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

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

Correction: Potential for expanded application of endoscopic hand suturing: A pilot study of 15 cases.

[This corrects the article DOI: 10.1055/a-2284-9492.].

Potential for expanded application of endoscopic hand suturing: A pilot study of 15 cases.

Endoscopic hand suturing (EHS) was first developed to firmly close a mucosal defect following endoscopic submucosal dissection and has the potential for expanded applications. This study aimed to investigate the feasibility and safety of EHS in various clinical settings. In this single-center pilot study, 15 patients who had diseases with potential indications for EHS were prospectively recruited. Technical success, clinical success after the procedure, and severe EHS-related adverse events (AEs) were evaluated. EHS was applied for defect closure after gastric subepithelial lesion removal under laparoscopic observation (n = 9), defect closure after rectal endoscopic full-thickness resection (EFTR) (n = 2), defect closure after thoracoscopy-assisted esophageal EFTR (n = 1), mucosal closure for gastric ulcer bleeding (n = 1), mucosal closure after peroral endoscopic myotomy (POEM) (n = 1), and postoperative anastomotic leak (n = 1). EHS was completed without severe AEs and the clinical courses were also favorable in 13 patients (87%). The median suturing time was 61 minutes. In patients with POEM and anastomotic leak, EHS was discontinued because of the narrow lumen. In conclusion, EHS appears feasible and safe in situations.

Tumor size discrepancy between endoscopic and pathological evaluations in colorectal endoscopic submucosal dissection.

BACKGROUND: Tumor size impacts the technical difficulty and histological curability of colorectal endoscopic submucosal dissection (ESD); however, the preoperative evaluation of tumor size is often different from histological assessment. Analyzing influential factors on failure to obtain an accurate tumor size evaluation could help prepare optimal conditions for safer and more reliable ESD. AIM: To investigate the tumor size discrepancy between endoscopic and pathological evaluations and the influencing factors. METHODS: This was a retrospective study conducted at a single institution. A total of 377 lesions removed by colorectal ESD at our hospital between April 2018 and March 2022 were collected. We first assessed the difference in size with an absolute percentage of the scaling discrepancy. Subsequently, we compared the clinicopathological characteristics of the correct scaling group (> -33% and < 33%) with that of the incorrect scaling group (< -33% or > 33%), which was further subdivided into the underscaling group (-33% or less of the discrepancy) and overscaling group (33% or more of the discrepancy), respectively. As secondary outcome measures, parameters on size estimation were compared between the underscaling and correct scaling groups, as well as between the overscaling and correct scaling groups. Finally, multivariate analysis was performed in terms of the following relevant parameters on size estimation: Pathological size, location, and possible influential factors (P < 0.1) in the univariate analysis. RESULTS: The mean of absolute percentage in the scaling discordance was 21%, and 91 lesions were considered to be incorrectly estimated in size. The incorrect scaling was significantly remarkable in larger lesions (40 mm vs 28 mm; P < 0.001) and less experience (P < 0.001), and these two factors were influential on the underscaling (75 lesions; P < 0.001). Conversely, compared with the correct scaling group, 16 lesions in the overscaling group were significantly small (20 mm vs 28 mm; P < 0.001), and the small lesion size was influential on the overscaling (P = 0.002). CONCLUSION: Lesions indicated for colorectal ESD tended to be underestimated in large tumors, but overestimated in small ones. This discrepancy appears worth understanding for optimal procedural preparation.

Treatment Decision for Locally Resected T1 Colorectal Carcinoma-Verification of the Japanese Guideline Criteria for Additional Surgery Based on Long-Term Clinical Outcomes.

