence effector genes functionally linked to CRC risk, many of which had no previously established role in CRC. These have multiple different functions and specifically indicate that variation in normal colorectal homeostasis, proliferation, cell adhesion, migration, immunity and microbial interactions determines CRC risk. Crosstissue analyses indicated that over a third of effector genes most probably act outside the colonic mucosa. Our findings provide insights into colorectal oncogenesis and highlight potential targets across tissues for new CRC treatment and chemoprevention strategies., (© 2022. The Author(s), under exclusive licence to Springer Nature America, Inc.)

Several polygenic risk scores (PRSs) have been developed to predict the risk of colorectal cancer (CRC) in European descendants. We used genome-wide association study (GWAS) data from 22 702 cases and 212 486 controls of Asian ancestry to develop PRSs and validated them in two case-control studies (1454 Korean and 1736 Chinese). Eleven PRSs were derived using three approaches: GWAS-identified CRC risk SNPs, CRC risk variants identified through fine-mapping of known risk loci and genome-wide risk prediction algorithms. Logistic regression was used to estimate odds ratios (ORs) and area under the curve (AUC). PRS 115-EAS , a PRS with 115 GWAS-reported risk variants derived from East-Asian data, validated significantly better than PRS 115-EUR derived from European descendants. In the Korea validation set, OR per SD increase of PRS 115-EAS was 1.63 (95% CI = 1.46-1.82; AUC = 0.63), compared with OR of 1.44 (95% CI = 1.29-1.60, AUC = 0.60) for PRS 115-EUR . PRS 115-EAS/EUR derived using meta-analysis results of both populations slightly improved the AUC to 0.64. Similar but weaker associations were found in the China validation set. Individuals among the highest 5% of PRS 115-EAS/EUR have a 2.52-fold elevated CRC risk compared with the medium (41-60th) risk group and have a 12% to 20% risk of developing CRC by age 85. PRSs constructed using results from fine-mapping and genome-wide algorithms did not perform as well as PRS 115-EAS and PRS 115-EAS/EUR in risk prediction, possibly due to a small sample size. Our results indicate that CRC PRSs are promising in predicting CRC risk in East Asians and highlights the importance of using population-specific data to build CRC risk prediction models., (© 2022 UICC.)

Introduction: The high prevalence of multiple chronic conditions (MCC), multimorbidity, and frailty may affect treatment and outcomes for older adults with cancer. The goal of this study was to use three conceptually distinct measures of morbidity to examine the association between these measures and mortality., Materials and Methods: Using Medicare claims data linked with the 2012-2016 Ohio Cancer Incidence Surveillance System we identified older adults with incident primary cancer sites of breast, colorectal, lung, or prostate (n = 29,140). We used claims data to identify their Elixhauser comorbidities, Multimorbidity-Weighted Index (MWI), and Claims Frailty Index (CFI) as measures of MCC, multimorbidity, and frailty, respectively. We used Cox proportional hazard models to examine the association between these measures and survival time since diagnosis., Results: Lung cancer patients had the highest levels of MCC, multimorbidity, and frailty. There was a positive association between all three measures and a greater hazard of death after adjusting for age, sex (colorectal and lung only), and stage. Breast cancer patients with 5+ comorbidities had an adjusted hazard ratio (aHR) of 1.63 (95% confidence interval [CI]: 1.38, 1.93), and those with mild frailty had an aHR of 3.38 (95% CI; 2.12, 5.41). The C statistics for breast cancer were 0.79, 0.78, and 0.79 for the MCC, MWI, and CFI respectively. Similarly, lung cancer patients who were moderately or severely frail had an aHR of 1.82 (95% CI: 1.53, 2.18) while prostate cancer patients had an aHR of 3.39 (95% CI: 2.12, 5.41) and colorectal cancer patients had an aHR of 4.51 (95% CI: 3.23, 6.29). Model performance was nearly identical across the MCC, multimorbidity, and frailty models within cancer type. The models performed best for prostate and breast cancer, and notably worse for lung cancer. The frailty models showed the greatest separation in unadjusted survival curves., Discussion: The MCC, multimorbidity, and frailty indices performed similarly well in predicting mortality among a large cohort of older cancer patients. However, there were notable differences by cancer type. This work highlights that although model performance is similar, frailty may serve as a clearer indicator in risk stratification of geriatric oncology patients than simple MCCs or multimorbidity., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Self-expandable metal stent (SEMS) placement is commonly used for palliation of left-sided malignant colorectal obstruction (MCO). However, right-sided MCO is usually treated surgically. Recent studies that compared palliative SEMS insertion and emergency surgery in right-sided MCOs have reported conflicting results. This study aimed to compare the effectiveness of palliative SEMS placement in left-sided MCOs and right-sided MCOs and to investigate the predictive factors for clinical success and risk factors for complications. Data from 469 patients who underwent palliative SEMS placement for MCO at 6 hospitals in the Honam province of South Korea between 2009 and 2018 were reviewed. Among them, 69 patients with right-sided MCO and 400 patients with left-sided MCO who underwent SEMS placement for palliative purposes were enrolled. Clinical success, overall survival, complications, and predictive factors for clinical success and risk factors for complications were included as the main outcome measures. The clinical success rates were 97.1% (65/67) in right-sided MCO patients and 88.2% (353/400) in left-sided MCO patients. Complications including stent migration, tumor ingrowth, outgrowth, perforation, bacteremia/fever, and bleeding occurred in 10.1% (7/69) of right-sided MCO patients and 19.9% (79/400) of left-sided MCO patients. The mean overall survival of right-sided MCO was 28.02 months and 18.23 months for left-sided MCO. In multivariate logistic regression analysis, T3 stage tumors and the use of uncovered stents were significant factors for the clinical success of SEMS. The use of covered stents and performance status score of 0 to 2 were independent significant risk factors for complications. Palliative SEMS placement in right-sided MCO showed better clinical success rates than left-sided MCO. The use of uncovered stents is recommended for higher clinical success rates and lower complication rates., Competing Interests: The authors have no funding and conflicts of interest to disclose., (Copyright © 2022 the Author(s). Published by Wolters Kluwer Health, Inc.)

