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.

Prognostic impact and survival outcomes of colon perforation in patients with metastatic colorectal cancer: a multicenter retrospective cohort study.

BACKGROUND: Colon perforation caused by colorectal cancer (CRC) is a fatal condition requiring emergency intervention. For patients with metastatic lesions, surgeons face difficult decisions regarding whether to resect the primary and metastatic lesions. Moreover, there is currently no established treatment strategy for these patients. This study aimed to investigate the clinical practice and long-term outcomes of patients with metastatic CRC diagnosed with the onset of colon perforation. METHODS: We performed a population-based multicenter cohort study. Consecutive patients diagnosed with stage IV CRC between 2008 and 2015 at all designated cancer hospitals in Fukushima Prefecture, Japan, were enrolled in this study. We evaluated the impact of colon perforation on the survival outcomes of patients with metastatic CRC. The main outcome was the adjusted hazard ratio (aHR) of perforation for overall survival (OS). Survival time and HRs were estimated using Kaplan‒Meier and Cox proportional regression analyses. RESULTS: A total of 1258 patients were enrolled (perforation: n = 46; non-perforation: n = 1212). All but one of the patients with perforation underwent primary resection or colostomy and 25 cases were able to receive chemotherapy. The median OS for the perforation and non-perforation groups was 19.0 and 20.0 months, respectively (p = 0.96). Moreover, perforation was not an independent prognostic factor (aHR: 0.99; 95% confidence interval: 0.61-1.28). CONCLUSIONS: In metastatic CRC, perforation is not necessarily a poor prognostic factor. Patients with perforation who undergo primary tumor resection or colostomy and prompt initiation of systemic chemotherapy might be expected to have a survival time similar to that of patients with non-perforated colon.

Clinical impact of gastrectomy for gastric cancer patients with positive lavage cytology without gross peritoneal dissemination.

BACKGROUND: The prognosis of gastric cancer patients with positive lavage cytology without gross peritoneal dissemination (P0CY1) is poor. The survival benefit of gastrectomy for these patients has not been established. PATIENTS AND METHODS: In this population-based cohort study, we investigated the impact of radical gastrectomy with lymph node dissection for P0CY1 patients. Patients who were diagnosed with Stage IV gastric cancer from 2008 to 2015 in all nine cancer-designated hospitals in a tertiary medical area were listed. Patients who were diagnosed with histologically proven adenocarcinoma in both the primary lesion and lavage cytology during the operation or a diagnostic laparoscopic examination were enrolled. Patients with a gross peritoneal lesion or other metastatic lesions were excluded. The primary outcome was the adjusted hazard ratio (aHR) of gastrectomy for overall survival. We also evaluated the survival time in patients who underwent gastrectomy or chemotherapy in comparison to patients managed without primary surgery or with best supportive care. RESULTS: One hundred patients were enrolled. The aHR (95% confidence interval) of gastrectomy was 0.677 (0.411-1.114, p = 0.125). The median survival time in patients who received gastrectomy (n = 74) was 21.7, while that in patients managed without primary surgery (n = 30) was 20.5 months (p = 0.155). The median survival time in patients who received chemotherapy (n = 76) was 23.0 months, while that in patients managed without chemotherapy was 8.6 months (p < 0.001). CONCLUSION: Gastrectomy was not effective for improving the survival time in patients with P0CY1 gastric cancer. Surgeons should prioritize the performance of chemotherapy over surgery as the initial treatment.

Relationship between physical activity and bone mineral density loss after gastrectomy in gastric cancer patients.

PURPOSE: The prevention of osteoporosis is a particularly relevant issue for gastric cancer survivors. We investigated the relationship between postoperative physical activity and the change of bone mineral density (BMD) in patients with gastric cancer. METHODS: Patients who underwent radical gastrectomy for gastric cancer were enrolled in this single-center prospective cohort study. Physical activity was evaluated using the International Physical Activity Questionnaire Short Form at postoperative month (POM) 6 and patients were classified into high, middle, and low physical activity groups accordingly. The primary outcome was the change in BMD from baseline at POM 12, which was expressed as a percentage of the young adult mean (YAM). The YAM of the lumbar spine and femoral neck was measured by dual-energy X-ray absorptiometry. RESULTS: One hundred ten patients were enrolled in this study. The physical activity level at POM 6 was classified as high (n = 50; 45%), middle (n = 25; 23%), and low (n = 35; 32%). The mean decrease of YAM% was 5.1% in the lumbar spine and 4.2% in the femoral neck at POM 12. A multivariable-adjusted logistic regression model revealed that low physical activity at POM 6 was a significant risk factor for BMD loss at POM 12 (odds ratio, 3.76; 95% confidence interval, 1.48-9.55; p = 0.005). CONCLUSION: Low physical activity after gastrectomy is an independent risk factor for decreased BMD at POM 12. The introduction of exercise may prevent osteoporosis after the surgical treatment of gastric cancer.