INTRODUCTION: To verify the value of the pathological criteria for additional treatment in locally resected pT1 colorectal carcinoma (CRC) which have been used in the Japanese Society for Cancer of the Colon and Rectum (JSCCR) guidelines since 2009. METHODS: We enrolled 4,719 patients with pT1 CRC treated at 27 institutions between July 2009 and December 2016 (1,259 patients with local resection alone [group A], 1,508 patients with additional surgery after local resection [group B], and 1,952 patients with surgery alone [group C]). All 5 factors of the JSCCR guidelines (submucosal resection margin, tumor histologic grade, submucosal invasion depth, lymphovascular invasion, and tumor budding) for lymph node metastasis (LNM) had been diagnosed prospectively. RESULTS: Any of the risk factors were present in 3,801 patients. The LNM incidence was 10.3% (95% confidence interval 9.3-11.4) in group B/C patients with risk factors, whereas it was 1.8% (95% confidence interval 0.4-5.2) in those without risk factors ( P < 0.01). In group A, the incidence of recurrence was 3.4% in patients with risk factors, but it was only 0.1% in patients without risk factors ( P < 0.01). The disease-free survival rate of group A patients classified as risk positive was significantly worse than those of groups B and C patients. However, the 5-year disease-free survival rate in group A patients with no risk was 99.2%. DISCUSSION: Our large-scale real-world multicenter study demonstrated the validity of the JSCCR criteria for pT1 CRC after local resection, especially regarding favorable outcomes in patients with low risk of LNM.

White Blood Cell Counts and Future Relapse in Ulcerative Colitis under Low-Dose Thiopurine Treatment in Real-World Practice: A 3-Year Japanese Multi-Center Retrospective Cohort Study.

Introduction: Whether white blood cell (WBC) counts are predictors for the effectiveness of thiopurine treatment in ulcerative colitis (UC) has been inconclusive in previous studies with small sample sizes. We investigated the association between WBC counts and future relapses in UC patients in a large-scale multi-center study. Methods: This retrospective cohort study enrolled a total of 723 UC patients in remission from 33 hospitals and followed up for 3 years. Relapse was defined as a need for treatment intensification. The risk of relapse was compared among patients with the baseline WBC counts <3,000/µL (N = 31), 3,000-4,000/µL (N = 167), 4,000-5,000/µL (N = 241), and ≥5,000/µL (N = 284) using a Cox regression model analysis. Moreover, exploratory analyses were conducted to identify other factors predicting relapse. Results: During a median follow-up period of 1,095 (interquartile range, 1,032-1,119) days, relapse occurred in 17.2% (125/723). In a crude analysis, WBC counts were not associated with relapse; hazard ratios (HRs) (95% confidence interval [CI]) were 1.50 (0.74-3.06), 1.02 (0.66-1.59), and 0.67 (0.43-1.05) in WBC <3,000/µL, 3,000-4,000/µL, and 4,000-5,000/µL groups, respectively (WBC ≥5,000/µL group, as reference). Multivariable-adjusted analyses showed similar results; HRs (95% CI) were 1.21 (0.59-2.49), 1.08 (0.69-1.69), and 0.69 (0.44-1.07), in <3,000/µL, 3,000-4,000/µL, and 4,000-5,000/µL groups, respectively. In the exploratory analyses, thiopurine use <1 year and a mean corpuscular volume <90 fL were predictors for relapse. Discussion/Conclusion: WBC counts were not predictors for future relapses in patients with UC treated with thiopurine as a maintenance therapy.

Potential of Direct Oral Anticoagulant in Bleeding After Gastric Endoscopic Submucosal Dissection: A Systematic Review and Meta-Analysis.

BACKGROUND AND AIMS: An increasing number of patients are undergoing gastric endoscopic submucosal dissection (ESD) with active prescriptions of direct oral anticoagulants (DOACs). Only a few reports have described the effects of DOAC intake on postoperative bleeding. We aimed to investigate the bleeding risk associated with DOACs after gastric ESD. METHODS: Clinical studies published up to April 2022 showing bleeding rates after gastric ESD in patients taking DOACs were identified using electronic searches. The primary outcome was the rate of bleeding after gastric ESD in patients receiving DOACs compared to those not receiving antithrombotic therapy. In this meta-analysis, odds ratios (ORs) were calculated and pooled using a random effects model. The secondary outcome was the difference in the bleeding rate between patients treated with DOACs and those treated with warfarin and antiplatelet drugs. RESULTS: Seven studies were included in this meta-analysis. The pooled analysis showed that DOACs had a higher bleeding rate than non-thrombotic therapy (17.0% vs. 3.4%; OR 5.72; 95% confidence interval [CI], 4.33-7.54; I2 = 0%). The bleeding risk associated with DOAC administration was similar to that associated with warfarin (17.0% vs. 20.0%; OR 0.83; 95% CI 0.59-1.18; I2 = 0%), whereas it was higher than that associated with antiplatelet administration (16.9% vs. 11.0%; OR 1.63; 95% CI 1.14-2.34; I2 = 8%). CONCLUSIONS: This meta-analysis reveals that the bleeding risk of DOACs is higher than that of non-antithrombotics and antiplatelets, whereas it is comparable to that of warfarin. Gastric ESD in patients on anticoagulants requires careful postoperative management.