Purpose: This study aimed to compare the treatment outcomes of radiofrequency ablation (RFA) and stereotactic body radiation therapy (SBRT) for colorectal cancer liver metastases (CRLM) and to determine the favorable treatment modality according to tumor characteristics., Materials and Methods: We retrospectively analyzed the records of 222 colorectal cancer patients with 330 CRLM who underwent RFA (268 tumors in 178 patients) or SBRT (62 tumors in 44 patients) between 2007 and 2014. Kaplan-Meier method and Cox models were used by adjusting with inverse probability of treatment weighting (IPTW)., Results: The median follow-up duration was 30.5 months. The median tumor size was significantly smaller in the RFA group than in the SBRT group (1.5 cm vs 2.3 cm, p<0.001). In IPTW-adjusted analysis, difference in treatment modality was not associated with significant differences in 1-year and 3-year recurrence-free survival (35% vs 43%, 22% vs 23%; p=0.198), overall survival (96% vs 91%, 58% vs 56%; p=0.508), and freedom from local progression (FFLP; 90% vs 72%, 78% vs 60%; p=0.106). Significant interaction effect between the treatment modality and tumor size was observed for FFLP (p=0.001). In IPTW-adjusted subgroup analysis of patients with tumor size >2 cm, the SBRT group had a higher FFLP compared with the RFA group (HR, 0.153; p<0.001)., Conclusion: SBRT and RFA showed similar local control in the treatment of patients with CRLM. Tumor size was an independent prognostic factor for local control and SBRT may be preferred for larger tumors.

Background: Self-expandable metal stent (SEMS) placement is commonly used as a bridge to surgery (BTS) for left-sided malignant colorectal obstruction (MCO). However, the optimal time interval between BTS stenting and surgery for left-sided MCO is unclear, and the results of previous studies are conflicting. This study aimed to determine the differences in clinical outcomes according to the time interval between BTS stenting and surgery in left-sided MCO., Methods: Data from 594 patients who underwent SEMS placement for MCO between January 2009 and December 2018 were reviewed. Among them, 148 patients who underwent SEMS placement as BTS treatment and curative surgery were enrolled. The enrolled patients were divided into three groups according to the interval between BTS stenting and surgery: group 1 (interval ≤2 weeks), group 2 (interval 2-3 weeks), and group 3 (interval >3 weeks)., Results: Group 2 and 3 patients underwent significantly higher rates of laparoscopic surgery than those in group 1 (83.7, 81.0 vs. 53.2 %, respectively; P=0.003, P=0.003, respectively). Also, rates of stoma formation directly after resection were significantly higher in group 1 compared to groups 2 and 3 (21.3 vs 2.3, 6.9%, respectively; P=0.008, P=0.043, respectively). Bridging interval had no effect on SEMS-related complications, resection-related complications, 90-day mortality, permanent stoma formation, 3-year disease-free survival, and 3-year overall survival., Conclusions: A bridging interval of > 2 weeks between BTS stenting and surgery for left-sided MCO is preferable for lower stoma formation rates and higher rates of laparoscopic approach operation, with no difference in short-term and long-term outcomes including complication, mortality, and survival., (© 2022. The Author(s).)

Background: The etiology of colorectal cancer is not fully understood., Methods: Using genetic variants and metabolomics data including 217 metabolites from the Framingham Heart Study (n = 1,357), we built genetic prediction models for circulating metabolites. Models with prediction R2 > 0.01 (Nmetabolite = 58) were applied to predict levels of metabolites in two large consortia with a combined sample size of approximately 46,300 cases and 59,200 controls of European and approximately 21,700 cases and 47,400 controls of East Asian (EA) descent. Genetically predicted levels of metabolites were evaluated for their associations with colorectal cancer risk in logistic regressions within each racial group, after which the results were combined by meta-analysis., Results: Of the 58 metabolites tested, 24 metabolites were significantly associated with colorectal cancer risk [Benjamini-Hochberg FDR (BH-FDR) < 0.05] in the European population (ORs ranged from 0.91 to 1.06; P values ranged from 0.02 to 6.4 × 10-8). Twenty one of the 24 associations were replicated in the EA population (ORs ranged from 0.26 to 1.69, BH-FDR < 0.05). In addition, the genetically predicted levels of C16:0 cholesteryl ester was significantly associated with colorectal cancer risk in the EA population only (OREA: 1.94, 95% CI, 1.60-2.36, P = 2.6 × 10-11; OREUR: 1.01, 95% CI, 0.99-1.04, P = 0.3). Nineteen of the 25 metabolites were glycerophospholipids and triacylglycerols (TAG). Eighteen associations exhibited significant heterogeneity between the two racial groups (PEUR-EA-Het < 0.005), which were more strongly associated in the EA population. This integrative study suggested a potential role of lipids, especially certain glycerophospholipids and TAGs, in the etiology of colorectal cancer., Conclusions: This study identified potential novel risk biomarkers for colorectal cancer by integrating genetics and circulating metabolomics data., Impact: The identified metabolites could be developed into new tools for risk assessment of colorectal cancer in both European and EA populations., (©2022 American Association for Cancer Research.)