The additional diagnostic impact of positron emission tomography-computed tomography for lymph node metastasis from colorectal cancer: A prospective lymph node level analysis.

BACKGROUND: We conducted a prospective study to determine the diagnostic performance of positron emission tomography-computed tomography (PET-CT) for lymph node metastasis in colorectal cancer patients. METHODS: We enrolled patients scheduled to receive curative surgery with lymph node dissection for colorectal adenocarcinoma who underwent contrast-enhanced abdominopelvic CT and PET-CT before surgery and who had primary lesions of cT2 or deeper. A radiologist determined the fluorodeoxyglucose uptake and the standardized uptake value (SUV) and metabolic volume (MV) to diagnose metastasis in cases with enlarged lymph nodes (≥7 mm long in minor diameter) on contrast-enhanced CT. Two gastrointestinal surgeons intraoperatively identified target lymph nodes to assess the association between images and pathological findings. The diagnostic performance (i.e., sensitivity, specificity, and positive and negative predictive values) for lymph node metastasis was determined using multilevel logistic modeling. RESULTS: A total of 205 colorectal cancer patients were enrolled from February 2018 to April 2020 and 194 patients were analyzed in this study. The sensitivity, specificity, and positive and negative predictive values of PET-CT were 15.3% (13.4%-17.5%), 100.0% (99.0%-100.0%), 100.0% (51.2%-100.0%), and 98.7% (98.5%-99.0%), respectively. CONCLUSION: PET-CT is a useful modality for determining the presence of metastasis in swollen lymph nodes on contrast-enhanced CT in colorectal cancer patients.

A grading system for predicting the prognosis of gastric cancer with liver metastasis.

OBJECTIVE: The prognosis of patients with liver metastases from gastric cancer is determined using tumor size and number of metastases; this is similar to the factors used for the prediction of liver metastases from colorectal cancer. The relationship between the degree of liver metastasis from gastric cancer and prognosis with reference to the classification of liver metastasis from colorectal cancer was investigated. METHODS: This was a multi-institutional historical cohort study. Among patients with stage IV gastric cancer, who visited the cancer hospitals in Fukushima Prefecture, Japan, between 2008 and 2015, those with simultaneous liver metastasis were included. Abdominal pretreatment computed tomography images were reviewed and classified into H1 (four or less liver metastases with a maximum diameter of ≤5 cm); H2 (other than H1 and H3) or H3 (five or more liver metastases with a maximum diameter of ≥5 cm). The hazard ratio for overall survival according to the H grade (H1, H2 and H3) was calculated using the Cox proportional hazards model. RESULTS: A total of 412 patients were analyzed. Patients with H1, H2 and H3 grades were 118, 162 and 141, respectively, and their median survival time was 10.2, 5.7 and 3.1 months, respectively (log-rank P < 0.001). The adjusted hazard ratio for overall survival was H1: H2: H3 = reference: 1.39 (95% confidence interval: 1.04-1.85): 1.69 (95% confidence interval: 1.27-2.27). CONCLUSIONS: The grading system proposed in this study was a simple and easy-to-use prognosis prediction index for patients with liver metastasis from gastric cancer.

Impact of chest subcutaneous fat on the occurrence of central venous port-related infectious complications in cancer patients.

