Background: s/Aims: Reported incidence of extrahepatic bile duct cancer is higher in Asians than in Western populations. Korea, in particular, is one of the countries with the highest incidence rates of extrahepatic bile duct cancer in the world. Although research and innovative therapeutic modalities for extrahepatic bile duct cancer are emerging, clinical guidelines are currently unavailable in Korea. The Korean Society of Hepato-Biliary-Pancreatic Surgery in collaboration with related societies (Korean Pancreatic and Biliary Surgery Society, Korean Society of Abdominal Radiology, Korean Society of Medical Oncology, Korean Society of Radiation Oncology, Korean Society of Pathologists, and Korean Society of Nuclear Medicine) decided to establish clinical guideline for extrahepatic bile duct cancer in June 2021. Methods: Contents of the guidelines were developed through subgroup meetings for each key question and a preliminary draft was finalized through a Clinical Guidelines Committee workshop. Results: In November 2021, the finalized draft was presented for public scrutiny during a formal hearing. Conclusions The extrahepatic guideline committee believed that this guideline could be helpful in the treatment of patients.

Viral load and the duration of viral shedding of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are important determinants of the transmission of coronavirus disease 2019.In this study, we examined the effects of viral doses on the lung and spleen of K18-hACE2 transgenic mice by temporal histological and transcriptional analyses. Approximately, 1×105 plaque-forming units (PFU) of SARS-CoV-2 induced strong host responses in the lungs from 2 days post inoculation (dpi) which did not recover until the mice died, whereas responses to the virus were obvious at 5 days, recovering to the basal state by 14 dpi at 1×102 PFU. Further, flow cytometry showed that number of CD8+ T cells continuously increased in 1×102 PFU-virusinfected lungs from 2 dpi, but not in 1×105 PFU-virus-infected lungs. In spleens, responses to the virus were prominent from 2 dpi, and number of B cells was significantly decreased at 1×105PFU; however, 1×102 PFU of virus induced very weak responses from 2 dpi which recovered by 10 dpi. Although the defense responses returned to normal and the mice survived, lung histology showed evidence of fibrosis, suggesting sequelae of SARS-CoV-2 infection. Our findings indicate that specific effectors of the immune response in the lung and spleen were either increased or depleted in response to doses of SARS-CoV-2. This study demonstrated that the response of local and systemic immune effectors to a viral infection varies with viral dose, which either exacerbates the severity of the infection or accelerates its elimination.

Objectives: Limited information is available concerning the epidemiology of stroke and acute myocardial infarction (AMI) in the Republic of Korea. This study aimed to develop a national surveillance system to monitor the incidence of stroke and AMI using national claims data. Methods: We developed and validated identification algorithms for stroke and AMI using claims data. This validation involved a 2-stage stratified sampling method with a review of medical records for sampled cases. The weighted positive predictive value (PPV) and negative predictive value (NPV) were calculated based on the sampling structure and the correspondingsampling rates. Incident cases and the incidence rates of stroke and AMI in the Republic ofKorea were estimated by applying the algorithms and weighted PPV and NPV to the 2018National Health Insurance Service claims data. Results: In total, 2,200 cases (1,086 stroke cases and 1,114 AMI cases) were sampled from the 2018 claims database. The sensitivity and specificity of the algorithms were 94.3% and 88.6% for stroke and 97.9% and 90.1% for AMI, respectively. The estimated number of cases, including recurrent events, was 150,837 for stroke and 40,529 for AMI in 2018. The age- and sex-standardized incidence rate for stroke and AMI was 180.2 and 46.1 cases per 100,000 person-years, respectively, in 2018. Conclusion This study demonstrates the feasibility of developing a national surveillance system based on claims data and identification algorithms for stroke and AMI to monitor their incidence rates.

Objective: Dysphagia is a common clinical condition characterized by difficulty in swallowing. It is sub-classified into oropharyngeal dysphagia, which refers to problems in the mouth and pharynx, and esophageal dysphagia, which refers to problems in the esophageal body and esophagogastric junction. Dysphagia can have a significant negative impact one’s physical health and quality of life as its severity increases. Therefore, proper assessment and management of dysphagia are critical for improving swallowing function and preventing complications. Thus a guideline was developed to provide evidence-based recommendations for assessment and management in patients with dysphagia. Methods: Nineteen key questions on dysphagia were developed. These questions dealt with various aspects of problems related to dysphagia, including assessment, management, and complications. A literature search for relevant articles was conducted using Pubmed, Embase, the Cochrane Library, and one domestic database of KoreaMed, until April 2021. The level of evidence and recommendation grade were established according to the Grading of Recommendation Assessment, Development and Evaluation methodology. Results: Early screening and assessment of videofluoroscopic swallowing were recommended for assessing the presence of dysphagia. Therapeutic methods, such as tongue and pharyngeal muscle strengthening exercises and neuromuscular electrical stimulation with swallowing therapy, were effective in improving swallowing function and quality of life in patients with dysphagia. Nutritional intervention and an oral care program were also recommended. Conclusion This guideline presents recommendations for the assessment and management of patients with oropharyngeal dysphagia, including rehabilitative strategies.

