Colorectal cancer is the third most common cancer in Korea and the third leading cause of death from cancer. Treatment outcomes for colon cancer are steadily improving due to national health screening programs with advances in diagnostic methods, surgical techniques, and therapeutic agents.. The Korea Colon Cancer Multidisciplinary (KCCM) Committee intends to provide professionals who treat colon cancer with the most up-to-date, evidence-based practice guidelines to improve outcomes and help them make decisions that reflect their patients’ values and preferences. These guidelines have been established by consensus reached by the KCCM Guideline Committee based on a systematic literature review and evidence synthesis and by considering the national health insurance system in real clinical practice settings. Each recommendation is presented with a recommendation strength and level of evidence based on the consensus of the committee.

Background: Recent reports have suggested that pneumonitis is a rare complication following vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).However, its clinical features and outcomes are not well known. The aim of this study was to identify the clinical characteristics and outcomes of patients with vaccine-associated pneumonitis following vaccination against SARS-CoV-2. Methods: In this nationwide multicenter survey study, questionnaires were distributed to pulmonary physicians in referral hospitals. They were asked to report cases of development or exacerbation of interstitial lung disease (ILD) associated with the coronavirus disease 2019 vaccine. Vaccine-associated pneumonitis was defined as new pulmonary infiltrates documented on chest computed tomography within 4 weeks of vaccination and exclusion of other possible etiologies. Results: From the survey, 49 cases of vaccine-associated pneumonitis were identified between February 27 and October 30, 2021. After multidisciplinary discussion, 46 cases were analyzed. The median age was 66 years and 28 (61%) were male. The median interval between vaccination and respiratory symptoms was 5 days. There were 20 (43%), 17 (37%), and nine (19%) patients with newly identified pneumonitis, exacerbation of pre-diagnosed ILD, and undetermined pre-existing ILD, respectively. The administered vaccines were BNT162b2 and ChAdOx1 nCov-19/AZD1222 each in 21 patients followed by mRNA-1273 in three, and Ad26.COV2.S in one patient. Except for five patients with mild disease, 41 (89%) patients were treated with corticosteroid. Significant improvement was observed in 26 (57%) patients including four patients who did not receive treatment. However, ILD aggravated in 9 (20%) patients despite treatment. Mortality was observed in eight (17%) patients. Conclusion These results suggest pneumonitis as a potentially significant safety concern for vaccines against SARS-CoV-2. Clinical awareness and patient education are necessary for early recognition and prompt management. Additional research is warranted to identify the epidemiology and characterize the pathophysiology of vaccine-associated pneumonitis.

Background: Swallowing of foreign bodies (FBs) is the most common indication of therapeutic endoscopy in children. Endoscopic removal may be necessary depending on the type of FB, age of the child, and location of the FB. We attempted to analyze the characteristics of each device used for the endoscopic removal of FBs in children. Methods: Medical records of the patient’s age, sex, weight, type, location, size, shape, type of device used for endoscopic removal, and endoscopic time were retrospectively collected. Results: A total of 424 FB removal procedures were analyzed. The average age of the patients at the time of FB removal was 4.1 ± 3.7 years. Coins were the most common FBs (192, 45.3%). The most common locations of the FBs were the esophagus (45.7%) and the stomach (48.3%), respectively. For a total of 371 cases, forceps were used in 96 cases (25.9%) for esophageal FBs and in 25 cases for gastric FBs (6.7%), while nets were used in 250 cases (67.4%) for gastric FBs retrieval; the average durations of the procedures were 7.2 ± 7.4 minutes, 8.5 ± 7.2 minutes, and 5.7 ± 7.3 minutes, respectively (P = 0.003). The procedure time was significantly shorter, in the group of patients with low body weights, when nets were used than when forceps were used to remove gastric FBs (P = 0.001). Conclusion The endoscopic procedure duration, in low-weight children, was shorter when retrieval nets were used than that with forceps.

Background and Objectives: Zonulin is a human protein that regulates intercellular tight junctions and increases the permeability of the intestinal epithelium. In light of the increasing focus on zonulin’s role in numerous chronic inflammatory diseases, this study aimed to investigate whether differences exist in serum zonulin levels and bronchial epithelium zonulin expression in vivo between asthma and normal groups, using a mouse model. Methods: Sixteen mice were utilized in this study, divided evenly between the normal and asthma groups. Serum zonulin levels, the expression of zonulin antibody in the bronchial epithelium, and serum cytokine levels were evaluated in both groups. Enzyme-linked immunosorbent assay and RNA in situ hybridization were utilized for the analysis. Results: The asthma group exhibited significantly higher levels of serum zonulin. High zonulin antibody expression was also observed in the bronchial epithelium of the asthma group. Given that our mouse model demonstrated a significant difference in interleukin (IL)-4 and IL-6 between the normal and asthma groups, zonulin may be associated not only with type 2 responses but also with various subtypes of asthma. Further studies are required to investigate this relationship in greater detail. Conclusion Zonulin may play a role in the complex pathophysiology of asthma and could serve as a biomarker in various asthma-related situations.