In the current study, the underlying anti-metastatic mechanism of melatonin contained in some edible plants was explored in association with transmembrane protease serine 4 (TMPRSS4) mediated metastasis and epithelial-mesenchymal transition (EMT) signaling in human HCT15 and SW620 colorectal cancer cells. Here, TMPRSS4 was highly expressed in HCT15, but was weakly expressed in SW620 cells. Melatonin exerted weak cytotoxicity, decreased invasion, adhesion, and migration, and attenuated the expression of TMPRSS4, cyclin E, pro-urokinase-type plasminogen activator (pro-uPA), p-signal transducer and activator of transcription 3 (p-STAT3), p-focal adhesion kinase (p-FAK), Snail and increased the expression of E-cadherin, p27, pp38 and p-Jun N-terminal kinases (p-JNK) in HCT15 cells. Conversely, overexpression of TMPRSS4 reduced the ability of melatonin to activate E-cadherin and reduce Snail. Furthermore, even in SW620 cells transfected with TMPRSS4-overexpression plasmid, melatonin effectively suppressed invasion and migration along with decreased expression of Snail, cyclin A, cyclin E, pro-uPA and p-FAK and increased expression of E-cadherin and p27. Overall, these findings provide evidence that melatonin suppresses metastasis in colon cancer cells via inhibition of TMPRSS4 mediated EMT., (© 2021 John Wiley & Sons Ltd.)

Background: The impact of adherence to follow-up examination after a fecal occult blood test (FOBT) remains ill-defined., Aim: To evaluate the impact of adherence to the follow-up examination on clinical outcomes in individuals with positive FOBT results., Methods: This was a retrospective cohort study involving Korean individuals aged 50 years or older who participated in the National Cancer Screening Program for CRC from 2009 to 2010. Individuals who underwent a confirmative examination within a year after positive FOBT results were included in compliant group, and those who did not were included in non-compliant group. The incidence and stage of CRC, and 5-year survival were compared between two groups., Results: 5,914 were diagnosed with CRC in the compliant group and 2,973 in the non-compliant group. The proportion of advanced-stage CRC was significantly higher in the non-compliant group (localized CRC 44.6% vs. 36.7% and distant CRC 8.7% vs. 12.5%, p< 0.0001). The survival probability within 5 years was 71.0% in the non-compliant group and 85.9% in the compliant group (hazard ratio 1.70, 95% CI, 1.52-1.90, p< 0.001)., Conclusion: Individuals who underwent follow-up examination 1 year or more after positive FOBT had a lower survival rate compared with that in those who underwent examination within 1 year., Competing Interests: Declaration of Competing Interest Declaration of personal interests: Authors have no conflict of interest., (Copyright © 2021 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.)

Purpose: To describe the favorable procedural profile of CT colonography (CTC) during the COVID-19 pandemic., Conclusion: Postponement of cancer screening due to COVID-19 has resulted in a backlog of individuals needing to undergo structural examination of the colon. The experience during the initial COVID-19 surge with urgent evaluation of the colon for transplant patients prior to transplant suggests that CTC can be done in a lower risk manner as compared to other structural examinations. The procedural profile of CTC is advantageous during this pandemic as maintaining social distancing and preserving healthcare supplies including PPE are of paramount importance. CTC is an important option to utilize in the screening armamentarium to allow effective screening of average risk asymptomatic individuals in the COVID-19 era.

Background Although occult hemoglobin in feces is universally valued as a screening tool for colorectal cancer (CRC), only few studies investigated the clinical meaning of fecal immunochemical test (FIT) in other diseases. We evaluated the clinical utility of FIT in patients with cardiovascular diseases (namely, ischemic stroke and myocardial infarction [MI]). Methods and Results Using the National Health Insurance database, participants (aged >50 years) with CRC screening records from 2009 to 2012 were screened and followed up. Subjects with a history of cardiovascular diseases and CRC were excluded. Ischemic stroke, MI, and other comorbidities were defined by International Classification of Diseases, Tenth Revision ( ICD-10 ), codes. Age, sex, smoking, alcohol consumption, regular exercise, diabetes mellitus, hypertension, dyslipidemia, and body mass index were adjusted in a multivariate analysis. A total of 6 277 446 subjects were eligible for analysis. During the mean 6.79 years of follow-up, 168 570 participants developed ischemic stroke, 105 983 developed MI, and 11 253 deaths were observed. A multivariate-adjusted model revealed that the risk of ischemic stroke was higher in the FIT-positive population (adjusted hazard ratio [HR], 1.09; 95% CI, 1.07-1.11). Similarly, FIT-positive subjects were at an increased risk of MI (adjusted HR, 1.09; 95% CI, 1.06-1.12). Moreover, increased all-cause mortality was observed in the FIT-positive population (adjusted HR, 1.15; 95% CI, 1.07-1.23). The increased risk remained consistent in the stratified analysis on anemia and CRC status. Conclusions Positive FIT findings were associated with ischemic stroke, MI, and mortality. Occult blood in feces may offer more clinical information than its well-known conventional role in CRC screening.