The aim of this study was to develop evidence-based recommendations for determining the surgical extent in patients with locally invasive differentiated thyroid cancer (DTC). Locally invasive DTC with gross extrathyroidal extension invading surrounding anatomical structures may lead to several functional deficits and poor oncological outcomes. At present, the optimal extent of surgery in locally invasive DTC remains a matter of debate, and there are no adequate guidelines. On October 8, 2021, four experts searched the PubMed, Embase, and Cochrane Library databases; the identified papers were reviewed by 39 experts in thyroid and head and neck surgery. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to assess the quality of evidence, and to develop and report recommendations. The strength of a recommendation reflects the confidence of a guideline panel that the desirable effects of an intervention outweigh any undesirable effects, across all patients for whom the recommendation is applicable. After completing the draft guidelines, Delphi questionnaires were completed by members of the Korean Society of Head and Neck Surgery. Twenty-seven evidence-based recommendations were made for several factors, including the preoperative workup; surgical extent of thyroidectomy; surgery for cancer invading the strap muscles, recurrent laryngeal nerve, laryngeal framework, trachea, or esophagus; and surgery for patients with central and lateral cervical lymph node involvement. Evidence-based guidelines were devised to help clinicians make safer and more efficient clinical decisions for the optimal surgical treatment of patients with locally invasive DTC.

OBJECTIVES: Proteinuria is widely used to predict cardiovascular risk. However, there is insufficient evidence to predict how changes in proteinuria may affect the incidence of cardiovascular disease. METHODS: The study included 265,236 Korean adults who underwent health checkups in 2003-2004 and 2007-2008. They were categorized into 4 groups based on changes in proteinuria (negative: negative → negative; resolved: proteinuria ≥1+ → negative; incident: negative → proteinuria ≥1+; persistent: proteinuria ≥1+ → proteinuria ≥1+). We conducted 6 years of follow-up to identify the risks of developing ischemic heart disease (IHD), acute myocardial infarction (AMI), and angina pectoris according to changes in proteinuria. A multivariate Cox proportional-hazards model was used to calculate adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for incident IHD, AMI, and angina pectoris. RESULTS: The IHD risk (expressed as HR [95% CI]) was the highest for persistent proteinuria, followed in descending order by incident and resolved proteinuria, compared with negative proteinuria (negative: reference, resolved: 1.211 [95% CI, 1.104 to 1.329], incident: 1.288 [95% CI, 1.184 to 1.400], and persistent: 1.578 [95% CI, 1.324 to 1.881]). The same pattern was associated with AMI (negative: reference, resolved: 1.401 [95% CI, 1.048 to 1.872], incident: 1.606 [95% CI, 1.268 to 2.035], and persistent: 2.069 [95% CI, 1.281 to 3.342]) and angina pectoris (negative: reference, resolved: 1.184 [95% CI, 1.065 to 1.316], incident: 1.275 [95% CI, 1.160 to 1.401], and persistent: 1.554 [95% CI, 1.272 to 1.899]). CONCLUSIONS Experiencing proteinuria increased the risks of IHD, AMI, and angina pectoris even after proteinuria resolved.

Purpose: Mycoplasma pneumoniae pneumonia (MP) is a major cause of community-acquired pneumonia (CAP) in children and is associated with extrapulmonary manifestations (EPM). The incidence and risk factors for EPM in children are unknown. Methods: This was a retrospective study involving 65,243 pediatric patients with CAP between 2010 and 2015 at 23 nationwide hospitals in South Korea. Medical records were reviewed to collect information regarding the clinical characteristics, radiological results, and laboratory findings. Logistic regression with multivariate analysis was performed to evaluate the risk factors associated with EPM in MP. Results: The incidence of EPM was 23.9%, including elevation of liver enzymes (18.1%), mucocutaneous manifestations (4.4%), proteinuria (4.1%), cardiovascular and neurological manifestations (0.4%), hematologic manifestations (0.2%), and arthritis (0.2%). Statistical analysis showed that mucocutaneous manifestations significantly increased with elevated alanine aminotransferase (adjusted odds ratio [aOR], 3.623; 95% confidence interval [CI], 1.933-6.790) and atopic sensitization (aOR, 2.973; 95% CI, 1.615–5.475) and decreased with respiratory virus coinfection (aOR, 0.273; 95% CI, 0.084–0.887). Elevated liver enzymes were significantly associated with elevated lactate dehydrogenase (aOR, 3.055; 95% CI, 2.257–4.137), presence of pleural effusion (aOR, 2.635; 95% CI, 1.767–3.930), and proteinuria with respiratory virus coinfection (aOR, 2.245; 95% CI, 1.113–4.527). Conclusion Approximately 24% of pediatric patients with MP had various EPM. As the risk factors associated with each EPM were different, it is necessary to evaluate the various clinical aspects and findings of MP to predict and prepare for the occurrence of EPM.

