Purpose: The association between the fecal microbiota and colorectal cancer (CRC) risk has been suggested in epidemiologic studies. However, data from large-scale population-based studies are lacking. Materials and Methods: In this case-control study, we recruited 283 CRC patients from the Center for Colorectal Cancer, National Cancer Center Hospital, Korea to perform 16S rRNA gene sequencing of fecal samples. A total of 283 age- and sex-matched healthy participants were selected from 890 cohort of healthy Koreans that are publicly available (PRJEB33905). The microbial dysbiosis index (MDI) was calculated based on the differentially abundant species. The association between MDI and CRC risk was observed using conditional logistic regression. Sparse Canonical Correlation Analysis was performed to integrate species data with microbial pathways obtained by PICRUSt2. Results: There is a significant divergence of the microbial composition between CRC patients and controls (permutational multivariate analysis of variance p=0.001). Those who were in third tertile of the MDI showed a significantly increased risk of CRC in the total population (odds ratio [OR], 6.93; 95% confidence interval [CI], 3.98 to 12.06; p-trend < 0.001) compared to those in the lowest tertile. Similar results were found for men (OR, 6.28; 95% CI, 3.04 to 12.98; p-trend < 0.001) and women (OR, 7.39; 95% CI, 3.10 to 17.63; p-trend < 0.001). Bacteroides coprocola and Bacteroides plebeius species and 12 metabolic pathways were interrelated in healthy controls that explain 91% covariation across samples. Conclusion Dysbiosis in the fecal microbiota may be associated with an increased risk of CRC. Due to the potentially modifiable nature of the gut microbiota, our findings may have implications for CRC prevention among Koreans.

Purpose: The association between the fecal microbiota and colorectal cancer (CRC) risk has been suggested in epidemiologic studies. However, data from large-scale population-based studies are lacking. Materials and Methods: In this case-control study, we recruited 283 CRC patients from the Center for Colorectal Cancer, National Cancer Center Hospital, Korea to perform 16S rRNA gene sequencing of fecal samples. A total of 283 age- and sex-matched healthy participants were selected from 890 cohort of healthy Koreans that are publicly available (PRJEB33905). The microbial dysbiosis index (MDI) was calculated based on the differentially abundant species. The association between MDI and CRC risk was observed using conditional logistic regression. Sparse Canonical Correlation Analysis was performed to integrate species data with microbial pathways obtained by PICRUSt2. Results: There is a significant divergence of the microbial composition between CRC patients and controls (permutational multivariate analysis of variance p=0.001). Those who were in third tertile of the MDI showed a significantly increased risk of CRC in the total population (odds ratio [OR], 6.93; 95% confidence interval [CI], 3.98 to 12.06; p-trend < 0.001) compared to those in the lowest tertile. Similar results were found for men (OR, 6.28; 95% CI, 3.04 to 12.98; p-trend < 0.001) and women (OR, 7.39; 95% CI, 3.10 to 17.63; p-trend < 0.001). Bacteroides coprocola and Bacteroides plebeius species and 12 metabolic pathways were interrelated in healthy controls that explain 91% covariation across samples. Conclusion Dysbiosis in the fecal microbiota may be associated with an increased risk of CRC. Due to the potentially modifiable nature of the gut microbiota, our findings may have implications for CRC prevention among Koreans.

Purpose: The association between the fecal microbiota and colorectal cancer (CRC) risk has been suggested in epidemiologic studies. However, data from large-scale population-based studies are lacking. Materials and Methods: In this case-control study, we recruited 283 CRC patients from the Center for Colorectal Cancer, National Cancer Center Hospital, Korea to perform 16S rRNA gene sequencing of fecal samples. A total of 283 age- and sex-matched healthy participants were selected from 890 cohort of healthy Koreans that are publicly available (PRJEB33905). The microbial dysbiosis index (MDI) was calculated based on the differentially abundant species. The association between MDI and CRC risk was observed using conditional logistic regression. Sparse Canonical Correlation Analysis was performed to integrate species data with microbial pathways obtained by PICRUSt2. Results: There is a significant divergence of the microbial composition between CRC patients and controls (permutational multivariate analysis of variance p=0.001). Those who were in third tertile of the MDI showed a significantly increased risk of CRC in the total population (odds ratio [OR], 6.93; 95% confidence interval [CI], 3.98 to 12.06; p-trend < 0.001) compared to those in the lowest tertile. Similar results were found for men (OR, 6.28; 95% CI, 3.04 to 12.98; p-trend < 0.001) and women (OR, 7.39; 95% CI, 3.10 to 17.63; p-trend < 0.001). Bacteroides coprocola and Bacteroides plebeius species and 12 metabolic pathways were interrelated in healthy controls that explain 91% covariation across samples. Conclusion Dysbiosis in the fecal microbiota may be associated with an increased risk of CRC. Due to the potentially modifiable nature of the gut microbiota, our findings may have implications for CRC prevention among Koreans.