Enrichment of Bacteroides fragilis and enterotoxigenic Bacteroides fragilis in CpG island methylator phenotype-high colorectal carcinoma.

OBJECTIVES: Data support that enterotoxigenic Bacteroides fragilis (ETBF) harbouring the Bacteroides fragilis toxin (bft) gene may promote colorectal tumourigenesis through the serrated neoplasia pathway. We hypothesized that ETBF may be enriched in colorectal carcinoma subtypes with high-level CpG island methylator phenotype (CIMP-high), BRAF mutation, and high-level microsatellite instability (MSI-high). METHODS: Quantitative PCR assays were designed to quantify DNA amounts of Bacteroides fragilis, ETBF, and each bft gene isotype (bft-1, bft-2, or bft-3) in colorectal carcinomas in the Health Professionals Follow-up Study and Nurses' Health Study. We used multivariable-adjusted logistic regression models with the inverse probability weighting method. RESULTS: We documented 4476 colorectal cancer cases, including 1232 cases with available bacterial data. High DNA amounts of Bacteroides fragilis and ETBF were positively associated with BRAF mutation (p ≤ 0.0003), CIMP-high (p ≤ 0.0002), and MSI-high (p < 0.0001 and p = 0.01, respectively). Multivariable-adjusted odds ratios (with 95% confidence interval) for high Bacteroides fragilis were 1.40 (1.06-1.85) for CIMP-high and 2.14 (1.65-2.77) for MSI-high, but 1.02 (0.78-1.35) for BRAF mutation. Multivariable-adjusted odds ratios for high ETBF were 2.00 (1.16-3.45) for CIMP-high and 2.86 (1.64-5.00) for BRAF mutation, but 1.09 (0.67-1.76) for MSI-high. Neither Bacteroides fragilis nor ETBF was associated with colorectal cancer-specific or overall survival. DISCUSSION: The tissue abundance of Bacteroides fragilis is associated with CIMP-high and MSI-high, whereas ETBF abundance is associated with CIMP-high and BRAF mutation in colorectal carcinoma. Our findings support the aetiological relevance of Bacteroides fragilis and ETBF in the serrated neoplasia pathway.

Relationship Between Immunophenotypes, Genetic Profiles, and Clinicopathologic Characteristics in Small Bowel Adenocarcinoma.

Small bowel adenocarcinoma (SBA) is rare, and scant data exist regarding its molecular and clinicopathologic characteristics. This study aimed to clarify the correlation between immunophenotypes, DNA mismatch repair status, genomic profiling, and clinicopathologic characteristics in patients with SBA. We examined 68 surgical resections from patients with primary SBA for immunohistochemical analyses of CK7, CK20, CD10, CDX2, MUC1, MUC2, MUC4, MUC5AC, and MUC6 expression as well as mismatch repair status. Genomic profiling was performed on 30 cases using targeted next-generation sequencing. Tumor mucin phenotypes were classified as gastric, intestinal, gastrointestinal, or null based on MUC2, MUC5AC, MUC6, and CD10 immunostaining. The expression of these proteins was categorized into 3 classifications according to their relationship to: (1) tumor location: CK7/CK20, MUC4, and MUC6; (2) histologic type: mucinous adenocarcinoma was positive for MUC2 and negative for MUC6; and (3) TNM stage: CD10 was downregulated, whereas MUC1 was upregulated in advanced TNM stages. CDX2 was a specific marker for SBA generally expressed in the small intestine. MUC1 and MUC4 expression was significantly associated with worse prognosis. MUC2 expression correlated with better prognosis, except for mucinous adenocarcinoma. Although the difference was not statistically significant, gastric-type tumors were more frequently located in the duodenum and were absent in the ileum. APC and CTNNB1 mutations were not found in the gastric-type tumors. The SBA immunophenotype correlated with tumor location, biological behavior, and genomic alterations. Our results suggest that the molecular pathway involved in carcinogenesis of gastric-type SBA differs from that of intestinal-type SBA.