PURPOSE: There is no concrete evidence to support the association between the amount of subcutaneous fat area (SFA) in the central venous port-insertion site (precordium) and port-related complications. We aimed to investigate the relationship between SFA in the midclavicular line and postoperative infectious complications in patients undergoing port-insertion surgery. METHODS: This was a single-institute and historical cohort study of 174 patients who underwent first central venous port implantation surgery for chemotherapy between January 2014 and December 2018. SFA in the midclavicular line was measured using preoperative computed tomography scans. The patients were divided into three groups according to SFA amount tertiles, and we investigated the association of SFA with infectious and all-cause complication events within 1 year. RESULTS: Within a median follow-up of 306 days, the patients with intermediate SFA had significantly higher infection-free survival than those with low and high SFA (low vs. intermediate vs. high: 80.4% vs. 97.7% vs. 83.4%, respectively, p=0.034). In contrast, there was no significant difference in the overall complication-free survival among the groups (low vs. intermediate vs. high: 80.4% vs. 88.9% vs. 81.8%, respectively, p=0.29). Low SFA was independently associated with high risk of infectious complications (hazard ratio, 9.45; 95% confidence interval, 1.07-83.22, p=0.043). CONCLUSION: Low SFA in the midclavicular line was an independent risk factor for infectious complications in the chemotherapy setting. This practical indicator can be useful for optimizing patients' nutritional status and when considering other types of vascular access to support administration of intravenous chemotherapy.

Impact of Primary Tumor Resection on Mortality in Patients with Stage IV Colorectal Cancer with Unresectable Metastases: A Multicenter Retrospective Cohort Study.

BACKGROUND: Primary tumor resection (PTR) before commencing systemic chemotherapy in patients with stage IV colorectal cancer and unresectable metastases (mCRC) remains controversial. This study aimed to assess whether PTR before systemic chemotherapy is associated with mortality in mCRC patients, after adjusting for confounding factors, such as the severity of the primary tumor and metastatic lesions. METHODS: We analyzed hospital-based cancer registries from nine designated cancer hospitals in Fukushima Prefecture, Japan. Patients were divided into two groups (PTR and non-PTR), based on whether PTR was performed as initial therapy for mCRC or not. The primary outcome was all-cause mortality. Kaplan-Meier survival analysis was performed, and survival estimates were compared using the log-rank test. Adjusted hazard ratios were calculated using Cox regression to adjust for confounding factors. All tests were two-sided; P-values < 0.05 were considered statistically significant. RESULTS: Between 2008 and 2015, 616 mCRC patients were included (PTR: 414 [67.2%]; non-PTR: 202 [32.8%]). The median follow-up time was 18.0 (interquartile range [IQR]: 8.4-29.7) months, and 492 patients (79.9%) died during the study period. Median overall survival in the PTR and non-PTR groups was 23.9 (IQR: 12.2-39.9) and 12.3 (IQR: 6.2-23.8) months, respectively (P < 0.001, log-rank test). PTR was significantly associated with improved overall survival (adjusted hazard ratio: 0.51; 95% confidence interval: 0.42-0.64, P < 0.001). CONCLUSIONS: PTR before systemic chemotherapy in patients with mCRC was associated with improved survival.

Benefit of intensive chemotherapy for elderly patients aged 80 years or older with metastatic colorectal cancer: a state-wide multicenter cohort study.

BACKGROUND: It remains unclear whether intensive chemotherapy for Stage IV colorectal cancer (CRC) patients aged 80 years or older is beneficial prognostically. This study aimed to investigate the overall survival of Stage IV CRC patients aged ≥ 80 years receiving intensive chemotherapy. METHODS: The study design was a population-based, multicenter, historical cohort study. The extracted participants' data were consecutive patients diagnosed as Stage IV CRC between January 2008 and May 2015 in nine hospitals in Japan. Patients were classified into two groups according to age: aged group (≥ 80 years) and younger group (< 80 years old). Intensive chemotherapy was defined as at least two courses of doublet chemotherapy with oxaliplatin-or irinotecan-based regimens. The primary outcome was the adjusted hazard ratio (HR) of age ≥ 80 years in patients who undergoing intensive chemotherapy. RESULTS: During the study period, 1259 patients were treated for Stage IV CRC in the participating hospitals. In total, 231 patients (18.3%) were in the aged group, and 1028 (81.7%) were in the younger group, and 788 (62.6%) underwent intensive chemotherapy. The median overall survival for the aged and younger group patients was 21.0 months (interquartile range (IQR), 10.6-34.1 months) and 24.3 months (IQR 12.6-39.3 months), respectively. The adjusted HR of age ≥ 80 years was 1.29 (confidence intervals 0.84-2.00). CONCLUSION: Stage IV CRC patients aged 80 years or older receiving intensive chemotherapy had a similar prognosis to those aged < 80 years. Avoiding intensive chemotherapy for mCRC patients simply because they are ≥ 80 years old is not recommended.

The effects of intensive oral care before surgery for gastric cancer patients.