Nuclear factor erythroid 2-related factor 2 (Nrf2) has dual effects on inflammation and cancer progression depending on the microenvironment. Estrogens have a protective effect on colorectal cancer (CRC) development. The aim of this study was to investigate CRC development in Nrf2 knockout (KO) mice. Azoxymethane (AOM) and dextran sulfate sodium (DSS)-treated wild-type (WT) and Nrf2 KO male mice were sacrificed at weeks 2 and 16 after AOM injection with/without 17β-estradiol (E2) treatment during week 1. Disease activity index and colon tissue damage at week 2 showed strong attenuation following E2 administration in WT mice but to a lesser extent in Nrf2 KO male mice. At week 16, E2 significantly diminished AOM/DSS-induced adenoma/cancer incidence at distal colon in the Nrf2 KO group, but not in the WT. Furthermore, mRNA or protein levels of NF-κB-related mediators (i.e., iNOS, TNF-α, and IL-1β) and Nrf2-related antioxidants (i.e., NQO1 and HO-1) were significantly lower in the Nrf2 KO group regardless of E2 treatment compared to the WT. The expression of estrogen receptor beta (ERβ) was higher in the Nrf2 KO group than in the WT. In conclusion, estrogen further inhibits CRC by upregulating ERβ-related alternate pathways in the absence of Nrf2., (Copyright © 2020 The Author(s). Published by Elsevier Inc. All rights reserved.)

Human exposure to aluminum (Al) mainly occurs through food intake. However, influences of Al on the gastrointestinal tract have been rarely reported. In particular, the effect of Al on the metastasis and angiogenesis of colorectal cancer cells has not been studied. Thus, we investigated the effect of Al on the metastatic proclivity using the human colorectal cancer cell line, HT-29. Cells were exposed to 1-16 mM AlCl 3 for 3-72 h. The effects of AlCl 3 on HT-29 cells for migration/invasion/adhesion, and metastasis-associated protein and gene expression were evaluated. AlCl 3 promoted cell migration and invasion, whereas it suppressed cell adhesion. AlCl 3 -exposed cells showed decreased E-cadherin and increased vimentin and Snail. AlCl 3 increased transforming growth factor-beta (TGF-β) mRNA expression and Smad2/3 nuclear translocation. AlCl 3 -treated cells had a higher mRNA expression of matrix metalloproteinase (MMP)-7 and -9 than the control. Particularly, AlCl 3 -treated HT-29 cells promoted the angiogenesis of endothelial cells via increasing the secretion of vascular endothelial growth factor. Taken together, AlCl 3 can promote the metastatic proclivity of colorectal cancer cells through MMP-7, -9, and TGF-β/Smad2/3 pathway. Our data suggest that Al exposure of the gastrointestinal tract may be a risk factor for metastasis initiation in colorectal cancer cells., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Background: Various animal models have been introduced into the study of liver metastasis of colorectal cancer, but they have not been compared under the same conditions. The aim of this study was to identify an optimized mouse model that showed a high rate of hepatic metastasis and expression of clonal dynamics., Materials and Methods: Athymic nude mice (n=30) were divided into two equal groups for the creation of a splenic injection model (SIM) and surgically orthotopic implantation model (SOIM) of liver metastasis of colorectal cancer using HCT116 cells. Hepatic metastasis was confirmed by gross and microscopic examinations. Expression of MET transcriptional regulator MACC1 (MACC1) in colon cancer cell lines and metastatic tumors in the group with a higher liver metastasis rate was confirmed by quantitative reverse-transcription-polymerase chain reaction., Results: The observation time was significantly shorter for SIM than for SOIM (33.0±6.8 vs. 41.2±7.2 days, p<0.001). The rate of hepatic metastasis was significantly higher in SIM than in SOIM (76.9% vs. 38.4%, p=0.038). MACC1 was expressed in Colo201, HCT116, HT29, LS513, SW620, and WiDr cells but not in SW480 cells. All hepatic metastases in SIM mice expressed MACC1, and metastatic HCT116 cells had significantly greater expression than did the original HCT116 cells (p<0.001)., Conclusion: With a higher rate of hepatic metastasis with clonal dynamics in a shorter observation time than the SOIM, SIM appears to be a good animal model for identifying new targets and in drug development for colorectal cancer liver metastasis. SOIM should also be considered for the study of the full steps of metastasis., (Copyright© 2020, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