How Does Omitting Additional Surgery After Local Excision Affect the Prognostic Outcome of Patients With High-risk T1 Colorectal Cancer?

OBJECTIVE: To investigate how omitting additional surgery after local excision (LE) affects patient outcomes in high-risk T1 colorectal cancer (CRC). BACKGROUND: It is debatable whether additional surgery should be performed for all patients with high-risk T1 CRC regardless of the tolerability of invasive procedures. METHODS: Patients who had received LE for T1 CRC at the Japanese Society for Cancer of the Colon and Rectum institutions between 2009 and 2016 were analyzed. Those who had received additional surgical resection and those who did not were matched one-on-one by the propensity score-matching method. A total of 401 propensity score-matched pairs were extracted from 1975 patients at 27 Japanese Society for Cancer of the Colon and Rectum institutions and were compared. RESULTS: Regional lymph node metastasis was observed in 31 (7.7%) patients in the LE + surgery group. Comparatively, the incidence of oncologic adverse events was low in the LE-alone group, such as the 5-year cumulative risk of local recurrence (4.1%) or overall recurrence (5.5%). In addition, the difference in the 5-year cancer-specific survival between the LE + surgery and LE-alone groups was only 1.8% (99.7% and 97.9%, respectively), whereas the 5-year overall survival was significantly lower in the LE-alone group than in the LE + surgery group [88.5% vs 94.5%, respectively ( P = 0.002)]. CONCLUSIONS: Those who had decided to omit additional surgery at the dedicated center for CRC treatment presented a small number of oncologic events and a satisfactory cancer-specific survival, which may suggest an important role of risk assessment regarding nononcologic adverse events to achieve a best practice for each individual with high-risk T1 tumors.

Clinical significance of programmed cell death-ligand expression in small bowel adenocarcinoma is determined by the tumor microenvironment.

BACKGROUND: Comprehensive genomic analysis has shown that small bowel adenocarcinoma (SBA) has different genomic profiles from gastric and colorectal cancers. Hence, it is essential to establish chemotherapeutic regimens based on SBA characteristics. The expression of programmed cell death-ligand 1 (PD-L1) and programmed cell death-ligand 2 (PD-L2) in SBA is not fully understood. Anti-PD-L1/PD-1 therapy uses tumor-infiltrating lymphocytes (TILs); therefore, the status of TILs in the tumor microenvironment (TME) may influence their efficacy. The ratio of FoxP3+ to CD8+ T cells has been reported to be useful in predicting the prognosis of digestive system cancers. AIM: To investigate the clinicopathological significance of PD-L1/2 expression according to the status of TILs in SBA tissues. METHODS: We performed immunohistochemical analysis for PD-L1, PD-L2, CD8, FoxP3, and DNA mismatch repair (MMR) proteins using formalin-fixed, paraffin-embedded tissues from 50 patients diagnosed with primary SBA. The immunoreactivities of PD-L1 and PD-L2 were determined separately in tumor cells and tumor-infiltrating immune cells throughout the tumor center and invasive margins, and finally evaluated using the combined positive score (CPS). We assessed CD8+ and FoxP3+ T cells in the intratumoral and tumor-surrounding stroma. Subsequently, we calculated and summed the ratio of FoxP3 to CD8+ T cell counts. Immune-related cell densities were graded as low or high. Immunohistochemical results were compared with clinicopathological factors and patient prognosis. The distribution of cancer-specific survival (CSS) was estimated using the Kaplan-Meier method, and the log-rank test was used to test for significant differences in CSS. A Cox proportional hazard model was also used to assess the effect of tumor variables on CSS. RESULTS: PD-L1 expression was positive in 34% in tumor cells (T-PD-L1) and 54% in tumor-infiltrating immune cells (I-PD-L1) of the cases examined. T-PD-L2 was positive in 34% and I-PD-L2 was positive in 42% of the cases. PD-L1 CPS ≥ 10 and PD-L2 CPS ≥ 10 were observed in 50% and 56% of the cases, respectively. Deficient MMR (dMMR) was 14% of the cases. T-PD-L1, I-PD-L1 and PD-L1 CPS ≥ 10 were all significantly associated with dMMR (P = 0.037, P = 0.009, and P = 0.005, respectively). T-PD-L1, I-PD-L1, and PD-L1 CPS ≥ 10 were all associated with deeper depth of invasion (P = 0.001, P = 0.024, and P = 0.002, respectively). I-PD-L2 expression and PD-L2 CPS ≥ 10 were significantly higher in the differentiated histological type (P = 0.015 and P = 0.030, respectively). The I-PD-L1 and I-PD-L2 levels were significantly associated with better CSS (P = 0.037 and P = 0.015, respectively). CD8-high was significantly associated with less lymph node metastasis (P = 0.047), less distant metastasis (P = 0.024), less peritoneal dissemination (P = 0.034), and earlier TNM stage (P = 0.047). The CD8-high group had better prognosis than the CD8-low group (P = 0.018). FoxP3 expression was not associated with any clinicopathological factors or prognosis. We found that patients with PD-L2 CPS ≥ 10 tended to have worse prognosis in the FoxP3/CD8-low group (P = 0.088). CONCLUSION: The clinicopathological significance of PD-L1/2 expression may differ depending on the TME status. Immune checkpoint inhibitors may improve the prognosis of SBA patients with low FoxP3/CD8 ratio and PD-L2 expression.