Objective: Mood disorder and borderline personality pathology (BPP) are frequently comorbid and relate to childhood trauma. We investigated the relationship between childhood trauma and BPP features in mood disorder patients versus controls. Methods: A total of 488 mood disorder patients, particularly major depressive disorder (MDD), bipolar I disorder (BD I), and bipolar II disorder (BD II), and 734 controls were included. We examined between-group BPP-related differences and correlated between BPP and childhood trauma using the Childhood Trauma Questionnaire-Short Form (CTQ) and the Personality Assessment Inventory–Borderline Features Scale. Results: BD II patients showed significantly higher BPP. Emotional abuse and neglect were prominently associated with BPP, while affective instability and negative relationships exhibited a stronger association with childhood trauma. We also found a positive relationship between childhood trauma and BPP in MDD, BD I, and BD II patients. Conclusion The findings of the present study imply that BPP features are more likely to be found in patients with BD II than BD I or MDD. Mood disorder patients with severe childhood trauma may have higher BPP features. Thus, further study of the relationship between childhood trauma and BPP features could improve the therapeutic approaches and help understand patients with mood disorders.

Background/Aims: Treatment decisions for locally advanced head and neck squamous cell carcinoma (LA-HNSCC) are complicated, and multi-modal treatments are usually indicated. However, it is challenging for older patients to complete treatments. Thus, we investigated disease characteristics, real-world treatment, and outcomes in older LA-HNSCC patients. Methods: Older patients (aged ≥ 70 years) were selected from a large nationwide cohort that included 445 patients with stage III–IVB LA-HNSCC from January 2005 to December 2015. Their data were retrospectively analyzed and compared with those of younger patients. Results: Older patients accounted for 18.7% (83/445) of all patients with median age was 73 years (range, 70 to 89). Proportions of primary tumors in the hypopharynx and larynx were higher in older patients and older patients had a more advanced T stage and worse performance status. Regarding treatment strategies of older patients, 44.5% of patients received concurrent chemoradiotherapy (CCRT), 41.0% underwent surgery, and 14.5% did not complete the planned treatment. Induction chemotherapy (IC) was administered to 27.7% (23/83) of older patients; the preferred regimen for IC was fluorouracil and cisplatin (47.9%). For CCRT, weekly cisplatin was prescribed 3.3 times more often than 3-weekly cisplatin (62.2% vs. 18.9%). Older patients had a 60% higher risk of death than younger patients (hazard ratio, 1.6; p = 0.035). Oral cavity cancer patients had the worst survival probability. Conclusions Older LA-HNSCC patients had aggressive tumor characteristics and received less intensive treatment, resulting in poor survival. Further research focusing on the older population is necessary.

Purpose: Certain patient subgroups who do not respond to induction chemotherapy (IC) show inherent chemoresistance in locally advanced head and neck squamous cell carcinoma (LA-HNSCC). This study aimed to assess the prognostic value of IC, and role of IC in guiding the selection of a definitive locoregional therapy. Materials and Methods: Out of the 445 patients in multi-institutional LA-HNSCC cohort, 158 (36%) receiving IC were enrolled. The study outcome was to assess overall survival (OS) through IC responsiveness and its role to select subsequent treatments. Results: Among 135 patients who completed subsequent treatment following IC, 74% responded to IC (complete response in 17% and partial response in 58%). IC-non-responders showed 4.5 times higher risk of mortality than IC-responders (hazard ratio, 4.52; 95% confidence interval, 2.32 to 8.81; p < 0.001). Among IC-responders, 84% subsequently received definitive concurrent chemoradiotherapy (CCRT) and OS was not differed by surgery or CCRT (p=0.960). Regarding IC-non-responders, 54% received CCRT and 46% underwent surgery, and OS was poor in CCRT (24-month survival rate of 38%) or surgery (24-month survival rate of 63%). Conclusion Response to IC is a favorable prognostic factor. For IC-responders, either surgery or CCRT achieved similar survival probabilities. For IC-non-responder, multidisciplinary approach was warranted reflecting patients’ preference, morbidity, and prognosis.