OBJECTIVE. Serrated polyps include hyperplastic polyps, sessile serrated polyps, and traditional serrated adenomas (TSAs). Hyperplastic polyps and sessile serrated polyps account for approximately 99% of all serrated lesions; TSAs are rare. However, both sessile serrated polyps and TSAs are now recognized as precursor lesions to carcinogenesis, representing approximately one-fourth of all sporadic colorectal cancers. We report what is, to our knowledge, the first series describing the characteristics of CTAs on CT colonography (CTC). MATERIALS AND METHODS. An international, multicenter, retrospective review of CT colonography-detected TSAs diagnosed between 2008 and 2018 was conducted. Data collected included patient demographics and data from CTC, optical colonoscopy, and pathologic analysis. RESULTS. A total of 67 proven TSAs in 58 patients (mean age, 67 years) were identified. The majority (66%) were located in the distal colon (descending colon, sigmoid colon, and rectum), and their mean size was 19 mm (range, 3-80 mm). Small (< 10 mm) TSAs typically had a simple sessile or pedunculated morphologic appearance, whereas large (≥ 10 mm) TSAs tended to be more lobulated and irregular, pedunculated, or carpetlike. The majority (88%) showed at least some contrast medium surface coating. CONCLUSION. We report what we believe to be the first multicenter experience describing the characteristics of TSAs on CTC. Unlike sessile serrated lesions, TSAs are more often left-sided and tend to be more lobulated and irregular. However, like sessile serrated polyps, most TSAs show contrast medium surface coating. Detection of these rare lesions on CTC is important, given their malignant potential.

Background: Risk variants identified so far for colorectal cancer explain only a small proportion of familial risk of this cancer, particularly in Asians., Methods: We performed a genome-wide association study (GWAS) of colorectal cancer in East Asians, including 23,572 colorectal cancer cases and 48,700 controls. To identify novel risk loci, we selected 60 promising risk variants for replication using data from 58,131 colorectal cancer cases and 67,347 controls of European descent. To identify additional risk variants in known colorectal cancer loci, we performed conditional analyses in East Asians., Results: An indel variant, rs67052019 at 1p13.3, was found to be associated with colorectal cancer risk at P = 3.9 × 10 -8 in Asians ( OR per allele deletion = 1.13, 95% confidence interval = 1.08-1.18). This association was replicated in European descendants using a variant (rs2938616) in complete linkage disequilibrium with rs67052019 ( P = 7.7 × 10 -3 ). Of the remaining 59 variants, 12 showed an association at P < 0.05 in the European-ancestry study, including rs11108175 and rs9634162 at P < 5 × 10 -8 and two variants with an association near the genome-wide significance level (rs60911071, P = 5.8 × 10 -8 ; rs62558833, P = 7.5 × 10 -8 ) in the combined analyses of Asian- and European-ancestry data. In addition, using data from East Asians, we identified 13 new risk variants at 11 loci reported from previous GWAS., Conclusions: In this large GWAS, we identified three novel risk loci and two highly suggestive loci for colorectal cancer risk and provided evidence for potential roles of multiple genes and pathways in the etiology of colorectal cancer. In addition, we showed that additional risk variants exist in many colorectal cancer risk loci identified previously., Impact: Our study provides novel data to improve the understanding of the genetic basis for colorectal cancer risk., (©2019 American Association for Cancer Research.)

There is a wide array of pathological lesions seen in the anorectal region with CT colonography (CTC), much of which is unique to this location. Many relatively common findings in the anorectal region are typically benign, but can be misinterpreted as malignant. There are also technique-related pitfalls that can impede accurate diagnosis of anorectal findings at CTC. Understanding common and uncommon lesions in the anorectal region as well as recognizing technical pitfalls will optimize interpretation of CTC and decrease the number of missed cancers and false positives. This review will systematically cover that they key pitfalls confronting the radiologist at CTC interpretation of the anorectal region, primarily dividing them into those related to underlying anatomy and those related to technique. Tips for how to effectively handle these potential pitfalls will also be discussed.

The association between red meat intake and colorectal cancer (CRC) may be modulated by genetic polymorphisms of cytochrome P450 2E1 (CYP2E1), a key enzyme in the metabolism of nitrosamines, and peroxisome proliferator-activated receptor gamma (PPARγ), a transcription factor involved in adipogenesis and lipid and glucose metabolism. We conducted a case-control study of 971 patients with CRC and 658 controls who were admitted to two university hospitals between 1995 and 2004 in Seoul, Korea. Participants were asked about red meat intake by using a validated food frequency questionnaire. Polymorphisms of CYP2E1 (rs3813867) and PPARγ (rs1801282 or rs3856806) were identified using the TaqMan assay. We calculated odds ratios (ORs) and 95% confidence intervals (CIs) using multivariable logistic regression models. We found that the association between red meat and CRC varied by CYP2E1 polymorphisms; ORs (95% CIs) for at least five or more vs. less than one time/week of red meat intake were 2.77 (1.23-6.25) among individuals with C alleles of CYP2E1 and 0.89 (0.51-1.54) among individuals with the GG allele (Pinteraction=0.05). Compared with those individuals with the CC allele, increasing risk of CRC with increasing red meat intake was more pronounced among individuals with T alleles of PPARγC161T (rs3856806), but the association was not significant. Our data provide evidence that East Asians with the variant type of CYP2E1 may have high susceptibility to development of CRC risk.