Inverse relationship between Fusobacterium nucleatum amount and tumor CD274 (PD-L1) expression in colorectal carcinoma.

Objectives: The CD274 (programmed cell death 1 ligand 1, PD-L1)/PDCD1 (programmed cell death 1, PD-1) immune checkpoint axis is known to regulate the antitumor immune response. Evidence also supports an immunosuppressive effect of Fusobacterium nucleatum. We hypothesised that tumor CD274 overexpression might be inversely associated with abundance of F. nucleatum in colorectal carcinoma. Methods: We assessed tumor CD274 expression by immunohistochemistry and F. nucleatum DNA within tumor tissue by quantitative PCR in 812 cases among 4465 incident rectal and colon cancer cases that had occurred in two prospective cohort studies. Multivariable logistic regression analyses with inverse probability weighting were used to adjust for selection bias because of tissue data availability and potential confounders including microsatellite instability status, CpG island methylator phenotype, LINE-1 methylation level and KRAS, BRAF and PIK3CA mutations. Results: Fusobacterium nucleatum DNA was detected in tumor tissue in 109 (13%) cases. Tumor CD274 expression level was inversely associated with the amount of F. nucleatum in colorectal cancer tissue (P = 0.0077). For one category-unit increase in three ordinal F. nucleatum categories (negative vs. low vs. high), multivariable-adjusted odds ratios (with 95% confidence interval) of the low, intermediate and high CD274 categories (vs. negative) were 0.78 (0.41-1.51), 0.64 (0.32-1.28) and 0.50 (0.25-0.99), respectively (P trend = 0.032). Conclusions: Tumor CD274 expression level was inversely associated with the amount of F. nucleatum in colorectal cancer tissue, suggesting that different immunosuppressive mechanisms (i.e. PDCD1 immune checkpoint activation and tumor F. nucleatum enrichment) tend to be used by different tumor subgroups.

Prophylactic use of steroids for a mucosal defect with a circumference of less than three-fourths prevents both symptomatic and asymptomatic stricture after esophageal endoscopic submucosal dissection.