Purpose: The clinical implications of tumor-infiltrating T cell subsets and their spatial distribution in biliary tract cancer (BTC) patients treated with gemcitabine plus cisplatin were investigated. Materials and Methods: A total of 52 BTC patients treated with palliative gemcitabine plus cisplatin were included. Multiplexed immunohistochemistry was performed on tumor tissues, and immune infiltrates were separately analyzed for the stroma, tumor margin, and tumor core. Results: The density of CD8+ T cells, FoxP3- CD4+ helper T cells, and FoxP3+ CD4+ regulatory T cells was significantly higher in the tumor margin than in the stroma and tumor core. The density of LAG3- or TIM3-expressing CD8+ T cell and FoxP3- CD4+ helper T cell infiltrates was also higher in the tumor margin. In extrahepatic cholangiocarcinoma, there was a higher density of T cell subsets in the tumor core and regulatory T cells in all regions. A high density of FoxP3- CD4+ helper T cells in the tumor margin showed a trend toward better progression-free survival (PFS) (p=0.092) and significantly better overall survival (OS) (p=0.012). In multivariate analyses, a high density of FoxP3- CD4+ helper T cells in the tumor margin was independently associated with favorable PFS and OS. Conclusion The tumor margin is the major site for the active infiltration of T cell subsets with higher levels of LAG3 and TIM3 expression in BTC. The density of tumor margin-infiltrating FoxP3- CD4+ helper T cells may be associated with clinical outcomes in BTC patients treated with gemcitabine plus cisplatin.

Objective: Body mass index (BMI) is a major determinant of N-terminal pro-brain natriuretic peptide (NT-proBNP). However, the relationship of BMI with pneumonia has not been entirely characterized. Methods: Adult patients with pneumonia, who visited the emergency department from January 2017 to December 2019, were included. According to BMI, they were divided into two groups, including normal-weight and obesity groups. Data were retrospectively reviewed via the prospectively collected pneumonia registry and medical chart. NT-proBNP, BMI and pneumonia severity index (PSI) were determined for all subjects. The moderating effect between NT-proBNP and BMI was examined by entering interaction terms into the multivariable regression model predicting mortality. Using the area under the curve (AUC), the predictive performance of NT-proBNP was evaluated. Results: Of 327 enrolled patients, 118 patients belonged to the obesity group. In a multivariable model including BMI, NT-proBNP was identified as an independent predictor of mortality. The AUC of the adjusted NT-proBNP including BMI, significantly increased the AUC of the adjusted NT-proBNP excluding BMI and tended to be superior to that of PSI. A positively significant BMI-by-NT-proBNP interaction for mortality was observed. NT-proBNP showed significant prognostic power in both BMI groups, but NT-proBNP of the obesity group had significantly higher AUC than that of the normalweight group. In the obesity group, the AUC of NT-proBNP tended to be higher than that of PSI. Conclusion BMI is a significant factor enhancing the prognostic power of NT-proBNP in pneumonia. The prognostic utility of NT-proBNP was significantly differed by BMI groups, which is more useful in the obesity group than the normalweight group.

Objective: N-terminal pro-B-type natriuretic peptide (NT-proBNP) is suggested as a prognostic biomarker for communityacquired pneumonia (CAP). However, its predictive value for an individual adult and elderly CAP patients has not been fully investigated. Methods: Patients with CAP aged 18 years and older, who visited the emergency department (ED) from March 1, 2016 to March 31, 2019, were included in this study. Patients were divided into the adult group and the elderly group (age ≥70 years). Data was collected from the ED-based registry, and medical charts were retrospectively reviewed. The registry data included sociodemographic and past medical characteristics, as well as laboratory findings including NT-proBNP and C-reactive protein (CRP), Pneumonia Severity Index (PSI), and CURB65 (confusion, urea, respiratory rate, blood pressure, and aged 65 or more). The independent potential of NT-proBNP to predict mortality was assessed in both groups using multivariable logistic regression, and its predictive ability was evaluated in terms of performance (using areas under the curve [AUCs]) and goodness-of-fit (using the Bayesian information criterion [BIC]). Results: Totally, 325 CAP patients were evaluated, of which 208 (64%) belonged to the elderly group. NT-proBNP was identified as an independent predictor of CAP mortality in elderly patients, but not in adult patients. Moreover, AUC of the NT-proBNP for mortality was comparable to AUC of the PSI, but was higher than that of the CURB65, in elderly CAP patients. Similarly, the NT-proBNP had a better overall fit (lower BIC value) compared to the CURB65, for mortality. Additionally, both AUC and overall fit of the NT-proBNP for mortality were significantly superior to values obtained for CRP. Conclusion For elderly CAP patients in the ED, the NT-proBNP is an independent and useful predictor of mortality.