Colorectal cancer (CRC) is diagnosed with colonoscopy and treated with focal therapies. CRC is a good candidate for nanoparticle-mediated photothermal ablation (PTA) therapy. Herein, we developed a near-infrared fluorescent (NIRF) endoscopic image-guided PTA approach using a nanoparticle capable of simultaneously diagnosing and treating CRC. Dual-modal NIR heating and fluorescent gold nanorods (dual-modal GNRs) were synthesized by conjugation of GNRs to an NIRF probe. To validate the translational potential of our approach, a well-characterized transgenic TS4 CRE/APC loxΔ468 colon cancer mouse model was used to carry out NIRF image-guided PTA using our dual-modal GNRs under clinically relevant conditions. Intravenously infused dual-modal GNRs were effectively targeted at colon polyps by immunogenic capturing of the GNRs within tumor-infiltrating innate immune cells. NIRF endoscopic image-guided PTA using the GNRs permitted successful detection and ablation of inflammatory colon polyps. NIRF endoscopy image-guided PTA using dual-modal GNRs can be utilized for diagnosis and treatment of CRC and various inflammatory diseases.

Interval colorectal cancers detected after colonoscopy are known to be highly associated with proximal colorectal neoplasms (CRNs). This cross-sectional study investigated whether periodontitis could be a risk factor for proximal CRNs in healthy individuals. A total of 2504 subjects who received a colonoscopy and dental exam were enrolled in this study. We divided the subjects into the periodontitis group (n = 216) and the control group (n = 2288). The periodontitis group was defined as subjects who had one or more teeth with a probing pocket depth (PPD) ≥4 mm. The prevalence of proximal CRNs was significantly higher in the periodontitis group (25.0%) than in the control group (12.3%) (P < 0.001). Independent risk factors for proximal CRNs in the multivariate analysis were periodontitis, smoking, age, waist circumference, and triglycerides, and those for proximal advanced CRNs were periodontitis, age, and family history of CRC. However, periodontitis was not a risk factor for overall CRNs and advanced CRNs. Periodontitis was associated with an increased risk of proximal CRNs (odds ratio [OR], 1.525; 95% confidence intervals [95% CI], 1.071-2.172) and proximal advanced CRNs (OR, 2.671; 95% CI, 1.088-6.560). Periodontitis might be associated with proximal CRNs and proximal advanced CRNs.

Background: With the recent development of molecular tests for various biomarkers, it has become even more important to prepare adequate tissue samples. However, little is known about how the effect of cold ischemia time or formalin fixation time can affect KRAS mutation detection in colorectal cancer., Methods: This study included the results of KRAS mutation tests for colorectal cancer in 401 specimens. We investigated clinicopathologic factors that may affect DNA quality of formalin-fixed, paraffin-embedded (FFPE) tissue including specimen type, cold ischemia time, and formalin fixation time and assessed the detection rate of the KRAS mutation in samples with varying DNA quality., Results: Sample DNA quality for KRAS mutation test was better in biopsy specimens, which showed markedly shorter cold ischemia time and shorter formalin fixation time compared to resection specimens. A cold ischemia time of one hour or less was associated with better sample DNA quality. But the formalin fixation time was not a significant factor when it fell within the range performed in routine pathology diagnosis. When prolonged formalin fixation was tested, we confirmed that the specimen DNA quality gradually got worse from one month to three months., Conclusions: The biopsy specimens showed better sample DNA quality for KRAS mutation test compared to resection specimens. In a routine diagnostic pathology setting, the cold ischemia time was an important factor affecting DNA quality and the formalin fixation had a wide time range for optimal DNA quality., (Copyright © 2019. Published by Elsevier GmbH.)