BACKGROUND: Subclinical stricture after esophageal endoscopic submucosal dissection (ESD) makes the detection and re-ESD of metachronous lesions difficult. This study aimed to investigate the effectiveness of prophylactic steroid use after esophageal ESD for mucosal defects with a circumference less than 75% for the prevention of symptomatic and asymptomatic stricture. METHODS: In 80 retrospectively enrolled patients, we collected paired endoscopic images of a mucosal defects immediately after resection and a scar thereafter. After calculating circumference by image analysis software, all patients were classified into three groups in reference to mucosal defect circumference (MDC; ≤ 50%, 50-75%, ≥ 75%). Frequency of steroid use and symptomatic stricture were compared, and in < 75% MDC patients, a degree of asymptomatic stricture with or without steroid was compared by calculating a scar contraction rate (SCR). RESULTS: In the ≤ 50% (43 patients), 50-75% (27 patients) and ≥ 75% (10 patients) MDC groups, steroids were used in 12%, 59% and 100%, respectively, and symptomatic stricture occurred in 0%, 7% and 40%, respectively. In < 75% MDC patients, SCR in the steroid cohort was significantly lower than that in the nonsteroid cohort (42% vs. 65%, p = 0.002). No steroid-related adverse events occurred. CONCLUSION: Steroid use even for mucosal defects with < 75% circumference appears effective for the reduction of the risk on both symptomatic and asymptomatic stricture after esophageal ESD.

Comparison of Linked Color Imaging and White Light Imaging Colonoscopy for Detection of Colorectal Adenoma Requiring Endoscopic Treatment: A Single-Center Randomized Controlled Trial.

BACKGROUND: Linked color imaging (LCI) improves detection of colorectal neoplastic lesions during colonoscopy. However, polyps <5 mm in diameter often do not require resection, and the benefits of LCI are unclear for detection of colorectal polyps ≥5 mm that are indicated for endoscopic resection in clinical practice. This randomized controlled trial compared rates of detection of adenoma polyps, stratified by size, for LCI and white light imaging (WLI). METHODS: We compared ADR (5 mm-) and PDR (5 mm-), which were defined as the proportion of patients with at least one adenoma or polyp with a diameter of 5 mm or larger in the LCI and WLI groups. Moreover, we estimated ADR and PDR for diameters between 5 and 10 mm (ADR (5-9 mm), PDR (5-9 mm) ) and for diameters larger than 10 mm (ADR (10 mm-), PDR (10 mm-) ). RESULTS: Data from 594 patients (LCI, n=305; WLI, n=289) were analyzed. ADR (5 mm-) and PDR (5 mm-) were significantly higher in the LCI group than in the WLI group (ADR (5 mm-): P=0.016, PDR (5 mm-): P=0.020). In the assessment of adenoma and polyp size, ADR (5-9 mm) and PDR (5-9 mm) were significantly higher in the LCI group than in the WLI group, although no significant differences were seen in ADR (10 mm-) and PDR (10 mm-) between these groups. CONCLUSIONS: Polyps ≥5 mm, which are indicated for endoscopic treatment, were more easily visualized with LCI mode than with WLI mode. The improvement in detection rate was obvious for polyps <10 mm, which are easier to miss.

Prognostic role of detailed colorectal location and tumor molecular features: analyses of 13,101 colorectal cancer patients including 2994 early-onset cases.

BACKGROUND: The pathogenic effect of colorectal tumor molecular features may be influenced by several factors, including those related to microbiota, inflammation, metabolism, and epigenetics, which may change along colorectal segments. We hypothesized that the prognostic association of colon cancer location might differ by tumor molecular characteristics. METHODS: Utilizing a consortium dataset of 13,101 colorectal cancer cases, including 2994 early-onset cases, we conducted survival analyses of detailed tumor location stratified by statuses of microsatellite instability (MSI), CpG island methylator phenotype (CIMP), and KRAS and BRAF oncogenic mutation. RESULTS: There was a statistically significant trend for better colon cancer-specific survival in relation to tumor location from the cecum to sigmoid colon (Ptrend = 0.002), excluding the rectum. The prognostic association of colon location differed by MSI status (Pinteraction = 0.001). Non-MSI-high tumors exhibited the cecum-to-sigmoid trend for better colon cancer-specific survival [Ptrend < 0.001; multivariable hazard ratio (HR) for the sigmoid colon (vs. cecum), 0.80; 95% confidence interval (CI) 0.70-0.92], whereas MSI-high tumors demonstrated a suggestive cecum-to-sigmoid trend for worse survival (Ptrend = 0.020; the corresponding HR, 2.13; 95% CI 1.15-3.92). The prognostic association of colon tumor location also differed by CIMP status (Pinteraction = 0.003) but not significantly by age, stage, or other features. Furthermore, MSI-high status was a favorable prognostic indicator in all stages. CONCLUSIONS: Both detailed colonic location and tumor molecular features need to be accounted for colon cancer prognostication to advance precision medicine. Our study indicates the important role of large-scale studies to robustly examine detailed colonic subsites in molecular oncology research.