Purpose: To analyze adenoma detection rate (ADR) and related quality indicators of colonoscopy among trainees and make recommendations for appropriate colonoscopy training. Methods: ADR and related indicators of colonoscopies performed by 3 trainees and 5 colonoscopy experts between March and November 2022 were analyzed. These indicators were analyzed in both the entire patients and the screening/surveillance group. In addition, the training period of the 3 trainees was divided into 3 sections, and the changes in these indicators were examined. Results: The mean ADR of the 3 trainees was 50.6%. In the screening/surveillance group, the mean ADR of the 3 trainees was 51.8%, showing no significant difference from the experts' ADR (53.4%). When the training period was divided into 3 sections and analyzed in the screening/surveillance group, the mean ADR of the trainees gradually increased to 49.4%, 52.6%, and 53.6%, respectively; however, the difference was insignificant. Analyzing each trainee’s ADR, there was a significant difference among the 3 trainees (58.5% vs. 44.7% vs. 50.2%, P=0.008). However, in the third section of the training period, the 3 trainees’ ADRs were 53.0%, 49.2%, and 57.3%, respectively, showing no significant difference (P=0.606). Conclusion In the early stages of training, the ADR was higher than recommended; however, there were variances in ADR between individuals. As the training period passed, the ADR became similar at the expert level, whereas the difference in ADR between trainees decreased. Therefore, efforts to increase ADR should be made actively from the beginning of training and continued during the training period.

Purpose: To analyze adenoma detection rate (ADR) and related quality indicators of colonoscopy among trainees and make recommendations for appropriate colonoscopy training. Methods: ADR and related indicators of colonoscopies performed by 3 trainees and 5 colonoscopy experts between March and November 2022 were analyzed. These indicators were analyzed in both the entire patients and the screening/surveillance group. In addition, the training period of the 3 trainees was divided into 3 sections, and the changes in these indicators were examined. Results: The mean ADR of the 3 trainees was 50.6%. In the screening/surveillance group, the mean ADR of the 3 trainees was 51.8%, showing no significant difference from the experts' ADR (53.4%). When the training period was divided into 3 sections and analyzed in the screening/surveillance group, the mean ADR of the trainees gradually increased to 49.4%, 52.6%, and 53.6%, respectively; however, the difference was insignificant. Analyzing each trainee’s ADR, there was a significant difference among the 3 trainees (58.5% vs. 44.7% vs. 50.2%, P=0.008). However, in the third section of the training period, the 3 trainees’ ADRs were 53.0%, 49.2%, and 57.3%, respectively, showing no significant difference (P=0.606). Conclusion In the early stages of training, the ADR was higher than recommended; however, there were variances in ADR between individuals. As the training period passed, the ADR became similar at the expert level, whereas the difference in ADR between trainees decreased. Therefore, efforts to increase ADR should be made actively from the beginning of training and continued during the training period.

Purpose: To analyze adenoma detection rate (ADR) and related quality indicators of colonoscopy among trainees and make recommendations for appropriate colonoscopy training. Methods: ADR and related indicators of colonoscopies performed by 3 trainees and 5 colonoscopy experts between March and November 2022 were analyzed. These indicators were analyzed in both the entire patients and the screening/surveillance group. In addition, the training period of the 3 trainees was divided into 3 sections, and the changes in these indicators were examined. Results: The mean ADR of the 3 trainees was 50.6%. In the screening/surveillance group, the mean ADR of the 3 trainees was 51.8%, showing no significant difference from the experts' ADR (53.4%). When the training period was divided into 3 sections and analyzed in the screening/surveillance group, the mean ADR of the trainees gradually increased to 49.4%, 52.6%, and 53.6%, respectively; however, the difference was insignificant. Analyzing each trainee’s ADR, there was a significant difference among the 3 trainees (58.5% vs. 44.7% vs. 50.2%, P=0.008). However, in the third section of the training period, the 3 trainees’ ADRs were 53.0%, 49.2%, and 57.3%, respectively, showing no significant difference (P=0.606). Conclusion In the early stages of training, the ADR was higher than recommended; however, there were variances in ADR between individuals. As the training period passed, the ADR became similar at the expert level, whereas the difference in ADR between trainees decreased. Therefore, efforts to increase ADR should be made actively from the beginning of training and continued during the training period.

Purpose: To analyze adenoma detection rate (ADR) and related quality indicators of colonoscopy among trainees and make recommendations for appropriate colonoscopy training. Methods: ADR and related indicators of colonoscopies performed by 3 trainees and 5 colonoscopy experts between March and November 2022 were analyzed. These indicators were analyzed in both the entire patients and the screening/surveillance group. In addition, the training period of the 3 trainees was divided into 3 sections, and the changes in these indicators were examined. Results: The mean ADR of the 3 trainees was 50.6%. In the screening/surveillance group, the mean ADR of the 3 trainees was 51.8%, showing no significant difference from the experts' ADR (53.4%). When the training period was divided into 3 sections and analyzed in the screening/surveillance group, the mean ADR of the trainees gradually increased to 49.4%, 52.6%, and 53.6%, respectively; however, the difference was insignificant. Analyzing each trainee’s ADR, there was a significant difference among the 3 trainees (58.5% vs. 44.7% vs. 50.2%, P=0.008). However, in the third section of the training period, the 3 trainees’ ADRs were 53.0%, 49.2%, and 57.3%, respectively, showing no significant difference (P=0.606). Conclusion In the early stages of training, the ADR was higher than recommended; however, there were variances in ADR between individuals. As the training period passed, the ADR became similar at the expert level, whereas the difference in ADR between trainees decreased. Therefore, efforts to increase ADR should be made actively from the beginning of training and continued during the training period.