Cannabidiol (CBD), one of the compounds present in the marijuana plant, has anti-tumor properties, but its mechanism is not well known. This study aimed to evaluate the apoptotic action of CBD in colorectal cancer (CRC) cells, and focused on its effects on the novel pro-apoptotic Noxa-reactive oxygen species (ROS) signaling pathway. CBD experiments were performed using the CRC cell lines HCT116 and DLD-1. CBD induced apoptosis by regulating many pro- and anti-apoptotic proteins, of which Noxa showed significantly higher expression. To understand the relationship between Noxa and CBD-induced apoptosis, Noxa levels were downregulated using siRNA, and the expression of apoptosis markers decreased. After ROS production was blocked, the level of Noxa also decreased, suggesting that ROS is involved in the regulation of Noxa, which along with ROS is a well-known pro-apoptotic signaling agents. As a result, CBD induced apoptosis in a Noxa-and-ROS-dependent manner. Taken together, the results obtained in this study re-demonstrated the effects of CBD treatment in vivo, thus confirming its role as a novel, reliable anticancer drug., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Background & Aims: Genome-wide association studies (GWASs) have associated approximately 50 loci with risk of colorectal cancer (CRC)-nearly one third of these loci were initially associated with CRC in studies conducted in East Asian populations. We conducted a GWAS of East Asians to identify CRC risk loci and evaluate the generalizability of findings from GWASs of European populations to Asian populations., Methods: We analyzed genetic data from 22,775 patients with CRC (cases) and 47,731 individuals without cancer (controls) from 14 studies in the Asia Colorectal Cancer Consortium. First, we performed a meta-analysis of 7 GWASs (10,625 cases and 34,595 controls) and identified 46,554 promising risk variants for replication by adding them to the Multi-Ethnic Global Array (MEGA) for genotype analysis in 6445 cases and 7175 controls. These data were analyzed, along with data from an additional 5705 cases and 5961 controls genotyped using the OncoArray. We also obtained data from 57,976 cases and 67,242 controls of European descent. Variants at identified risk loci were functionally annotated and evaluated in correlation with gene expression levels., Results: A meta-analyses of all samples from people of Asian descent identified 13 loci and 1 new variant at a known locus (10q24.2) associated with risk of CRC at the genome-wide significance level of P < 5 × 10 -8 . We did not perform experiments to replicate these associations in additional individuals of Asian ancestry. However, the lead risk variant in 6 of these loci was also significantly associated with risk of CRC in European descendants. A strong association (44%-75% increase in risk per allele) was found for 2 low-frequency variants: rs201395236 at 1q44 (minor allele frequency, 1.34%) and rs77969132 at 12p11.21 (minor allele frequency, 1.53%). For 8 of the 13 associated loci, the variants with the highest levels of significant association were located inside or near the protein-coding genes L1TD1, EFCAB2, PPP1R21, SLCO2A1, HLA-G, NOTCH4, DENND5B, and GNAS. For other intergenic loci, we provided evidence for the possible involvement of the genes ALDH7A1, PRICKLE1, KLF5, WWOX, and GLP2R. We replicated findings for 41 of 52 previously reported risk loci., Conclusions: We showed that most of the risk loci previously associated with CRC risk in individuals of European descent were also associated with CRC risk in East Asians. Furthermore, we identified 13 loci significantly associated with risk for CRC in Asians. Many of these loci contained genes that regulate the immune response, Wnt signaling to β-catenin, prostaglandin E2 catabolism, and cell pluripotency and proliferation. Further analyses of these genes and their variants is warranted, particularly for the 8 loci for which the lead CRC risk variants were not replicated in persons of European descent., (Copyright © 2019 AGA Institute. Published by Elsevier Inc. All rights reserved.)

For decades, colorectal screening strategies have been largely driven by static features, particularly polyp size. Although cross-sectional features of polyp size, morphology, and location are important determinants of clinical relevance before histology, they lack any dynamic information on polyp growth rates. Computed tomography colonography allows for in vivo surveillance of colorectal polyps, providing volumetric growth rates that are providing new insights into tumorigenesis. In this article, existing cross-sectional and longitudinal data on colorectal polyps are reviewed, with an emphasis on how these features may affect clinical relevance and patient management., (Copyright © 2018 Elsevier Inc. All rights reserved.)

This article serves as a practical reference to optimize the performance of computed tomography colonography in the detection of colorectal neoplasia. A specific protocol in use at 2 US university programs as well as defined interpretation strategies will be described. With this framework in place, various clinical pearls as well as pitfalls to avoid will be a major focus of this article., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Background: Incidence and mortality from colorectal cancer (CRC) are higher among African Americans where CRC screening rates lag behind non-Hispanic whites. The purpose of this investigation was to evaluate CT colonography (CTC) performance and outcome measures in an African-American cohort., Materials and Methods: This study is an institutional review board-approved and Health Insurance Portability and Accountability Act-compliant study. Retrospective evaluation of the African-American cohort from the Atlanta VA Medical Center (Decatur, Georgia) CTC screening program. Colonoscopy referral rates and histologic diagnoses were evaluated., Results: CTC studies (n = 2490; mean age, 59.5 years [range, 50-80 years]; 85.5% male; all African American) were performed between 2007 and 2016. The per-patient CTC positive rate was 9.8% for polyps from 6 to 9 mm, 5.4% for polyps from 10 to 29 mm, and 1.3% for masses ≥ 30 mm. Based on CTC findings and patient preference, 13.9% of patients were referred to optical colonoscopy and 2.9% were referred to CTC follow-up. Of patients recommended to undergo colonoscopy, 80.6% completed the procedure and colonic pathology was confirmed in 83.2% thereof. Histologic diagnoses were 221 tubular adenomas (161 6-9 mm; 60 ≥ 10 mm), 59 tubulovillous adenomas/villous adenomas (14 6-9 mm; 45 ≥ 10 mm), 34 hyperplastic-serrated polyps (27 6-9 mm; 7 ≥ 10 mm), 18 adenocarcinomas (all ≥ 10 mm), and 11 adenomas with high-grade dysplasia (all ≥ 10 mm). The per-patient positivity rate for patients who had optical colonoscopy (n = 279) was 71.3% for adenoma, 9.7% for hyperplastic polyp, and 6.1% for adenocarcinoma., Conclusions: CTC is an effective screening modality for African-American adults and could potentially improve rates of colorectal screening in this underserved population., (Copyright © 2018 Elsevier Inc. All rights reserved.)