OBJECTIVES: Oral function management has been recognized as important strategy for preventing postoperative complications. In this historical cohort study, we focused on the patients who planed gastrectomy, and investigated the appropriate duration and frequency of preoperative oral care to prevent complications after surgery. METHODS: Patients who planed surgery for gastric cancer between 2012 and 2018 were enrolled. We defined intensive oral care (IOC) as initial intervention at least three weeks before surgery and follow-up intervention within a week before surgery. As the primary outcome, the incidence of postoperative infectious complications was compared between the IOC and non-intensive oral care groups. RESULTS: A total of 576 patients were enrolled, including 66 with IOC. The incidence of infectious complications was 2/66 (3.0%) in the IOC group and 64/510 (12.5%) in the non-intensive oral care group. After adjusting for confounding factors, patients with IOC exposure had a lower chance of developing postoperative infectious complications (odds ratio; 0.217, 0.051-0.927). CONCLUSIONS: Intensive oral care can help prevent postoperative infectious complications after gastrectomy. These findings suggest that appropriate preoperative oral care includes at least two interventions: three weeks or more before and within one week before surgery.

Effect of adjuvant chemotherapy on survival benefit in stage III colon cancer patients stratified by age: a Japanese real-world cohort study.

BACKGROUND: Adjuvant chemotherapy is relatively underused in older patients with colon cancer in Japan, and its age-specific effects on clinical outcomes remain unclear. This study aimed to assess the effect of adjuvant chemotherapy on survival benefit in stage III colon cancer patients stratified by age in a Japanese real-world setting. METHODS: In this multi-center retrospective cohort study, we analyzed patient-level information through a record linkage of population-based cancer registry data and administrative claims data. The study population comprised patients aged ≥18 years who received a pathological diagnosis of stage III colon cancer and underwent curative resection between 2010 and 2014 at 36 cancer care hospitals in Osaka Prefecture, Japan. Patients were divided into two groups based on age at diagnosis (< 75 and ≥ 75 years). The effect of adjuvant chemotherapy was analyzed using Cox proportional hazards regression models for all-cause mortality with inverse probability weighting of propensity scores. Adjusted hazard ratios were estimated for both age groups. RESULTS: A total of 783 patients were analyzed; 476 (60.8%) were aged < 75 years and 307 (39.2%) were aged ≥75 years. The proportion of older patients who received adjuvant chemotherapy (36.8%) was substantially lower than that of younger patients (73.3%). In addition, the effect of adjuvant chemotherapy was different between the age groups: the adjusted hazard ratio was 0.56 (95% confidence interval: 0.33-0.94, P = 0.027) in younger patients and 1.07 (0.66-1.74, P = 0.78) in older patients. CONCLUSIONS: The clinical effectiveness of adjuvant chemotherapy in older patients with stage III colon cancer appears limited under current utilization practices.

Clinical impact of periodontal disease on postoperative complications in gastrointestinal cancer patients.

BACKGROUND: The effectiveness of perioperative oral management in gastrointestinal surgery remains unclear. To elucidate the clinical significance of oral care, we investigated the relationship between the oral environment and postoperative infectious complications (POICs) in patients undergoing gastrointestinal surgery. METHODS: This was a single-institute and historical cohort study of 341 patients. The participants were isolated from consecutive patients undergoing planned radical resection for gastrointestinal carcinoma from January 2016 to June 2017. Dentists assessed the oral environment for periodontal disease, hygiene status, dry mouth, fur on tongue, and tooth stumps. All patients received scaling and tooth brushing instructions. A stepwise logistic regression analysis was conducted to identify risk factors for POICs among the different oral statuses. RESULTS: The surgical procedures performed were gastrectomy in 123 (36.1%), colorectal resection in 185 (54.2%), and pancreatoduodenectomy or others in 38 (11.1%). POICs occurred in 48 patients (14.1%), including deep organ space infection in 20, surgical site infection in 11, anastomotic leakage in 5, urinary tract infection in 4, pneumonia in 2, and others in 6. After adjusting for confounding factors, periodontal disease was isolated as an independent risk factor for POICs (odds ratio 2.091, p = 0.037, 95% confidence interval 1.045-4.183). Other variables of oral environment such as hygiene status, dry mouth, fur on tongue, and tooth stumps did not have a significant impact on POICs. CONCLUSIONS: Periodontal disease is a risk factor for infectious complications after gastrointestinal surgery.