Purpose: To analyze adenoma detection rate (ADR) and related quality indicators of colonoscopy among trainees and make recommendations for appropriate colonoscopy training. Methods: ADR and related indicators of colonoscopies performed by 3 trainees and 5 colonoscopy experts between March and November 2022 were analyzed. These indicators were analyzed in both the entire patients and the screening/surveillance group. In addition, the training period of the 3 trainees was divided into 3 sections, and the changes in these indicators were examined. Results: The mean ADR of the 3 trainees was 50.6%. In the screening/surveillance group, the mean ADR of the 3 trainees was 51.8%, showing no significant difference from the experts' ADR (53.4%). When the training period was divided into 3 sections and analyzed in the screening/surveillance group, the mean ADR of the trainees gradually increased to 49.4%, 52.6%, and 53.6%, respectively; however, the difference was insignificant. Analyzing each trainee’s ADR, there was a significant difference among the 3 trainees (58.5% vs. 44.7% vs. 50.2%, P=0.008). However, in the third section of the training period, the 3 trainees’ ADRs were 53.0%, 49.2%, and 57.3%, respectively, showing no significant difference (P=0.606). Conclusion In the early stages of training, the ADR was higher than recommended; however, there were variances in ADR between individuals. As the training period passed, the ADR became similar at the expert level, whereas the difference in ADR between trainees decreased. Therefore, efforts to increase ADR should be made actively from the beginning of training and continued during the training period.

Purpose: This study aimed to evaluate the long-term clinical outcomes based on the ligation level of the inferior mesenteric artery (IMA) in patients with rectal cancer. Methods: This was a retrospective analysis of a prospectively collected database that included all patients who underwent elective low anterior resection for rectal cancer between January 2013 and December 2019. The clinical outcomes included oncological outcomes, postoperative complications, and functional outcomes. The oncological outcomes included overall survival (OS) and relapse-free survival (RFS). The functional outcomes, including defecatory and urogenital functions, were analyzed using the Fecal Incontinence Severity Index, International Prostate Symptom Score, and International Index of Erectile Function questionnaires. Results: In total, 545 patients were included in the analysis. Of these, 244 patients underwent high ligation (HL), whereas 301 underwent low ligation (LL). The tumor size was larger in the HL group than in the LL group. The number of harvested lymph nodes (LNs) was higher in the HL group than in the LL group. There were no significant differences in complication rates and recurrence patterns between the groups. There were no significant differences in 5-year RFS and OS between the groups. Cox regression analysis revealed that the ligation level (HL vs. LL) was not a significant risk factor for oncological outcomes. Regarding functional outcomes, the LL group showed a significant recovery in defecatory function 1 year postoperatively compared with the HL group. Conclusion LL with LNs dissection around the root of the IMA might not affect the oncologic outcomes comparing to HL; however, it has minimal benefit for defecatory function.

Purpose: Whether to perform surgery or conservatively manage appendicitis in immunosuppressed patients is a concern for clinicians. This study aimed to compare the outcomes of these 2 treatment options for appendicitis in patients with cancer undergoing chemotherapy. Methods: This retrospective study included 206 patients with cancer who were diagnosed with acute appendicitis between August 2001 and December 2021. Among them, patients who received chemotherapy within 1 month were divided into surgical and conservative groups. We evaluated the outcomes, including treatment success within 1 year, 1-year recurrence, and the number of days from the diagnosis of appendicitis to chemotherapy restart, between the 2 groups. Results: Among the 206 patients with cancer who were diagnosed with acute appendicitis, 78 received chemotherapy within 1 month. The patients were divided into surgery (n = 63) and conservative (n = 15) groups. In the surgery group, the duration of antibiotic therapy (7.0 days vs. 16.0 days, P < 0.001) and length of hospital stay (8.0 days vs. 27.5 days, P = 0.002) were significantly shorter than conservative groups. The duration from the diagnosis of appendicitis to the restart of chemotherapy was shorter in the surgery group (20.8 ± 15.1 days vs. 35.2 ± 28.2 days, P = 0.028). The treatment success rate within 1 year was higher in the surgery group (100% vs. 33.3%, P < 0.001). Conclusion Surgical treatment showed a significantly higher success rate than conservative treatment for appendicitis in patients less than 1 month after chemotherapy. Further prospective studies will be needed to clinically determine treatment options.