The aim of this study was to investigate the influence of American Society of Anesthesiologists (ASA) scores on postoperative complication rates and total hospital charges following laparoscopic surgery for colorectal cancer.All patients (n = 664) underwent laparoscopic colorectal cancer surgery. A group of patients with an ASA score of 1 or 2 (n = 575) and a group of patients with an ASA score of 3 (n = 89) were compared.The mean age was higher in the group of patients with an ASA score of 3 than in the group of patients with an ASA score of 1 or 2 (70 vs 67 years). The rate of ICU admission (27% vs 15%) was higher in the ASA score 3 group. The mean hospital stay (14 vs 12 days) was longer in the ASA score 3 group. Postoperative 30-day complications (38% vs 27%), 30-day mortality (2% vs 0%), and a Clavien-Dindo classification of ≥3 (21% vs 11%) occurred more frequently in the ASA score 3 group. Mean total hospital charges were significantly higher in the ASA score 3 group (13,906 vs 11,575 USD). Independent risk factors that affected postoperative complications were older age [≥80 years, hazard ratio (HR) = 2.8], an ASA score of 3 (HR = 1.6), and the presence of a primary rectal tumor (HR = 1.6). Postoperative complication rates were 21.9%, 28.5%, and 38.2% in the ASA score 1, 2, and 3 groups, respectively. Total hospital charges were 14,376 USD and 10,877 USD in the groups with and without postoperative complications, respectively. Mean total hospital charges were 10,769 USD, 11,756 USD, and 13,906 USD in the ASA score 1, 2, and 3 groups, respectively.Preoperative ASA scores may be a predictor of postoperative complications and hospital costs when planning laparoscopic surgery for colorectal cancer.

This review summarizes the relevant literature regarding colorectal screening with imaging. For individuals at average or moderate risk for colorectal cancer, CT colonography is usually appropriate for colorectal cancer screening. After positive results on a fecal occult blood test or immunohistochemical test, CT colonography is usually appropriate for colorectal cancer detection. For individuals at high risk for colorectal cancer (eg, hereditary nonpolyposis colorectal cancer, ulcerative colitis, or Crohn colitis), optical colonoscopy is preferred because of its ability to obtain biopsies to detect dysplasia. After incomplete colonoscopy, CT colonography is usually appropriate for colorectal cancer screening for individuals at average, moderate, or high risk. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment., (Copyright © 2018 American College of Radiology. Published by Elsevier Inc. All rights reserved.)

Objectives: To determine if identifiable hepatic textural features are present at abdominal CT in patients with colorectal cancer (CRC) prior to the development of CT-detectable hepatic metastases., Methods: Four filtration-histogram texture features (standard deviation, skewness, entropy and kurtosis) were extracted from the liver parenchyma on portal venous phase CT images at staging and post-treatment surveillance. Surveillance scans corresponded to the last scan prior to the development of CT-detectable CRC liver metastases in 29 patients (median time interval, 6 months), and these were compared with interval-matched surveillance scans in 60 CRC patients who did not develop liver metastases. Predictive models of liver metastasis-free survival and overall survival were built using regularised Cox proportional hazards regression., Results: Texture features did not significantly differ between cases and controls. For Cox models using all features as predictors, all coefficients were shrunk to zero, suggesting no association between any CT texture features and outcomes. Prognostic indices derived from entropy features at surveillance CT incorrectly classified patients into risk groups for future liver metastases (p < 0.001)., Conclusions: On surveillance CT scans immediately prior to the development of CRC liver metastases, we found no evidence suggesting that changes in identifiable hepatic texture features were predictive of their development., Key Points: • No correlation between liver texture features and metastasis-free survival was observed. • Liver texture features incorrectly classified patients into risk groups for liver metastases. • Standardised texture analysis workflows need to be developed to improve research reproducibility.

Background/aims: Knowledge regarding the quality metrics of fecal immunochemical test (FIT)-based colorectal cancer screening programs is limited. The aim of this study was to investigate the performance and quality metrics of a FIT-based screening program., Methods: In our screening program, asymptomatic subjects aged ≥50 years underwent an annual FIT, and subjects with positive FIT results underwent a subsequent colonoscopy. The performance of the FIT and colonoscopy was analyzed in individuals with a positive FIT who completed the program between 2009 and 2015 at a university hospital., Results: Among the 51,439 screened participants, 75.1% completed the FIT. The positive rate was 1.1%, and the colonoscopy completion rate in these patients was 68.6%. The positive predictive values of cancer and advanced neoplasia were 5.5% and 19.1%, respectively. The adenoma detection rate in the patients who underwent colonoscopy after a positive FIT was 48.2% (60.0% for men and 33.6% for women). The group with the highest tertile quantitative FIT level showed a significantly higher detection rate of advanced neoplasia than the group with the lowest tertile (odds ratio, 2.6; 95% confidence interval, 1.4 to 5.1; p＜0.001)., Conclusions: The quality metrics used in the United States and Europe may be directly introduced to other countries, including Korea. However, the optimal quality metrics should be established in each country.

CT colonography (CTC) has demonstrated equivalent accuracy to optical colonoscopy in the detection of clinically relevant polyps and tumors but this is only possible when technique is optimized. The two most important features of a high-quality CTC are a well-prepared colon and a distended colon. This article will discuss the dietary, bowel preparation, and fecal/fluid tagging options to best prepare the colon. Strategies to optimally distend the colon will also be discussed. CT scan techniques including patient positioning and radiation dose optimization will be reviewed. With proper technique which includes sufficient bowel preparation, fecal/fluid tagging, bowel distension, and optimized scan technique, high-quality CTC examinations should become more feasible, easier to interpret, and more consistently reproducible leading to increased utilization and increased referrals.