[Four Patients Who Underwent Proton Beam Therapy after Debulking Surgery and Omental Wrapping of the Residual Tumor as a Spacer for Unresectable Local Recurrence of Rectal Cancer].

We report 4 patients who underwent proton beam therapy after debulking surgery for unresectable local recurrence of rectal cancer. Case 1: A 55-year-old man underwent radiotherapy and systemic chemotherapy for local recurrence; however, the lesion exhibited evident regrowth. Combination therapy of debulking surgery, omental wrapping of the residual tumor as a spacer, and postoperative proton beam therapy was performed. He died of lung metastasis after 24 months. Case 2: A 79- year-old woman who underwent surgical resections and radiotherapy twice in a previous hospital was referred to our hospital. Similar to that in case 1, proton beam therapy after debulking surgery and omental wrapping was performed. She died of lymph node metastasis after 31 months. Case 3: A 75-year-old man was diagnosed with unresectable local recurrence of rectal cancer. He underwent combination therapy and is doing well without any recurrence for 43 months. Case 4: A 57-yearold woman was also diagnosed with unresectable local recurrence. She underwent the same combination therapy after systemic chemotherapy. She died of lymph node metastasis after 11 months.

Characteristics and Prognostic Factors of Bone Metastasis in Patients With Colorectal Cancer.

BACKGROUND: Because bone metastasis from colorectal cancer is rare, there are little available data regarding such cases. OBJECTIVE: The study aim was to identify the prognostic factors and characteristics associated with survival in colorectal cancer patients with bone metastasis. DESIGN: This was a retrospective study from a prospectively collected database. SETTINGS: The study took place in a multidisciplinary, high-volume tertiary cancer center in Japan. PATIENTS: Examined were records from 104 consecutive patients treated between 2004 and 2015 for bone metastasis from colorectal cancer. MAIN OUTCOME MEASURES: The primary outcome measure was overall survival. RESULTS: The spine was the most common site of bone metastasis from colorectal cancer. Right colon cancer correlated significantly with long bone metastasis (p = 0.046), whereas left colon cancer correlated significantly with spinal bone metastasis (p = 0.034). Liver metastasis was also significantly correlated with spinal bone metastasis (p = 0.036). The median interval between the primary therapy for colorectal cancer and the metachronous diagnosis of bone metastasis was 20.0 months (quartile 1 to quartile 3, 9.0-46.5 mo). The median survival time from diagnosis of bone metastasis from colorectal cancer was 5.0 months (95% CI, 4.0-9.0 mo), and the 1-year survival rate was 30.0% (95% CI, 21.1%-39.4%). Multivariate analysis revealed that ≥2 extra-bone metastatic organs, hypercalcemia, and pathologic fractures were independent poor prognostic factors (p < 0.001, 0.001, and 0.033). The number of extra-bone metastatic organs correlated with prognosis. LIMITATIONS: This study was limited by its retrospective, nonrandomized design, as well as selection bias and performance at a single institute. CONCLUSIONS: The location of colorectal cancer correlates significantly with the site of bone metastasis; the prognosis of patients with bone metastasis from colorectal cancer is very poor, and the significant prognostic factors are number of extra-bone metastatic organs, hypercalcemia, and pathologic fractures. See Video Abstract at http://links.lww.com/DCR/A589.

Comparison of the survival outcomes between retrocolic and antecolic Roux-en-Y reconstruction after gastrectomy for gastric cancer.

Background: There are two methods of Roux-en-Y (RY) reconstruction after gastrectomy: the antecolic route (ACR) and retrocolic route (RCR). There is no evidence to support that the ACR achieves comparable long-term survival. Methods: This was a multi-center historical cohort study. Patients diagnosed with clinical T3/4a and any N stage who underwent open gastrectomy and R0 resection for gastric adenocarcinoma between January 2006 and December 2012 were enrolled. The primary outcome was the hazard ratio of ACR for overall survival, with adjustment for confounding factors by propensity score matching, and a Cox proportional hazards model. Results: A total of 1758 eligible patients were identified from the database. After matching, 410 patients in the ACR and RCR groups were included in the final analysis. The adjusted hazard ratio (95% CI) for ACR was 1.148 (0.870-1.492). The five-year survival rates in the ACR and RCR groups were 74.3% (69.5-78.4) and 77.3% (72.3-81.2), respectively. The short-term surgical outcomes of the two groups did not differ to a statistically significant extent. Conclusion: The route used to lift the jejunum in RY reconstruction did not affect the incidence of long-term survival or postoperative complications. The ACR and RCR are both acceptable options for RY reconstruction during gastric cancer surgery.