Purpose: The aims of the present study were twofold. First, the research investigated the effect of an individual’s risk factors and the prevalence of psychotropic drugs on QTc prolongation, TdP (torsades de pointes), and death. Second, the study compared the risk scoring systems (the Mayo Pro-QT risk score and the Tisadale risk score) on QTc prolongation. Methods: The medical records of intoxicated patients who visited the emergency department between March 2010 and February 2019 were reviewed retrospectively. Among 733 patients, the present study included 426 psychotropic drug-intoxicated patients.The patients were categorized according to the QTc value. The known risk factors of QTc prolongation were examined, and the Mayo Pro-QT risk score and the Tisadale risk score were calculated. The analysis was performed using multiple logistic regression, Spearman correlation, and ROC (receiver operating characteristic). Results: The numbers in the mild to moderate group (male: 470≤QTc<500 ms, female: 480≤QTc<500 ms) and severe group (QTc≥500 ms or increase of QTc at least 60ms from baseline, both sex) were 68 and 95, respectively. TdP did not occur, and the only cause of death was aspiration pneumonia. The statically significant risk factors were multidrug intoxications of TCA (tricyclic antidepressant), atypical antipsychotics, an atypical antidepressant, panic disorder, and hypokalemia. The Tisadale risk score was larger than the Mayo Pro-QT risk score. Conclusion Multiple psychotropic drugs intoxication (TCA, an atypical antidepressant, and atypical antipsychotics), panic disorder, and hypokalemia have been proven to be the main risk factors of QTc prolongation, which require enhanced attention. The present study showed that the Tisadale score had a stronger correlation and predictive accuracy for QTc prolongation than the Mayo Pro-QT score. As a result, the Tisadale risk score is a crucial assessment tool for psychotropic drug-intoxicated patients in a clinical setting.

Purpose: The aims of the present study were twofold. First, the research investigated the effect of an individual’s risk factors and the prevalence of psychotropic drugs on QTc prolongation, TdP (torsades de pointes), and death. Second, the study compared the risk scoring systems (the Mayo Pro-QT risk score and the Tisadale risk score) on QTc prolongation. Methods: The medical records of intoxicated patients who visited the emergency department between March 2010 and February 2019 were reviewed retrospectively. Among 733 patients, the present study included 426 psychotropic drug-intoxicated patients.The patients were categorized according to the QTc value. The known risk factors of QTc prolongation were examined, and the Mayo Pro-QT risk score and the Tisadale risk score were calculated. The analysis was performed using multiple logistic regression, Spearman correlation, and ROC (receiver operating characteristic). Results: The numbers in the mild to moderate group (male: 470≤QTc<500 ms, female: 480≤QTc<500 ms) and severe group (QTc≥500 ms or increase of QTc at least 60ms from baseline, both sex) were 68 and 95, respectively. TdP did not occur, and the only cause of death was aspiration pneumonia. The statically significant risk factors were multidrug intoxications of TCA (tricyclic antidepressant), atypical antipsychotics, an atypical antidepressant, panic disorder, and hypokalemia. The Tisadale risk score was larger than the Mayo Pro-QT risk score. Conclusion Multiple psychotropic drugs intoxication (TCA, an atypical antidepressant, and atypical antipsychotics), panic disorder, and hypokalemia have been proven to be the main risk factors of QTc prolongation, which require enhanced attention. The present study showed that the Tisadale score had a stronger correlation and predictive accuracy for QTc prolongation than the Mayo Pro-QT score. As a result, the Tisadale risk score is a crucial assessment tool for psychotropic drug-intoxicated patients in a clinical setting.

Purpose: The current standard chemotherapy for advanced biliary tract cancer (BTC) has limited benefit,and novel therapies need to be investigated. Materials and Methods: In this prospective cohort study, programmed death ligand-1 (PD-L1)–positive BTC patientswho progressed on first-line gemcitabine plus cisplatin were enrolled. Pembrolizumab 200mg was administered intravenously every 3 weeks. Results: Between May 2018 and February 2019, 40 patients were enrolled. Pembrolizumab wasgiven as second-line (47.5%) or  third-line therapy (52.5%). The objective response ratewas 10% and 12.5% by Response Evaluation Criteria in Solid Tumor (RECIST) v1.1 andimmune-modified RECIST (imRECIST) and median duration of response was 6.3 months.Among patients with progressive disease as best response, one patient (1/20, 5.0%)achieved complete response subsequently. The median progression-free survival (PFS) andoverall survival (OS) were 1.5 months (95% confidence interval [CI], 0.0 to 3.0) and 4.3months (95% CI, 3.5 to 5.1), respectively, and objective response per imRECIST was significantlyassociated with PFS (p < 0.001) and OS (p=0.001). Tumor proportion score  50%was significantly associated with higher response rates including the response after pseudoprogression(vs. < 50%; 37.5% vs. 6.5%; p=0.049). Conclusion Pembrolizumab showed modest anti-tumor activity in heavily pretreated PD-L1–positiveBTC patients. In patients who showed objective response, durable response could beachieved.