Nomogram as a novel predictive tool for lymph node metastasis in T1 colorectal cancer treated with endoscopic resection: a nationwide, multicenter study.

BACKGROUND AND AIMS: Since 2009, the Japanese Society for Cancer of the Colon and Rectum guidelines have recommended that tumor budding and submucosal invasion depth, in addition to lymphovascular invasion and tumor grade, be included as risk factors for lymph node metastasis (LNM) in patients with T1 colorectal cancer (CRC). In this study, a novel nomogram was developed and validated by usirge-scale, real-world data, including the Japanese Society for Cancer of the Colon and Rectum risk factors, to accurately evaluate the risk of LNM in T1 CRC. METHODS: Data from 4673 patients with T1 CRC treated at 27 high-volume institutions between 2009 and 2016 were analyzed for LNM risk. To prepare a nonrandom split sample, the total cohort was divided into development and validation cohorts. Pathologic findings were extracted from the medical records of each participating institution. The discrimination ability was measured by using the concordance index, and the variability in each prediction was evaluated by using calibration curves. RESULTS: Six independent risk factors for LNM, including submucosal invasion depth and tumor budding, were identified in the development cohort and entered into a nomogram. The concordance index was .784 for the clinical calculator in the development cohort and .790 in the validation cohort. The calibration curve approached the 45-degree diagonal in the validation cohort. CONCLUSIONS: This is the first nomogram to include submucosal invasion depth and tumor budding for use in routine pathologic diagnosis based on data from a nationwide multi-institutional study. This nomogram, developed with real-world data, should improve decision-making for an appropriate treatment strategy for T1 CRC.

A successful treatment case of refractory hemorrhagic ulcer with eosinophilic gastritis by endoscopic hand suturing.

A 78-year-old man was admitted to our hospital with a tarry stool. Esophagogastroduodenoscopy identified tiny oozing on the greater curvature at the antrum. Despite repeated endoscopic hemostasis by coagulation and clipping, rebleeding occurred. On the third rebleeding, we performed endoscopic hand suturing to completely close the ulcer surface. Biopsy showing massive infiltration of eosinophils at the ulcer edge indicated eosinophilic gastritis. After the endoscopic closure by endoscopic hand suturing, the patient had no symptoms of bleeding thereafter and was discharged 19 days after the procedure by taking oral prednisolone. The patient remained well and was continuously treated with a small dose of steroids in outpatient. This is the first case report of the successful application of endoscopic hand suturing to a refractory hemorrhagic ulcer. Further accumulation of clinical experiences is desired to confirm the usefulness of this technique for the prevention of refractory ulcer bleeding.

Molecular Characteristics of Early-Onset Colorectal Cancer According to Detailed Anatomical Locations: Comparison With Later-Onset Cases.