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.

Radiological Cutoff Values for Diagnosis of Lymph Node Metastasis in Colorectal Cancer With Multilevel Analysis.

Background/Aim: A cutoff value for lymph node diameter in colorectal cancer lymph node metastases has not been established. This prospective study aimed to investigate the direct association between swollen lymph nodes identified on preoperative computed tomography (CT) and pathological findings and proposed a cutoff value. Patients and Methods: We enrolled patients scheduled to undergo curative surgery with lymph node dissection for colorectal adenocarcinoma who underwent preoperative contrast-enhanced CT and had swollen lymph nodes ≥7 mm in diameter. Two gastrointestinal surgeons intraoperatively identified the target lymph nodes to assess the association between lymph node diameter and pathological findings. The diagnostic performance for lymph node metastasis was determined using multi-level logistic modelling. Results: A total of 109 patients were enrolled, and 225 swollen lymph nodes were pathologically evaluated. Using a cutoff value of ≥9 mm for the short diameter, the positive and negative predictive values, sensitivity, and specificity were 100.0% (99.6%-100.0%), 99.9% (99.1%-100.0%), 62.0% (45.6%-76.0%), and 84.9% (67.0%-94.0%), respectively. Conclusion: The cutoff value for improving the positive predictive value for the preoperative lymph node metastasis diagnosis in colorectal cancer patients should be at least 9 mm in diameter.

Clinical Indicators to Determine the Timing of Surgery for Adhesive Small Bowel Obstruction.

BACKGROUND: Decompression of the intestine with a long tube or nasogastric tube is the first-choice treatment for adhesive small bowel obstruction (ASBO). Scheduling surgery while weighing the risks of surgery against conservative care is a crucial factor in clinical decision-making. Whenever feasible, unnecessary surgeries should be avoided, and it is essential to provide clinical markers for this. This study aimed to obtain evidence regarding the optimal timing of ASBO and when conservative treatment options are not successful. METHODS: The data of patients diagnosed with ASBO and receiving long tube insertion for more than 7 days were reviewed. We investigated transit ileal drainage volume and recurrence. The primary outcomes were the change in the drainage volume from the long tube over time and the percentage of patients who required surgery. We evaluated some cutoff values to determine the indication for surgery based on the insertion duration and volume of long tube drainage. RESULTS: Ninety-nine patients were enrolled in this study. Fifty-one patients showed improvement with conservative treatment, whereas 48 ultimately required surgery. When a daily drainage volume of ≥500 mL was considered an indication for surgery, 13-37 cases (25%-72%) would be judged unnecessary within 6 days of long tube insertion, while 5 cases (9.8%) would be judged unnecessary on day 7. DISCUSSION: Unnecessary surgical interventions for ASBO might be avoided by assessing the drainage volume on day 7 after inserting a long tube.

Clinical Features and Survival of Young Adults with Stage IV Gastric Cancer: a Japanese Population-Based Study.

PURPOSE: With the aging of society, the mean age of patients with gastric cancer (GC) in Japan has increased. However, there are few documented outcomes for young patients with stage IV GC. We investigated the clinical characteristics and prognosis of such patients aged < 40 years using a dataset from an integrated population-based cohort study. METHODS: We conducted this multicenter population-based cohort study to determine whether earlier onset of GC was a poor prognostic factor. We enrolled patients with metastatic GC aged < 40 years (young group) and those aged between 60 and 75 years (middle-aged group). Patients were histologically diagnosed as having gastric adenocarcinoma. We evaluated the overall survival (OS) of both groups and the hazard ratio (HR) for OS based on age. The adjusted HR with 95% confidence interval (CI) was evaluated using the Cox proportional hazards model after adjusting for confounding factors, including sex, histology, number of metastatic lesions, surgical resection, and chemotherapy. RESULTS: This study enrolled 555 patients. The patients were classified into the young (n = 20) and the middle-aged group (n = 535). The median OS durations were 5.7 and 8.8 months in the young and middle-aged groups, respectively (p = 0.029). The adjusted HR (95% CI) of the young group was 1.88 (1.17-3.04, p = 0.009). CONCLUSION: Age was an independent prognostic factor in patients with stage IV GC. Further studies investigating the genomic characteristics of GC and exploring more effective chemotherapeutic agents are required.

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.