INTRODUCTION: Early-onset colorectal cancer diagnosed before the age of 50 years has been increasing. Likely reflecting the pathogenic role of the intestinal microbiome, which gradually changes across the entire colorectal length, the prevalence of certain tumor molecular characteristics gradually changes along colorectal subsites. Understanding how colorectal tumor molecular features differ by age and tumor location is important in personalized patient management. METHODS: Using 14,004 cases with colorectal cancer including 3,089 early-onset cases, we examined microsatellite instability (MSI), CpG island methylator phenotype (CIMP), and KRAS and BRAF mutations in carcinomas of the cecum, ascending colon, transverse colon, descending colon, sigmoid colon, and rectum and compared early-onset cases with later-onset cases. RESULTS: The proportions of MSI-high, CIMP-high, and BRAF -mutated early-onset tumors were lowest in the rectum (8.8%, 3.4%, and 3.5%, respectively) and highest in the ascending colon (46% MSI-high; 15% CIMP-high) or transverse colon (8.6% BRAF -mutated) (all Ptrend <0.001 across the rectum to ascending colon). Compared with later-onset tumors, early-onset tumors showed a higher prevalence of MSI-high status and a lower prevalence of CIMP-high status and BRAF mutations in most subsites. KRAS mutation prevalence was higher in the cecum compared with that in the other subsites in both early-onset and later-onset tumors ( P < 0.001). Notably, later-onset MSI-high tumors showed a continuous decrease in KRAS mutation prevalence from the rectum (36%) to ascending colon (9%; Ptrend <0.001), followed by an increase in the cecum (14%), while early-onset MSI-high cancers showed no such trend. DISCUSSION: Our findings support biogeographical and pathogenic heterogeneity of colorectal carcinomas in different colorectal subsites and age groups.

Chronological Changes in Mucosal Deformity by Endoscopic Suturing after Gastric Endoscopic Submucosal Dissection: A Multicenter Retrospective Analysis.

INTRODUCTION: Endoscopic suturing of a mucosal defect is expected to prevent postoperative bleeding after endoscopic submucosal dissection (ESD). Endoscopic suturing causes mucosal deformity, which may interfere with endoscopic surveillance thereafter. We retrospectively investigated long-term chronological changes in mucosal suturing by endoscopic suturing. METHODS: Forty-three patients who underwent endoscopic hand suturing (EHS) after gastric ESD at three institutions were enrolled. First, our hypothesis that the suturing sites healed via inflammation, disappearance of mucosal inversion, and flattening was validated. Subsequently, the duration required to reach each healing step was evaluated. RESULTS: A total of 137 follow-up endoscopies were assessed, in which all cases showed the hypothesized chronological course on the suturing sites. The 95th percentiles of the duration when showing the disappearance of the inflammatory change and the inverted change were 63 days and 15.5 months after the procedure, respectively. DISCUSSION/CONCLUSION: The data show that the mucosal deformity induced by EHS disappeared within 16 months. Endoscopic suturing is thus considered to have a negligible effect on endoscopic surveillance following the procedure.

Prognostic role of inflammatory diets in colorectal cancer overall and in strata of tumor-infiltrating lymphocyte levels.

BACKGROUND: Certain dietary patterns can elicit systemic and intestinal inflammatory responses, which may influence adaptive anti-tumor immune responses and tumor behavior. We hypothesized that pro-inflammatory diets might be associated with higher colorectal cancer mortality and that the association might be stronger for tumors with lower immune responses. METHODS: We calculated an empirical dietary inflammatory pattern (EDIP) score in 2829 patients among 3988 incident rectal and colon carcinoma cases in the Nurses' Health Study and Health Professionals Follow-up Study. Using Cox proportional hazards regression analyses, we examined the prognostic association of EDIP scores and whether it might be modified by histopathologic immune reaction (in 1192 patients with available data). RESULTS: Higher EDIP scores after colorectal cancer diagnosis were associated with worse survival, with multivariable-adjusted hazard ratios (HRs) for the highest versus lowest tertile of 1.41 (95% confidence interval [CI]: 1.13-1.77; Ptrend = 0.003) for 5-year colorectal cancer-specific mortality and 1.44 (95% CI, 1.19-1.74; Ptrend = 0.0004) for 5-year all-cause mortality. The association of post-diagnosis EDIP scores with 5-year colorectal cancer-specific mortality differed by degrees of tumor-infiltrating lymphocytes (TIL; Pinteraction = .002) but not by three other lymphocytic reaction patterns. The multivariable-adjusted, 5-year colorectal cancer-specific mortality HRs for the highest versus lowest EDIP tertile were 1.59 (95% CI: 1.01-2.53) in TIL-absent/low cases and 0.48 (95% CI: 0.16-1.48) in TIL-intermediate/high cases. CONCLUSIONS: Pro-inflammatory diets after colorectal cancer diagnosis were associated with increased mortality, particularly in patients with absent or low TIL.